Findings from two Phase III alemtuzumab studies for relapsing-remitting MS

Study 1 - Alemtuzumab vs interferon beta 1a as first-line therapy in previously untreated relapsing-remitting MS, Phase III


Summary
Findings from a phase III study assessing the safety and efficacy of alemtuzumab (a lymphocyte-depleting humanized monoclonal antibody) compared with interferon beta 1a as a first line therapy in previously untreated people with relapsing-remitting MS demonstrated treatment with alemtuzumab to be more effective at the end of the study period than treatment with interferon beta 1a. [Jeff rey A Cohen*, Alasdair J Coles*, Douglas L Arnold, Christian Confavreux, Edward J Fox, Hans-Peter Hartung, Eva Havrdova, Krzysztof W Selmaj,Howard L Weiner, Elizabeth Fisher, Vesna V Brinar, Gavin Giovannoni, Miroslav Stojanovic, Bella I Ertik, Stephen L Lake, David H Margolin,Michael A Panzara, D Alastair S Compston, for the CARE-MS I investigators. The Lancet, Early Online Publication, 1 November 2012 doi.org/10.1016/ S0140-6736(12)61769-3]


The Study
The 2-year randomized controlled Phase III trial enrolled 526 people between the ages of 18 and 50 with previously untreated relapsing-remitting multiple sclerosis. In total, 362 people were randomly assigned in a 2:1 ratio to the alemtuzumab treatment group and 164 to the interferon beta 1a treatment group. Participants in the alemtuzumab treatment group received daily 12 mg intravenous infusions for 5 days at baseline and then once daily for 3 days at 12 months. Those in the interferon beta 1a treatment group received 44µg 3 times per week.

Study endpoints were relapse rate and time to 6 month sustained disability progression. The alemtuzumab treatment group experienced fewer relapses (22%) compared with the interferon beta 1a treatment group (44%). Of the people in the interferon beta 1a group, 11% had sustained accumulation of disability compared with 8% in the alemtuzumab group.

Adverse events were higher in the alemtuzumab group, including infusion-associated reactions, infections and autoimmune disorders. Alemtuzumab continues to provide evidence of efficacy in treating relapsing-remitting MS however its efficacy should be weighed against its potentially serious, but manageable, adverse effects.


Study 2 - Alemtuzumab in relapsing-remitting MS after treatment with first-line Disease-Modifying Therapy, Phase III


Summary
Findings from a separate phase III study assessing the safety and efficacy of alemtuzumab compared with interferon beta 1a in people with relapsing-remitting MS who have relapsed despite first-line treatment (interferon beta or glatiramer acetate) suggest that alemtuzumab was more effective in reducing relapse rate and disability progression compared with interferon beta 1a. [Alasdair J Coles, Cary L Twyman, Douglas L Arnold, Jeff rey A Cohen, Christian Confavreux, Edward J Fox, Hans-Peter Hartung, Eva Havrdova, Krzysztof W Selmaj, Howard L Weiner, Tamara Miller, Elizabeth Fisher, Rupert Sandbrink, Stephen L Lake, David H Margolin, Pedro Oyuela, Michael A Panzara, D Alastair S Compston, for the CARE-MS II investigators* The Lancet, Early Online Publication, 1 November 2012 doi:10.1016/S0140-6736(12)61768-1]


The Study
The 2-year randomized controlled Phase III trial enrolling over 400 people between the ages of 18-55 with relapsing-remitting MS who had at least one relapse on interferon beta 1a or glatiramer acetate. In total, 202 people were randomly assigned to the 3 times weekly 44µg interferon beta 1a treatment group and 426 people were assigned to the alemtuzumab treatment group, receiving a 12mg dose of alemtuzumab once a day for 5 days at baseline and then once a day for 3 days at 12 months.

Study endpoints were relapse rate and time to 6 month sustained disability progression. Those in the alemtuzumab treatment group experienced significant reductions in relapse rate and disability progression compared with the interferon beta 1a treatment group. At the 2-year mark, 65% of the people in the alemtuzumab treatment group were relapse-free compared with 47% of the people in the in the beta 1a treatment group. Finally, 13% of the people in the alemtuzumab group had sustained accumulation of disability compared with 20% in the interferon beta 1a group.

Adverse effects reported in the alemtuzumab treatment group were notably higher than those reported in the interferon beta 1a treatment group and included, infusion-associated reactions (90%), mild-moderate infections (77%) and thyroid disorders (16%).

Researchers state that with appropriate monitoring to reduce the risk of the potentially serious but treatable adverse effects, alemtuzumab could potentially be an effective treatment option in people with relapsing-remitting MS whose disease has advanced despite use of a first-line treatment.

The MS Society of Canada will continue to monitor activities related to alemtuzumab and will provide updates as they become available.