Halting hyaluronidase hopping to maintain the integrity of Medicare drug price negotiation

The Inflation Reduction Act empowered Medicare to negotiate drug prices for certain drugs, but the initial program guidance treated fixed-dose combination drugs separately, which would allow manufacturers of biologics to launch subcutaneous versions coformulated with hyaluronidase to defer negotiation eligibility, which we call "hyaluronidase hopping." In May 2025, the Centers for Medicare & Medicaid Services issued draft guidance requesting comments on a policy that could partially address hyaluronidase hopping by selecting and negotiating fixed-dosed combination products that contain therapeutically inactive ingredients (eg, hyaluronidase) alongside the original noncombination product. This proposed change was not adopted in the final guidance released in September 2025, although it will still be under consideration in future years. Adopting the proposed change is one of several policies needed to safeguard negotiation from hyaluronidase hopping to protect savings and patient access.