Genentech Does it Again, Wins FDA Approval for ‘Son of Rituxan’

Genentech is the “goose that keeps laying golden eggs” in the words of one biotech entrepreneur I spoke with last week, who worked there as a scientist in the ‘80s.

Another golden egg just came out today.

South San Francisco-based Genentech, a unit of Roche, said today it has won FDA approval of obinutuzumab (Gazyva), as a new treatment for people with chronic lymphocytic leukemia, in combination with chlorambucil chemotherapy. The new Genentech drug (pronounced guh-ZY-vuh) was previously known as GA101, or as the next-generation follow-up molecule to one of the company’s greatest hits—rituximab (Rituxan). About 5,000 people die each year in the U.S. of chronic lymphocytic leukemia, making it one of the more common forms of blood cancer.

FDA approval of this medicine was about as close to a no-brainer as you see in drug development. That’s partly because Genentech had the guts to test its new treatment head-to-head against its own blockbuster, and show the new drug is superior. The latest approval is the fifth new Genentech cancer medicine approved by the FDA in the past three years, a time when many industry observers fretted it might lose its mojo under Roche ownership.

The new drug, in tandem with chlorambucil chemotherapy, was able to keep tumors from spreading for a median time of 23 months for patients with chronic lymphocytic leukemia, according to clinical trial results presented in June at the American Society of Clinical Oncology (ASCO). Patients who were randomly assigned to rituximab and the same chemo drug were able to keep their tumors in check for 15.7 months, while patients stayed that way for only 10.9 months on the chemo alone, according to results presented at ASCO. In today’s press release, Genentech offered some more data, including a line about how more than one-fourth of patients on the new drug and the chemo had their cancer completely wiped out (27.8 percent), compared with 0.9 percent who did that well on the chemo alone.

For biostatistics geeks out there, the new drug had an amazingly good hazard ratio of 0.16. That means the new drug and a chemo agent offered an 84 percent lower risk of disease worsening or death during the study than the chemo alone. A 20-30 percent reduced risk of disease worsening or death is more commonly seen among new cancer drugs. More detailed follow-up results are expected to be released at the American Society of Hematology conference next month in New Orleans.

Like all cancer drugs, the new product has side effects that aren’t trivial. About two-thirds of patients (67 percent) on the new drug combo reported moderate to severe side effects, most of which were infusion reactions the first time patients got the new treatment, according to data presented at ASCO. Patients on the new drug also reported a higher rate of neutropenia, a depletion of infection-fighting white blood cells, than was seen in the control group. About 34 percent of those on the new drug reported moderate to severe neutropenia, compared with 25 percent who got rituximab. About 16 percent of patients on the chemo alone had that moderate-to-severe form of neutropenia. Genentech said the increased rate of neutropenia didn’t appear to increase the rate of infections in patients on the new medicine.

Taken together, those results helped move Genentech’s application up the priority list at the FDA. The agency gave it “Breakthrough” status, and approved the medicine several weeks before its mid-December legal deadline to complete its regulatory review.

“Today’s approval represents an important new addition to the treatments for patients with CLL,” said Richard Pazdur, director of the FDA’s cancer drug office, in a statement. “This approval reflects the promise of the Breakthrough Therapy Designation program, allowing us to work collaboratively with companies to expedite the development, review and availability of important new drugs.”

The new drug is estimated to cost $41,300 for

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.