March 29, 2017
By Mark Terry, BioSpace.com Breaking News Staff
The U.S. Food and Drug Administration (FDA) approved Genentech ‘s Ocrevus (ocrelizumab) for multiple sclerosis (MS). It is now the first and only drug approved for both relapsing and primary progressive forms of MS.
Primary-progressive MS is the most aggressive form of the disease, marked by gradual worsening of neurological symptoms. The most brutal of the symptoms include difficult walking and paralysis below the waist in some patients. It accounts for 10 to 15 percent of all MS cases.
Ocrevus was also approved for the more common form of the disease, relapse-remitting MS. This form is marked by attacks of inflammation that trigger early symptoms like visions problems, tingling in the feet, weakness, and muddled thoughts.
The company indicates the drug will be available to patients in two weeks. The catch? It is priced at $65,000 for a yearly treatment, which is made up of two infusions. In its defense, the company notes that Ocrevus is priced 25 percent less than competitor Rebif. Rebif was used in two of the trials that led to Ocrevus’ approval, where Ocrevus outperformed Rebif. Rebif costs $86,000 for a year’s treatment.
MS is an autoimmune disease, where the immune system attacks the body’s own tissues. The cause of the immune system malfunction is unknown, but it primarily results in an immune and inflammatory attack on the myelin sheaths that surround nerves. It shows up mostly in people between 20 and 40 years of age and is more common in women.
One of the key findings that over the course of the last 40 years has led to treatments, including Ocrevus and others, was that both T and B immune cells were involved in the disease. Stephen Hauser, now director of the Weill Institute for Neurosciences at the University of California, San Francisco, started working on MS therapeutics in the late 1970s. It wasn’t until the 1990s that the discovery of B-cell involvement was made. Hauser convinced Genentech in 2001 to work on using rituximab in people. It took another two years before the company agreed to try it.
And around the same time, Biogen merged with Idec, and gained the company’s rights to rituximab. So again the studies were delayed. Then the FDA didn’t allow the placebo arm of the trial to go on for a full year, insisting on only a single dose, instead of two. However, even with that, the results were positive, “It was a grand slam home run,” Hauser told Stat News.
Genentech pivoted away from rituximab, due to safety issues, focusing on what it viewed as a better drug, ocrelizumab. Stat News writes, “It had a key advantage over rituximab, which, like other monoclonal antibodies developed during the early days of the technology, is comprised of part human and part mouse protein. Over time, some patients develop immune responses to the mouse component, leading to problematic side effects or undercutting the drug’s benefits.”
Ocrelizumab is fully humanized, and as a result, less likely to cause an immune response.
Although ocrelizumab appears to be quite effective in its patient subpopulation, it only provides about a 25 percent benefit to patients with primary progressive disease. Not everything is known about MS yet, and Hauser points out, “our foot is in the door, but we’re not there yet.”
“The FDA’s approval of Ocrevus is the beginning of a new era for the MS community and represents a significant scientific advance with this first-in-class B cell targeted therapy,” said Sandra Horning, chief medical officer and head of Global Product Development for Genentech, in a statement. “Until now, no FDA-approved treatment has been available to the primary progressive MS community, and some people with relapsing forms of MS continue to experience disease activity and disability progression despite available therapies. We believe Ocrevus, given every six months, has the potential to change the disease course for people with MS, and we are committed to helping those who can benefit gain access to our medicine.”
