A first-in-class medication is a prototype drug that uses a "new and unique mechanism of action" to treat a particular medical condition. While the Food and Drug Administration's Center for Drug Evaluation and Research tracks first-in-class medications and reports on them annually, first-in-class is not considered a regulatory category. Although many first-in-class medications qualify as breakthrough therapies, Regenerative Medicine Advanced Therapies and/or orphan drugs, first-in-class status itself has no regulatory effect.

Examples

DrugClassTargeted conditionsYear approved (FDA)Year approved (EMA)
Inotuzumab ozogamicin (Besponsa)Anti-CD22 monoclonal antibody-drug conjugateRelapsed or refractory B cell precursor acute lymphoblastic leukemia2017
Tagraxofusp (Elzonris)Interleukin 3-diphtheria toxin fusion protein targeting plasmacytoid dendritic cellsBlastic plasmacytoid dendritic cell neoplasm20182021
Midostaurin (Rydapt)Multi-target tyrosine kinase inhibitor not inhibited by the D816V cKit mutationSystemic mastocytosis, myelodysplastic syndrome, acute myeloid leukemia20172017
Teprotumumab (Tepezza)Anti-IGF-1R monoclonal antibodyGraves' ophthalmopathy2020
Romosozumab (Evenity)Anti-sclerostin monoclonal antibodyOsteoporosis20192019
Ocrelizumab (Ocrevus)Anti-CD20 monoclonal antibodyMultiple sclerosis20172018
Ivosidenib (Tibsovo)Small molecule inhibitor of isocitrate dehydrogenase 1Acute myeloid leukemia, cholangiocarcinoma20182023
Bempedoic acid (Nexletol)Adenosine triphosphate-citrate lyase inhibitorHypercholesterolemia20202020
Tafamidis (Vyndaqel, Vyndamax)Transthyretin chaperone (stabilizer)Familial amyloid polyneuropathy and other transthyretin amyloidoses20112019
Voxelotor (Oxbryta)Hemoglobin oxygen affinity modulatorSickle cell disease2019
Lonafarnib (Zokinvy)Farnesyltransferase inhibitorHutchinson-Gilford progeria syndrome20202022
Dupilumab (Dupixent)Interleukin-4 receptor alpha subunit inhibitorAsthma, atopic dermatitis, allergic diseases2017
Lasmiditan (Reyvow)Selective 5-HT1F serotonin receptor agonistMigraine20192022
Tazemetostat (Tazverik)Selective EZH2 inhibitorEpithelioid sarcoma2020
Tirzepatide (Mounjaro)GLP-1 and GIP activatoradult type 2 diabetes20222022

Controversy

Safety

By definition, a first-in-class drug does not have the safety evidence from analogous products that not-first-in-class drugs would have. However, a study investigating recalls and warnings in relation to first-in-class drugs approved between 1997 and 2012 by Health Canada has found that first-in-class drugs actually have a more favourable benefit-to-harm ratio.

Economics

First-in-class drugs are often seen as commercially more attractive as they may tap into a market segment that has hitherto been underserved, but this may be illusory. In fact, most blockbuster drugs (drugs with annual sales revenues exceeding US$1,000,000,000) were not first-in-class drugs. The economic potential of a first-in-class drug, which is typically priced higher than later drugs in the same class, has been largely declining due to efforts by health insurers to restrict what specialty drugs are covered and prevent incumbency advantages.

Costs

A lower number of available therapeutic options correlates with higher prices. In addition, many first-in-class medications are specialty drugs and orphan drugs, which means that manufacturers have to recoup development costs from a smaller market. This raises ethical questions about the sustainability of the high prices on these costs.