Consistency in DMT Use ‘Low’ in US, Influenced by Side Effects, Insurance

Persistent use of a single disease-modifying therapy (DMT) over a three-year period was low among people with relapsing forms of multiple sclerosis (MS), a U.S. study found.

DMT discontinuations or switches were initiated in some cases by prescribers, specialty pharmacists, or patients for reasons that included treatment side effects, insurance changes, and disease stability or worsening.

The study, by researchers at Vanderbilt University Medical Center in Tennessee, also noted a role for specialty pharmacists who are directly involved in patient care.

“Long-term persistence to DMTs is low, with many patients switching or discontinuing DMT treatment,” the researchers wrote. “Specialty pharmacists identify the need for DMT discontinuation or switch and are uniquely positioned to assist during therapy transitions.”

Recommended Reading

May 18, 2022 by Mary Chapman

Newly diagnosed with MS: 12 questions to ask your doctor

The study, “A Cross-Sectional Analysis of Persistence to Disease-Modifying Therapies in Treatment Naïve and Experienced Patients with Relapsing Multiple Sclerosis at a Health-System Specialty Pharmacy,” was published in the journal Multiple Sclerosis and Related Disorders. 

DMTs work to prevent relapses and slow disability progression in MS. But rates of persistence to a prescribed treatment regimen are “concerningly low,” the researchers reported. Poor persistence is associated with an increased risk of relapses and hospital stays, in addition to increased disease-associated costs.

To learn more about the reasons for stopping or switching a DMT, the team examined long-term treatment data covering 540 people with relapsing forms of MS. They were followed at the Nashville university’s medical center, which includes specialty pharmacies whose pharmacists are involved in monitoring patient records, lab tests, and insurance changes to ensure the appropriateness and safety of ongoing treatments.

Most participants were female (74%) and white (84%), with a median age of 49. The vast majority (93%) had experience with DMTs, while the remaining patients were initially naive to treatment.

The most commonly prescribed DMTs at the study’s start were Copaxone (glatiramer acetate) which was used by 115 people, Tecfidera (dimethyl fumarate) by 107 people, and Gilenya (fingolimod) by 96 people.

Over about three years, from May 2017 through October 2020, the team examined how many people stayed on their prescribed therapy, stopped DMT use, or switched DMTs.

Researchers found that 193 people (36%) stayed on the therapy over those years. Among those who did not, 91 (17%) discontinued DMT use, and 136 (25%) switched to a different DMT. The remaining participants either transferred care (92 people), were lost to follow-up (21 people), or died (seven people).

“Almost one-half of patients did not remain on index DMT due to discontinuation (17%) or switch (25%),” the team reported.

Overall, the median time on a prescribed DMT was 642 days (between 1.5 and two years), and the probability of DMT persistence for three years was 51%.

DMTs were discontinued for a variety of reasons and were determined by patients, prescribers, or pharmacists. The most common given for stopping treatment were side effects (32%), stable disease (13%) and prescriber-mandated treatment hold for reasons such as surgery, chemotherapy, or infection (12%).

An additional 11% stopped due to non-adherence, 9% stopped due to pregnancy, and 7% of patients stopped for unspecified reasons. Changes in insurance also led to the decision to stop treatment in some cases.

The median time to discontinuation was 470 days (between one and 1.5 years).

Reasons most commonly cited for switching to a new DMT included insurance changes (36%), worsening disease or clinical declines (32%), side effects (22%), and no clinical benefit (10%). Glatiramer acetate was the most common DMT that patients switched to, followed by Ocrevus (ocrelizumab), Tecfidera, teriflunomide (e.g., Aubagio), and Gilenya.

Younger patients, particularly women, and older men were more likely to discontinue or change their treatment course. A therapy’s route of administration and insurance type (such as private or commercial insurance) also were significantly associated with an increased risk of treatment discontinuation or change.

Specifically, patients using injectable medications were 1.5 times more likely to stop or switch treatments than patients on oral medications, and patients with non-commercial insurance (Medicare, Medicaid, or uninsured) were 1.4 times more likely to discontinue or switch DMTs that those on commercial insurance.

Relapse rates and being new to any DMT showed trends towards influencing a non-persistence risk, but none reached statistical significance.

In summary, “in patients with [relapsing MS], long-term persistence to a single DMT was low,” the researchers wrote. “Patients commonly discontinued or switched their initial DMT over a 3-year period due to insurance formulary changes, side effects, stable disease, and clinical decline,” they added.

Findings also highlight an important role for speciality pharmacists in managing the care of MS patients, the researchers wrote, noting they “initiated 7% of DMT discontinuations and 36% of DMT switches.” These pharmacists, the team added, are “uniquely positioned to assist patients during DMT transitions due to the direct, frequent engagement with patients and providers.”

Future studies should more closely examine how MS subtype influences persistence outcomes, the researchers noted.