Roche Experimental Leukemia Drug Helps Shrink Tumors

Roche Holding AG’s experimental leukemia drug shrank tumors in more patients when added to chemotherapy, according to study results that may aid the company in expanding its line of blood-cancer treatments.

Combined with chemotherapy, the drug, GA101, shrank tumors in 76 percent of patients with chronic lymphocytic leukemia compared with 30 percent for those getting just chemotherapy, according to a summary of the 589-patient trial. The results will be presented at the American Society of Clinical Oncology’s meeting starting May 31 in Chicago.

The data are the first results from a two-part trial as Roche tries to position GA101 as heir to its top-selling drug Rituxan, which will face competition from biosimilar products. Results were good enough to show that GA101 may be more active than Rituxan, said Bill Wierda, a professor in the department of leukemia at the University of Texas MD Anderson Cancer Center.

“It’s exciting because it appears that it may be more active, but we need to see the final data,” Wierda, who has worked with Roche on other research but wasn’t involved in this trial, said in a telephone interview. “This is very encouraging data.”

Roche fell 0.5 percent to 246.50 Swiss francs at 10:30 a.m. in Zurich after rising as much as 1.1 percent earlier in the session. The stock has gained 34 percent this year.

Study Findings

The Roche trial reported yesterday also compared Rituxan, combined with chemotherapy, to chemotherapy alone. Both the GA101 and Rituxan combinations performed better the solo chemotherapy, with Rituxan shrinking tumors in about 66 percent of patients -- less than GA101’s 76 percent.

Rituxan helped the patients live a median of 15.7 months without their cancer progressing, compared with 10.8 months on chemotherapy alone. Compared with GA101, chemotherapy patients lived 10.9 months without cancer progressing. Patients who got GA101 as well lived more than twice as long, 23 months, though the results on that measure weren’t definitive.

The data will probably support GA101’s regulatory approval, Wierda said, for the CLL patients the trial studied: older, less-fit people with other ailments who haven’t had a CLL treatment before.

A cancer of the bone marrow and white blood cells, CLL is the second-most common type of leukemia in adults and usually affects people in middle age or older, according to the National Institutes of Health. About 15,680 U.S. residents will probably be diagnosed with the disease this year, and about 4,580 people will die of it, according to National Cancer Institute statistics. Patients in the trial were a median 73 years old.

Side Effects

About two-thirds of the patients who got GA101 experienced side effects graded as severe or worse during the course of treatment, compared with 41 percent who had chemotherapy alone.

“After the data are presented at ASCO we’ll have a new view of the potency of this drug,” Niko Andre, Roche’s global head of medical affairs, said in an interview before the results were released. The second stage of the trial is a head-to-head comparison of GA101 and Rituxan. Roche said in a statement that it had filed for regulatory approval of the drug with the U.S. Food and Drug Administration and the European Medicines Agency.

Like Rituxan, GA101 targets CD20, a type of immune cell that plays a role in non-Hodgkin’s lymphoma and chronic lymphocytic leukemia. Roche is also testing the drug in non-Hodgkin’s lymphoma patients.

Smarter Version

“In theory it’s a smarter-designed version of Rituxan,” Tim Race, a London-based analyst for Deutsche Bank AG, said in an interview before the results were released. “The problem is that Rituxan is a brilliant drug, and being better than a brilliant drug is always difficult.”

Also known by its generic name rituximab, Rituxan generated 6.7 billion Swiss francs ($7.4 billion) in sales last year. Roche’s patents on Rituxan expire in 2018 in the U.S. and earlier in Europe. Biogen Idec Inc. markets the drug in the U.S.

Also published yesterday before the cancer meeting were final results for an early-stage study of Gilead Sciences Inc.’s idelalisib, also known as GS-1101. The medicine shrank tumors in 30 of the 54 CLL patients and patients lived a median of 17 months without their cancer progressing, the data showed. Patients had taken a median of five other therapies before starting idelalisib.

Gilead Drug

The drug, which Gilead gained in its 2011 purchase of Calistoga Pharmaceuticals Inc. for $375 million, is in five late-stage trials in CLL and indolent non-Hodgkin lymphoma, Gilead said on a May 2 conference call. It is being tested in combination with drugs such as rituximab and bendamustine.

In the early-stage trial of Gilead’s drug alone, idelalisib helped with splenomegaly, or enlarged spleen, and low blood cell counts, the data showed. Most common adverse effects included fatigue, diarrhea and fever.

“Drugs like idelalisib are probably going to change the landscape of the disease in the next few years,” Jennifer Brown, assistant professor of medicine at Dana-Farber Cancer Institute and lead author of the study, said in a statement, referring to CLL. “While this research is early and ongoing, we hope this drug, along with others like it, will lead to prolonged survival and eventually help turn CLL into a condition that is treated like high blood pressure.”