Biochemistry word parts: prefixes, suffixes, roots (with examples) to help figure out terms
A non-exhaustive list of some key prefixes, suffixes, roots, etc. you may see (some lots!)
Biochemistry word parts
| Initial order | Category | Term | Definition |
|---|---|---|---|
| 1 | Small molecules | small molecule drug | Your typical, conventional, small "drug"; typically chemically-defined and synthesized in the lab but can also be a "natural product" such as an antibiotic made by bacteria |
| 2 | Drug discovery and development | biologic | "Aka biotherapeutics, biodrugs, biopharmaceuticals, biologic drugs, biological agents . . .are generally large-sized entities" (proteins, mRNA, genes, cells, etc.) "typically MW greater than 1,000 Da, and may be produced from living biological sources or through biological processes. Structurally speaking, they are, in general, more complex than small-molecule drugs as they involve many additional levels of structural complexity, for example, the formation of polymeric chains with variable chemical structures and modifications, with each subunit of the polymer being a potential site for structural modifications." – Calzeda, Cerecetto, and Tosar, 2024; "Examples of biologics include therapeutic proteins (e.g., insulins, monoclonal antibodies, growth factors, enzymes), and other types of products such as allergenic products (e.g., allergen extracts, allergen patch tests), cellular and gene therapies, and vaccines." – FDA |
| 3 | Nucleic acid therapeutics | ASO (antisense oligonucleotide) | Short strand of modified DNA that binds directly and sequence-specifically to mRNA to block translation and/or cause cleavage by RNase H or to pre-mRNA to direct splicing. |
| 4 | Nucleic acid therapeutics | siRNA (small interfering RNA) | Short (~20 nucleotide-long) strands of RNA (potentially coming from shRNAs) that act through the RNA interference (RNAi) pathway - they bind to a protein called Argonaute (Ago), directing Ago to bind to specific mRNAs (based on sequence complementarity) & shut down translation by cutting (slicing) the mRNA. |
| 5 | Nucleic acid therapeutics | RNAi (RNA interference) | A technique for genetic "knock-down" – it reduces levels of specific mRNA transcripts (and thus the levels of the proteins that would be made from them) without altering the underlying DNA gene. It does this by using short (~20 nucleotide-long) strands of RNA that bind to a protein called Argonaute (Ago), directing Ago to bind to specific mRNAs (based on sequence complementarity) & shut down translation (e.g. by cutting (slicing) the mRNA). |
| 6 | Nucleic acid therapeutics | shRNRA (short hairpin RNA) | Precursor to miRNAs & siRNAs that can be genetically encoded (e.g. delivered through gene therapy) to allow cells to make a specific miRNAs or siRNAs in-cell to allow for longer-lasting effects. The name comes from the hairpin shape of the folded RNA that provides a double-stranded RNA substrate for processing into miRNAs & siRNAs. |
| 7 | Nucleic acid therapeutics | aptamer | Like an antibody, but made of nucleic acids not proteins. Aptamers are (typically chemically modified) single strands of RNA, DNA, or XNA (other unnatural nucleic acids) that fold up into unique structures that allow them to bind specifically to other things. Unlike most other nucleic acid-based tools & therapeutics (siRNAs, ASOs, etc.), they bind based on shape, not sequence complementarity. This allows them to bind to a larger number of types of things, while maintaining ease of synthesis. Unlike those others as well, they can act outside the cell. |
| 8 | Drug discovery and development | biosimilar | The equivalent of a generic for a biologic – a biologic that is super similar in composition to the original and functions at least as well (is bioequivalent/non-inferior). It's not called a generic because the complex nature of biologics and their (typically) biological source makes it so that even batches from the same company can't be "identical." |
| 9 | Drug discovery and development | generic | Small molecule drug which has the same formula and structure as a drug that is already on the market (though it may vary in manufacturing process, formulation, excipients, etc.), but is (typically) marketed by a different company than the company that first introduced them. They're often cheaper because they don't have to go through as much development and testing – rather, they just have to show equivalence to the already-marketed drug. |
| 10 | Legal stuff | patent | Legal protection for an invention in exchange for the inventor disclosing how to recreate it. In the US, patents are regulated by the US Patent and Trade Organization (USPTO) and can be granted at any point in the therapeutic development process. If approved, the inventor has 20 years post-filing in which any company that wants to use their invention has to pay them. A single therapeutic may have many patents associated with it and the same patent may be associated with many therapeutics. |
| 11 | Protein therapeutics | recombinant protein | Basically, a "lab-made" protein. "Recombinant" refers to the recombining of pieces of DNA to provide expression cells (the cells that the protein will be made in) with the instructions for making that protein. |
| 12 | Protein therapeutics | antibody | A small protein that can bind specifically to a molecule of interest (e.g. a location on an out-of-control protein). Antibodies have both constant regions that are "generic" for the source organism and variable regions, which are the parts that bind specifically to different molecules. |
| 13 | Protein therapeutics | monoclonal antibody | One specific antibody (typically, tons of copies of it) that binds one specific thing at one specific place. These can be used to block unwanted binding between molecules (e.g., preventing a signaling molecule from binding to a receptor) |
| 14 | Protein therapeutics | bispecific antibody | One antibody that binds two specific things at two specific places (or one specific thing at two specific places). These can be used to increase specificity, bridge 2 molecules (e.g., a tumor cell and an immune cell), target a rouge cell from 2 angles to reduce resistance, etc. |
| 15 | Protein therapeutics | antibody fragments | Fabs, nanobodies, and other small antibody pieces that have some advantages such as smaller size allowing them to access smaller places and potentially be stabler |
| 16 | Protein therapeutics | antibody-drug conjugates (ADCs) | These consist of an antibody that targets a specific cell type, tumor, etc. stably connected (conjugated) through a linker to a drug (often referred to as a payload) that kills the cell (e.g., for cancer therapy) or has some other effect. They have the potential to minimize side effects while delivering potent medicines where they’re needed. |
| 17 | Protein therapeutics | dual-payload ADCs | An antibody-drug conjugate consisting of one antibody bound to 2 different drugs (either through a single linker or different linkers) |
| 18 | Regulation | FDA (Food and Drug Administration) | The US Food and Drug Administration; the government agency responsible for regulating pharmaceutical development in the US (clinical trials, approval, post-approval regulation of marketing, etc.) |
| 19 | Legal stuff | Orphan Drug Act (ODA) | This 1983 legislation was passed to promote development of therapeutics for rare diseases and conditions by providing financial incentives including tax credits, expedited review pathways, and extended market exclusivity periods. It has led to development of life-saving treatment for rare diseases, but it has also been exploited in various ways. |
| 20 | Gaining approval | orphan designation | A designation given to a drug being developed if the developers apply for the designation and are able to satisfactorily show that the disease/condition is rare and their drug could plausibly help treat it |
| 21 | Clinical trials, etc. | Phase 0 clinical trial | Aka an exploratory clinical trial; A trial conducted early in Phase 1 that involve limited human exposure for short time frame (e.g. 1 wk), with no intent to treat or diagnose but rather to investigate feasibility for further development. One may be performed to help choose among multiple candidate compounds to take into Phase 1 studies and/or to allow compounds to fail early, saving money and time. Unlike typical clinical trials, where drugs are first tested in healthy volunteers, Phase 0 trials can test them in patients due to the low levels given. Parameters measured may include pharmacodynamics, pharmacokinetics, and/or target engagement (e.g. binding to target molecules in the body) and may involve using radiolabeled compounds for tracking. The format of Phase 0 trials can vary and may include a single microdose of a single compound, a series of microdoses of the same quantity of a single compound, a series of escalating doses or a single compound, or simultaneous administration of microdoses of multiple compounds (cassette microdosing). Some Phase 0 trials involve intratarget microdosing (ITM) which delivers a tiny dose, but into the target, momentarily generating a potential therapeutic dose at the site of interest, as well as microdoses throughout the body, which can provide valuable information. |
| 22 | Clinical trials, etc. | Phase 1 clinical trial | A clinical trial to 1 trial to test for safety - the treatment’s given to a small group of people (typically 20-80 people) to check for potential side effects. Sometimes the people are healthy volunteers and other times they have the disease. |
| 23 | Clinical trials, etc. | Phase 2 clinical trial | A clinical trial to start to look at whether the treatment is actually helpful (i.e., they look for efficacy)! In Phase 2 trials, more people (often ~100-300) are given the treatment with an eye on whether it’s effective (and further make sure it’s safe). They also may test to see what dose might be ideal (enough to improve the condition but not so much that it causes intolerable side effects). |
| 24 | Clinical trials, etc. | Phase 3 clinical trial | A large clinical trial (typically 1000-3000 participants), often with the intention of gathering enough evidence of efficacy and safety to gain FDA approval. |
| 25 | Clinical trials, etc. | Phase 4 clinical trial | A clinical trial conducted *after* a treatment is FDA approved - scientists are just trying to figure out some more about it and/or follow up on potential side effects |
| 26 | Protein therapeutics | peptide | A short amino acid sequence. Peptides can come from processing of larger precursors and/or proteasomal chopping up of proteins, or can be synthesized in their peptide form in a lab. |
| 27 | Nucleic acid therapeutics | nucleic acid therapeutic | A nucleic-acid based therapy in which a gene is inserted into cells in order to get the cells to make specific proteins (e.g., a "normal" version of a protein whose gene is mutated in that patient's cells or a gene that equips the cells with new abilities, such as the ability to seek out and destroy cells displaying tumor-associated proteins on their surfaces) and/or functional RNAs (e.g. shRNAs for RNAi). |
| 28 | Nucleic acid therapeutics | gene editing | A therapy in which a person's genetic makeup is altered, such as to "fix" a genetic mutation |
| 29 | Nucleic acid therapeutics | AAV (adenoassociated virus) | Adeno-associated virus (AAV) vectors are largely gutted-out versions of a type of single-stranded DNA virus that typically remains episomal (doesn’t integrate with the genome) and when it does integrate, it tends to be at okay places. A great feature is its low immunogenicity, but a large disadvantage is its small size. It can only deliver up to ~4.7 kb of DNA, but strategies to overcome this include use of helper viruses that allow additional genes to be removed from the viral vectors and the corresponding proteins provided by other viruses cultured alongside them during lab production. You might see the term “rAAV” which stands for recombinant AAV, which is a version of AAV genetically engineered to be optimized for therapeutic purposes. P.S.: These viruses of the parvovirus family have “nothing” to do with adenoviruses other than they were first discovered as a contaminant of adenoviral culture! |
| 30 | Nucleic acid therapeutics | viral vector | A mostly-gutted-out and rendered harmless virus used to deliver nucleic acids into cells. They consist of viruses that are stripped down to their bare necessities (e.g. genes needed to produce proteins to allow the viruses to inject genetic instructions into cells) and filled with desired cargo. They take advantage of virus’ natural ability to infect cells and deliver nucleic acids (a process called transduction) and are typically used for delivery of genes (but that could include a gene for making a miRNA or shRNA!). |
| 31 | Nucleic acid therapeutics | LNP (lipid nanoparticle) | Greasy “bubbles” that encapsulate the nucleic acid (or other molecular) cargo and help them get into cells. Their main components are typically: 1) Cationic (positively-charged) or ionizable (chargeable) lipid; 2) Helper lipid (typically a glycerophospholipid); 3) PEG (polyethylene glycol)-lipid; 4) Cholesterol. The exact components and their amounts can be optimized for different applications, and a lot of work is underway to try to optimize LNPs to target specific tissues and/or cell types |
| 32 | Drug discovery and development | SAR (Structure Activity Relationship) | Studies that try to determine what core part of the hit is responsible for desired effects and how making various additions to that core part affects the activity |
| 33 | Regulation | off-label | When a drug is used for an indication it hasn't been approved for. Doctors can prescribe drugs for patients off-label, but insurance companies may not cover off-label use. Drug companies can't advertise for off-label use. |
| 34 | Drug discovery and development | lead optimization | The process of improving a lead compound to have better drugginess (bioavailability, etc.) |
| 35 | Drug discovery and development | medicinal chemist | Chemist that works to help design and optimize drugs. They do things like turning assay hits into compounds able to be given to people effectively (improve solubility, etc.) |
| 36 | Clinical trials, etc. | Phase 1/2 clinical trial | A small trial where scientists look for both safety (the goal of Phase I trials) and efficacy (the goal of Phase 2 trials). These are often done for treatments of orphan diseases and/or complicated, risky, and/or customized treatments. |
| 37 | Drug discovery and development | excipient | Inactive ingredients included with the active ingredient(s) in a drug in order to make it more administrable – things like fillers to bulk up the size so you can see what you're taking, binders which glue the ingredients together, preservatives, dyes, lubricants, etc. |
| 38 | Drug discovery and development | drug repurposing | When a drug developed/approved for one indication is then developed/approved for another indication |
| 39 | Drug discovery and development | hit expansion | When drug developers take a hit from an assay and then make various modifications to explore compounds with related structures to try to find an even better one. |
| 40 | Clinical trials, etc. | postmarketing studies | Studies done after a drug is approved, such as Phase IV clinical trials |
