FDA posts Cayston briefing documents

FDA posted briefing documents ahead of Thursday's Anti-Infective Drugs Advisory Committee meeting to discuss an NDA from Gilead Sciences Inc. (NASDAQ:GILD) for Cayston inhaled aztreonam lysine to improve respiratory symptoms and pulmonary function in cystic fibrosis patients with Pseudomonas aeruginosa infections. Last year, Gilead received a complete response letter for Cayston in which FDA requested an additional trial to establish the compound's efficacy. Gilead responded to the letter by submitting a reanalysis of data from the double-blind, placebo-controlled Study CP-AI-005, one of the two Phase III trials on which the NDA was based. In its briefing documents, the agency raised additional concerns related to the reanalysis, including the use of a post hoc analysis and the strength of the evidence. The agency also raised concerns about an imbalance in the number of subjects who received placebo vs. Cayston in Study CP-AI-005, which was due to a higher dropout rate in the Cayston arm.

The panel will be asked whether the data support the efficacy and safety of 75 mg thrice-daily Cayston for the indication and whether Gilead has identified the correct dose and regimen for the compound. ...