The Food and Drug Administration is asking one of its panels of outside experts to help it make a decision about GlaxoSmithKline's (GSK -0.44%) request to add data to the label of Trelegy Ellipta, its chronic obstructive pulmonary disease (COPD) drug. The pulmonary-allergy drugs advisory committee will meet on April 21 to discuss whether the claim that Trelegy Ellipta reduces mortality should be added to the drug's label. That would allow the company to use the information in its marketing materials.

Results from the Informing the Pathway of COPD Treatment (IMPACT) clinical trial showed that Trelegy Ellipta reduced the risk of on-treatment all-cause mortality by 42.1% compared to Anoro, which contains two of the three medications in Trelegy Ellipta.

But the FDA seems to be concerned that 70% of patients treated with Anoro in the study were taking inhaled corticosteroids beforehand, and had to go off of them during the trial, which might have affected the results. An editorial in the New England Journal of Medicine chastised the company for the trial's "design peculiarity."

Senior man using an inhaler

Image source: Getty Images.

Investors in Innoviva (INVA 0.49%), which developed the drug back when the company was called Theravance, and licensed it to GlaxoSmithKline, should also be watching the advisory committee meeting since Innoviva gets royalties on sales of the drug.

Investors will get a first look at what the FDA thinks of the claim on April 18 when the agency posts the documents it will send to the committee.