| 41 | Drug discovery and development | mode of action | "The cellular changes, functional or anatomical, that result from exposure to the agent" – Calzada, Cerecetto, and Tosar. Biotherapeutics: From small to large molecules and cells, 2024 |
| 42 | Drug discovery and development | mechanism of action | How a drug works at the molecular level |
| 43 | Drug discovery and development | pharmacodynamics (PD) | What the drug does to the body. What effects (desired and undesired) it has at what levels/concentrations and for how long. It often measures molecular markers. |
| 44 | Drug discovery and development | pharmacophore | "aka a pharmacophoric pattern: it is the ensemble of steric and electronic features that are necessary to ensure the optimal supramolecular interactions with a specific biological target structure and to trigger (or block) its bioresponse. A pharmacophore represents not a real molecule or a real association of functional groups but a purely abstract concept that accounts for the common molecular interaction capacities of a group of compounds toward their target structure. The pharmacophore can be considered the largest common denominator shared by a set of active molecules." – Calzada, Cerecetto, and Tosar. Biotherapeutics: From small to large molecules and cells, 2024 |
| 45 | Business stuff | blockbuster | A drug that rakes in > $1 billion dollars in a year |
| 46 | Gaining approval | IND (Investigational New Drug) | An application to gain approval to begin clinical testing of a new drug or new biologic OR to gain approval to begin testing of a non-new drug or biologic in a new population, for a different condition, at a new dose, etc. |
| 47 | Drug discovery and development | bioavailability | "Rate and extent to which a drug is absorbed or is otherwise available to the treatment site in the body." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 48 | Drug discovery and development | immunogenicity | A measure of how much something triggers an immune response. |
| 49 | Nucleic acid therapeutics | vector | A "vehicle" for delivering nucleic acids, such as a viral vector. |
| 50 | Drug discovery and development | adjuvant | Something that's given along with the core active ingredient to help enhance the active component's efficacy (e.g. an immune-triggering molecule in a vaccine) |
| 51 | Business stuff | PhRMA | Pharmaceutical Research and Manufacturers of America – main trade group and lobbying organization representing the pharmaceutical industry. |
| 52 | Gaining approval | accelerated approval | "These regulations allowed drugs for serious conditions that filled an unmet medical need to be approved based on a surrogate endpoint.” – FDA This was established in 1992 to speed up review of drugs for life-threatening diseases by, among other things, allowing for the use of surrogate endpoints (e.g. molecular signs) rather than traditional endpoints showing benefit to patients. Established in large part in response to the AIDS epidemic. (Note: it’s listed some places as 1991, because that’s when it was devised, but it wasn’t formally established until 1992). Basically, this makes it so that things like blood levels of molecules thought to be correlated with disease status (biomarkers) can be used instead of measures of actual clinical benefit to patients. This can be appropriate in some cases, such as cases where disease symptoms progress over years, or if there’s a pressing need for a treatment and can be hard to know in a reasonable amount of time if a treatment actually has clinical efficacy (does it actually help people). But it can also be misleading. Thus, the companies are then supposed to continue following patients and/or do additional studies to confirm the treatment actually is effective, but these are not always completed. |
| 53 | Gaining approval | expanded access | Sometimes called "compassionate care," this provides a route for patients to gain access to not-yet-approved drugs outside of a clinical trial in certain cases (such as if the patient is dying and has exhausted all other options). |
| 54 | Clinical trials, etc. | IRB (Institutional Review Board) | A committee that decides whether a proposed study is ethical and scientifically-sound before the study can begin. |
| 55 | Clinical trials, etc. | DALY (Disability Adjusted Life Year) | A measure of disease burden: "One DALY represents the loss of the equivalent of one year of full health. DALYs for a disease or health condition are the sum of years of life lost due to premature mortality (YLLs) and years of healthy life lost due to disability (YLDs) due to prevalent cases of the disease or health condition in a population." – WHO |
| 56 | Clinical trials, etc. | QALY (Quality Adjusted Life Year) | A measure of disease burden, similar to a DALY (Disability Adjusted Life Year), but it also takes into account quality of life. |
| 57 | Drug discovery and development | structural biology | Discipline that tries to figure out molecules' (proteins, etc.) forms (3D shapes) and the relationship between their forms and their functions. It often combines techniques like x-ray crystallography and cryo-electron microscopy (cryoEM) with functional and biophysical (binding, etc.) experiments and computational modeling. |
| 58 | Drug discovery and development | efficacy | How well a drug works in a controlled environment like a lab or a controlled trial |
| 59 | Clinical trials, etc. | RCT (Randomized Controlled Trial) | A clinical trial in which patients are randomized into treatment and control arms, with the control arm receiving a placebo or current standard of care. |
| 60 | Clinical trials, etc. | pivotal phase II clinical trial | A Phase II trial that serves as pivotal trial, meaning that it seeks to collect sufficient evidence to gain approval. Typically, pivotal trials are Phase III trials, but in some cases, such as for rare diseases, Phase II trials can be pivotal. |
| 61 | Clinical trials, etc. | single-arm | A trial without a control group. This may be done for personalized therapies for rare diseases, etc. |
| 62 | Business stuff | precision medicine | Medicine that aims to deliver the right treatment to the right patient at the right time, often by taking advantage of genetic information and pricy, fancy, treatments. Often, this term is used interchangeably with personalized medicine. |
| 63 | Drug discovery and development | selectivity | Does the drug only affect what you want it to? Or does it also affect other molecules (which could lead to off-target activity and side effects) |
| 64 | Business stuff | CRO (Contract Research Organization) | These organizations "have been in existence since the 1930s and support biopharmaceutical R&D on a pay for service arrangement providing an economical alternative to in-house provision of expensive development activities." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 Examples: ICON, IQVIA, Parexel, Syneos Health, Fortrea, PPD, Medpace, Charles River Laboratories, CTI |
| 65 | Business stuff | CMO (Contract Manufacturing Organization) | Organizations that companies can pay to manufacture their products. |
| 66 | Regulation | CDER (Center for Drug Evaluation and Regulation) | FDA department that oversees conventional small molecule drugs as well as most biologics including recombinant proteins and nucleic acids |
| 67 | Regulation | CBER (Center for Biologics Evaluation and Regulation) | FDA department that oversees most vaccines, blood products, and cell-based products |
| 68 | Gaining approval | BLA (Biologics License Application) | The equivalent of an NDA (New Drug Application) for a biologic. It's what biologics developers file after clinical trials to try to get FDA approval. The equivalent for biosimilars is an abbreviated BLA (aBLA) |
| 69 | Business stuff | value-based arrangements (VBAs) | Payment arrangements in which the costs of treatments are linked to the quality and/or success of those treatments. |
| 70 | Legal stuff | IP (Intellectual Property) | Includes: "copyright, trade secrets, trademarks, bailments and patents" – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 71 | Legal stuff | Bailment | "A legal term used to describe the property rights of a donor who gives physical materials to a third party. These materials may be biotechnology products, for example, in which there is a great deal of associated know-how that must be protected. A common bailment is the Material Transfer Agreement that occurs between laboratories in academia and industry." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 72 | Legal stuff | MTA (Material Transfer Agreement) | A legal agreement when someone gives someone physical material to use. It specifies things like how the material can and can't be used. It's a type of bailment often used when labs share things with one another and/or scientists order things like cell lines or plasmids from a repository. |
| 73 | Legal stuff | Provisional patent | A patent that "lasts for one year before making the decision to file a non-provisional patent (which is published after 18 months). This is a useful way of keeping the costs down while assembling the data required to proceed to a full patent, or to abandon the process at an early stage." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 74 | Legal stuff | TRIPS (The Agreement on Trade-Related Aspects of Intellectual Property Rights) | Global regulations seeking to harmonize patent law in different countries. |
| 75 | Legal stuff | PCT (Patent Cooperation Treaty) | Allows drug developers to file short-term (~30 month) patents in multiple territories prior to filing in each territory individually (there are no global patents, so this is a bit of a compromise) |
| 76 | Legal stuff | composition of matter patent | A patent on the material contents of something, as opposed to a process of making something. More technically-speaking, "These protect novel compounds that possess a unique chemical structure, have defined practical applications and be non-obvious to experts in the field" – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 77 | Legal stuff | patent cliff | Revenues plummet when patents expire and generics or biosimilars enter the competition |
| 79 | Business stuff | PLM (Product Life-cycle Management) | Deals with strategically managing "product development, introduction, growth, maturity, and decline" with an aim towards maximizing profits and minimizing patent cliff impacts on the company. – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 80 | Business stuff | evergreening | Preventing competition through "secondary patents to maximize the commercial returns on a branded medicine. These patents are used to extend the patent life of drugs through reformulation, finding new indications, or producing different chemical or physical forms." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 81 | Legal stuff | patent thicket | When drug developers prevent competition by getting tons of patents, patenting lots of different aspects of their drug composition, manufacturing, etc. |
| 82 | Drug discovery and development | orthogonal approaches | When different, independent techniques are used to measure an attribute. |
| 83 | Small molecules | agonist | Molecules that bind to receptors and activate them. They often resemble the receptor's natural ligand (binding partner). |
| 84 | Small molecules | antagonist | Molecules that bind to receptors and inactivate them and/or block activation. They often resemble the receptor's natural ligand (binding partner). |
| 85 | Small molecules | inverse agonist | A molecule that binds to a receptor and reduces its baseline activity (as well as typically blocking the agonist from binding). So you get less activity than you get normally in the absence of agonist (below basal levels). |
| 86 | Drug discovery and development | discovery research | The phase of drug development when scientists are focused on discovering targets and/or hits. |
| 87 | Gaining approval | aNDA (abbreviated NDA) | A New Drug Application for a generic drug; it's less extensive than a typical NDA. It only needs to show that: |
| 88 | Drug discovery and development | ATMP (Advanced Therapy Medicinal Product) | Therapeutics based on genes, tissues, and/or cells. |
| 89 | Drug discovery and development | API (Active Pharmaceutical Ingredient) | A part of a drug that actually does stuff |
| 90 | Drug discovery and development | BCS (Biopharmaceutics Classification System) | Classification system for oral drugs that classifies them based on high/low water solubility and intestinal permeability |
| 91 | Drug discovery and development | ADME | An acronym used to refer to the fundamentals of pharmacokinetics (PK): Absorption, Distribution, Metabolism, & Excretion |
| 92 | Drug discovery and development | safety pharmacology | "Discipline that seeks to predict whether a drug (in the widest sense of the word), if administered to human (or animal) populations, is likely to be found unsafe, and its professional mandate is to prevent such an occurrence." – Pugsley, Authier, and Curtis. Principles of Safety Pharmacology. Br J Pharmacol 2008 |
| 93 | Clinical trials, etc. | MRSD (Maximum Recommended safe Starting Dose) | The highest dose recommended for first use in first-in-human (FIH) studies. Often determined via MABEL (Minimum Anticipated Biological Effect Level) or NOAEL (No-observed-adverse-effect level) calculations. |
| 94 | Clinical trials, etc. | MABEL (Minimum Anticipated Biological Effect Level) | The lowest dose at which a measurable biological effect is predicted to be seen. It can be used to determine, based on pre-clinical data, what starting dose to test in first-in-human (FIH) trials. You often see the term used along with "maximum recommended starting dose (MRSD)." Compared to NOAEL (no observed adverse effect level), it relies more on pharmacology studies and PK/PD modeling than on animal toxicology and is often more conservative. |
| 95 | Clinical trials, etc. | microdosing | Use of teeny tiny (typically sub-therapeutic) amounts of a compound, typically in a Phase 0 (exploratory) clinical trial to assess how it is processed by the body, etc. |
| 96 | Clinical trials, etc. | pharmacovigilance | A discipline focused on the detection and assessment of adverse effects of therapeutics, with an aim towards understanding and preventing them. |
| 97 | Regulation | GLP (Good Laboratory Practices) | Regulations companies must follow when producing materials and carrying out non-clinical studies; required for premarket approval |
| 98 | Clinical trials, etc. | GCP (Good Clinical Practices) | Regulations companies must follow when conducting clinical trials. It seeks to ensure safety and rights of study participants. |
| 99 | Regulation | GMP (Good Manufacturing Practices) | Regulations companies must follow to ensure safe manufacturing, packaging, & processing of biopharmaceutical products; required for a product to be marketed. |
| 100 | Gaining approval | EUA (Emergency Use Authorization) | A pathway in which unapproved products can be authorized for use in the case of emergencies. |
| 101 | Gaining approval | CMA (Critical Material Attribute) | A measure of the quality of starting materials going into drug manufacturing. |
| 102 | Drug discovery and development | molecular docking | Using computer modeling to predict how molecules might bind one another. Among other things, it can help scientists rationally design compounds to bind better and/or more specifically. |
