Jedd D. Wolchok, MD, discusses the implications of the expanded FDA approval of nivolumab, and the potential for the PD-1 inhibitor as both a single agent and as part of a combination regimen in advanced melanoma
Jedd D. Wolchok, MD, PhD
The FDA recently granted an expanded approval to nivolumab (Opdivo) as a single agent and in combination with ipilimumab (Yervoy) for the treatment of patients with melanoma who harbor BRAF V600 mutations. As a result of the expansion, nivolumab is now available as a frontline treatment for all patients with advanced melanoma, regardless of BRAF status.
The approval was based on the 3-arm CheckMate-067 study, in which the dual checkpoint inhibitor combination reduced the risk of progression by 58% compared with ipilimumab alone (HR, 0.42; P <.0001) in patients with advanced melanoma. Single-agent nivolumab reduced the risk of progression by 43% versus ipilimumab (HR, 0.57; P <.0001).
The trial randomized 945 patients with untreated unresectable or metastatic melanoma to receive nivolumab (n = 316), ipilimumab (n = 315), or nivolumab plus ipilimumab followed by nivolumab (n = 314).
In the monotherapy arms, nivolumab was administered at 3 mg/kg every 2 weeks and ipilimumab was administered at 3 mg/kg every 3 weeks. In the combination arm, nivolumab at 1 mg/kg was administered with 3 mg/kg of ipilimumab every 3 weeks for 4 doses followed by 3 mg/kg of nivolumab every 2 weeks.
Patients were stratified by M-stage, PD-L1 status, and BRAF mutation status. Approximately one-third of patients were BRAF-mutation positive. The coprimary endpoints were progression-free survival (PFS) and overall survival, with objective response rate, safety, and other measures as secondary endpoints.
At more than 9 months of follow-up, the median PFS was 11.5 months for the combination, 6.9 months for nivolumab monotherapy, and 2.9 months for single-agent ipilimumab. Outcomes were similar regardless of BRAF mutation status.
To better understand the implications of the expanded approval and the potential for nivolumab as both a single agent and as part of a combination regimen in advanced melanoma, OncLive spoke to the CheckMate-067 lead investigator Jedd D. Wolchok, MD, PhD, chief, Melanoma and Immunotherapeutics Service, Department of Medicine and Ludwig Center at Memorial Sloan Kettering Cancer Center.Wolchok: The approval brings the combination regimen to approximately twice as many patients on-label, now that the BRAF status is no longer considered.Fortunately, there are now numerous medications available for patients with metastatic melanoma harboring a BRAF V600 mutation. These include 2 different combinations of BRAF and MEK inhibitors, the nivolumab combination, monotherapy with each agent, and pembrolizumab monotherapy.The combination of nivolumab plus ipilimumab produces significantly longer progression-free survival compared with ipilimumab alone. The phase III CheckMate-067 trial was not powered for a formal comparison of the combination with nivolumab alone; however, the hazard ratio for progression-free survival was 0.74 in favor of the combination.
In general, immunotherapy yields durable responses and the initial data from this trial showed that median duration of response was not reached in any of the 3 groups—ipilimumab, nivolumab, or the combination.The combination treatment results in a higher frequency of high-grade adverse events, compared with monotherapy. These are generally reversible with the exception of endocrinopathies, which may require long-term hormone replacement.â€¨â€¨This is best accomplished through a thoughtful discussion of risks and benefits. In a subset analysis, patients whose tumors express lower levels of PD-L1 appear to gain the most with the combination compared with nivolumab alone.This testing can provide a nonbinary assessment of likelihood of response from PD-1 pathway blockade; however, we still need to learn more about the relative importance of expression on tumor cells versus infiltrating immune cells and the most appropriate definition of high/low/no expression.
This testing is a first step in better stratification of likelihood of response. However, in my opinion, it is not yet optimal for determining if a patient with melanoma should or should not receive a specific therapy.It is certainly evolving. Clinical trials are currently exploring PD-1 blockade with nivolumab or pembrolizumab in the postsurgical adjuvant setting, and innovative combinations are being investigated in more advanced disease.
Larkin J, Chiarion-Sileni V, Gonzalez R, et al. Combined nivolumab and ipilimumab or monotherapy in untreated melanoma. N Engl J Med. 2015;373:23-34.