Merck KGaA and Pfizer’s cancer immunotherapy Bavencio (avelumab) has failed to meet its primary endpoint in a lung cancer trial.

In the Phase III JAVELIN Lung 200 trial comparing avelumab to docetaxel in patients with unresectable, recurrent or metastatic non-small cell lung cancer (NSCLC) whose disease progressed after treatment with a platinum-containing doublet therapy, the drug did not meet its prespecified endpoint of improving overall survival in patients with PD-L1+ tumours.

In a statement Merck added that the proportion of patients in the chemotherapy arm crossing over to immune checkpoint inhibitors outside the study was higher than previously reported in post-platinum immunotherapy clinical trials, and this may have confounded this trial outcome.

However, improvements in OS versus the control arm were observed in the moderate-to-high PD-L1+ expression and high PD-L1+ expression population.

“We are committed to understanding the data in the context of the subpopulations and the impact of access to other immune checkpoint inhibitors,” said Chris Boshoff, senior vice president and head of immuno-oncology, early development and translational oncology, Pfizer Global Product Development. “We will continue to progress the broad avelumab program, exploring various indications.”