Although rare diseases affect relatively small patient populations, the cost and complexity of developing treatments is high.
US policy has long recognized this challenge, beginning with the Orphan Drug Act of 1983 and continuing with recent exemptions for certain orphan indications from Medicare negotiation in the One Big Beautiful Bill Act. These measures have supported investment and helped make the US the global leader in rare disease treatment availability.
Many higher-income countries use price control mechanisms, such as external reference pricing, to manage pharmaceutical spending. While these policies can reduce costs, they are often associated with delays in approval, reimbursement, and patient access to orphan medicines. A most-favored-nation (MFN) pricing model in the US, which would link domestic drug prices to those abroad, risks importing these barriers.
Charles River Associates (CRA), commissioned by the Rare Disease Company Coalition (RDCC), analyzed 142 novel FDA-approved drugs between 2022 and 2024, including 74 orphan therapies. Our study found that orphan drugs were more likely to be approved by international regulators than nonorphan drugs, but less likely to be reimbursed or launched, and faced longer delays to patient access.
The findings show that applying a most-favored-nation (MFN) pricing model in the US could undermine incentives for rare disease innovation and jeopardize patient access to life-saving treatments.