| 103 | Drug discovery and development | false positive | "False alarm" - signal is seen even when the thing that normally gives the signal is not present. |
| 104 | Drug discovery and development | true positive | When a signal is seen and the molecule that should give a signal is there. It got things correct! |
| 105 | Drug discovery and development | false negative | Lack of a signal when the thing that should give the signal is actually present. |
| 106 | Drug discovery and development | true negative | When no signal is seen and the molecule that should give a signal is not there. It got things correct! |
| 107 | Clinical trials, etc. | intention to treat | This considers data from all people in a trial, even if they dropped out of the trial, didn't take the medication as intended, etc. Although it might sound counterintuitive to include their data, it could be that they dropped out due to side effects or something, which is important to know! And leaving them out could mask that. |
| 108 | Clinical trials, etc. | subgroup analysis | Looking at whether certain people in a trial with a shared trait (age, etc.) responded differently than others without the trait. It can be done to help figure out who might respond best, etc. but can also be used to try to place a positive spin on less-than-stellar overall results. |
| 109 | Gaining approval | bioequivalency | The criteria for similarity between a brand name drug and a proposed generic that must be met for a generic to be approved. |
| 110 | Clinical trials, etc. | statistical power | Basically, the more patients, animals, samples, etc. you test something in, the higher your statistical power and thus the more confident you can be in any effects and/or differences you find and the smaller the effect needs to be for you to be confident in it (at least statistically-speaking (i.e., to reach statistical significance)). Conversely, if you have few patients/animals/samples, you have low statistical power so an effect needs to be larger for you to be more confident in it. Statisticians can calculate the sample size needed for an effect of a certain size to be able to cross a significance threshold. This then can be used to design studies. |
| 111 | Clinical trials, etc. | number needed to treat | Number of people you have to treat to (on average) have 1 person benefit. 100/absolute risk |
| 112 | Clinical trials, etc. | P-hacking | When people engage in fishy practices (such as cherry-picking data, changing the goalpost, looking only at specific timepoints, etc.) to pass the threshold for "statistical significance" (with statistical significance often determined by a value called a P-value, which basically is a measure of how likely a finding is to be due to chance alone – but it's not quite that, I'm oversimplifying it, so statisticians please don't come running with pitchforks!) |
| 113 | Drug discovery and development | polypharmacology | Use of a single molecule that targets multiple things. |
| 114 | Gaining approval | Type A FDA meeting | An "urgent" (within 30 days of request) meeting between drug developers and the FDA to address safety issues that have led to clinical trial holds and/or otherwise stalled product development projects. |
| 115 | Business stuff | personalized medicine | Medicine specifically tailored to a person –it aims to deliver the right treatment to the right patient at the right time, often by taking advantage of genetic information and pricy, fancy, treatments. Often, this term is used interchangeably with precision medicine. |
| 116 | Business stuff | venture philanthropy | "VC [venture capital] funding directed at philanthropic organizations. As well as providing capital, such VCs will offer hands-on expertise to help the organization develop." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 117 | Clinical trials, etc. | equipoise | The condition of not knowing which treatment arm in a trial (if any) will be more beneficial, basically why you need to do the trial! |
| 118 | Business stuff | biobetter | New and supposedly improved versions of biologics – basically upgraded versions of a biologic, engineered to have better properties such as better stability. |
| 119 | Regulation | indication | What, specifically, is a drug approved to be used for – what condition, what population, etc. |
| 120 | Drug discovery and development | stereoisomers | Versions of a compound that have the same chemical composition in terms of numbers and connectivity of atoms, but differ in the 3D orientation of some of the linkages. Sometimes equivalent to "handedness" and sometimes indicated by "S" and "R" prefixes. |
| 121 | Business stuff | compendium expansion | Phrase typically used in a critical tone to refer to the tactic of getting a drug approved for one purpose, such as through small studies for a rare disease indication, and then expanding its use to larger, more lucrative, populations. |
| 122 | Business stuff | medical tourism | Traveling somewhere to get medications and/or medical treatment that is unavailable or unaffordable where one lives. |
| 123 | Regulation | prevalence | How many people have a condition |
| 124 | Business stuff | incidence | What is the rate at which new cases arise |
| 125 | Clinical trials, etc. | pharmacoepidemiology | A discipline that combines pharmacology with epidemiology to study the effects of therapeutic use in large groups of people in the real world and evaluate benefits and risks. It can, for example, be used to see if drugs are affecting different populations differently and/or to detect signals of safety problems (a key component of pharmacovigilance). |
| 126 | Gaining approval | fast track | "A process designed to facilitate the development, and expedite the review of drugs to treat serious conditions and fill an unmet medical need.” – FDA; Through this pathway, companies can submit completed components of their required application materials on a rolling basis along the way, rather than having to wait until it’s all finished to submit for review. |
| 127 | Regulation | market exclusivity | A set number of years in which companies have the exclusive right to manufacture and sell a treatment they developed once approved. The length of this period depends on the type of approval. |
| 128 | Gaining approval | eIND (exploratory Investigational New Drug) | application to conduct Phase 0 studies, conducted early in Phase 1 that involve limited human exposure for short time frame (e.g. 1 wk), with no intent to treat or diagnose but rather to investigate feasibility for further development. They may be performed to help choose among multiple candidate compounds to take into Phase 1 studies and/or to allow compounds to fail early, saving money and time. eIND requirements are less strict than conventional IND requirements because people are being given such tiny doses. |
| 129 | Genetics | polygenic risk score | A quantitative measure of how likely a person is to develop some condition based on what alleles (versions of genes) of multiple genes they have. |
| 130 | Genetics | monogenic | Caused by a single gene. |
| 131 | Business stuff | biobuck | The promise of money if certain milestones in drug development are met. |
| 132 | Business stuff | ICER (Institute for Clinical and Economic Review) | Non-profit organization that recommends appropriate pricing for novel therapies |
| 133 | Clinical trials, etc. | dose escalation study | A type of clinical trial (often Phase 1) where increasing doses of a drug are given to small groups (cohorts) of volunteers (often 3) to find how much can safely be given. This can inform what doses are chosen for future trials. |
| 134 | Drug discovery and development | candidate | A lead compound that has been optimized to the point it's being considered for use in clinical trials. |
| 135 | Clinical trials, etc. | subtherapeutic microdosing | Giving teeny tiny doses of a drug to get a first idea of how the drug interacts with the human body (see phase 0 trials) |
| 136 | Clinical trials, etc. | cassette microdosing | Simultaneous testing of very small amounts of multiple drug candidates in people to compare how they interact with the body (and potentially with each other) |
| 137 | Clinical trials, etc. | ITM (intratarget microdosing) | “Administration of microdoses locally to generate momentarily therapeutic level exposures in targets of interest . . . ” and in parallel generating longer-term systemic microdose exposures.” – Burt et al., 2020 |
| 138 | Nucleic acid therapeutics | tropism | The cell population that a virus can infect. |
| 139 | Gaining approval | interchangeable biosimilar | A biosimilar that has passed additional tests to allow it to be substituted for a brand name product (such as switching studies in which patients switch between a brand name product and a biosimilar) – all interchangeable biologics are biosimilars but not all biosimilars are interchangeable biologics |
| 140 | Legislation | Biologics Price Competition and Innovation Act (BPCIA) | 2009 US law to promote development and adoption of biosimilars. Among other things, it sets guidelines for biosimilars and interchangeable biosimilars and provides them with an abbreviated approval pathway compared to original biologics. It also offers 12 years of exclusivity for the original biologics to incentivize the development of new biologics and not just biosimilars. |
| 141 | Nucleic acid therapeutics | transduction | When viruses deliver genetic information into cells |
| 142 | Drug discovery and development | therapeutic class | "A group of compounds that are often, but not always, structurally related to each other, that are characterized by a common pharmacological mode of action, and that are primarily used for the same therapeutic indications" – Aronson & Green, 2020 |
| 143 | Drug discovery and development | First-in-class drug | "The first drug in a class of drugs to be given marketing authorization for one or more therapeutic indications; also called breakthrough drug or originator drug" – Aronson & Green, 2020 |
| 144 | Drug discovery and development | originator drug | "A term that is synonymous with first-in-class drug, but typically used in reference to biologics for comparison with their biosimilars" – Aronson & Green, 2020 |
| 145 | Drug discovery and development | First/second generation etc. | "Vague terms intended to distinguish groups of drugs that have similar properties from later drugs in the same class, but regarded as having properties that are thought important to distinguish" – Aronson & Green, 2020 |
| 146 | Business stuff | me-too drug | "A pharmacologically active compound that is structurally related to a first-in-class compound, regarded as belonging to the same therapeutic class as the original compound, and used for the same therapeutic purposes, but which may differ in some respects, such as specificity of pharmacological action, adverse reactions profile, or drug–drug interactions" – Aronson & Green, 2020; e.g. stereoisomers |
| 147 | Business stuff | follow-on drug | "A drug of a pharmacological class that is not structurally related to a first-in-class compound but is in other respects a me-too drug" – Aronson & Green, 2020 |
| 148 | Business stuff | spin-off drug | "A compound with a similar structure to another compound, but a different pharmacological target" – Aronson & Green, 2020 |
| 149 | Business stuff | me-too product | "A medicinal product containing a me-too drug" – Aronson & Green, 2020 |
| 150 | Business stuff | follow-on product | "A medicinal product containing a follow-on drug or a previously marketed drug in a different formulation" – Aronson & Green, 2020; e.g. slow release formulations of a marketed drug |
| 151 | Clinical trials, etc. | pivotal trial | Trial (often a Phase III one) designed to gather information needed for regulatory (e.g. FDA) approval |
| 152 | Drug discovery and development | drug product | "A finished dosage form (e.g., tablet, capsule, solution) that contains an active drug ingredient generally, but not necessarily, in association with inactive ingredients, or a finished dosage form that does not contain an active ingredient but is intended to be used as a placebo.” – FDA 2006 eIND guidelines |
| 153 | Drug discovery and development | drug substance | "Any component that is intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body”” – FDA 2006 eIND guidelines |
| 154 | Clinical trials, etc. | microdose | A teeny tiny (typically sub-therapeutic) amount of a compound. More officially, "Less than 1/100th of the dose of a test substance calculated (based on animal data) to yield a pharmacologic effect of the test substance with a maximum dose of <100 micrograms (for imaging agents, the latter criterion applies)” – FDA 2006 eIND guidelines |
| 155 | Clinical trials, etc. | first in human (FIH) studies/trials | Experiments or clinical trials that test a drug in humans (often healthy volunteers) for the first time. |
| 156 | Clinical trials, etc. | first in patient studies | Experiments that test a drug in an intended patient population for the first time. |
| 157 | Clinical trials, etc. | NOAEL (No-observed-adverse-effect level) | The highest dose at which no toxicity is observed in a non-human animal model. It can be used to determine, based on pre-clinical data, what starting dose to test in first-in-human (FIH) trials. You often see the term used along with "maximum recommended starting dose (MRSD)." Compared to MABEL (minimal anticipated biological effect level), which relies more on pharmacology studies and PK/PD modeling than on animal toxicology, it is often less conservative. |
| 158 | Nucleic acid therapeutics | safe harbor site (SHS) | A place in the genome that genes can be integrated into without causing problems and allowing for reliable expression |
| 159 | Drug discovery and development | epieffectors | Epigenome editors (molecules that alter modifications to DNA and/or histones (methylation, acetylation, etc.) without altering the DNA sequence. |
| 160 | Cell therapies and immunotherapy | HPSCs | Hematopoietic stem and progenitor cells; located in the bone marrow, these cells give rise to blood cells and can be editing and/or replaced to treat blood disorders.; "Blood cell development progresses from a hematopoietic stem cell, which can undergo either self-renewal or differentiation into a common lymphoid progenitor cell or a common myeloid progenitor cell. Red blood cells are derived from common myeloid cell progenitors." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 161 | Gaining approval | CQA (Critical Quality Attributes) | "The physical, chemical, biological, or microbiological properties/characteristics that should be within an appropriate limit, range, or distribution to ensure the desired product quality." – FDA; The QAs to be evaluated vary depending on the nature of the product and what features are important for its function; As part of the process of the approval of a biosimilar, quality attributes of the biosimilar and the biologic are compared. For a biologic, these could include things like post-translational modifications, binding and/or enzymatic activity, etc. |
| 162 | Drug discovery and development | TMDD (target-mediated drug disposition) | Saturation of a target molecule by a drug when given at low doses - it can influence how well findings from microdose studies can be extrapolated to larger doses. |
