Impact of Limited Medicare Drug Coverage on Multiple Sclerosis Outcomes

Recent research from the USC Schaeffer Center highlights a concerning link between narrower Medicare drug coverage and increased relapse rates in patients with multiple sclerosis (MS). The study reveals that MS patients enrolled in Medicare plans with limited coverage of disease-modifying therapies face higher risks of experiencing new or worsening symptoms over time. These findings underscore the importance of broader formulary inclusion to support better health outcomes.

In the study, investigators analyzed drug coverage among approximately 85,000 Medicare beneficiaries with relapse-remitting MS, the most prevalent form of the disease characterized by episodic neurological flare-ups. They compared those in stand-alone Part D plans, which often cover fewer medications, to those in more comprehensive Medicare Advantage plans. Results showed that coverage variations significantly impacted patient health, with broader drug coverage associated with a notable reduction (8–12%) in the likelihood of MS relapses.

Pharmacy benefit managers play a pivotal role in shaping medication access by negotiating drug benefits and sometimes excluding costly or complex treatments from formularies. While cost containment strategies are valuable, they can inadvertently hinder access to individualized therapies essential for managing MS, which often requires multiple medication trials for effectiveness.

As of 2022, there are around 15 high-cost oral and injectable MS drugs grouped into seven classes. Despite their potential to slow disease progression and prevent relapses, many are not designated as protected by Medicare, allowing private insurers to restrict coverage. The study found that many of these treatments, including older options like teriflunomide, are excluded from numerous plans, especially standalone Part D plans.

The researchers also noted that expanding formulary coverage could lead to better patient outcomes, with broader access linked to fewer relapses. However, upcoming policy changes, such as the out-of-pocket expenditure cap on Medicare, may incentivize plans to further exclude high-cost medications, complicating efforts to improve access.

Innovative financing models—such as outcome-based payments or subscription schemes—might offer sustainable solutions to broaden access while managing costs. Joyce emphasized the need for sustainable approaches to ensure all MS patients have access to potentially life-changing treatments.

This study emphasizes the critical role of policy and coverage decisions in shaping treatment accessibility and outcomes for MS patients. Ensuring broader coverage of high-cost therapies is essential for optimizing disease management and improving quality of life.

Source: https://medicalxpress.com/news/2025-07-narrower-medicare-drug-coverage-linked.html