Pharmaceutical Glossary
Essential drug development and FDA terminology
Most Searched Terms
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Accelerated Approval
Accelerated Approval allows FDA approval based on a surrogate endpoint (like tumor shrinkage) rather than clinical outcomes (like survival). Post-approval confirmatory trials are required to verify clinical benefit.
AdCom (Advisory Committee)
An FDA Advisory Committee (AdCom) meeting brings together independent experts to review drug applications and vote on approval recommendations. While non-binding, FDA typically follows AdCom recommendations ~75% of the time.
ANDA
An Abbreviated New Drug Application (ANDA) is the FDA submission for generic drug approval. ANDAs don't require clinical trials proving safety and efficacy - they only need to demonstrate bioequivalence to the reference drug.
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Biomarker
A biomarker is a measurable indicator (gene, protein, or molecule) that predicts drug response or disease status. Companion diagnostic biomarkers identify patients likely to benefit from targeted therapies.
Biosimilar
A biosimilar is a biological product highly similar to an already-approved biologic (reference product) with no clinically meaningful differences in safety, purity, or potency. Biosimilars are the biologic equivalent of generic drugs.
BLA
A Biologics License Application (BLA) is the FDA submission required for approval of biological products like vaccines, blood products, and therapeutic proteins. BLAs are similar to NDAs but specifically for biologics.
Breakthrough Therapy
Breakthrough Therapy designation is granted by the FDA for drugs intended to treat serious conditions where preliminary clinical evidence shows substantial improvement over existing therapies. It provides intensive FDA guidance and may enable faster approval.
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Companion Diagnostic
A companion diagnostic is an FDA-approved test that identifies patients suitable for a specific drug treatment. For example, HER2 testing is a companion diagnostic for trastuzumab (Herceptin).
Complete Response Letter (CRL)
A Complete Response Letter (CRL) is issued by the FDA when an application cannot be approved in its current form. It outlines deficiencies that must be addressed before approval, such as additional clinical data, manufacturing issues, or labeling changes.
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Fast Track
Fast Track is an FDA designation for drugs treating serious conditions that fill an unmet medical need. It enables more frequent FDA meetings, rolling review of application sections, and eligibility for Priority Review and Accelerated Approval.
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Mechanism of Action (MOA)
Mechanism of Action describes how a drug produces its therapeutic effect at the molecular level. For example, a PD-1 inhibitor's MOA is blocking the PD-1 receptor to reactivate T cells against cancer.
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ODAC
The Oncologic Drugs Advisory Committee (ODAC) is an FDA advisory committee that reviews cancer drug applications. ODAC votes on whether benefits outweigh risks and if approval should be granted.
Orphan Drug
An orphan drug treats a rare disease affecting fewer than 200,000 people in the US. Orphan Drug Designation provides 7 years of market exclusivity, tax credits, and reduced FDA fees to incentivize development.
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Patent Cliff
A patent cliff refers to the sharp decline in revenue when a drug's patent protection expires and generic or biosimilar competitors enter the market. Revenue can drop 80-90% within months of patent expiration.
PDUFA Date
A PDUFA (Prescription Drug User Fee Act) date is the FDA's target deadline to complete review of a drug application. The FDA aims to make approval decisions by this date, typically 10-12 months after submission for standard reviews or 6 months for priority reviews.
Phase 1 Clinical Trial
Phase 1 trials are the first stage of human testing, typically involving 20-100 healthy volunteers. The primary goals are to evaluate safety, determine dosing, and identify side effects. About 70% of drugs pass Phase 1.
Phase 2 Clinical Trial
Phase 2 trials test drug efficacy and side effects in 100-300 patients with the target disease. They help determine optimal dosing and identify common adverse effects. About 33% of drugs pass Phase 2.
Phase 3 Clinical Trial
Phase 3 trials are large-scale studies involving 300-3,000+ patients to confirm efficacy, monitor side effects, and compare to standard treatments. Successful Phase 3 results support FDA approval. About 25-30% of drugs pass Phase 3.
Priority Review
Priority Review is an FDA designation that shortens the review timeline from 10-12 months to 6 months. It's granted for drugs that offer significant improvements over existing treatments for serious conditions.