Genentech's multiple sclerosis drug granted Breakthrough status

Genentech's drug ocrelizumab has been granted Breakthrough Therapy Designation for patients with primary progressive multiple sclerosis (PPMS).

The drug is the first ever multiple sclerosis treatment to be granted Breakthrough status by the FDA, and was granted after phase 3 trials showed it reduced the progressive disability and other markers of the disease compared to placebo.

There are currently no approved treatments for PPMS, a debilitating form of MS characterised by steadily worsening symptoms and typically without distinct relapses or periods of remission.

The drug, to be known under the brand name Ocrevus, is likely to be a major challenger in an already highly competitive MS drug market.

Genentech plans to pursue marketing authorisation for both PPMS and relapsing multiple sclerosis (RMS), a more common form of the disease, and will submit data from three pivotal phase 3 studies to the FDA in the first half of 2016.

Genentech and its parent company Roche do not currently have a presence in multiple sclerosis, but analysts think Ocrevus could be among three or four newer treatments which will dominate the market over the next decade.

Biogen's oral drug Tecfidera, interferon treatment Avonex, Teva's Copaxone and Novartis' oral Gilenya are the current dominant players. Genentech's new drug is being tipped to supplant Biogen's Tysabri as the second line treatment of choice. Ocrevus needs to be administered only twice a year, and is likely to have superior efficacy against disease progression.

Analysts believe that Ocrevus could go on from there to compete as a front line treatment, and forecast peak annual sales of up to $5 billion.

Ocrelizumab is a humanised monoclonal antibody which selectively target CD20-positive B cells – the same mechanism used by ofatumumab, a molecule being developed by Novartis for relapse and remitting MS which is about to enter phase 3 trials.