| 163 | Drug discovery and development | PBPK (physiologically based pharmacokinetic) modeling and simulation | Computer simulations used to try to predict how drugs will act in and be acted upon by the body |
| 164 | Drug discovery and development | DDI (drug-drug interaction) | When 2 drugs interact with one another (sometimes with unwanted consequences). The possibility for DDIs may lead to contraindications to be put on labels to prevent people from taking one drug if they're already taking another drug. |
| 165 | Drug discovery and development | fill finish | The final step in drug production, where the product is (aseptically) put in containers, sealed, & labeled. |
| 166 | Legal stuff | copyright | “This often relates to written material or images where the originator has an automatic right to ownership. From a pharmaceutical R&D perspective, this will most likely apply to material in technical or commercial publications.” – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 167 | Legal stuff | trade secrets | “These only last so long as they remain secret, i.e. are not disclosed to others without a prior legal contract, such as a confidentiality or non-disclosure agreement (CDA or NDA).” – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 168 | Legal stuff | patents (aka letters patent) | “Legal instruments which are designed to prevent the exploitation of an invention by competitors The USA and UK system originated in eighteenth century England, in the reign of Queen Anne. Each country has its own patent law, but harmonization through the World Trade Organization encourages individual countries to comply with global regulations. The Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) has helped to bring the trade in pharmaceuticals under a global umbrella.” – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 169 | Regulation | rare disease | “The FDA defines a rare disease as one affecting fewer than 200,000 individuals, and for the EMA, fewer than 5 in 10,000.” – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 170 | Drug discovery and development | prodrug | "Any entity that undergoes biotransformation before exhibiting its pharmacological effects" – Calzeda, Cerecetto, and Tosar, 2024 |
| 171 | Drug discovery and development | dual action drug | "An entity that combines two desired different pharmacological actions at a similarly efficacious dose." – Calzeda, Cerecetto, and Tosar, 2024 |
| 172 | Small molecules | hybrid drug | "Agents with different structural domains with different biological actions" – Calzeda, Cerecetto, and Tosar, 2024 |
| 173 | Drug discovery and development | symbiotic drug | An entity "designed to recognize two (or more) distinct biological targets involved in the same pathology and belonging to different biochemical pathways to promote a more efficient bioresponse " – Calzeda, Cerecetto, and Tosar, 2024 |
| 174 | Drug discovery and development | animal model | "A non-human species used in biomedical research because it can mimic aspects of a biological process or disease found in humans. Animal models are used to study the development and progression of diseases and to test new treatments before they are given to humans." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 175 | Gaining approval | Breakthrough Therapy designation | "Breakthrough Therapy designation is a US Food and Drug Administration (FDA) process designed to expedite the development and review of drugs that are intended to treat a serious condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint(s)." Drug applications getting this distinction get fast track benefits as well as more access to meetings with and guidance from the FDA throughout the development and approval process. |
| 176 | Drug discovery and development | discovery toxicology | "The focus of toxicology on preventing adverse effects of drugs by anticipating and addressing potentially problematic features of candidate molecules before initiation of clinical trials." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 177 | Drug discovery and development | toxicology | "The study of the adverse effects of chemical, physical or biological agents on people, animals and the environment." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 178 | Clinical trials, etc. | dose response | When giving more of a drug leads to more of an effect (up to a certain point); This can be a good sign that the drug is causing the effect |
| 179 | Drug discovery and development | formulation | Basically, how the active component is made into an actual drug. "The process of devising and assembling an active ingredient with other materials, such as solvents, fillers, binders, lubricants, preservatives and delivery vehicles (such as those needed for capsules, tablets, ointments etc.)." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 180 | Protein therapeutics | antibody humanization | "The process of making an antibody drug candidate with protein sequences derived from animals more human-like and less likely to be attacked by the human immune system." – Pao, Breakthrough |
| 181 | Business stuff | International nonproprietary name (INN) | "A unique name that is globally recognized and public property, which identifies pharmaceutical substances or active pharmaceutical ingredients. The INN name is established by the World Health Organization (WHO)." – – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 182 | Drug discovery and development | Lipinski's rule of 5 | "A concept frequently used in drug discovery to help predict if a biologically active molecule is likely to have the chemical and physical properties to be orally bioavailable" – Pao, Breakthrough |
| 183 | Clinical trials, etc. | mass balance study | "A study that looks at how an investigational drug is absorbed, distributed, metabolized and excreted in the human body."– Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 184 | Drug discovery and development | oral bioavailability | "Rate and extent to which an orally administered drug is absorbed through the gut and becomes available to the treatment site in the body." |
| 185 | Gaining approval | reference product | The first marketed version of a biologic, to which biosimilars are compared; "a biological product that has been approved in a stand-alone application that contains all data to demonstrate the product’s safety and effectiveness for each of the indications being sought by the manufacturer and is the product against which a proposed biosimilar is evaluated." – FDA |
| 186 | Drug discovery and development | pharmacokinetics (PK) | What the body does to a drug; "The characteristic movements of drugs within biological systems, as affected by absorption, distribution, binding, elimination, metabolism and excretion; particularly the rates of such movements." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 187 | Gaining approval | new molecular entity (NME) | A new small molecule or a new biologic (in contrast to an NCE (new chemical entity) which refers only to a new small molecule drug.) |
| 188 | Drug discovery and development | pre-clinical studies | Investigation of a drug before it's given to any people; this typically involves both in vitro studies, studies in animal models, and toxicology studies in animals. |
| 189 | Drug discovery and development | pre-clinical toxicology review | "The review of potential adverse events of a drug candidate before clinical trials in humans are to be carried out. Potential chemical, physical or biological causes of adverse events are evaluated." – Pao, Breakthrough: The Quest for Life-Changing Medicines, 2024 |
| 190 | Business stuff | parallel indication development | When a drug developer develops a drug with the intention of treating different indications, and tests it for multiple conditions at the same time (e.g. in parallel trials). |
| 191 | Genetics | whole genome sequencing (WES) | A DNA sequencing technique that only sequences the parts of DNA with protein instructions (coding regions called exons) – basically, it sequences DNA versions of messenger RNA. |
| 192 | Genetics | whole exome sequencing (WGS) | A DNA sequencing technique that sequences “everything” – those protein-coding regions (exons) as well as regulatory regions called introns that are interspersed with those exons and intergenic (between gene) regions. |
| 193 | Genetics | GWAS (Genome-Wide Association Study) | A DNA sequence analysis technique that looks at lots of locations across the genome where people may vary in sequence (e.g. single nucleotide polymorphisms (SNPs) or single nucleotide variants (SNVs) and sees which versions of the sequence are present in people with certain traits but not people without those traits (i.e., which genetic variants are potentially associated with a trait/condition). |
| 194 | Genetics | single nucleotide polymorphism (SNP) | A location in a DNA sequence where a single DNA letter (single base pair) is different than that in a reference genome. Although often used interchangeably with SNV (single nucleotide variant), a SNP is technically defined as a SNV present in >1% of the population. |
| 195 | Genetics | single nucleotide variant (SNV) | A location in a DNA sequence where a single DNA letter (single base pair) is different than that in a reference genome. Although often used interchangeably with SNP (single nucleotide polymorphism), SNV is a broader term for any single nucleotide difference, whereas a SNP is technically defined as a SNV present in >1% of the population. |
| 196 | Drug discovery and development | loci of disequilibrium | A region of DNA where nearby variants tend to be inherited together due to linkage disequilibrium. |
| 197 | Drug discovery and development | linkage disequilibrium | The phenomenon whereby regions of the genome that are physically close tend to be co-inherited due to the mechanics of meiosis and crossing over. |
| 198 | Genetics | Manhattan plot | A type of graph often used to display results of GWAS studies. Each dot is a genetic variant, typically a SNP (Single Nucleotide Polymorphism). The x-axis is chromosomal location and the higher the dots are on the y-axis, the more likely that location is really associated with the trait. |
| 199 | Drug discovery and development | linkage analysis | A method to look for genetic causes of a trait or disease/disorder by looking at inheritance patterns at the genotypic level–what versions (alleles) of genes do affected and unaffected people have. Typically, scientists used techniques such as RFLP (restriction fragment length polymorphism) and/or PCR-based methods taking advantage of copy number variation to see what genetic "markers" (easily observable, but typically non-consequential genetic differences in regions that tend to vary between people) were co-inherited with a causal mutation, and then they homed in to find the causal mutation. These markers don’t directly tell them what gene might be involved, but, since near-together genes are more likely to be inherited together, the markers serve as a “proxy” for nearby genes. So, if scientists find a “hit,” a shared marker, they can then look to the actual sequences to see if there are genes in the region which might help explain things, then investigate those genes more closely and look for mutations in those genes in affected people. |
| 200 | Drug discovery and development | forward genetics | Scientific techniques that start with a phenotype and try to track down the associated genotype (what versions of what genes cause what observable effects). |
| 201 | Drug discovery and development | reverse genetics | Scientific techniques that start with a genotype and try to figure out what effects that version of that gene has on observable features (phenotypes). |
| 202 | Genetics | genotype | What version (allele) of what gene(s) does one have. |
| 203 | Genetics | phenotype | What observable traits does one have |
| 204 | Drug discovery and development | in vitro | Experiments conducted in a lab, outside of organisms and, in its purest sense, outside of cells (e.g., in a test tube). It often involves using purified components, sometimes uses cellular lysates (the content of broken open cells), or in cell culture (work with cells adapted to grow in the lab). It offers the most experimental control but is the least realistic – it's best for dissecting mechanisms to figure out how things work (or why they don't!) |
| 205 | Drug discovery and development | in vitro cell culture (in cells/in cellulo) | Experiments done in culture-adapted cells outside of an organism, in a highly controlled system. Offers a medium level of control and realism. |
| 206 | Drug discovery and development | in vivo | In an organism. Experiments or work done inside of organisms. It offers the least experimental control and the most variation, but has the potential to be the most realistic. |
| 207 | Drug discovery and development | ex vivo | Outside of a source organism. Experiments or work done on outside of the source organism. but with minimal disruption and as natural of conditions as possible. Note: This contrasts with in vitro cell culture work, where scientists break tissues up into individual cells and use highly artificial conditions in order to allow them to survive for a long time |
| 208 | Drug discovery and development | in situ | In the original place/on site. |
| 209 | Drug discovery and development | in silico | In computer land. “Dry work” techniques that typically depend on data collected through physical “wet lab” experiments, often by many scientists. |
| 210 | Drug discovery and development | organoids | Lab-grown clumps of cells that try to mimic tissues and organs in vitro. |
| 211 | Cell therapies and immunotherapy | iPSCs (induced Pluripotent Stem Cells) | Stem cells made from non-stem cells (e.g. skin cells) taken from an organism and treated (via introduction of genes for regulatory proteins called transcription factors or by exposure to various chemicals) to revert back to stemness so they can then be treated with cell-type-specific signals to get them to differentiate into desired cell types. |
| 212 | Cell therapies and immunotherapy | stem cell | A cell with the potential to develop (differentiate) into multiple types of cells. |
| 213 | Drug discovery and development | libraries | Large collections of molecules often used in screening methods (e.g. a compound library) or sequencing methods (e.g. a DNA sequencing library) |
| 214 | Drug discovery and development | phenotypic screens | Screens that test compounds against cells from patients with the condition and/or models of the condition to see which if any of the molecules reduce signals associated with the condition (e.g. cell death). They are target-agnostic, caring only about readout at this stage, not what cellular molecule(s) the test compound may bind. |
| 215 | Drug discovery and development | target-based screens | Screens that test compounds against (often purified versions of) proteins or other molecules associated with a condition. Rather than amelioration of disease signals, they often look for signs like reduction or increase in enzyme activity. |
| 216 | Drug discovery and development | high-throughput screens (HTS) | Screens that test LOTS of molecules at once – special caution must be used in HTS methods, because the more things you test the more “false” hits you’re likely to find. Statistical analyses of HTS data must take this into account to apply stricter standards for deeming a hit “statistically significant” and the hits (as in smaller screens) must be validated with additional studies. |
