While the Inflation Reduction Act (IRA) was designed to lower drug prices, at the same time it exempted drugs for rare diseases (i.e. orphan drugs) from drug price negotiations. However, this exemption is only valid if the orphan drug has a single approved indication. Therefore, a key question is how often orphan drugs are later developed for other indications. If so, the IRA could undercut R&D investment for new indications of orphan drugs.
A new paper by Chambers et al. (2023) exist JAMA Network Open Database of FDA approvals from 2003 to 2022 to understand how common new indications for orphan drugs are. They found:
From 2003 to 2022, FDA approved 282 new orphan drugs… Overall, FDA approved 152 separate follow-up indications; 92 of these follow-up indications (61%) also apply to orphan drug conditions. The mean (SD) time from novel orphan drug approval to subsequent indications was 53 (43) months… FDA placed 58 (38%) subsequent indications under an expedited review program and 46 (30%) Subsequent indications were included in 2 items, and 17 (11%) in 3 items; none were included in all 4 plans.
You can read the full text here.
