The FDA has issued a “not approvable” letter for GlaxoSmithKline’s sNDA for the 500/50 strength of Advair Diskus for the treatment of chronic obstructive pulmonary disease (COPD). Specifically, the agency questioned how the new dose compared to the currently approved 250/50 strength in order to allow for appropriate dosing recommendations. GSK will be meeting with FDA to discuss this request and determine next steps, including discussion of GSK’s recent data on the reduct...