The FDA announced Tuesday that it has approved the Novartis lung cancer drug Zykadia, or ceritinib (previously known as LDK378).

The approval is for patients with anaplastic lymphoma kinase-positive (ALK+) metastatic non-small cell lung cancer (NSCLC), specifically those who were previously treated with Pfizer’s Xalkori (crizotinib). Xalkori is the only other approved ALK tyrosine kinase inhibitor but one which (like many molecular targeted drugs) encounters resistance.

The approval is the fourth drug with the FDA’s Breakthrough Therapy designation to be approved by the agency.

The drug is also considered an orphan product and is notable for its approval speed: the approval deadline was August 24, four months from now.