FDA Halts Trial of GSK MS Drug Amid Concerns Over Tysabri
Biogen Idec's and Elan's recent withdrawal of multiple sclerosis (MS) drug Tysabri is starting to have some fallout for other drugmakers, including GlaxoSmithKline (GSK), which has been ordered to halt a clinical trial of a drug candidate in the same class as Tysabri.
The FDA recently suspended a clinical trial involving GSK's experimental MS candidate '699, which, like Tysabri (natalizumab), works by inhibiting alpha-4 integrin, a substance that has been linked to a rare and frequently fatal demyelinating disease of the central nervous system. Tysabri was pulled from the market Feb. 28 after two patients participating in a postmarketing trial of the drug were diagnosed with the disease, known as progressive multifocal leukoencephalopathy (PML).
"The FDA has taken the precautionary measure of placing a clinical hold on investigational new drugs in the alpha-4 integrin antagonist class being tested on human subjects, which includes '699," a GSK spokesman said. The company is not aware of any instances of PML in patients taking '699, the spokesman said.
GSK's drug is currently in Phase IIb trials, and the company is aiming for market approval in 2008. The product is being developed jointly with Japanese drugmaker Tanabe Seiyaku.