FDA deals a blow to GlaxoSmithKline's post-Advair hopes with Nucala COPD rebuff

GlaxoSmithKline has big hopes for Nucala, one of the respiratory meds charged with rebuilding the franchise after behemoth Advair finally faces generic competition. Key to those hopes? A new indication in chronic obstructive pulmonary disease (COPD).

Too bad the FDA isn't on board.

Friday, the drug giant said U.S. regulators had stiff-armed Nucala as an add-on treatment for COPD, a much bigger market than the asthma approval it now bears. The rejection wasn't wholly unexpected—an FDA advisory panel voted against approval in June—but sometimes the agency can be persuaded to go against its panels' advice.

Not this time. The agency agreed with its panel in saying there's not enough evidence to support an approval in patients with high levels of eosinophils, a type of white blood cell Nucala targets. In short, GSK will need to come up with more clinical data to show that Nucala is effective for eosinophilic COPD.

"GSK will work closely with the FDA to determine the appropriate next steps," the company said in announcing the rejection, which came in the form of a complete response letter (CRL).

The word from the FDA essentially negates one advantage GSK thought it had over chief respiratory rival AstraZeneca and its rival therapy Fasenra: That drug has repeatedly failed trials in COPD, whereas Nucala had put up enough positive data to underpin an approval application. Had Nucala nabbed the new indication, it wouldn't have had to deal with Fasenra competition, at least not anytime soon.

Nucala brought in £344 million for GSK last year—three times its 2016 sales—and that included £236 million in the U.S. Impressive growth, but compare that with Advair, which delivered £3.1 billion, £1.6 billion of that in the U.S. And consider the fact that GSK is expecting generics to take a huge bite out of that; the company projected Advair sales of just £750 million if U.S. generics hit midyear. They haven't so far, but the projection is telling.

Nucala does have other avenues for growth. It won an approval to treat a rare disease called eosinophilic granulomatosis with polyangiitis last December, and GSK is studying the drug as a treatment with nasal polyps.

But it also faces more potential competition in the form of Regeneron and Sanofi's Dupixent, a biologic that's now approved in severe eczema but is seeking another nod in asthma and under study for nasal polyps, too. The companies see Dupixent as something of a pipeline in a drug for its potential to treat a range of anti-inflammatory diseases. Plus, AZ and Amgen just last week won a breakthrough designation for tezepelumab in severe asthma.