SUMMARY
Genzyme and Schering AG announced on September 16 the temporary suspension of a Phase 2 clinical trial comparing the immune-suppressing monoclonal antibody Campath^® (alemtuzumab, currently approved to treat a form of leukemia) with Rebif^® (interferon beta-1a, an immune-modulating agent approved for treating relapsing forms of MS) in treating relapsing-remitting multiple sclerosis. First-year data found that Campath was effective in reducing MS attacks, but several serious adverse events had occurred, including two deaths.

DETAILS
Genzyme and Schering AG announced on September 16 the temporary suspension of a Phase 2 clinical trial comparing the immune-suppressing monoclonal antibody Campath (alemtuzumab, currently approved to treat a form of leukemia) with Rebif (interferon beta-1a, an immune-modulating agent approved for treating relapsing forms of MS) in treating relapsing-remitting multiple sclerosis.

The clinical trial involves 334 participants at 49 centres in Europe and the U.S., treated once a year with low or high dose infusions of Campath or the standard dose of Rebif administered three times per week. In a press release and public conference call, the companies released some first-year results of the three-year trial, suggesting that although Campath appeared to be effective at reducing MS attacks, serious adverse events occurred, including two deaths. The companies are no longer giving the drug to participants, but state that they will continue to collect data on efficacy and safety as they begin planning for a more definitive, Phase 3 trial.

Three persons on Campath, one of whom died, developed severe idiopathic thrombocytopenic purpura (ITP), a condition in which low blood platelet counts can lead to abnormal bleeding. Other adverse effects thus far include two patients who developed Graves disease, an autoimmune thyroid condition identified as a risk in previous studies of Campath in MS, and one case of listeria meningitis (an infection causing inflammation of the membrane that covers the brain and spinal cord). One participant died of unknown causes.

The companies have notified participants and regulatory authorities about the risk of ITP, and are working to develop tests that would provide earlier indications of possible adverse side effects or help identify patients who might be more at risk for adverse events. The sponsors emphasized that Campath should not be used off-label at this time for the treatment of MS.

According to the company news release, after one year of treatment participants who took Campath at both the low and high doses had at least a 75 percent reduction in the risk of an MS attack compared to participants taking Rebif. This difference was statistically significant. Participants taking Campath also had at least a 60 percent reduction in the risk for progression of disability compared to the Rebif group. This result did not achieve statistical significance.

The MS Society will continue to monitor developments and provide more information when it is available.

[With information from the National MS Society (USA)]

ASK MS Information System Code: 1.4.1.12.2.t

Disclaimer
The Multiple Sclerosis Society of Canada is an independent, voluntary health agency and does not approve, endorse or recommend any specific product or therapy but provides information to assist individuals in making their own decisions.