FDA cuts the regulatory fuse on Roche's heir to Rituxan

Roche's ($RHHBY) heir to the megablockbuster cancer drug Rituxan has been put on the inside regulatory track at the FDA, earning priority review status on top of a breakthrough drug designation that is intended to speed a final marketing decision at the FDA. The agency set an action date of Dec. 20 for obinutuzumab (GA101) as a new treatment for chronic lymphocytic leukemia.

The work on obinutuzumab at Roche's big Genentech subsidiary is crucial to its long-term prospects. Rituxan will likely face biosimilar competition relatively soon, threatening a $7 billion franchise. While some big players in the biosimilars market have backed off programs for Rituxan, Novartis's ($NVS) Sandoz recently boasted that it's pushing ahead on a late-stage study which could reshape the market.

Roche's best hope is to come up with a better Rituxan--fast--and it's been pushing hard on a two-part pivotal trial for obinutuzumab. Investigators used glycoengineering technology to craft an anti-CD20 antibody that could directly terminate cancer cells at the same time that it spurs the immune system to go after leukemia. In the first leg of the study the treatment provided promising evidence of activity, reducing tumors in three out of every four patients. Survival rates haven't been finalized, but progression-free survival was 23 months for obinutuzumab plus chemo, compared to 10.9 months for another arm receiving a Rituxan/chemo combo.

Roche has been running against the clock on this drug. At the time Roche started its randomized Phase III study, it had data on only 33 patients, including some midstage single-arm results. Investigators started off by testing 6 patients to see if there were any big red safety flags that would prevent testing, then pushed ahead and essentially cut out the randomized Phase II study that has long been a standard trial feature. At the beginning of the clinical program, investigators paid especially close attention to side effects to make sure they hadn't overlooked anything in the abbreviated safety study. 

Doing that cut anywhere from two to three years out of the development process, investigators say. The clinical program, from first dosing to its first regulatory filing, took less than 6 years.

"We're excited that the FDA has granted GA101 in CLL both breakthrough therapy designation and priority review," Hal Barron, chief medical officer and head of global product development, said in a release. "These FDA designations acknowledge the promising trial results with GA101 and will hopefully allow this novel medicine to reach the people who need it in an expedited time frame."

- here's the press release