It can pay to play with the FDA when it needs help with drug shortages. In a push to ease a months-long shortage of Johnson & Johnson's ($JNJ) cancer drug Doxil, the FDA fast-tracked a generic from Sun Pharma, approving it Monday.

Since February, the FDA had been allowing Sun to import its unapproved version of the Doxil substitute as one way for the agency to address the shortage. 

Doxorubicin hydrochloride liposome injection sits on the FDA's drug shortage list, meaning the regulatory agency's Office of Generic Drugs can use a priority review system to bump a generic application for the drug to the front of the line. Sun's product, which will be available in 20-mg and 50-mg vials, will help patients who suffer from ovarian cancer, AIDS-related Kaposi's sarcoma and multiple myeloma.

Manufacturing problems at Ben Venue Laboratories, a unit of Boehringer Ingelheim that makes Doxil, forced the contractor to suspend operations in November 2011, exacerbating supply issues for the drug. By February 2012, FDA Commissioner Margaret Hamburg had called upon Sun Pharma to import Lipodox, a Doxil substitute that the FDA had not approved. The company manufactured the injection at an FDA-approved facility in India.