Pharmacyclics’ Leukemia Drug Beats Glaxo’s in Clinical Trial

May 31, 2014 3:29 pm ET

(Updates with analyst opinions in third paragraph.)

May 31 (Bloomberg) -- Pharmacyclics Inc.’s Imbruvica, introduced this year for chronic lymphocytic leukemia, helped patients live longer without their disease worsening than GlaxoSmithKline Plc’s treatment for the blood cancer.

In a head-to-head comparison, 391 patients whose leukemia had relapsed got either Imbruvica or Glaxo’s Arzerra. After six months, 88 percent of patients still taking Imbruvica hadn’t seen their cancer worsen, compared with 65 percent of those on Arzerra, according to research published in the New England Journal of Medicine and presented today at the American Society of Clinical Oncology meeting in Chicago.

Analysts have been split on the stock, with 7 of 20 rating it as a hold, according to data compiled by Bloobmerg. The results could boost Pharmacyclics’ shares after an already strong launch of the drug, said Ian Somaiya, an analyst with Nomura Holdings Inc. The drug, also known as ibrutinib, is projected to sell $3.37 billion by 2018, according to analysts surveyed by Bloomberg.

“This is the first randomized study that demonstrates ibrutinib improves progression free survival and overall survival compared to a standard therapy,” John Byrd, director of hematology at Ohio State University in Columbus, said in an interview. “It establishes ibrutinib as the most appropriate and probably the best therapy.”

Byrd was the lead investigator on the trial and is an unpaid consultant to Sunnyvale, California-based Pharmacyclics. The drug is co-marketed with New Brunswick, New Jersey-based Johnson & Johnson.

16,000 Cases

About 16,000 new cases of chronic lymphocyctic leukemia will be diagnosed in the U.S. this year and 4,600 people will die, according to the National Cancer Institute. In the disease, also called CLL, white blood cells in bone marrow turn cancerous, multiplying rapidly and then moving into the blood. It often grows slowly and is diagnosed most often in older people, making tolerating the side effects of chemotherapy difficult.

Imbruvica also improved overall survival. After 12 months, 90 percent of the Imbruvica patients were alive, compared to 81 percent of those on Arzerra. In addition, 42.6 percent of patients taking Pharmacyclics’s drug showed a response when the cancer was measured with a CT scan, compared to 4.1 percent of those on London-based Glaxo’s drug.

The data might have looked even better for Pharmacyclics if patients hadn’t been allowed to switch from Arzerra to Imbruvica after their cancer progressed, a decision made by researchers overseeing the trial as results came in, Byrd said.

Side Effects

Side effects were similar between the two groups, Byrd said, though the rates of side effects were higher on Imbruvica because they were on the drug longer. Imbruvica is easier to use, and is taken as a pill instead of being given intravenously.

The study shows that Imbruvica “has significant efficacy and is well-tolerated,” Olatoyosi Odenike, an oncologist at University of Chicago Medicine. “These results provide a compelling new treatment option for patients with chronic lymphocytic leukemia, including older adults with the disease, and will significantly change practice,” she said in a statement announcing the results.