| 217 | Drug discovery and development | structure-aided design | The use of 3D structures of targets to design compounds to “fit” binding sites and/or bind more strongly, less strongly, and/or more specifically. |
| 218 | Drug discovery and development | on-target activity/on-target effects | When a molecule designed (or at least theorized) to bind one thing, the "target" (e.g., a drug binding an enzyme or a CRISPR guide RNA binding a specific DNA sequence) does bind that thing (target) and has some effect(s). Note: These "effects" still could be "good" or "bad" (e.g., too much inhibition), but they're caused by "hitting" (acting on) the "right" thing. |
| 219 | Drug discovery and development | off-target activity/off-target effects | When a molecule designed (or at least theorized) to bind one thing (the target), additionally (or instead) binds another thing and has some effect(s). Note: Although typically "bad," these effects sometime prove beneficial-but also prove scientists need to update their theories about the "target"! (and can be misleading if not discovered) |
| 220 | Drug discovery and development | pharmacological pleiotropy | When a single molecule has multiple effects (which can be due to on-target activity (e.g., because the target may do many things &/or hitting it sets off ripple effects on pathways, etc.), off-target activity, or a combination of both). |
| 221 | Drug discovery and development | hits | Molecules that give a desired response in a screen but may have undesired properties including ones not identified in the screen) and even if they don't, they typically need further development to be optimized for use as a drug (e.g. to improve potency and bioavailability) |
| 222 | Clinical trials, etc. | regression to the mean | Things are often going to get better no matter what. But if someone takes something when things are bad (as is typical), they might credit the thing they took with that improvement. |
| 223 | Clinical trials, etc. | placebo effect | Patients will often get hope just knowing they’re on a drug and this positive attitude can make them feel better (placebo effect). |
| 224 | Clinical trials, etc. | nocebo effect | If a patient has an “adverse event” like a seizure during the trial, and they think they’re on a drug, even if they aren’t, they might blame the drug, especially if they’re told the drug could cause seizures. |
| 225 | Clinical trials, etc. | trial arms | Groups of patients receiving different treatments in a clinical trial |
| 226 | Clinical trials, etc. | therapeutic arm | A group of patients receiving a therapy in a clinical trial. |
| 227 | Clinical trials, etc. | control arm | A group of patients receiving a placebo or the current standard of care in a clinical trial |
| 228 | Clinical trials, etc. | standard of care | The treatment a patient with a condition would typically get if they weren't in a clinical trial |
| 229 | Clinical trials, etc. | endpoint | A measurable target goal that scientists/clinicians can measure in order to see if their trial met the objectives it set out to accomplish. |
| 230 | Clinical trials, etc. | primary endpoint/outcome | The main thing measured/main target goal of a study, used to determine success of trial. |
| 231 | Clinical trials, etc. | secondary endpoint/outcome | Things other than the primary endpoint that are measured to gauge success of a trial and/or gain insight into a treatment's mechanism and/or groups most likely to benefit. |
| 232 | Drug discovery and development | biomarkers | (Typically molecular) indications that are believed to correlate with some other phenomenon, but are easier to measure than that other phenomenon (e.g. levels of various enzymes in the blood can serve as biomarkers indicating that the liver might be damaged). |
| 233 | Clinical trials, etc. | surrogate endpoints/outcomes | (Typically molecular) indications, sometimes in the form of “biomarkers” that are believed to correlate with clinical efficacy (e.g., lowering of levels of a misfolded protein or increase in levels of a wanted protein) and which may be used in lieu of true efficacy endpoints if a drug developer has received accelerated approval for the trial. This can be used in cases where disease symptoms progress over years, or if there’s a pressing need for a treatment, it can be hard to know in a reasonable amount of time if a treatment actually has clinical efficacy (does it actually help people). The companies are then supposed to continue following patients and/or do additional studies to confirm the treatment actually is effective, but these are not always completed.⠀ |
| 234 | Clinical trials, etc. | blinding/masking | When knowledge of who did or did not get what is hidden from doctors (etc.) and/or patients in a trial. |
| 235 | Clinical trials, etc. | double-blinded/double-masked | Neither doctor nor patient knows who’s getting what (of course, someone knows, but not the people who could potentially affect the results) |
| 236 | Clinical trials, etc. | single-blinded/single-masked | Doctors, but not patients, know who’s getting what |
| 237 | Clinical trials, etc. | open-label | Doctors and patients both know who’s getting what |
| 238 | Clinical trials, etc. | randomization | Patients are randomly placed into one arm (e.g. it’s random whether or not they are selected to receive the treatment or a placebo). |
| 239 | Clinical trials, etc. | placebo | A sham treatment - can be a "sugar pill" or some other harmless fake treatment that ideally is as close to the real treatment as possible with regards to how it looks, how it's given, etc. so it's indistinguishable to the participants. |
| 240 | Clinical trials, etc. | interim analysis | Midway analysis of clinical trial results by an “independent” data monitoring committee to see if it would be unethical to proceed either because the treatment is causing severe side effects or because the treatment is super effective so it’s unfair not to give it to more people. |
| 241 | Clinical trials, etc. | Data Monitoring Committee (DMC) | aka a Data Safety and Monitoring Board (DSMB), this group of people monitors the safety of trial participants and performs interim analysis in clinical trials to see if it would be unethical to proceed either because the treatment is causing severe side effects or because the treatment is super effective so it’s unfair not to give it to more people. |
| 242 | Clinical trials, etc. | Data Safety and Monitoring Board (DSMB) | aka a Data Monitoring Committee (DMC), this group of people monitors the safety of participants and performs interim analysis in clinical trials to see if it would be unethical to proceed either because the treatment is causing severe side effects or because the treatment is super effective so it’s unfair not to give it to more people. |
| 243 | Clinical trials, etc. | systematic review | A type of scientific article trying to determine and report a “consensus” from multiple studies – scientists use predefined criteria to mine the literature and select papers to include the results of. |
| 244 | Clinical trials, etc. | meta-analysis | A type of scientific article where authors pool results from different studies and do statistics on them to try to reach a consensus from multiple studies. |
| 245 | Clinical trials, etc. | case reports | Scientific papers where doctors present "odd" or "unusual" findings or report on the treatment of a single patient using a non-conventional strategy. |
| 246 | Clinical trials, etc. | case series | Scientific papers where doctors present findings from multiple similar case reports of. These may provide impetus for larger, more official, studies |
| 247 | Drug discovery and development | phenotypic assay | "A laboratory test that determines the effect of test molecules on some observable trait of a cell, tissue, or organism" – Cordes, Hallelujah Moments |
| 248 | Drug discovery and development | development candidate | "A lead molecule meeting all pre- specified criteria for advancement to Good Laboratory Practices safety assessment. In general, a molecule in this category will be highly potent and highly specific, show good oral bioavailability, acceptable duration of action, resistance to metabolism, and acceptable stability and will have passed preliminary safety studies, generally in rodents. It may require the synthesis of a thousand or more molecules to identify a molecule in this category (though there is no guarantee of getting this far regardless of how many molecules are synthesized)." – Cordes, Hallelujah Moments |
| 249 | Drug discovery and development | clinical candidate | "A molecule that has passed rigorous Good Laboratory Practices safety assessment, usually in two or three species, typically rats, mice, and dogs. A molecule in this category is ready for phase 1 clinical studies, assuming that appropriate regulatory authorities agree." – Cordes, Hallelujah Moments |
| 250 | Drug discovery and development | product candidate | "A molecule that has progressed to phase 2B clinical trials. A molecule in this category is ready for clinical work to define the dose and dosage regimen that will be employed in the definitive phase 3 studies." – Cordes, Hallelujah Moments |
| 251 | Drug discovery and development | actives | Another term for "hits" |
| 252 | Drug discovery and development | lead/lead compound | "An active molecule meeting a specified set of properties justifying a larger, focused chemistry/ biology effort. A lead will generally have better potency than the earlier actives, will show significant specificity for the intended" – Cordes, Hallelujah Moments |
| 253 | Drug discovery and development | oral bioavailability | "This is a measure of the fraction of a dose given by mouth that gets out of the gut and past the liver into the systematic circulation" – Cordes, Hallelujah Moments |
| 254 | Drug discovery and development | elimination | How a drug gets out of the body – urine, feces, both? |
| 255 | Drug discovery and development | duration of action | How long a drug effects the body |
| 256 | Drug discovery and development | stability | How long will a drug last outside the body? Does it need special storage conditions? |
| 257 | Clinical trials, etc. | tolerability | Are any side effects tolerable enough that the patient will keep taking it? |
| 258 | Drug discovery and development | safety | Is it safe? Involves not just outward, "experienced" side effects but also biomarkers and other indications of internal issues caused by the drug. |
| 259 | Regulation | Office of Prescription Drug Promotion (OPDP) | An FDA department that regulates ads for prescription drugs. |
| 260 | Legislation | Drug Efficacy Study Implementation (DESI) | An FDA program that evaluated drugs that had been approved before the FDA requirement that drugs had to actually work (1938-1962). |
| 261 | Legislation | Prescription Drug User Fee Act (PDUFA) | Pronounced pa-doo-fah (seriously!), this 1992 act requires drug manufacturers to pay fees for applications they submit, etc. and those fees are used in part to fund application reviewers. |
| 262 | Regulation | Drug Safety Board | "consisting of FDA staff and representatives from the National Institutes of Health and the Veterans Administration. The Board will advise the Director, Center for Drug Evaluation and Research, FDA, on drug safety issues and work with the agency in communicating safety information to health professionals and patients." – FDA website |
| 263 | Clinical trials, etc. | switching study | A comparative drug study in which patients are switched between 2 drugs (e.g. a brand name "reference product" and a biosimilar) to see if there's any difference – such studies may be done to try to gain approvable for a biosimilar to be designated as an interchangeable |
| 264 | Gaining approval | comparative analytical assessment (CAA) | Studies comparing reference products (brand name biologics) to proposed biosimilars to determine biosimilarity; may include physiochemical (structural) and biological (functional) assays from multiple lots of both the reference and the proposed biosimilar. Per the FDA, they "generate data about selected quality attributes that help provide information and assurance about the identity, quality, safety, purity, and potency of the proposed biosimilar as compared to the reference product." |
| 265 | Gaining approval | priority review | "Priority Review designation means FDA’s goal is to take action on an application within 6 months.” – FDA; Note: companies may be granted priority review vouchers for doing things like developing treatments for orphan diseases. They are then able to apply those vouchers to speed up approval of other medications or sell them to other companies. This is explained well in Rethinking Medications by Jerry Avorn. |
| 266 | Gaining approval | biosimilarity | The criteria for similarity between a brand name biologic and a proposed biosimilar that must be met for a biosimilar to be approved. |
| 267 | Legal stuff | patent term extension (PTE) | An extension of the time before a patent expires. Of up to 5 years may be granted to make up for time spent in the approval process (this is a key component of the 1984 Drug Price Competition and Patent Restoration Act (more commonly referred to as the Hatch-Waxman Act). |
| 268 | Gaining approval | New Chemical Entity Exclusivity (NCE) | 5-year market exclusivity period for typical new drug approval. |
| 269 | Gaining approval | Reference Product Exclusivity (RPE) | 12-year market exclusivity period, including 4 years data in which competitors can’t even file an aNDA for a biosimilar. This is the exclusivity period for a new biologic. Biologics get a longer exclusivity period with the rationale they’re more complicated and pricy to develop. This is dictated by the Biologics Price Competition and Innovation Act (BPCIA). |
| 270 | Gaining approval | Orphan Drug Exclusivity (ODE) | 7-year market exclusivity period for orphan drugs. This longer exclusivity period is meant to incentivize development of therapeutics for indications (diseases/disorders) with a small treatable population that might not otherwise be an “attractive” target for development |
| 271 | Gaining approval | Generating Antibiotic Incentives Now (GAIN) Exclusivity | A 5-year extension on market exclusivity for new antibiotics. This longer exclusivity period is meant to incentivize development of much-needed antibiotics. Antibiotic development is urgently needed, but generally not very lucrative. |
| 272 | Gaining approval | New Clinical Investigation Exclusivity | 3-year market exclusivity period for a drug that isn’t new, but has gained approved for an additional indication. |
| 273 | Gaining approval | Pediatric Exclusivity (PED) | 6-month extension to market exclusivity period to incentivize development of therapeutics for pediatrics, which can be seen as “riskier” and thus incentive-needing. |
| 274 | Gaining approval | Competitive Generic Therapy (CGT) | 180-day generic exclusivity period for the first generic version of a product that’s approved – during this short exclusivity period, other generics can’t be sold (but the brand name still can) |
