The FDA approved two drugs for rare bone marrow cancers: Amgen’s Blincyto for Philadelphia chromosome-negative precursor B-cell acute lymphoblastic leukemia (ALL) and Incyte’s Jakafi for a new indication to treat polycythemia vera.

Blincyto (blinatumomab), the first drug to stimulate the body’s own immune T cells to destroy leukemia cells, is intended for patients who have relapsed or who did not respond to previous treatments, the FDA says. Approval was based on a clinical trial of 185 adults in which 32 percent of patients showed no evidence of disease. The FDA has asked Amgen to conduct further studies to evaluate the drug’s effect on survival rates.

The FDA is requiring a boxed warning to reflect the fact some patients had low blood pressure and difficult breathing due to cytokine release, as well as nervous system difficulties, such as trouble thinking. The drug’s approval also was contingent on a Risk Evaluation and Mitigation Strategy.

The FDA granted Jakafi (ruxolitinib) a second indication for patients who have an inadequate response to or cannot tolerate hydroxyurea chemotherapy. It first was approved in 2011 for patients with intermediate or high-risk myelofibrosis.

Approval was based on a Phase III trial of 222 patients who had been diagnosed with this form of ALL at least six months prior and who had enlarged spleens, could not tolerate hydroxyurea and had undergone a phlebotomy. Results showed that not only did more patients given Jakafi show a complete response to the drug, but also that they needed fewer phlebotomies and had smaller spleens than did patients given the best available therapy. — Lena Freund

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.