PD-1 Checkpoint Inhibitor Opdivo First to Demonstrate Survival Benefit in Phase III

source: The Cancer Letter, December 2014

A study comparing Opdivo to dacarbazine chemotherapy in treatment naïve advanced melanoma patients marks first PD-1 immune checkpoint inhibitor to demonstrate a survival benefit in a phase III trial.

The trial, CheckMate-066, met its primary endpoint of overall survival, with median OS not reached in the Opdivo (nivolumab) arm, compared to 10.8 months in patients receiving dacarbazine chemotherapy.

The one-year survival rate was 73 percent for Opdivo vs. 42 percent for DTIC, and there was a 58 percent decrease in the risk of death for patients treated with Opdivo (HR: 0.42, p<0.0001).

The trial enrolled 418 patients with treatment naïve BRAF wild-type advanced melanoma, and the survival benefit was observed in both PD-L1 positive and PD-L1 negative patients treated with Opdivo.

The rate of objective response was significantly higher for Opdivo than dacarbazine, at 40 percent and 14 percent, respectively—and it included a higher percentage of complete responses, at 7.6 percent compared to 1 percent.

The data was published in The New England Journal of Medicine and presented during an oral session at the Society for Melanoma Research 2014 International Congress in Zurich, Switzerland.

The trial enrolled 418 patients who were randomized to receive either Opdivo 3 mg/kg every two weeks (n=210) or DTIC 1000 mg/m2 every three weeks (n=208). Treatment continued until there was disease progression or an unacceptable level of toxicity. Thirty-eight percent of patients in the DTIC arm received Yervoy (ipilimumab) after stopping study treatment.