Positive Topline Results for Investigational MS Drug

Pauline Anderson

July 09, 2015

Ocrelizumab, an investigational humanized monoclonal antibody, is superior to interferon β-1a in reducing relapses and disability progression in patients with relapsing multiple sclerosis (MS), according to the drug's manufacturer, Genentech.

Results from 2 phase 3 studies — OPERA 1 and OPERA II — showed that compared with the interferon β-1a Rebif (EMD Serono/Pfizer), treatment with ocrelizumab significantly reduced the annualized relapse rate (ARR) as well as the progression of clinical disability as measured by the Expanded Disability Status Scale, and the number of lesion in the brain as measured by MRI.

"Ocrelizumab showed remarkable improvements over a standard-of-care medicine across clinical and imaging endpoints in 2 pivotal studies," Sandra Horning, MD, chief medical officer and head of Genentech's global product development, said in a release. "Ocrelizumab has the potential to make a meaningful difference for people with MS, a chronic and debilitating disease."

The randomized, double-blind, double-dummy studies evaluated the efficacy and safety of ocrelizumab (600-mg dose administered by intravenous infusion every 6 months) compared with interferon β-1a (44-μg dose administered by subcutaneous injection three times per week) in patients with relapsing MS. The studies enrolled a total of 1656 patients at 307 sites in 40 countries.

The primary endpoint was ARR at 2 years. Secondary endpoints included time to onset of confirmed disability progression, the total number of T1 gadolinium-enhancing lesions, and total number of new and/or enlarging T2 hyperintense lesions as detected by brain MRI.

According to background information in the press release, ocrelizumab is designed to selectively target CD20-positive B cells, which are thought to be a key contributor to myelin and axonal damage. It binds to CD20 cell surface proteins expressed on certain B cells, but not on stem cells or plasma cells, thus preserving the ability of patients taking the drug to make new B cells.

Adverse Events

Overall, the incidence of adverse events associated with ocrelizumab was similar to that with interferon β-1a in both studies. The most common adverse events were mild-to-moderate infusion-related reactions.  The incidence of serious adverse events associated with ocrelizumab, including serious infections, was also similar to that with interferon β-1a.

On the basis of these positive results, the company plans to submit the data for review to the US Food and Drug Administration and the European Union in the first quarter of 2016.

A phase 3 randomized, double-blind, multicenter, placebo-controlled study in patients with primary progressive MS — ORATORIO — is ongoing.


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