GlaxoSmithKline and partner Human Genome Sciences have announced that Benlysta has failed to hit secondary endpoints in a late-stage trial in patients with the chronic autoimmune disease lupus.

Data from week 76 of the BLISS-76 trial showed that while patients taking Benlysta (belimumab) plus standard of care showed higher response rates than those in the placebo group, the difference was not statistically significant.

On the plus side, the results did add further evidence to support the drug’s safety profile, after the data showed that it was generally well-tolerated with comparable side effects and a similar rate of discontinuations because of them observed across treatment groups, the companies said.

But news of Benlysta’s failure to hit secondary goals will be particularly disappointing as the firms reported back in November that it had met its primary goal in the study, after a significant improvement was shown in patient response rate for the drug versus placebo (43.2% for 10 mg/kg Benlysta, 40.6% for 1 mg/kg Benlysta and 33.8% for placebo) at 52 weeks, fuelling hopes that the drug might become the first treatment to receive approval for lupus in over 50 years.

Filings in second quarter
Still, despite the setback, which indicates that the drug loses efficacy over time, GSK remains confident in its future. “Based on the totality of data in BLISS-52 and BLISS-76, we believe that belimumab could deliver a significant therapeutic option for patients with lupus, a chronic condition which has a devastating effect on the lives of patients living with the disease,” noted Carlo Russo, senior vice president of Biopharm Development at GSK.

The companies said they are working together to submit regulatory applications for Benlysta - a human monoclonal antibody - on both sides of the Atlantic in the second quarter of this year.