UPDATE 2-US panel backs Seattle Genetics drug for Hodgkin's 1:40pm EDT * FDA panel votes 10-0 to approve drug for Hodgkin's
* Still to vote for use vs anaplastic large cell lymphoma
* FDA to make final decision by Aug. 30
* Seattle Genetics shares halted ahead of meeting (Adds quotes from panel members, byline)
By Anna Yukhananov
SILVER SPRING, Md., July 14 (Reuters) - A U.S. advisory panel backed an experimental drug from Seattle Genetics Inc (SGEN.O: Quote, Profile, Research, Stock Buzz) for treating patients with Hodgkin's lymphoma who have already tried a stem cell transplant to treat the relatively rare type of blood cancer.
The Food and Drug Administration advisory committee unanimously voted on Thursday to recommend accelerated approval of the drug, to be marketed under the proposed name of Adcetris.
About 9,000 Americans are diagnosed with Hodgkin's lymphoma each year, but the limitation to those who have already tried a stem cell transplant could also limit sales.
The expert panel will decide later on Thursday if the drug should also be approved for anaplastic large cell lymphoma (ALCL), an even rarer type of blood cancer.
The FDA usually follows the recommendations of its advisory panels and is due to make a final decision on the drug by Aug. 30. Seattle Genetics shares were halted ahead of the panel meeting.
Howard Liang, an analyst at Leerink Swann, sees U.S. sales at more than $400 million for both types of cancer in 2015.
Under accelerated approval for Hodgkin's lymphoma, Seattle Genetics must conduct at least one follow-up trial to confirm the drug is safe and effective before receiving full approval.
"No one is debating the level of activity of this drug," said panel chairman Dr. Wyndham Wilson, chief of the lymphoma therapeutics section at the National Cancer Institute.
"This to me seems the perfect example of a drug that should be approved under accelerated approval."
In mid-stage trials, three-quarters of patients had some tumor shrinkage after taking Adcetris for Hodgkin's and about a third had complete remission, or disappearance, of the disease.
FDA staff reviewers had suggested narrowing the approved patient group for the drug in documents released on Tuesday, sending Seattle Genetics shares down 3.6 percent. [ID:nN1E76B0AB]
Some advisory panel members said on Thursday the drug should be tested on all treated patients in future trials, not just those who have had stem cell transplants.
"Looking at the complete remission rate, this should go head to head with transplants in some fashion," said panel member Dr. Deborah Armstrong, associate professor of oncology at the Johns Hopkins School of Medicine. (Reporting by Anna Yukhananov; editing by Tim Dobbyn and Andre Grenon)