Study: Genzyme’s multiple sclerosis drug alemtuzumab effective over five years

Genzyme reported results from a mid-stage study at the European Committee for Treatment and Research in Multiple Sclerosis meeting demonstrating that patients with relapsing remitting multiple sclerosis (RRMS) treated with its experimental drug, alemtuzumab, continued to benefit from the agent four years after treatment cessation. The drug, which is already marketed as Campath for the treatment of B-cell chronic lymphocytic leukaemia, is being evaluated in two late-stage trials by Genzyme and partner Bayer, with data expected next year.

Three-year results of the CAMMS223 trial, which enrolled 334 patients who had not previously received treatment for MS, were released in 2008, with four-year data presented in April of this year. The four-year results showed that 71 percent of patients with MS taking alemtuzumab were free of clinically-active disease at up to three years post-treatment, compared to 35 percent of patients treated with Merck KGaA's Rebif (interferon beta-1a).

The five-year results showed that alemtuzumab reduced the disease relapse rate by 69 percent when compared to Rebif, and 87 percent of patients receiving Genzyme's drug experienced no worsening of disability, compared with 62 percent of patients taking Rebif. Furthermore, patients taking alemtuzumab saw an improvement in disability scores as opposed to a worsening among those on Rebif. Genzyme also noted that patients taking alemtuzumab had an annualised relapse rate of 0.11, compared with a relapse rate of 0.35 for Rebif.

Michael Panzara, head of Genzyme's clinical development on MS and immune system drugs, commented that "the most remarkable thing about this data is that it hasn't changed much from the four-year data." Panzara called the data "unique," adding "is this what remission in MS looks like?"

The Phase II trial was halted early in 2005 after the drug was linked to the development of immune thrombocytopenic purpura, from which one patient died. Panzara noted that in the Phase III trials, the safety monitoring committee hasn't yet raised any safety concerns.

Genzyme has previously indicated it expects alemtuzumab, which has received FDA fast-track status for the treatment of RRMS, to capture a significant portion of the $13 billion global MS market if it is launched in 2012.

RBC Capital Markets analyst, Michael Yee, speculated that the drug may generate annual sales of as much as $1 billion, a figure that he says could prompt sanofi-aventis to increase its current $69 per share takeover offer for the company into a range of about $78 per share. However, Cowen & Co. analyst, Phil Nadeau, cautioned that "we're not convinced that Campath is going to be a big product in multiple sclerosis," noting that while "efficacy looked great…what will really determine how successful it is will be safety and side effects. In Phase 2 it had some issues." He projected that the drug could garner annual revenue of about $500 million if approved in the multiple sclerosis indication.

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