first-in-class medication first-in-class medication a first-in-class medication is a pharmaceutical 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 drug class targeted conditions year approved (fda) year approved (ema) inotuzumab ozogamicin (besponsa) anti-cd22 monoclonal antibody-drug conjugate relapsed or refractory b cell precursor acute lymphoblastic leukemia 2017 tagraxofusp (elzonris) interleukin 3-diphtheria toxin fusion protein targeting plasmacytoid dendritic cells blastic plasmacytoid dendritic cell neoplasm 2018 2021 midostaurin (rydapt) multi-target tyrosine kinase inhibitor not inhibited by the d816v ckit mutation systemic mastocytosis, myelodysplastic syndrome, acute myeloid leukemia 2017 teprotumumab (tepezza) anti-igf-1r monoclonal antibody graves' ophthalmopathy 2020 romosozumab (evenity) anti-sclerostin monoclonal antibody osteoporosis 2019 2019 ocrelizumab (ocrevus) anti-cd20 monoclonal antibody multiple sclerosis 2017 2018 ivosidenib (tibsovo) small molecule inhibitor of isocitrate dehydrogenase 1 acute myeloid leukemia, cholangiocarcinoma 2018 bempedoic acid (nexletol) adenosine triphosphate-citrate lyase inhibitor hypercholesterolemia 2020 2020 tafamidis (vyndaqel, vyndamax) transthyretin chaperone (stabilizer) familial amyloid polyneuropathy and other transthyretin amyloidoses 2011 2019 voxelotor (oxbryta) hemoglobin oxygen affinity modulator sickle cell disease 2019 lonafarnib (zokinvy) farnesyltransferase inhibitor hutchinson-gilford progeria syndrome 2020 dupilumab (dupixent) interleukin-4 receptor alpha subunit inhibitor asthma, atopic dermatitis, allergic diseases 2017 lasmiditan (reyvow) selective 5-ht1f serotonin receptor agonist migraine 2019 tazemetostat (tazverik) selective ezh2 inhibitor epithelioid sarcoma 2020 tirzepatide (mounjaro) glp-1 and gip activator adult type 2 diabetes 2022 2022 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.