Bristol-Myers Squibb’s checkpoint inhibitors Opdivo and Yervoy are together more powerful against melanoma than the latter alone, according to Phase III data presented at the American Society of Clinical Oncology conference in Chicago.

Findings from CheckMate-067 showed that both the combination of Opdivo (nivolumab)/Yervoy (ipilimumab) and Opdivo monotherapy demonstrated superiority to Yervoy, the current standard of care, for the co-primary endpoint of progression-free survival (PFS). 

Median PFS was 11.5 months for the Opdivo/Yervoy arm and 6.9 months for Opdivo, versus 2.9 months for Yervoy. And sparking much excitement the combination demonstrated a 58% reduction in the risk of disease progression compared to Yervoy, while Opdivo cut the risk by 43%.

Side effects with the combo were slightly higher, with the treatment-related adverse event rate 95.5% for the Opdivo/Yervoy regimen compared to 82.1% for Opdivo and 86.2% for Yervoy, though most were resolved, the firm noted. 

Opdivo’s potential in non-squamous NSCLC takes a hit

On a more disappointing note, data from CheckMate-057 have taken the shine off of Opdivo’s potential in non-small cell lung cancer (NSCLC). 

The drug, which bagged a US nod for use in second-line squamous NSCLC patients in March, was shown to be much less effective in patients with low levels of PD-L1, which account for about half of non-squamous NSCLC patients and thus could hamper approval for this much bigger population.

Overall, Opdivo decreased risk of progression or death by 27% compared to standard of care, but in those with a PD-L1 expression level of more than 10% given the drug mean overall survival was 19.4 months versus 8 months in the chemo arm, while for those with less than 10% the figures were 9.9 months and 10.3 months, respectively.

Industry observers had largely expected Opdivo to be effective regardless of PD-L1, though results from the trial make it very likely that, if approved, only patients expressing higher levels of the protein would be eligible for treatment, substantially slashing its commercial potential.

But benefit confirmed in squamous NSCLC 

Meanwhile the firm also presented data from CheckMate-017 confirming the Opdivo’s benefit in squamous NSCLC patients, showing an overall survival rate of 42% versus 24% for docetaxel after one year, with a median overall survival of 9.2 months versus six months, respectively, and a 41% reduction in the risk of death.