By: Dermatology Times

Unlike the multiple sclerosis (MS) drug Tysabri (natalizumab, Biogen Idec), which was pulled from the U.S. market in 2005 for safety reasons, then reintroduced, Raptiva (efalizumab, Genentech) appears permanently shelved, sources say.

Natalizumab has survived despite an association with progressive multifocal leukoencephalopathy (PML), as has Rituxan (rituximab, Genentech), used to treat B-cell lymphoma and many other diseases off-label, observes Craig L. Leonardi, M.D., clinical professor of dermatology, Saint Louis University.

Similarly, "It might have been OK for efalizumab to be around — with a giant warning label and clear-cut informed consent for use in very specific situations," he says. "But the company has the right to stop the distribution and manufacture of the drug at any time."

Genentech was to stop marketing the drug after June 8.

Such decisions depend on the disease being treated and the doctors prescribing the medication, Dr. Leonardi says.

"Dermatology was not very motivated to keep efalizumab around for their tough-to-treat patients who needed it. Even though psoriasis can be horrific, it's not the same as MS or cancer," he says. "So dermatology made that risk-and-benefit assessment and voted with its feet."

Natalizumab demonstrates unparalleled efficacy in treating MS, particularly for patients who have failed other therapies, notes Ivor Caro, M.D., Genentech's senior medical director, dermatology.

"In psoriasis, alternative therapies are available," he says.

Moreover, natalizumab's risk evaluation and mitigation strategy (REMS) ensures that all prescribers and patients are registered and that every PML case will be reported, Dr. Caro says.

But it doesn't prevent new cases of PML from developing, he says. Because there would also be no way to prevent all PML cases in psoriasis patients, "It's highly unlikely that we would reintroduce Raptiva."

Eric Le Berrigaud, pharmaceutical equity analyst with Raymond James Euro Equities in Paris, adds that Roche, which now controls Genentech, declined to pursue Raptiva rights outside the United States.

"Merck obtained the rights," he says. "Roche does not believe in the product, and, whatever happens, will not reintroduce the drug in the United States." Another company could license the product here, he adds, although he doubts that any will.