Medicare drug plans are increasingly restricting coverage for new specialty medications designed to treat complex illnesses such as cancers and autoimmune disorders, with recent research revealing the potentially serious health consequences for patients. A comprehensive study conducted by the USC Schaeffer Center highlights the correlation between the extent of drug coverage in Medicare Part D plans and health outcomes among individuals living with relapsing-remitting multiple sclerosis (MS), the most common form of this chronic neurological disease.
Multiple sclerosis is characterized by episodic flare-ups of neurological symptoms caused by immune system attacks on the central nervous system. While no cure currently exists, a diverse array of disease-modifying therapies (DMTs) has been developed in recent years to slow disease progression and reduce the frequency of relapses. These medications fall into seven distinct pharmacological classes, with fifteen therapies approved for oral or injectable use as of 2022. However, the prohibitive cost of these specialty drugs—frequently ranging from $5,000 to $10,000 per prescription—along with Medicare’s flexible coverage guidelines outside the protected drug classes, have led many insurers administering Medicare Part D to impose formulary restrictions that limit patient access.
The study meticulously analyzed drug coverage data for approximately 85,000 Medicare beneficiaries diagnosed with relapsing-remitting MS, who were enrolled in either stand-alone Part D plans or Medicare Advantage plans. The investigation revealed stark contrasts in coverage breadth, with stand-alone plans typically including only four out of the fifteen available drugs, covering four of the seven drug classes. In contrast, Medicare Advantage plans offered broader formularies, generally encompassing eight drugs spanning five medication classes. Yet, even under the more comprehensive Medicare Advantage coverage, many crucial MS therapies remained largely excluded across plans.
The clinical implications of these coverage disparities emerged clearly through newly identified associations between formulary breadth and patient health outcomes. Participants enrolled in Medicare Advantage plans with broader formularies demonstrated an 8-12% reduction in the likelihood of experiencing MS relapses during any given quarter. Similarly, stand-alone plan enrollees with wider drug coverage exhibited a 6-9% lower probability of relapse. These findings underline the critical role broad drug access plays in mitigating disease activity and preserving neurological function in MS patients.
Pharmacy benefit managers (PBMs), tasked with negotiating drug reimbursements on behalf of plan sponsors, often use the exclusion of new specialty medications from formularies as leverage to extract favorable rebates from pharmaceutical manufacturers. While this practice can help control overall costs when multiple therapeutic options, including generics, are available, it becomes increasingly problematic for diseases like MS where patients frequently require individualized treatment trials to identify effective therapies. The heterogeneity of patient response calls for diversified treatment options, which broad formulary exclusions undermine.
The research team, led by Geoffrey Joyce, director of health policy at the USC Schaeffer Center, emphasized the importance of preserving patient choice in therapeutic regimens. Patients with MS may need to experiment with several medications to determine which best controls their disease symptoms. Restrictive formularies thus jeopardize personalized care strategies that are essential for effective disease management and improved quality of life.
Additionally, the study raises concerns about the evolving policy landscape and its effect on drug access for beneficiaries. The introduction of a $2,000 annual out-of-pocket spending cap for Part D enrollees, while beneficial in limiting individual financial burden, shifts greater cost responsibilities onto insurers. Since costs incurred for non-covered drugs do not count toward this cap, plans are further incentivized to restrict coverage by excluding expensive specialty treatments, potentially exacerbating access challenges.
Alternative financing models could provide a pathway to reconcile cost containment with expanded drug availability. Innovative payment approaches such as value-based contracts, which align reimbursement with treatment outcomes, and subscription-based models—where insurers pay a fixed fee for unlimited patient access to particular medications—hold promise in managing the financial risks associated with high-priced therapies. Such strategies could encourage plans to offer broader formularies without compromising their fiscal sustainability.
This research arrives at a crucial time as therapeutic advancements continue to accelerate in the realm of complex diseases. The proliferation of novel treatments brings new hope for slowing or halting disease progression in multiple sclerosis and other debilitating conditions. Yet the high costs attached to these breakthroughs pose perennial challenges to equitable access, especially in large public insurance programs like Medicare.
Health policy experts stress the imperative of balancing innovation with affordability. Assuring that all patients have access to potentially life-altering medications requires creative policy frameworks and industry cooperation. As Dr. Joyce affirms, “Innovative new treatments have made it possible to slow or prevent symptoms for some of the most complex diseases, but costs remain a challenge. We must find sustainable ways to ensure all patients can access these potentially life-changing treatments.”
Ultimately, this study spotlights the tangible health impacts of drug formulary restrictions in public insurance programs, calling for critical reassessment of current coverage policies. Expanding access to a wider array of MS therapies not only improves patient outcomes but also supports the broader societal goal of reducing the long-term burden of chronic neurological diseases through effective clinical management.
Subject of Research: Formulary Restrictions and Health Outcomes in Medicare Beneficiaries with Relapsing-Remitting Multiple Sclerosis
Article Title: Formulary Restrictions and Relapse Episodes in Persons With Relapsing-Remitting Multiple Sclerosis
News Publication Date: 1-Aug-2025
Web References: https://schaeffer.usc.edu/
Image Credits: USC Schaeffer Center
Keywords: Drug costs, Health care costs, Pharmaceuticals, Multiple sclerosis, Health insurance, Health care policy
