The Health Benefits, Costs, and Cost-Effectiveness of Ultraorphan Drugs.

Objectives: To examine ultraorphan drugs in terms of incremental health, costs, and cost-effectiveness compared with more prevalent disease drugs.

Methods: We identified Food and Drug Administration drug approvals from 1999 to 2019. For drugs approved for multiple indications, we considered each drug-indication pair separately. Utilizing Food and Drug Administration's orphan drug designation and US disease prevalence, we categorized drug-indication pairs as: ultraorphan (<10 000 patients), "other" orphan (≥10 000 and <200 000), and nonorphan (≥200 000). We searched the PubMed database for cost-effectiveness analyses and comparative effectiveness studies. We excluded manufacturer-funded studies. We extracted estimates of incremental health gains in terms of quality-adjusted life-years (QALYs) and incremental costs associated with drug-indication pairs compared with the standard of care at the time of their approval. We compared QALY gains, added costs, and incremental cost-effectiveness ratios (ICERs) using the Kruskal-Wallis, Mann-Whitney U (MWU), and Kolmogorov-Smirnov (KS) tests.

Results: Median incremental QALYs, costs, and ICERs differed across nonorphan, "other" orphan, and ultraorphan categories (Kruskal-Wallis P < .01). Compared with nonorphan drugs, ultraorphan drugs had larger QALY gains (0.700 vs 0.050, MWU P < .01, KS P < .01), larger costs ($172 231 vs $3360, MWU P < .01, KS P < .01), and larger ICERs ($1 216 184/QALY vs $114 061/QALY, MWU P < .01, KS P <.01). Compared with "other" orphan drugs, ultraorphan drugs had larger QALY gains (0.700 vs 0.310, MWU P =.65, KS P =.32), larger costs ($172 231 vs $69 308, MWU P = .03, KS P = .03), and larger ICERs ($1 216 184/QALY vs $223 472/QALY, MWU P <.01, KS P <.01).

Conclusions: Novel ultraorphan drugs typically offer larger incremental health gains than drugs for more prevalent diseases, but because of their substantial added costs, are typically less cost-effective.