Insurance plans that limit MS drugs may lead to worse patient outcomes
Medicare beneficiaries with broader coverage see lower risk of new symptoms
People with multiple sclerosis (MS) may be significantly more likely to have relapses if their Medicare insurance covers fewer disease-modifying therapies, a study shows.
The findings suggest that plans with narrower MS treatment coverage may be linked to worse health outcomes, possibly because the therapeutic response to complex diseases like MS varies widely among patients, and not all will benefit from the covered drugs.
“Innovative new treatments have made it possible to slow or prevent symptoms for some of the most complex diseases, but costs remain a challenge,” Geoffrey Joyce, PhD, the study’s senior author, said in a university press release. “We must find sustainable ways to ensure all patients can access these potentially life-changing treatments.” The study, “Formulary Restrictions and Relapse Episodes in Persons With Relapsing-Remitting Multiple Sclerosis,” was published in JAMA Network Open.
There isn’t a cure for MS, but several approved treatments can help reduce disease activity and slow its progression. As off 2022, 15 oral and injectable disease-modifying therapies (DMTs), across seven classes, were available in the U.S. These medications are expensive, however, and usually cost about $5,000 to $10,000 or more per prescription.
In the U.S., insurance providers can decide which MS DMTs to include on their list of covered drugs, or formulary, each quarter. Negotiators may threaten to exclude a medication to get better discounts from pharmaceutical companies.
This can be problematic for complex diseases like MS, according to Joyce. “Patients with MS may need to try multiple drugs to find what works best for them,” he said. “Broad formulary exclusions ultimately undermine the individualized care these patients need.”
Assessing Medicare plans
To assess these impacts on people with MS, researchers investigated DMT coverage by Medicare plans. In the U.S., Medicare is available to older people and people with disabilities, which may include some younger individuals with MS.
Using Medicare claims and records, they identified 84,870 people with a relapsing-remitting course of MS who had at least five quarters of Medicare coverage between 2018 and 2022. This included 50,162 people with standalone prescription drug plans (PDPs), which supplement medical insurance. The remainder were enrolled in Medicare Advantage Prescription Drug plans (MA-PDs), which combine medical insurance and drug coverage.
They first identified how many of the 15 oral or injectable DMTs were covered by each PDP and MA-PD. They didn’t consider DMTs typically delivered in a hospital setting, which often count under medical rather than drug insurance and were assumed to be covered by all plans.
Among PDPs, it was most common for insurance to cover four DMTs, spanning four of the seven categories. MA-PDs tended to have more coverage — most often including eight DMTs across five categories. The number of DMTs covered didn’t appear to consistently skew decisions to use one plan over another.
Almost all the plans included Gilenya (fingolimod), interferon beta-1b (sold as Betaseron, Extavia, and others), and Copaxone (glatiramer acetate) or generic equivalents. Most excluded older medications like Aubagio (teriflunomide) or generics.
Risk of relapse increases
During follow-up, beneficiaries of plans covering fewer than the median number of DMTs in the past year were significantly more likely to have a relapse than those in plans with broader coverage. This pattern was more pronounced in MA-PDs, where there was an 8%-12% lower risk in the higher coverage group of a relapse, but was also observed in PDPs, which had a 6%-9% lower risk.
“Formulary exclusions prevent all but the few who successfully appeal or can afford to pay out of pocket from getting the medication if it is prescribed by their physician,” the researchers wrote.
Because of this, narrower coverage might lead to fewer treatment options and less effective treatment, contributing to higher relapse rates. A formulary “tailored for patient need, not just management of costs and use” may be more effective, they said.
Insurance providers may exclude more specialty drugs after a 2025 Medicare policy capped out-of-pocket spending at $2,000 annually. This shifts costs to the insurance providers for covered medications, but not for uncovered therapies, meaning insurers may want to exclude expensive treatments to avoid paying higher costs.
“The cap increases plan liability above the threshold and restricts its ability to steer beneficiaries toward lower-cost treatments and may lead to narrower coverage of high-cost therapies, given that only covered drugs count toward the out-of-pocket cap,” the researchers wrote. “Health plans and pharmacy benefit managers have been relying on formulary exclusion to limit costs of new therapies. However, a more nuanced approach that also accounts for patient benefit (and potential harm) should also be considered.”
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