| 275 | Legal stuff | Patent Challenge (PC) | If the brand name manufacturer has infringed on patents or something along that lines, the first company wanting to market a generic that sues the brand name manufacturer gains some exclusivity (180 days). |
| 276 | Regulation | Orange Book | More formally, “Approved Drug Products with Therapeutic Equivalence Evaluations,” this is a database of approved drugs. This includes patents, exclusivity periods, etc. |
| 277 | Regulation | Purple Book | More formally, “Database of Licensed Biological Products,” this is a database of information on approved biologics. It also includes information about what biosimilars and interchangeable biosimilars there are for a biologic. |
| 278 | Regulation | EMA (European Medicines Agency) | Europe's equivalent of the FDA. Note: "The EMA equivalents of the FDA’s IND and NDA applications are the Clinical Trial Authorization (CTA) and Marketing Authorization Application (MAA) respectively." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 279 | Business stuff | Pharmacoeconomics | A discipline that "applies a cost-effectiveness analysis (CEA) to drug pricing. It includes the costs involved in drug development, pricing models and the ways in which payment for very expensive medicines could save money in the long term." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 280 | Business stuff | wholesale acquisition price (WAC) | List price of a drug |
| 281 | Business stuff | average selling price (ASP) | Average net price of a drug, which may be >40% lower than list price (WAC) due to negotiations |
| 282 | Business stuff | specialty drugs | Super expensive drugs that treat rare, chronic, and/or complex conditions |
| 283 | Drug discovery and development | extension drug | A drug that "incorporates the active ingredient previously approved by the FDA for the incumbent and then adds a new dosage, delivery method, or indication to extend the brand." – Hartman and Schramm, 2025 |
| 284 | Clinical trials, etc. | maximum tolerable dose (MTD) | The highest dose at which any side effects are considered tolerable. |
| 285 | Clinical trials, etc. | dose-limiting toxicity (DLT) | When side effects of a drug at some dose are too high for the drug to be safely given at that dose or at a higher dose. |
| 286 | Gaining approval | quality attributes (QAs) | Measurable properties of a substance that provide information about its quality. A subset of these are classified as critical quality attributes (CQAs) and a product must be shown to be within strict limits for those. |
| 287 | Gaining approval | totality of the evidence | "The approach used by FDA to evaluate the applicant’s structural, functional, and clinical data collectively to determine whether no clinically meaningful differences exist in a proposed biosimilar product’s quality, safety, or efficacy as compared with the reference product" – FDA |
| 288 | Business stuff | formulary | The drugs that an insurance company will pay for |
| 289 | Gaining approval | 351(a) | The approval pathway for a biologic in the US. It involves: clinical safety and efficacy studies for each indication; clinical pharmacology; animal/nonclinical studies; product quality studies |
| 290 | Gaining approval | 351(k) | The approval pathway for a biosimilar in the US. It's abbreviated compared to the 351(a) required for the original biologic. It does not require clinical safety and efficacy studies for each indication(with the assumption proof of biosimilarity to the reference product will ensure the results would be similar to those from the reference product), but it may require additional clinical studies, clinical pharmacology studies, comparative analytical assessment (CAA), and product quality studies. |
| 291 | Drug discovery and development | ligand efficiency | A measure of "how well a compound binds for its size (log potency divided by number of ‘heavy atoms’ i.e. non-hydrogen atoms, in a molecule)." – Hughes et al., 2011 |
| 292 | Drug discovery and development | data mining | Looking through masses of data in databases to find "hidden treasure" (overlooked potential targets, etc.) and/or trends, etc. |
| 293 | Drug discovery and development | focused screening | aka knowledge-based screening; Screening against a library of molecules (potentially a subset of a larger screening library), chosen based on knowledge of the target (e.g. compounds known to inhibit kinases if your target is a kinase) and/or prior hits (e.g., compounds with a similar structure to one you already found bound) |
| 294 | Drug discovery and development | fragment screening | Screening (often through crystal soaking for x-ray crystallography) using small chemical compounds that, on their own, might just be drug parts, but hint at potential binding structures that could be expanded upon (potentially connecting multiple fragments. It's often aided by 3D structures of the binding site and interaction (structure-aided design). |
| 295 | Drug discovery and development | physiological screening | Screening in tissues to look for an in-tissue effect |
| 296 | Drug discovery and development | knowledge-based screening | aka focused screening; Screening against a library of molecules (potentially a subset of a larger screening library), chosen based on knowledge of the target (e.g. compounds known to inhibit kinases if your target is a kinase) and/or prior hits (e.g., compounds with a similar structure to one you already found bound) |
| 297 | Drug discovery and development | virtual screening | Using computer modeling (e.g. docking) to predict what molecules might bind to a target; among other uses, it might help inform choosing a subset of a library for a focused screen |
| 298 | Drug discovery and development | CYP450 | Oxidizing enzymes in the body that can modify drugs and thereby affect the drugs' effects. Conversely, drugs themselves may have effects on these enzymes, which can influence how long the drug as well as other drugs taken at the same time stay in the body, etc. For example, inhibition of CYP450 can prevent the breakdown of drugs leading them to build up and cause toxicity. |
| 299 | Legislation | Best Pharmaceuticals for Children Act (BPCA) | 2002 legislation that improves safety and efficacy assurances for pediatric medicines and clarifies aspects of market exclusivity perks, etc. for developing drugs for kids (established in the 1997 FDAMA). |
| 300 | Legislation | Pediatric Research Equity Act (PREA) | 2003 act that gave the FDA clear authority to require treatments being developed for pediatric use be tested for those uses. |
| 301 | Legal stuff | ICH (International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use) | Initially formed between the US, Japan, and Europe (and later expanded to include other countries), this group harmonizes regulatory requirements in member countries. |
| 302 | Business stuff | reimbursement | "the money that the holders of healthcare funding will pay the front-line suppliers of that care, the NHS in the UK, for example, or Medicaid/ Medicare in the USA" – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 303 | Legal stuff | Myriad Genetics case | A 2013 US Supreme Court case (between the Association for Molecular Pathology and Myriad Genetics Inc.) that ruled that genes can't be patented because they're a product of nature. |
| 304 | Drug discovery and development | endocytosis | A process whereby a cell basically pinches off a part of its membrane (and whatever it’s attached to) and “swallows” it, bringing the membrane-bound contents into the cell, at first trapped in an endosome bubble that they can then escape from (but this escape from the endosome can itself be a large delivery hurdle to overcome!). |
| 305 | Nucleic acid therapeutics | GalNAc | GalNAc (N-acetylgalactosamine) is a type of sugar molecule that can be attached (conjugated) to nucleic acid therapeutics (especially small ones) to target them to the liver (specifically to hepatocytes). They bind to the liver cells’ asialoglycoprotein receptors (ASGPR) and then get internalized by endocytosis. Inside the cells, the GalNAc gets cleaved off. |
| 306 | Nucleic acid therapeutics | virus-like particle (VLP) | Delivery vesicles that don't contain any viral genetic material, just a shell |
| 307 | Nucleic acid therapeutics | electroporation | This strategy, almost always performed ex vivo or in vitro, involves the use of electric pulses to take advantage of nucleic acids’ negative charges to coax them into cells. |
| 308 | Nucleic acid therapeutics | transfection | A broad term for inserting genetic material into cells |
| 309 | Nucleic acid therapeutics | prime editing | A type of CRISPR/Cas based gene editing in which changes are made based on a template provided as part of the guide RNA. It involves the use of a reverse transcriptase enzyme attached to the cas protein. |
| 310 | Nucleic acid therapeutics | base editing | A type of CRISPR/Cas based gene editing in which single nucleotide bases are changed, often with the use of a deaminase. |
| 311 | Gaining approval | NCE (new chemical entity) | A new small molecule drug |
| 312 | Legal stuff | second medical use patents | A patent taken out for another use than was previously patented. |
| 313 | Drug discovery and development | target identification (target ID) | A stage of drug development involving a molecular target to treat a condition of interest. |
| 314 | Drug discovery and development | absorption | Diffusion through cellular membranes into the bloodstream |
| 315 | Drug discovery and development | AUC (area under the curve) | A measure of how much drug a body is exposed to; more technically, it typically looks at levels of the drug in blood plasma over time post-dosage and then calculates the area under that curve to determine total exposure. This can provide insight into things like bioavailability of different drug formulations. It can also be used to calculate the average blood levels of the drug. It's a fundamental tool in pharmacokinetics (PK). |
| 316 | Drug discovery and development | distribution | The movement of a drug throughout the body - where does it go? |
| 317 | Drug discovery and development | first-pass effect | Reduced concentration of ingested drugs in circulation because some of it gets broken down by the liver before even reaching general circulation. |
| 318 | Clinical trials, etc. | 3+3 phase I trial design | A dose escalation study in which 3 patients are given a dose before escalating the dose (with another group of 3). If one of them has a serious adverse event (SAE), another 3 people are given the same dose to see if the SAE was a fluke (in which case, another group at a higher dose can be started) or a real signal (in which the trial might be stopped or at least the dose lowered). |
| 319 | Clinical trials, etc. | medical altruism | When people do things like enroll in Phase I clinical trials they are unlikely to benefit from because they want to help future people. |
| 320 | Clinical trials, etc. | therapeutic misconception | The belief that a clinical trial is likely to help one, rather than just inform future studies, etc. |
| 321 | Drug discovery and development | therapeutic index (TI) | A quantitative measure of relative safety of a drug - compares how much is needed for a desired effect and how much is "needed" for a toxic effect; In technical terms, it's the TD50/ED50. Higher therapeutic index is better. |
| 322 | Drug discovery and development | therapeutic window | The goldilocks zone dose-wise; enough to cause desired effect but not enough to cause toxic effects. |
| 323 | Drug discovery and development | ED50 | The minimum dose needed to have a desired effect in 50% of a population. |
| 324 | Clinical trials, etc. | TD50 | The lowest dose at which toxicity is seen in 50% of a population. |
| 325 | Drug discovery and development | LD50 | The lowest dose which is lethal for 50% of an animal population. |
| 326 | Drug discovery and development | effectiveness | How well does the drug work in the real world (takes into account whether people actually take it as indicated, consistently, etc.) |
| 327 | Drug discovery and development | NAM (New Approach Modality) | "Umbrella term for non-animal, human-relevant methods and strategies, including in vitro, in silico and other emerging approaches, that aim to improve the prediction of human biological responses in preclinical assessment and related biomedical research stages. NAMs such as human organoids, organs‐on‐chips, and advanced computational models are being developed to generate more human‐relevant data and are attracting growing interest as more predictive preclinical tools in drug development" – FIlipova et al., 2026 |
| 329 | Drug discovery and development | valley of death | Time period between drug candidate selection and IND submission in which candidates often fail |
| 330 | Drug discovery and development | parenteral route | Administering medications via routes that bypass the digestive tract (injections (intravenous (IV), intramuscular (IM), subcutaneous (SC or subQ), or intradermal (ID)), inhalation, etc.); it can allow for faster action, more precise concentrations, etc. as well as (depending on the route) localized administration |
| 331 | Drug discovery and development | secondary pharmacology | The testing of drugs against off-targets |
| 332 | Clinical trials, etc. | hazard ratio (HR) | A ratio of how frequently something happens in one group compared to another group (often a control group). A hazard ratio >1 indicates that that "thing" happens more often in the group you're focusing on (the one on top of the ratio) than the other group (e.g., it happens more frequently than in the control group) and a ratio less than 1 indicates that it occurs less frequently. It can be assessed at any time and may change over time. |
| 333 | Drug discovery and development | enteral route | Administering medications via a route that involves the digestive tract (includes oral ingestion (PO), rectal, feeding tube, etc.) |
| 334 | Drug discovery and development | attrition | Failure of a drug candidate during development and/or clinical testing |
| 335 | Drug discovery and development | microphysiological systems | "Bioengineered in vitro systems, which recreate aspects of organ architecture and functionality, often with perfusion as vasculature equivalent forming (multi-) organ-on-chip systems" – Hartung, 2024 |
| 336 | Nucleic acid therapeutics | adenoviral vectors | Adenovirus (Ad) vectors are largely gutted-out versions of a type of double-stranded DNA virus that typically remains episomal (doesn’t integrate with the genome) and when it does integrate, it tends to be at okay places. A couple of key benefits are they can deliver large genetic payloads (>30 kb) and can transduce dividing & non-dividing cells. However, they are highly immunogenic – can be good for vaccines and cancer treatments, but bad for most gene therapies. |
| 337 | Nucleic acid therapeutics | lentiviral vectors | Largely gutted-out versions of HIV or related viruses used to deliver genes into cells. These RNA-based viruses include a reverse transcriptase that, once inside cells, makes a DNA copy of its RNA and integrates it into the host DNA. Because they integrate in the genome, they offer long-term expression, which may be desired, but also risk causing problems if they insert into a bad location (such as the middle of a gene). Integrase-deficient versions are being developed and tested for use in applications not requiring long-term expression (e.g., vaccines). A couple key features are that they can infect non-dividing and slowly-dividing cells and can deliver up to ~ 9 kb (kilobase pairs) of DNA. |
