Real-World Data Show Most Nusinersen Doses Administered on Time

Real-world data suggest that nusinersen treatment for spinal muscular atrophy (SMA) is adhered to as expected.

New data, coming from 2 large databases in the United States, show that most doses of nusinersen were received on time while also underscoring the importance of being meticulous with the methodological approaches used with real-world databases for evaluating treatment patterns. Findings appeared recently online in Advances in Therapy.

“Adherence to medicines in the real world is important for patients with chronic disease to see long-term benefits of treatment. This study shows the importance and challenges of measuring adherence using real-world administrative data sources,” detailed the researchers. “This is especially important for drugs given through lumbar puncture with unique dosing schedules, such as nusinersen for the treatment of SMA. In this study, most patients with SMA received their nusinersen doses on time.”

The study used data from the Optum de-identified electronic health records (EHR) database (from July 2017 through September 2019) and the Merative MarketScan Research Databases from both commercial (January 2017 to June 2020) and Medicaid claims (January 2017 and December 2019).

Together, the data showed that most patients received treatment on time. A total of 93.9% of doses for the 67 patients in the EHR database and 80.5% of the doses for the 291 patients in the claims were received on time.

The researchers observed conflicting levels of adherence reported for certain dose periods between the 2 databases. Within the EHR database, adherence did not differ significantly between the loading and maintenance doses (93% and 95%, respectively), whereas in the claims database, adherence was considerably higher for the maintenance doses than the loading doses (90.6% vs 71.1%). To be considered adherent, loading doses had a grace period of 7 days and maintenance doses had a grace period of 30 days.

“The different findings in the claims analyses suggest that, despite the methodology employed in this study, not all loading doses of nusinersen may be accurately captured in the claims databases. Identifying incident users in administrative claims databases has challenges,” the study investigators concluded. “As patients may enter the database at any time during the course of their treatment, the first 4 doses recorded in these databases may not always be the first 4 loading doses. Prevalent users (or existing users of nusinersen) who are already on maintenance doses may be misclassified as incident users (or new users of nusinersen) on loading doses, resulting in lower reported adherence during the loading dose phase.”

The researchers added that US commercial claims often don’t capture all medications taken by patients, particularly for the 40% of patients with SMA who have multiple insurance coverage.

Reference

Youn B, Proud C, Wang N, et al. Examining real-world adherence to nusinersen for the treatment of spinal muscular atrophy using two large US data sources. Adv Ther. Published online January 16, 2023. doi: 10.1007/s12325-022-02414-9