* 71 pct of patients see no disease activity after 4 years
* No new cases of ITP identified in Phase II trial
* Company sees drug becoming most effective MS treatment
By Toni Clarke
BOSTON, April 14 (Reuters) - New data from a clinical trial of Genzyme Corp’s GENZ.O experimental multiple sclerosis drug lends weight to the company’s conviction it could, if approved, become the most effective drug on the market.
Three-year results from a mid-stage trial of the drug, Campath, were published in 2008.
Data presented on Wednesday at the annual meeting of the American Academy of Neurology showed that after four years, 71 percent of patients had no relapse or worsening of disability.
Genzyme, which faces a proxy battle from billionaire investor Carl Icahn, is struggling to emerge from a manufacturing crisis that lead to shortages of two of its key drugs for rare diseases.
The latest data represents a rare piece of good news as the company seeks to penetrate the $8.6 billion multiple sclerosis drug market.
Multiple sclerosis is a chronic disease in which the body’s own immune system attacks the myelin sheaths that protect nerve fibers in the brain, spinal cord and optic nerves. The disease causes a range of symptoms, including muscle weakness, speech and visual disturbances, pain and cognitive difficulties.
Michael Panzara, who oversees clinical development of Genzyme’s multiple sclerosis and immune system drugs, said that, if the results seen in the mid-stage trial are replicated in two ongoing late-stage trials, the drug could set a new standard in treatment.
“This really holds promise to be the most effective drug in MS,” he said.
Panzara was, as recently as six months ago, responsible for late-stage clinical development of neurology drugs at Biogen Idec Inc (BIIB.O), which makes the MS drugs Avonex and Tysabri. Currently, Tysabri is considered the most effective drug on the market, but also carries the risk of a potentially deadly brain disorder known as progressive multifocal leukoencephalopathy (PML).
Panzara said it is not possible to draw direct comparisons between Tysabri and Campath, known generically as alemtuzumab, since they have not been compared in a head-to-head trial. But he said that, based on the data so far, Campath looks set to be in a class of its own.
Campath is given by infusion for five days in the first year. At the beginning of the second year it is given for three days.
Tysabri is infused once a month. If treatment is stopped the disease progresses.
“The question is whether we have finally seen a population of patients who may be in remission,” Panzara said.
Still, Campath carries its own risks.
Six patients in the mid-stage trial developed immune thrombocytopenic purpura, an autoimmune disease in which low blood platelet levels can lead to bruising and bleeding. One patient in the trial died of a cerebral hemorrhage.
The five other people who developed the disease were diagnosed more quickly and treated successfully. New data shows that all five patients continue to have normal platelet counts.
The company said no new cases of ITP have been identified.
Older generation multiple sclerosis treatments, including Avonex and Rebif are considered relatively safe. The newer, more potent products such as Tysabri, Campath and experimental oral treatments being developed by Novartis AG NOVN.VX and Merck KGaA, are more complicated.
“The neurology community is coming to grips with the reality that there is no free lunch,” Panzara said. “If you want the efficacy you have to take some risks.”
Campath is a monoclonal antibody already used to treat chronic lymphocytic leukemia. Its mechanism is not entirely clear, but Panzara said it is thought the drug selectively depletes T and B cells, while sparing other infection-fighting elements of the immune system.
The latest data showed that after four years, an estimated 91 percent of Campath-treated patients experienced a halt in their disability progression, compared with 68 percent of patients taking Rebif. Genzyme said 77 percent of Campath-treated patients were relapse-free, compared with 49 percent of patients taking Rebif.
Genzyme’s shares rose 0.27 percent to $52.75 in afternoon trading on Nasdaq. (Reporting by Toni Clarke; editing by Andre Grenon)