A panel of federal cancer experts has unanimously voted to grant accelerated approval to Seattle Genetics' innovative chemotherapy drug for two types of rare blood cancer.

WASHINGTON — A panel of federal cancer experts has unanimously voted to grant accelerated approval to Seattle Genetics’ innovative chemotherapy drug for two types of rare blood cancer.

All 10 members of the Food and Drug Administration’s oncology drug panel voted in favor of approving the drug based on a study of each in patients with Hodgkin’s disease and a type of lymphoma. Regular drug approval normally requires two late-stage trials for each indication. The FDA is not required to follow the group’s advice, though it usually does.

“This drug has extremely exciting activity and is a great example of the kind of drug that should go ahead with accelerated approval,” said panel chairman Dr. Wyndham Wilson, of the National Cancer Institute.

The Bothell company has submitted its drug, called Adcetris, as a treatment for patients whose cancer has not responded to other drugs or has returned.

Hodgkin’s disease and systemic anaplastic large cell lymphoma are both rare cancers that affect fewer than 5,000 new U.S. patients each year. The panel voted unanimously in two separate votes that the drug should be made available for patients with the diseases.

Under accelerated approval, drug companies must conduct follow-up studies to confirm that their drugs live up to their initial promise. Seattle Genetics will have to negotiate the size and structure of these confirmatory studies with FDA officials.

Adcetris uses a targeted antibody designed to deliver chemotherapy directly to cancerous tumor cells, sparing healthy cells.

If the drug is ultimately approved, Seattle Genetics will market it in the U.S. and Canada while Takeda Group will hold marketing rights for the rest of the world.

The product, which would be Seattle Genetics’ first commercialized drug, could generate peak sales of $850 million in 2020 if cleared for both uses, Rachel McMinn, an analyst with Bank of America Merrill Lynch, said last month in a note.

The FDA hasn’t approved a new drug for Hodgkin’s lymphoma since 1977, Seattle Genetics Chief Operating Officer Eric Dobmeier said. The companies haven’t announced pricing for the drug yet.

Trading in shares of Seattle Genetics was halted Thursday due to the pending panel vote.

The information from analyst McMinn and Seattle Genetics’ Dobmeier is from Bloomberg News