Pfizer wins approval for blood cancer drug Besponsa

Pfizer today won FDA approval for a new targeted drug for the treatment of relapsed or refractory acute lymphoblastic leukemia (ALL). The approval comes at a watershed moment for treating the disease as next-gen treatment options appear on the horizon.

The med, branded Besponsa, took an expedited trip through the regulatory review process, helped by the FDA’s breakthrough therapy and orphan drug designations. It had won a priority review in February. The drug carries a boxed warning that severe liver damage occurred in some patients that were given the targeted therapy.

But as the FDA’s Richard Pazdur, head of the FDA’s Oncology Center of Excellence, pointed out in a statement, "For adult patients with B-cell ALL whose cancer has not responded to initial treatment or has returned after treatment, life expectancy is typically low."

The FDA said nearly 6,000 people in the U.S. will be diagnosed with ALL this year and about 1,440 will die from the disease.

"The approval of Besponsa is an important step forward for adult patients with relapsed or refractory B-cell acute lymphoblastic leukemia, a rare disease that can be fatal within a matter of months if left untreated," Liz Barrett, global president, Pfizer Oncology, said in a release.  

There have been other developments in treating the disease. An FDA panel last month unanimously endorsed Novartis' CAR-T drug which offers the chance of a cure for some people. The panel gave it a thumbs up for patients aged 3 to 25 with relapsed/refractory B-cell ALL. If approved it will be the first CAR-T on the market, but is being chased by one from Kite Pharma.

The drugs are an entirely new class of individualized treatments manufactured from a patient's own T cells. They come with some risks and are expected to receive narrow approvals at first.

Following the vote, one panelist said the CAR-T treatment was among the most exciting treatments he’s seen in his lifetime. Another called it a "major advance" that’s "ushering in a new era of treatment."

But those drugs have yet to win approval, while Besponsa has. The approval of Pfizer’s new drug was based on a randomized trial in which patients received either the drug or an alternative chemotherapy regimen. Among other things, the trial measured the percentage of patients with complete remission. Of the 218 evaluated patients, 35.8% who received Besponsa experienced complete remission for a median 8.0 months; compared to 17.4% getting the chemo, which resulted in a median 4.9 months.