Looking at 6.5 years of follow-up data from the phase 3 CheckMate-067 trial shows maintained outcomes in patients with advanced melanoma on nivolumab alone, or with ipilimumab.
Nivolumab (Opdivo) monotherapy, or in combination with ipilimumab (Yervoy), continued to demonstrate durable improvements in overall survival (OS) compared with ipilimumab alone in patients with previously untreated advanced melanoma, according to 6.5 years of follow-up data presented during the 2021 virtual ASCO Annual Meeting.1
The long-term data of the phase 3 CheckMate-067 trial (NCT01844505) showed that the median OS with the combination was 72.1 months (95% CI, 38.2–not reached) and 36.9 months with nivolumab alone (95% CI, 28.2-58.7), compared with 19.9 months with ipilimumab alone (95% CI, 16.8-24.6). This is reportedly the longest median OS in phase 3 clinical trial of advanced melanoma.
Additionally, the 6.5-year progression-free survival (PFS) rate was 34% with nivolumab and ipilimumab and the median PFS was 11.5 months. The rates were 29% and 7% with nivolumab and ipilimumab as single agents, respectively; the median PFS was 6.9 months and 2.9 months, respectively.
“The sustained OS and PFS benefit shown with nivolumab-based treatment, particularly the nivolumab plus ipilimumab combination, has changed the way we look at long-term efficacy outcomes for patients with advanced melanoma,” Jedd D. Wolchok, MD, PhD, FASCO, lead author and chief of the Immuno-Oncology Service, Human Oncology and Pathogenesis Program, at Memorial Sloan Kettering Cancer Center, stated in a press release.2 “These new results from the CheckMate-067 trial, with nearly half of patients treated with the nivolumab and ipilimumab combination surviving to 6.5 years, confirm the durable, sustained benefit of the combination in patients with advanced melanoma.”
In 2015, the FDA approved the combination of nivolumab and ipilimumab for the treatment of patients with metastatic melanoma, based on earlier findings from CheckMate-067. Nivolumab is also approved for use as a single agent in this patient population.
In the double-blind, phase 3 CheckMate-067 study, investigators randomized patients with previously untreated unresectable advanced (stage III or IV) melanoma 1:1:1 to receive the combination of nivolumab at 1 mg/kg and ipilimumab at 3 mg/kg for 4 doses, followed by nivolumab at 3 mg/kg every 2 weeks (n = 314), nivolumab alone at 3 mg/kg every 2 weeks plus placebo (n = 316), or ipilimumab alone at 3 mg/kg every 3 weeks for 4 doses plus placebo (n = 315). Treatment was administered until disease progression or unacceptable toxicity.
Patients were stratified by PD-L1 status, BRAF mutational status, and metastasis stage.
The co-primary endpoints of the trial were PFS and OS; secondary endpoints included objective response rate, descriptive efficacy assessments, and safety.
At the 6.5-year analysis, 49% of patients were alive and in follow-up. Of this percentage, 77% of patients who were treated with nivolumab plus ipilimumab were reported to be off of therapy and did not receive subsequent systemic treatment. Sixty-nine percent of those on nivolumab alone, and 43% of those on single-agent ipilimumab also have been off of treatment and did not require subsequent systemic therapy.
The clinical benefit was sustained and observed with both nivolumab/ipilimumab and nivolumab alone across relevant key subgroups, which included those with BRAF-mutant and BRAF wild-type tumors, and patients with baseline liver metastases.
In patients with BRAF wild-type melanoma, the OS rate was 46% in those who received the combination, 42% for nivolumab alone, and 22% for ipilimumab alone. In those with liver metastases, the OS rates were 38%, 31%, and 22% for the combination, nivolumab monotherapy, and ipilimumab monotherapy, respectively.
In the combination arm, as well as in the single-agent nivolumab arm, the median duration of response (DOR) has still not yet been reached; the median DOR was 19.2 months for those on the ipilimumab arm.
Regarding safety, the profile of nivolumab and ipilimumab combined was found to be consistent with prior data of the regimen and no new safety signals were observed. No additional treatment-related deaths had occurred since the 5-year analysis of CheckMate-067.
Grade 3/4 treatment-related adverse events (TRAEs) occurred in 59% of patients on the nivolumab/ipilimumab arm, in 24% on the nivolumab-alone arm, and in 28% of patients on the ipilimumab arm.
“These results build upon our decade-long legacy in treating melanoma, which began when the average life expectancy following a diagnosis of metastatic melanoma was roughly six months and less than 10% of patients survived beyond five years,” stated Gina Fusaro, development lead, melanoma, Bristol Myers Squibb.2 “With some of the longest follow-up with immunotherapies to date, Opdivo and Yervoy have consistently demonstrated durable, long-term survival benefits for patients diagnosed with advanced melanoma.”
Previously, 5-year follow-up findings from CheckMate-067, which were published in the New England Journal of Medicine, showed that the median OS with nivolumab/ipilimumab was not reached and was 36.9 months with nivolumab alone, compared with 19.9 months with ipilimumab alone (HR, 0.52 for nivolumab/ipilimumab vs ipilimumab; HR, 0.63 for nivolumab vs ipilimumab). The median follow-up was 60 months.
At 5 years, the OS rate was 52% with nivolumab plus ipilimumab, 44% with nivolumab alone, and 26% with ipilimumab alone.