No Evidence of Disease Activity for 4 Years Following 2 Courses of Alemtuzumab and No Further Treatment: Long-Term Responders from Care-MS II

Background: In CARE-MS II (NCT00548405) and its extension study (NCT00930553), patients with active RRMS and an inadequate response (≥1 relapse) to prior therapy at baseline demonstrated improvements in clinical and MRI outcomes that were durable over 5 years. Durable efficacy was evident even though most patients received no therapy since Month 12.

Objectives: To evaluate long-term treatment response in alemtuzumab patients who had no evidence of disease activity (NEDA) during Year 2 of the core CARE-MS II study and entered the ongoing extension study.

Methods: Patients randomized to alemtuzumab in the core study received 2 annual courses at Months 0 and 12. In the extension, patients could receive as-needed alemtuzumab retreatment for relapse and/or new lesions on MRI, or another disease-modifying therapy at the investigator’s discretion. NEDA was defined as the absence of both clinical disease activity (CDA; relapse and 6-month confirmed disability progression) and MRI disease activity (new gadolinium-enhancing and/or new/enlarging T₂lesions).

Results: 393 (93%) CARE-MS II alemtuzumab-treated patients enrolled in the extension; of these, 232 had achieved NEDA in core study Year 2. 141 (61%) patients who achieved NEDA in core study Year 2 received no additional treatment for 4 years. In Years 2–5 (Months 12–60), 78% of patients with no additional treatment had sustained absence of CDA and 59% had sustained absence of MRI disease activity. Most patients (75%, 75%, 67%) achieved NEDA in Years 3, 4, and 5 in the extension and 48% had sustained NEDA over Years 2–5.

Conclusions: Most patients who achieved NEDA in Year 2 received no further treatment following the initial 2 courses of alemtuzumab. Of these patients who did not receive further treatment, nearly half had sustained NEDA through Year 5, demonstrating the durable efficacy of 2 treatment courses of alemtuzumab. Based on these findings, alemtuzumab may provide a unique treatment approach with durable efficacy in the absence of continued treatment for RRMS patients.

Study supported by Genzyme, a Sanofi company, and Bayer Healthcare Pharmaceuticals.