| 338 | Clinical trials, etc. | FDA Adverse Event Reporting System (FAERS/AERS) | Established in 1998 as AERS and later renamed FAERS after a facelift, this computerized database beefed-up post-marketing safety surveillance (but keep in mind that not everything reported there is actually caused by the drug's use. It is, however, important to track things that could be caused by the drug to see if there might be other similar cases, etc. which could point to safety problems with the drug's use). |
| 339 | Legislation | demographic rule | 1998 rule that if you want to sell a drug, you need to analyze its safety and effectiveness by age, gender, and racial background. |
| 340 | Legislation | pediatric rule | 1998 rule that if you want to sell certain drugs with pediatric uses, you need to test its safety and efficacy in kids. |
| 341 | Regulation | US Pharmacopeia | First compendium of drug standards in the US (1820) |
| 342 | Legislation | Drug Importation Act | 1848 Congressional act that requires customs inspections to stop import of adulterated drugs |
| 343 | Legislation | Biologics Control Act | 1902 Congressional act to ensure safety and purity of serums, vaccines, & similar products for human uses. |
| 344 | Legislation | Food and Drugs Act of 1906 | The OG Food and drug act passed by Congress was quite limited in scope, but did prohibit interstate commerce in misbranded and/or adulterated food, drinks, & drugs. It did not set required standards for safety or efficacy. Rather, it just required things contained what their labels said they contained (not that they did what they said they did). |
| 345 | Legislation | Shirley Amendment | 1912 amendment to the 1906 FDA act in response to the U.S. v Johnson Supreme Court ruling that, based on the OG Food and Drug Act, a company couldn’t be held accountable for false therapeutic claims, but only false claims about contents, this amendment sewed up that loophole. It prohibits labeling of medicines with false therapeutic claims. The catch? It required that the claims could be shown to be done with the intent to defraud the purchaser – another loophole that would later need to be sewn up… |
| 346 | Legislation | Harrison Narcotics Act | 1914 legislation that requires prescriptions for narcotics (exceeding certain levels) and strict record-keeping by those who dispense them. |
| 347 | Legislation | Federal Food, Drug, and Cosmetic (FDC) Act | Passed in 1938 in response to the death of more than 100 people from diethylene glycol (basically antifreeze) poisoning from a drug called elixir sulfanilamide, and the limited amount of recourse the FDA had to do anything about it (other than fine the company for mislabeling it as an elixir even though it didn’t contain alcohol), this new act provided the FDA with a lot more power. Among the most substantial components, it required drugs to be shown as safe before marketing; got rid of the requirement to prove intent to defraud with regards to misbranding claims; and authorized factory inspections. |
| 348 | Legislation | Alberty Food Products Co. v. U.S. | 1950 court ruling that required drug labels to state the purpose for which the drug is intended (basically sewing up another loophole) |
| 349 | Legislation | Durham-Humphrey Amendment | 1951 legislation that defines kinds of drugs that must be prescription only. |
| 350 | Legislation | Kefauver-Harris Drug Amendments | 1962 legislation that required drugs to show efficacy – they’ve finally gotta work to be marketed! They were passed in response to calls for stricter drug regulation in the wake of widespread birth defects caused by the drug thalidomide in Europe (as well as a number of cases in the US that were the result of “trials” – Frances Kelsey stopped the FDA from approving thalidomide in the US). |
| 351 | Legislation | Comprehensive Drug Abuse Prevention and Control Act | 1970 legislation that categorizes drugs based on therapeutic value versus potential for abuse and addiction. |
| 352 | Legislation | Proxmire Amendments (Vitamins & Minerals Amendments) | 1976 legislation that prevents (yep, you read that right) the FDA from regulating vitamins and minerals as drugs and/or establishing standards limiting how much of them can be in food supplements. |
| 353 | Legal stuff | Orphan Drug Act (ODA) | 1983 legislation passed to promote development of therapeutics for rare diseases and conditions by providing financial incentives including tax credits, expedited review pathways, and extended market exclusivity periods. It has led to development of life-saving treatment for rare diseases, but it has also been exploited in various ways. |
| 354 | Legislation | Hatch-Waxman Act (Drug Price Competition and Patent Term Restoration Act) | 1984 legislation that makes it easier to gain approval for generics (they don't have to go through all the clinical trials) and allows for extension of patents for up to 5 years to make up for patent protection time lost pre-marketing. |
| 355 | Legislation | Prescription Drug Marketing Act | 1988 legislation that, among other things, prevents prescription drugs from being resold, requires drug wholesalers to be licensed by states. |
| 356 | Legislation | Common Rule | 1991 guidance that enhances and formalizes human rights protections – requires informed consent; places special precautions for work with children, prisoners, etc.; provides further guidance for IRB (Institutional Review Board) requirements, etc. |
| 357 | Legislation | Generic Drug Enforcement Act | 1992 legislation that provides the FDA with more authority to punish generic drug manufacturers. |
| 358 | Clinical trials, etc. | MedWatch | This is a voluntary adverse reaction reporting system that was established in 1993 |
| 359 | Legislation | Food and Drug Administration Modernization Act (FDAMA) | This 1997 act reauthorized PDUFA and formalized a number of reforms enacted since the OG FDC act of 1938. Some features – accelerated review of devices, exclusivity period extensions for pediatric drugs, and stricter regulation of advertisement claims. |
| 360 | Clinical trials, etc. | adverse event (AE) | aka "adverse drug experience," it's something bad/unwanted that happens during the course of taking a treatment. It does not imply the treatment caused the event however. |
| 361 | Clinical trials, etc. | adverse drug reaction/event (ADR) | A type of adverse event that is thought to be directly caused by the drug's use |
| 362 | Clinical trials, etc. | individual case safety report (ICSR) | A reported adverse event for a single patient. Aka adverse drug reaction report or adverse event report. |
| 363 | Clinical trials, etc. | serious adverse event (SAE) | A serious bad event that occurs during the course of treatment; SAEs are defined differently in different places but include things like death, life-threatening events, things that cause hospitalization, things that cause permanent damage and/or disability, and things that cause birth defects |
| 364 | Clinical trials, etc. | ClinicalTrials.gov | Database founded in 1999 that initially focused on helping patients find trials. Later, it would serve as a sort of accountability and transparency measure where drug developers pre-register their trials, recruit patients, and report results (at least they're supposed to) |
| 365 | Legislation | current good manufacturing practice (cGMP) initiative | 2002 initiative that helps determine and standardize quality standards for drug manufacturing |
| 366 | Legislation | PDUFA III | 2002 legislation that provided another 5-year extension to PDUFA with some minor changes.Allows for use of fees for more post-marketing surveillance. |
| 367 | Legislation | Medicare Prescription Drug Improvement and Modernization Act | 2003 legislation that, among other things, added a voluntary prescription drug coverage plan called “Medicare Part D” |
| 368 | Business stuff | Medicare Part D | Voluntary prescription drug coverage plan for Medicare patients |
| 369 | Legislation | Food and Drug Administration Safety and Innovation Act (FDASIA) | 2012 legislation that, among other things, reauthorizes user fee programs including PDUFA and creates new ones for developers of generics and biosimilars. It also created the Breakthrough Therapy designation to expedite review of certain drugs that could offer significant benefit over existing ones for serious conditions. |
| 370 | Clinical trials, etc. | Final Rule (42 CFR Part 11) | 2017 rule that clinical trials must be pre-registered with ClinicalTrials.gov and their results posted there within 1 year of trial completion. |
| 371 | Legislation | FDA Modernization Act 2.0 | 2022 legislation that removed the strict requirement for animal testing, instead allowing for the use of NAMs (New Approach Modalities) such as organ-on-a-chips and other human-relevant preclinical methods to demonstrate a compound is safe enough for human testing. |
| 372 | Legislation | FDA Modernization Act 3.0 | Legislation that, if enacted, would make the FDA more formally incorporate the 2.0 provisions into its official guidelines and would allow for use of AI tools as NAMs, etc. |
| 373 | Drug discovery and development | absolute bioavailability | A measure of how the bioavailability of a drug given via a non-IV route compares to the drug given via IV. Provides a measure of how the formulation and/or route of administration impacts bioavailability. |
| 374 | Drug discovery and development | half-life | Time it takes for half of a drug to be inactivated and/or excreted and thus useless. Short half-lives can necessitate more frequent dosage. |
| 375 | Drug discovery and development | QSAR (Quantitative structure-activity relationships) | "Mathematical relationships linking chemical structure and pharmacological activity in a quantitative manner for a series of compounds. Methods that can be used in QSAR include various regression and pattern recognition techniques. In this sense, a three-dimensional quantitative structure-activity relationship (3D-QSAR) involves the analysis of the quantitative relationship between the biological activity of a set of compounds and their spatial properties using statistical methods." – Calzada, Cerecetto, and Tosar. Biotherapeutics: From small to large molecules and cells, 2024 |
| 376 | Genetics | OMIM (Online Mendelian Inheritance in Man) | Database with information about genetic diseases. |
| 377 | Drug discovery and development | QTL (Quantitative Trait Locus) | "A region of DNA associated with a specific phenotype or trait that varies within a population. The variance is continuous, like height as opposed to discrete, such as eye colour. QTL mapping is a statistical analysis to identify which molecular markers lead to a quantitative change of a particular trait." – Zanders, Twenty-first Century Drug Discovery: an Expanding Landscape, 2025, 2025 |
| 378 | Drug discovery and development | polytherapy (e.g. combination therapy, polypharmacotherapy) | Treating someone with multiple drugs at the same time. |
| 379 | Cell therapies and immunotherapy | autologous | Coming from the same source as where its being given. For example, if a patient is given “back” their own cells taken from their body either to store or to modify “ex vivo” before returning (potentially after wiping out the bone marrow). |
| 380 | Cell therapies and immunotherapy | allogeneic | Coming from a different source (typically a healthy donor). For example, if a patient is given cells taken from a healthy donor, such as to replace the patient's own diseased cells (often after removal of the patient's bone marrow). |
| 381 | Cell therapies and immunotherapy | CAR-T cell therapy | CAR-T stands for Chimeric Antigen Receptor-T cell, and it refers to a type of immune cell that has been genetically altered to bind to cancer cell-specific molecules to get the immune system to attack cancer cells. In CAR-T cell therapy, T cells are removed from a patient’s blood in a process called leukapheresis, genetically modified ex vivo (outside the body), then returned. |
| 382 | Drug discovery and development | bespoke | Custom, fit for purpose, or made to order. Basically, something you can’t just get off a shelf as a one size fits all. Rather, you (or a company or scientists etc.) have to custom-make something to meet the specific requirements, designs, specifications, etc. of the task at hand. Often comes up in discussions of personalized and/or precision medicine. |
| 383 | Cell therapies and immunotherapy | leukapheresis | A technique in which someone's blood is removed temporarily and passed through a machine to collect immune cells before returning the blood to the body. It may be used, for example, to collect T-cells for CAR-T therapy. |
| 384 | Cell therapies and immunotherapy | immune checkpoints | Safeguards that tell the immune system to back off and not attack a cell. Typically, a type of immune cell receptor sticking off an immune cell surface will bind to a “matching” partner (ligand) displayed on the surface of a normal cell. Kinda like a lock (receptor) and key (ligand) but not quite so simplistic, because the molecules typically change shape a bit when they bind (induced fit). A couple of the main immune checkpoints are PD-1 (Programmed Cell Death Protein 1) on T cells binding to PD-L1/PD-L2 on other cells and CTLA-4 (Cytotoxic T-Lymphocyte-Associated Protein 4) on dendritic cells (another type of immune cell) binding to CD80/CD86 on other cells. They can serve as targets for immune checkpoint inhibitors (ICIs) such as Keytruda. |
| 385 | Cell therapies and immunotherapy | neoantigens | Pieces of proteins that healthy cells don’t make but cancer cells make because of the accumulation of lots of mutations. These protein pieces can be displayed on the surface of cancer cells, bound by MHC (HLA) molecules. Those could bind T-cell receptors and set them off, but cancer cells often also have "checkpoint" molecules on their surface that tell the immune system to back off. Many cancer immunotherapies aim to inhibit the checkpoints to allow the T-cells to stop ignoring the neoantigens. |
| 386 | Cell therapies and immunotherapy | MHCs (Major Histocompatibility Complexes) | aka HLAs (human leukocyte antigen) in humans, these are membrane-bound antigen-presenting proteins that "present"/"display" pieces of proteins (peptides) on their surface to show immune cells called T-cells what's inside them. If the T-cell (through binding to a T-cell receptor) doesn't recognize the peptide as a "self" molecule, it can initiate an immune attack (if it doesn't get called off by immune checkpoint molecules). Different people have different versions of MHC/HLA, and MHC/HLA compatibility can be a major challenge for allogeneic transplants (giving someone cells from another person). (It's a lot more complicated than simple ABO blood typing) |
| 387 | Cell therapies and immunotherapy | HLAs (Human Leukocyte Antigens) | aka MHCs (major histocompatibility complexes), these are membrane-bound antigen-presenting proteins that "present"/"display" pieces of proteins (peptides) on their surface to show immune cells called T-cells what's inside them. If the T-cell (through binding to a T-cell receptor) doesn't recognize the peptide as a "self" molecule, it can initiate an immune attack (if it doesn't get called off by immune checkpoint molecules). Different people have different versions of MHC/HLA, and MHC/HLA compatibility can be a major challenge for allogeneic transplants (giving someone cells from another person). (It's a lot more complicated than simple ABO blood typing) |
