Abstract
The increasing number and high prices of orphan drugs have triggered concern among patients, payers, and policymakers about the affordability of new drugs approved using the incentives set by the Orphan Drug Act (ODA) of 1983. This study evaluated the factors associated to the differences in the treatment cost of new orphan and non-orphan drugs approved by the FDA from 2017 to 2021. A generalized linear model (GLM) with the Gamma log-link analysis was used to ascertain the association of drug characteristics with the treatment costs of orphan and non-orphan drugs. The results of the study showed that the median and interquartile range (IQR) drug cost was USD 218,872 (IQR = USD 23,105) for orphan drugs and USD 12,798 (IQR = USD 57,940) for non-orphan drugs (
p
< 0.001). Higher market entry prices were associated with biologics (108%;
p
< 0.001), orphan status (177%;
p
< 0.001), US sponsor companies (48%;
p
= 0.035), chronic use (1083%;
p
< 0.001), treatment intent (163%;
p
= 0.004), and indications for oncology (624%;
p
< 0.001) or genetic disorders (624%;
p
< 0.001). Higher market entry treatment cost for newly approved drugs were associated with biologics, orphan status, US sponsor companies, chronic use, therapeutic intent, and indications for oncology or genetic disorders.