Introduction: To better understand treatment patterns in US patients with multiple sclerosis (MS) initiating generic glatiramer acetate (GA), this study examined adherence, discontinuation and switching patterns from generic follow-on glatiramer acetate (FOGA) therapy in real-world patient cohorts.
Methods: Retrospective analyses utilized data from two large US databases (administrative claims and linked electronic medical records). Eligible adult MS patients had ≥1 pharmacy claim for FOGA during the identification period; the first FOGA claim was the index date. All analyses were descriptive; proportion of days covered (PDC) was calculated as a measure of adherence to FOGA during the follow-up period.
Results: The first cohort consisted of 95 patients, with 93.6% having a branded GA claim for Copaxone during the baseline period. Half these patients (48.4%) had high adherence to FOGA therapy (PDC: 0.8-1.0). Fifty-five patients (57.9%) initially discontinued FOGA with a mean persistence of 112 days. Of those who discontinued, 7.3% had no subsequent disease-modifying therapy (DMT), 30.9% restarted FOGA and 61.8% did not restart FOGA. The second cohort consisted of 1957 patients, with 63.8% having a branded GA claim for Copaxone during the baseline period and 33.5% were treatment naïve. The majority of patients (61.9%) had high adherence to FOGA therapy. A total of 1597 patients (81.6%) initially discontinued FOGA with a mean persistence of 93 days. Of those who discontinued, 55.8% switched to another DMT, 16.7% restarted FOGA and 37.5% had no subsequent DMT.
Conclusion: Adherence to FOGA therapy was reasonably high across cohorts; however, most patients discontinued their initial FOGA within four months of the index date and most switches from FOGA were to branded GA products.
Keywords: Relapsing multiple sclerosis; adherence; disease-modifying therapies; switching; treatment discontinuation.