Idelalisib withdrawn from U.S. market for relapsed FL and relapsed SLL indications

Less than a decade after the kinase inhibitor idelalisib received accelerated approval by the U.S. Food and Drug Administration (FDA) for the treatment of relapsed follicular B-cell non-Hodgkin lymphoma (FL) and relapsed small lymphocytic lymphoma (SLL), the two indications have been voluntarily withdrawn from the U.S. market.¹ The approval was based on a phase II study in indolent non-Hodgkin lymphoma demonstrating that 54% of those with FL and 58% of those with SLL achieved an objective response as assessed by an independent review committee. Nevertheless, a regulatory review of the drug's safety was launched by the European and U.S. regulators due to concerns over serious adverse events, including deaths.

Continued approval for these indications was dependent upon providing additional evidence establishing clinical benefit in FL and SLL. However, as the treatment landscape for FL and SLL has evolved over the years, enrollment into the confirmatory study was an ongoing challenge.

Idelalisib was also approved in 2014 to treat relapsed chronic lymphocytic leukemia, in combination with rituximab, and will continue to be sold in the U.S. market for this indication. In the European Union, United Kingdom, Canada, Australia, New Zealand, and Switzerland, the agent has marketing authorization to treat chronic lymphocytic leukemia and FL.