Treatment with Alemtuzumab in Relapsing Remitting Multiple Sclerosis Patients: The British Columbia Experience

Background: Results from clinical trials have established the efficacy of alemtuzumab in relapsing-remitting MS (RRMS), but data from non-controlled settings is limited. Here, we report real world data on alemtuzumab-treated RRMS patients in a British Columbia cohort, and compare their outcome to concurrent RRMS patients that were denied alemtuzumab by their drug insurance coverage and treated with other MS disease modifying therapies (DMTs)

Objectives: Clinical outcomes within the British Columbia cohort included annualized relapse rate (ARR) and change in EDSS. We defined improvement as a 1-point decrease on EDSS, stability when the difference was between -1 and 1, and worsening as a 1-point increase.

Methods: In a single center (UBC MS Clinic), a retrospective chart review of patients who met clinical criteria for treatment with alemtuzumab was conducted. Prior to government reimbursement of alemtuzumab, only patients with extended insurance coverage were eligible for therapy. The alemtuzumab cohort included those who had at least one cycle of therapy. Treatment time ranged from July 2014-July 2016. Patients with insufficient reimbursement were used as a contemporary control cohort. 

Results: 73 RRMS patients received alemtuzumab (41 received 2 cycles, 32 had 1 cycle). The comparison group consisted of 51 patients similar in regards to pre treatment ARR, EDSS and demographics. The duration of follow-up was 13.2 months (range 1-24 months). The ARR was 0.13 (95% CI: 0.04-0.22) for alemtuzumab versus 0.36 (0.17-0.56) for the comparator group. A two-sample t test between groups showed significant difference in ARR post treatment (p=0.0241). Within group comparisons to pretreatment values showed that mean EDSS improved in the alemtuzumab group by 0.5 at 12 months (SD 1.20; 95% CI: -0.9391 to -0.09121; p=0.0188). There was no statistically significant change in EDSS in the control group (mean EDSS improvment by 0.3 (SD 1.12; 95% CI: -0.7801 to 0.1263; p=0.1498)). At last follow-up, 39% of alemtuzumab-treated patients improved from pretreatment values on the EDSS Scale, 39% were stable, and 22% worsened. In the comparator group, 26% had improvement, 50% were stable, and 24% worsened. 

Conclusions: The effectiveness of alemtuzumab in RRMS in a real world setting is robust and similar to what is reported in phase 3 clinical trials. Alemtuzumab-treated patients had better relapses and disability outcomes than a similar group of RRMS patients denied alemtuzumab that then went on to other MS DMTs.