Sunday, June 5, 2011

Two Melanoma Drugs Prolong Survival For Some Patients

Two therapies showed success in prolonging survival of newly diagnosed patients with melanoma, a deadly form of skin cancer.

The drugs--Yervoy from Bristol-Myers Squibb Co. (BMY), and vemurafenib from Roche Holding AG (RHHBY) and Daiichi Sankyo Co. (4568.TO)--use sharply different methods of treating the disease. While both showed a benefit, the results from Yervoy--showing a two-month survival benefit--may disappoint those with high expectations following the drug's success in an earlier study and its Food and Drug Administration approval earlier this year.

Both studies were simultaneously published in the New England Journal of Medicine on Sunday.

"They are both important because they offer a survival benefit, but it now becomes a questions of how do you build upon both of them?" Stephen Hodi, director of the melanoma center at Dana Farber Cancer Institute said.

He said that studies need to be conducted to find the best way of using the drugs in patients that are eligible to use both. Until more is known, he will have conversations with his patients about the known data in order to decide how they want to proceed. It is too dangerous to attempt using them at the same time until that combination is tested.

There were 68,130 new cases of melanoma in the U.S. last year, with about 8,700 deaths, according to the National Cancer Institute. To be cured, the disease needs to be caught early. Patient with advanced forms of the disease typically live less than a year after diagnosis.

But those patients got a new option in March when the FDA approved Yervoy in all patients with the disease, despite expectations that it would be approved initially as a second-line treatment. The data in that setting were the basis of Bristol's application. The data Sunday were the first details of the drug's effectiveness as firstline treatment.

Yervoy works by bolstering the body's immune system to fight the disease, but the latest data may be disappointing to some on Wall Street that were expecting more-robust results from Yervoy.

The median overall survival was 11.2 months for Yervoy patients also on chemotherapy against 9.1 months on chemotherapy.

Last month, Goldman Sachs analysts projected that the survival benefit would be "at least four months" and Cowen & Co. recently cited consultants that made a similar projection.

In data that were released at last year's ASCO meeting, Yervoy extended average overall survival to 10 months from nearly 6.5 months in those that didn't get the drug, in a population of previously treated patients.

Michael Giordano, head of development for oncology and immunology at Bristol-Myers, said the company is "very delighted" with the success of the drug in prolonging lives.

"We aren't in any way disappointed with the results," he said in an interview.

Giordano said the reason for the difference in the two trials isn't known. He noted that some researchers have speculated that the difference in the survival results could be influenced by the accompanying chemotherapy regimen or differences in the patient population.

"The important thing is that some patients have a long-term benefit," Hodi said of Yervoy.

In the latest data, a study of 502 patients, Yervoy did show a long-term benefit. After three years, about 21% of patients getting the drug were still living compared to about 12% of the those getting chemotherapy alone.

On Yervoy, patients had little change in progression-free survival. Researchers attributed this to the drug needing more time to show its effects, thus making overall survival a "more accurate way to gauge treatment effectiveness."

Yervoy is known to have some severe side effects in certain patients, including risks of fatal allergic reactions.

Roche's vemurafenib works in a very different way, by blocking a genetic mutation known as BRAF, which may help the disease grow. Roche, which developed a diagnostic test for BRAF, recently submitted the drug and test for approval in both the U.S. and Europe.

On Sunday, Roche said that it received priority review from the agency, expecting a decision in late October.

In a trial of vemurafenib, the drug improved both overall survival and progression-free survival--the time from treatment until death or disease resumption--when compared to standard chemotherapy.

The study, including 675 patients with the BRAF mutation, showed that patients had a 63% reduction in the risk of death after three months. The study also found that 48.4% of those getting vemurafenib had a response compared to 5.5% of those in the chemotherapy group.

After six months, 84% of the patients on the drug were still alive compared to 64% of those on only chemotherapy.

The median overall survival can't be determined yet, but an estimate earlier this year showed survival of 10.5 months for patients on vemurafenib compared to 7.8 months on just chemotherapy.

The data were collected at an interim analysis, after which the patients on chemotherapy were offered the option to begin taking the drug because of its observed effectiveness.

The most common side effects in the study were skin rashes, light sensitivity, and joint pain, with 18% of patients developing a low-grade non-melanoma skin tumor that is easily treated, according to updated data.

Chris Bowden, vice president of oncology product development at Genentech, said the success of both drugs marks "the end of the beginning" for new treatment in melanoma after decades without new hope.

Last week, Bristol-Myers and Roche agreed to conduct a study of the two drugs in patients with the BRAF mutation and may further develop the combination based on those results.

Separately, early stage data presented earlier in the meeting showed GlaxoSmithKline PLC's (GSK, GSK.LN) own BRAF inhibitor GSK436 was safe and effective when used in combination with an experimental drug called a MEK inhibitor, GSK212. Roche is also studying vemurafenib with its investigational a MEK inhibitor GDC-0973, in patients who previously received vemurafenib alone.