| 388 | Protein therapeutics | antigen | A molecule that an antibody (or other immune cell molecule such as a T-cell receptor) binds to. |
| 389 | Protein therapeutics | epitope | The exact part of a molecule that an antibody binds to. |
| 390 | Cell therapies and immunotherapy | histocompatibility | Having good enough matching of cell surface immune-triggering proteins called MHCs/HLAs to allow safe transplant of cells from one person to another person without them being "rejected" and/or setting off a dangerous immune response called graft versus host disease (GVHD). It's a lot more complicated than simple ABO blood typing because humans have numerous MHCs/HLAs with lots of potential versions and combinations. |
| 391 | Cell therapies and immunotherapy | Immune Checkpoint Inhibitors (ICIs) | Drugs that prevent immune checkpoint interactions (e.g., PD-1/PD-L1 or CTLA-4/CD80) thereby preventing the immune system from getting the “hey, back off dude!” signal. They’re often in the form of monoclonal antibodies that bind to the receptor or ligand, although alternative blocking molecules and other strategies are being pursued to get around some of the challenges with use of monoclonal antibodies. A few prominent examples of monoclonal antibody-based ICIs: Anti-PD-1 antibodies (antibodies that bind to PD-1 on T cells): pembrolizumab (Keytruda), nivolumab, and cemiplimab; Anti-CTLA-4 antibodies (antibodies that bind to CTLA-4 on dendritic cells): atezolizumab, avelumab, and durvalumab. |
| 392 | Cell therapies and immunotherapy | cancer vaccines | Vaccines that typically aim to train a person’s immune system to recognize cancer cells as foreign and thus attack it, either as treatment, or to prevent cancer recurrence. Sometimes this is done by taking advantage of the fact that cancer cells often display different molecules on their surfaces than do healthy cells. These “new” molecules are called neoantigens and they can arise due to DNA mutations causing amino acid substitutions, mis-spliced RNA, etc. |
| 393 | Drug discovery and development | endogenous | Something that is made by an organism rather than taken in from outside, such as hormones the body produces |
| 394 | Drug discovery and development | exogenous | Something that is added “artificially” or from the outside, such as pharmaceutical drugs someone take |
| 395 | Cell therapies and immunotherapy | graft versus host disease (GVHD) | When a transplanted donor immune cells recognize the recipient as foreign, due to inadequate histocompatibility, and attacks them. This is a major risk of allogeneic cell transplant and thus requires wiping out of the recipient's bone marrow and close HLA typing to choose a donor unlikely to set off this potentially deadly condition. |
| 396 | Drug discovery and development | phage therapy | Treating patients with tricky bacterial infections with bacteria-infecting viruses (called bacteriophages, or phages for short) that can attack those bacteria). It can be used to combat bacteria resistant to conventional antibiotics. The use of phage therapy declined with the advent of antibiotics, but as bacteria develop resistance to those, phage therapy is coming back in style. (And it's been continuously used in some countries). |
| 397 | Legal stuff | non disclosure agreement (NDA) | A legal agreement in which someone promises not to blab. |
| 398 | Nucleic acid therapeutics | CRISPR/Cas | A gene editing technique that uses CRISPR guide RNAs to direct Cas proteins to specific DNA sequences to edit them. There are many forms of CRISPR/Cas and, depending on the form, it can inactivate (knock out) a gene, edit a gene, or insert a new gene. |
| 399 | Nucleic acid therapeutics | Cas9 | The classic CRISPR-associated protein. It makes double-stranded cuts to DNA at sites to which it's guided to by CRISPR guide RNAs. |
| 400 | Nucleic acid therapeutics | gRNA/sgRNA | Guide RNA used by Cas proteins in CRISPR/Cas systems. Sometimes the abbreviation sgRNA is used to indicate that it's a "single guide RNA" as opposed to the 2-component guide RNAs of bacterial CRISPR/Cas systems. But, single guides are basically always used, and the s is often left out of the abbreviation. |
| 401 | Nucleic acid therapeutics | pegRNA | prime editing guide RNA. An extended guide RNA used in prime editing. It contains a template for a Cas-bound reverse transcriptase (RT) protein to reverse transcribe into DNA that can get inserted at the site to which it directs Cas. |
| 402 | Nucleic acid therapeutics | Cas12a | A CRISPR-associated (Cas) protein that makes double-stranded cuts to DNA to which it's guided by a CRISPR guide RNA. It's similar to Cas9, but it makes staggered cuts, whereas Cas9 makes blunt cuts. |
| 403 | Nucleic acid therapeutics | PAM (protospacer adjacent motif) | With regards to CRISPR/Cas gene editing, it's a short sequence that needs to be nearby the site you want to edit in the target DNA. It's part of the target DNA that “matches” the Cas protein (has favorable interactions with the protein). Binding to the PAM snaps Cas to attention and gets it to unwind the DNA and do its thing. The PAM sequence is specific for the CAS protein. In the case of this Streptococcus pyogenes Cas9 it's NGG. where N is any nucleotide. So anything and then two G’s. Scientists can do things like use different Cas proteins and/or modify Cas9 to change the PAM specificity if there's not a PAM close enough to where they want to edit. |
| 404 | Nucleic acid therapeutics | protospacer | With regards to CRISPR/Cas gene editing, it's the part of the target DNA that matches the guide RNA, and more specifically, it matches the spacer part of the guide RNA, which is the unique part of the guide RNA. |
| 405 | Drug discovery and development | flow cytometry | A technique used to sort cells by using microfluidics machines to direct them into different channels based on properties. Often, it's used in FACS (Fluorescent Activated Cell Sorting), which sorts the cells based on fluorescence, such as coming from fluorescently-bound antibodies. |
| 406 | Drug discovery and development | FACS (fluorescence activated cell sorting) | A technique used to sort cells by using microfluidics machines to direct them into different channels based on fluorescence, such as coming from fluorescently-bound antibodies. |
| 407 | Drug discovery and development | x-ray crystallography | A structural biology technique used to figure out (solve) the 3D structures of proteins and other molecules based on how x-rays interact with crystals of those molecules. It can be used to see what drugs look like and where and how drugs or drug fragments bind to a target molecule, allowing for structure-aided design. |
| 408 | Drug discovery and development | cryo-electron microscopy (cryo-EM) | A structural biology technique used to figure out (solve) the 3D structures of proteins and other molecules based on how electrons interact with those molecules "frozen" in place a thin layer of water/buffer. It can be used to see where and how drugs or drug fragments bind to a target molecule, allowing for structure-aided design. |
| 409 | Drug discovery and development | NMR (nuclear magnetic resonance) | A structural biology technique used to figure out (solve) the 3D structures of proteins and other molecules based on how their atomic nuclei respond to magnetic fields. It can be used to see what drugs look like and how drugs or drug fragments bind to a target molecule, allowing for structure-aided design. |
| 410 | Drug discovery and development | AlphaFold | A commonly-used tool that uses AI to predict the structure of proteins based on their sequences. |
| 411 | Business stuff | pharmaceutical detailing | A marketing strategy where pharma sales reps (detailers) visit doctors, etc. to learn more about their needs and try to convince them their products are the solution. |
| 412 | Small molecules | TPD (Targeted Protein Degradation) | A technique that induces an interaction between a protein target and an E3 ubiquitin ligase using a small molecule, leading the protein to be ubiquitinated and degraded by the proteasome. The key forms are PROTACs and molecular glues. |
| 413 | Small molecules | PROTACs | Proteolysis-Targeting Chimeras. Small, heterobifunctional molecules used for targeted protein degradation (TPD). They have 2 parts connected by a linker: 1 part binds to the target protein and one part binds to a ubiquitin ligase, bringing the ligase near the target protein to (hopefully) cause the ligase to ubiquitinylate the protein (add chains of a little protein called ubiquitin to it), flagging the protein for subsequent degradation by the proteasome. |
| 414 | Small molecules | molecular glue | A small molecule that binds to 2 molecules, bringing them together when they otherwise might not interact or would only weakly interact. Often, molecular glues are used in reference to molecules used in targeted protein degradation (TPD) which bind to a target protein and a ubiquitin ligase, causing the target protein to be ubiquitinylated and degraded by the proteasome. Unlike PROTACs, they have a single part that binds both things, as opposed to 2 parts connected by a linker. |
| 415 | Drug discovery and development | proteasome | Basically a cellular woodchipper that chops up ubiquitinylated proteins. |
| 416 | Nucleic acid therapeutics | knock out | Inactivate a gene (such as through CRISPR/Cas gene editing), preventing the making of protein from its instructions. |
| 417 | Nucleic acid therapeutics | knock down | Temporarily reduce levels of a gene product (e.g., a protein), typically by reducing the levels of the corresponding mRNA, such as through RNAi. |
| 418 | Regulation | active surveillance | A type of pharmacovigilence in which drug developers, etc. actively reach out to drug users to see if they're having any adverse effects from taking the drug. |
| 419 | Regulation | passive surveillance | A type of pharmacovigilence that relies on spotaneous voluntary reporting of adverse events by patients or their doctors, rather than actively conducting surveys or anything. |
| 420 | Cell therapies and immunotherapy | xenotransplantation | Transplant of tissue or organs from one species to another. |
| 421 | Drug discovery and development | blood plasma | The part of blood without the cells (but still containing clotting factors). |
| 422 | Drug discovery and development | blood serum | The part of blood without the cells and without the clotting factors. |
| 423 | Drug discovery and development | blood brain barrier (BBB) | A tight-net layer of cells surrounding the brain and spinal cord. It protects the brain, but makes it harder to get drugs to it. |
| 424 | Drug discovery and development | immune privileged | Used to refer to places in the body that are out of reach to most of the immune system. They can be less risky places to administer biologics the immune system might otherwise freak out over. |
| 425 | Business stuff | product hopping | Getting patients to switch to newer versions of a drug right when the older version's patent and/or market exclusivity is expiring. |
| 426 | Protein therapeutics | fusion protein | A protein composed of 2 (or more) proteins linked together. |
| 427 | Cell therapies and immunotherapy | bone marrow conditioning | A pre-bone marrow transplant regimen where patients are given chemotherapy and/or radiation to "clear out" their bone marrow to get rid of faulty stem cells, make room for new stem cells (from the transplanted marrow), and suppress their immune system so their body won't reject the new marrow. |
| 428 | Gaining approval | skinny labeling | When generic/biosimilar companies seek approval to market a generic/biosimilar for a narrow application that isn't protected by a patent, even if other uses of the compound are still patent-protected. |
| 429 | Gaining approval | FDA advisory committee | A board made up of scientific experts as well as a consumer representative, an industry representative, and a patient representative that may be convened to discuss recommendations regarding approval of a drug, such as in the case of controversial and/or truly novel therapeutics. They may also be asked to meet to discuss other regulatory matters, such as revoking or limiting approval of a drug that's already on the market. The recommendations of the advisory committee are often, but not always, followed. |
| 430 | Gaining approval | FACA (Federal Advisory Committee Act) | 1972 legislation establishing FDA advisory committees. |
| 431 | Gaining approval | action letter | An official letter sent from the FDA to a drug developer telling them whether or not their drug was approved. |
| 432 | Gaining approval | complete response letter (CRL) | Rejection letter the FDA sends to a drug developer outlining problems with the evidence presented that need to be addressed if the drug is to be approved. |
| 433 | Gaining approval | sponsors | What the FDA calls drug developers of the applications they're reviewing. |
| 434 | Gaining approval | Division of Scientific Investigations (DSI) | FDA group that inspects clinical trial sites and IRB records during the course of drug application reviews. |
| 435 | Gaining approval | FDA Commissioner's National Priority Voucher (CNPV) pilot program | A 2025 program that grants super-speedy (1-2 month) reviews of drugs in line with national government priorities. |
| 436 | Drug discovery and development | compounding | A practice of combining and/or reformulating active ingredients of one or more drugs to meet the needs of individual patients (e.g., making liquid versions of a drug that's normally a pill for patients who can't swallow pills or making versions of a drug that don't have ingredients a patient is allergic to that are in the commercial version). Resultant compounded products, though legal, are not FDA-approved and/or regulated so be forewarned that some sketchy stuff can go down. |
| 437 | Drug discovery and development | first-in-class | A term used to describe drugs with a truly novel structure and/or mechanism of action. |
| 438 | Gaining approval | Twenty-first Century Cures Act (CURES) | 2016 legislation that among other things, gave the FDA more flexibility in approving drugs based on less evidence, such as fewer large trials (e.g., 1 instead of 2 Phase III trials) and the use of "real-world evidence" for things that previously would have needed clinical trial evidence. |
| Gaining approval | real-world evidence (RWE) | Evidence from various databases of health records, registries, insurance claims, etc. that is sometimes used to support a drug's approval. While this data is important, it is susceptible to many sources of potential bias, but the 21st-century Cures Act allows for greater reliance on it for things that used to require clinical trials to show. | |
| Gaining approval | Food and Drug Omnibus Reform Act (FDORA) | 2022 legislation that, among other things, requires greater diversity in clinical trial populations and takes measures to reform accelerated review pathways and make things stricter, such as by requiring that confirmatory studies already be underway before approval is granted. | |
| Initial order | Category | Term | Definition |
