New B cell hope, a humanized Rituxan from Genetech

A humanized B cell depletion therapy is successful in phase III clinical trials. This means that the FDA approval can likely be no more than two or three slow agonizing years away.

The only sad thing about this news is that this new B cell depletion therapy, monoclonal antibody is only "humanized". It is not a fully human monoclonal. Humanized means it is about 90% human. There will still be a chance for adverse reactions to the 10% of it that is mouse protein.

But since a portion of our B cells drive our autoimmune process with autoantibodies that they produce any new B cell depletion therapeutic product is a welcome addition to our arsenal against autoimmune.

Currently Rituxan is the only B cell depletion therapy on the market and it is about half mouse protein. No drug can be in the US market without FDA approval and Rituxan has that approval exclusively among drugs that could deplete B cells.

We know from many many trials with various autoimmune diseases that B cell depletion can turn off almost any autoimmune disease for months or even years. On the downside of B cell depletion it that dormant viruses, particularly the deadly PML virus, can be awaken when B cells are depleted. These virus without B cell to keep them in check can be fatal. Luckily reawakening of potentially deadly viruses is rare.

Here is the story:
http://sanfrancisco.bizjournals.com/sanfrancisco/stories/2009/12/07/daily71.html?t=printable

Business News - Local News
Friday, December 11, 2009, 11:04am PST
Genentech, Biogen: RA drug study positive
San Francisco Business Times - by Ron Leuty

A late-stage rheumatoid arthritis drug under development by Genentech Inc. and Biogen Idec Inc. showed that it improved the signs and symptoms of the disease.

South San Francisco-based Genentech, a subsidiary of the Roche Group, and Cambridge, Mass.-based Biogen Idec (NASDAQ: BIIB) said they will submit the data from the Phase III trial for presentation at an upcoming medical meeting.

The study is the first of four needed to win approval of the humanized monoclonal antibody ocrelizumab, which is similar to Genentech and Biogen Idec’s Rituxan, from the Food and Drug Administration.

The study combined ocrelizumab with methotrexate —the gold standard for treating rheumatoid arthritis — in patients with active RA but who had an inadequate response to prior treatment with methotrexate. It consisted of 1,015 patients and recorded their responses at 24 weeks and 48 weeks.

"These results are significant because they are the first data from a large Phase III trial to show that a humanized antibody targeted at B-cells improves the signs and symptoms of rheumatoid arthritis," said Dr. Hal Barron, Genentech's chief medical officer.

Deeper data about the study wasn’t released, but the companies said a higher percentage of serious infections occurred in those receiving ocrelizumab versus those receiving a placebo. Overall adverse events were comparable between the two groups, the companies said.

Results of the three other required Phase III studies of ocrelizumab are expected in the first half of 2010, the companies said.

Roche and Biogen split Rituxan profits, with 60 percent of the U.S. profit going to Roche, according to the Reuters news agency. Biogen would receive 30 percent of the profit from both Rituxan and ocrelizumab if the new product is approved, Reuters said.

A radiographic study of ocrelizumab in patients who hadn’t previously been exposed to methotrexate was placed on clinical hold and dosing was stopped.

Email Ron Leuty at rleuty@bizjournals.com / (415) 288-4939.