GlaxoSmithKline could reach the end of 2018 without generic competition to its big-selling Advair respiratory drug in the US, after the FDA rejected Novartis’ rival.
Earlier this week GSK said it was factoring in the possibility of generic challengers to the chronic obstructive pulmonary disease (COPD) and asthma blockbuster in the US this year, despite regulatory hold-ups for two other challengers – Mylan and Hikma/Vectura – which are both trying to resolve issues raised in complete response letters (CRLs).
Novartis’ Sandoz subsidiary – which was considered to have leapfrogged them to become the front-runner in the US – has been sent its own CRL from the FDA, which could delay the launch of its generic until 2019.
All three generics have been flummoxed by the complexity of Advair (salmeterol and fluticasone propionate) and the difficulty of showing sufficient equivalence with the Diskus dry powder inhaler used in the product to meet the substitution requirements of the FDA.
Teva won approval for its AirDuo product last year in the US, providing the same active ingredients as Advair but with a lower dose of salmeterol which means it is not a direct generic but a lower-priced branded alternative to GSK’s drug. At the same time Teva also launched an authorised generic of its own brand to try to eat further into Advair’s market share.
In its fourth-quarter results announcement, GSK had suggested that a mid-year introduction of an Advair generic in the US would cut US sales of the drug in half from £1.61bn ($2.24bn) in 2017 to £750m in 2018. The delay to Novartis’ generic therefore looks set to preserve much-needed revenues as the company tries to grow sales of its new products, including new COPD ‘triple’ Trelegy.
The FDA said last year it plans to introduce new measures to accelerate the approval of complex drugs generics, which Commissioner Scott Gottlieb said includes metered dose inhalers used to treat asthma as well as some costly injectable drugs.