Genentech’s leukemia drug Gazyva is the first to be approved under the FDA’s breakthrough therapy designation pathway, paving the way for 30 other breakthrough candidates under review.

Although Gazyva (obinutuzumab) qualified for streamlined review, its development timeline was not affected because the breakthrough designation was not requested and granted until after the Gazyva BLA was already received, FDA spokeswoman Tara Goodin told WDL. The time from its IND application in 2009 to approval was 4.9 years, with five months for a review.

The FDA has asked Genentech for two minor post-marketing commitments related to the commercial manufacturing process, Krysta Pellegrino, a spokesperson for the drugmaker told WDL, adding that the studies are ongoing and will be submitted to the FDA when completed.

Gazyva is designed to boost the immune system’s ability to attack cancer cells, the FDA says. It will be used in combination with chlorambucil, another drug used to treat patients with chronic lymphocytic leukemia (CLL).

Approval was based on clinical studies of 356 people. Those receiving both Gazyva and chlorambucil had an average of 23 months of progression-free survival compared to 11.1 months among participants who received chlorambucil alone, the FDA said.

The drug comes with a boxed warning about risks of hepatitis B virus reactivation and a rare brain disorder known as progressive multifocal leukoencephalopathy.

This may be just the first of Genentech’s breakthrough candidates to gain approval. The drugmaker in May received the coveted designation for obinutuzumab to treat CLL. The nod was based on data from a Phase III trial that showed a statistically significant drop in CLL risk when treated with obinutuzumab and chlorambucil, compared with chlorambucil alone (WDL, July 15).

Last week’s announcement follows another first-to-the-finish-line break for the Roche subsidiary, as last month Genentech’s breast cancer drug Perjeta (pertuzumab) was the first drug to gain approval via the FDA’s new accelerated approval pathway carved out for early-stage breast cancer before surgery (WDL, Oct. 7).

As of Oct. 25, CDER has granted 30 of 100 requests for breakthrough therapy designation. The FDA is required to issue final guidance detailing the benefits of breakthrough therapy designations by January 2014. Draft guidance was issued in June (WDL, July 1). — Nick Otto