Nucala (mepolizumab) was first approved as the first anti-IL5 treatment for adults and adolescents with severe asthma accompanied by eosinophilic phenotype in the United States during November 2015. Later it was approved to treat eosinophilic granulomatosis with polyangiitis (EGPA).

GSK pursued the U.S. approval in eosinophilic chronic obstructive pulmonary disease (COPD) in November 2017, in addition to Phase 3 METREX and METREO data studies. Nucala's crucial rivals in asthma treatment were Teva Pharmaceutical's Cinqair (reslizumab), which was approved for indication in March 2016, and Fasenra in November 2017.

Since COPD is a hard nut to crack, it will be the next market according to the GSK's predictions. Nucala would be used as an add-on maintenance treatment for people with COPD. During May, AstraZeneca withdrew from submitting Fasenra for COPD and Teva is not following this market for Cinqair.

The results of yesterday's panel will be eagerly watched, where the clinical data have been given to the committee members. The role of Nucala as an add-on treatment to lessen the severity of COPD guided by blood eosinophil counts will be focused on while discussing its safety and efficacy.

The discussions will be directed by a series of questions. Efficacy will be the major key factor of the discussion, where several points include the tolerability of dose; the effect of asthma history and previous treatments; the clinical significance of the efficacy data, including the lack of significant results for primary and secondary endpoints. The discussion will focus on the uncertainty of the eosinophilic COPD phenotype and their effect on efficacy.