VANCOUVER, BC—Patients with active relapsing-remitting multiple sclerosis (MS) who had an inadequate response to one or more prior therapies at baseline showed durable improvement in clinical efficacy with alemtuzumab at 5 years, despite many not having received the agent for 4 years, follow-up results from the CARE-MS II study reported in a poster presentation at the 68th AAN Annual Meeting.

These findings suggest alemtuzumab may provide a “unique” approach in the absence of continued treatment for this population, noted Alasdair Coles, PhD, of the department of clinical neurosciences at the University of Cambridge in Cambridge, UK, and colleagues.

In the CARE-MS II core study, patients with active relapsing-remitting MS who had received alemtuzumab at Months 0 and 12 showed superior efficacy when compared with subcutaneous interferon β-1a over 2 years. Of these patients, 393 (93%) opted to enter an extension study and received as-needed retreatment with alemtuzumab for relapse or radiological activity.

Study endpoints included annualized relapse rate, 6-month sustained accumulation of disability/confirmed disability progress, 6-month sustained reduced in disability, and no evidence of clinical disease activity.

The investigators reported that a low annualized relapse rate (ARR) was maintained over Years 3–5: 0.22 for Year 3, 0.23 for Year 4, and 0.18 for Year 5. 

“Disability scores improved or remained stable over 5 years in the majority of patients treated with alemtuzumab,” the coauthors reported.

Over Years 3–5, no evidence of clinical disease activity was observed in between 53% and 58% of patients. “Twenty-seven percent of patients had NEDA sustained over Years 3–5,” the coauthors noted.

Compared with the core study, incidences of infusion-associated reactions and infections during the extension study decreased, and incidence of serious adverse events was low. Incidence of thyroid adverse events peaked at Year 3 and declined thereafter.