GlaxoSmithKline’s struggling respiratory division has had more bad news, with new product Breo/Relvar failing to improve survival in a trial involving patients with chronic obstructive pulmonary disease (COPD).
The results are a blow to GSK’s ambition to position Breo (fluticasone furoate/vilanterol) as a successor to its big-selling Seretide/Advair (fluticasone/salmeterol) brand, the company’s biggest-selling drug with sales of £1.86bn ($2.86bn) in the first six month of the year.
GSK’s cash cow has seen around $1.5bn wiped off its annual sales since a peak in 2013 because competition from other combination products in the COPD and asthma sectors is driving down pricing, while direct generic competition is also looming with patent expiries in the US due in 2017.
Sales continued to slide (by 14%) in the first six half, and newer drugs like Breo and Anoro (umeclidinium bromide/vilanterol) are not growing quickly enough to compensate, mainly because they have not been able to generate a compelling argument to displace established, cheaper drugs.
The company and Breo development partner Theravance had hoped the large-scale SUMMIT trial would show a clear benefit for the drug on survival and kickstart sales, which were £94m in the first six months of 2015.
The study – which involved 16,485 COPD patients with moderate airway restriction – showed that Breo reduced the risk of dying by around 12% compared to placebo, although this was not a statistically significant improvement.
GSK’s drug was able to reduce the rate of lung function decline but the company noted that “as the primary endpoint was not met, statistical significance cannot be inferred from this result.” A non-significant 7% reduction in a cardiovascular event such as a heart attack or stroke was also seen.
Some analysts have said the results are not that surprising, considering Advair also failed to improve survival in the earlier TORCH trial in COPD, but it seems likely that the outcome will lead to reductions in forecasts for Breo’s peak sales.
The disappointment also comes after Breo was approved for asthma only in adults in the US, with the FDA following its advisory committee’s advice and rejecting use of the drug in children aged 12 to 17 without additional safety data.
GSK is also developing a three-drug combination combining the three active ingredients in Breo and Anoro that is in a phase III trial called IMPACT.