Adjuvant PEG-IFN alfa-2b shows modest RFS benefit in melanoma
Adjuvant pegylated interferon alfa-2b offered marginal improvements in relapse-free survival but no significant improvement in other survival outcomes in a cohort of patients with melanoma, according to results from the phase 3 EORTC 18991 trial.
The randomized trial examined adjuvant pegylated interferon (PEG-IFN) alfa-2b in 1,256 patients with resected stage III melanoma. Researchers assigned 627 patients to the treatment group and 629 to observation for an intended duration of 5 years.
Alexander M. M. Eggermont, MD, PhD, general director of the Institut de Cancérologie Gustave Roussy in France, and colleagues stratified patients with regard to microscopic or macroscopic nodal involvement, the number of positive nodes, ulceration and tumor thickness, sex and center.
RFS served as the primary endpoint. Researchers also conducted an intention-to-treat analysis for distant metastasis-free survival and OS.
At 7.6 years of follow-up, there were 384 recurrences or deaths in the study treatment group and 406 in the observation group (HR=0.87; 95% CI, 0.76-1.00).
At the 7-year mark, RFS rates were 39.1% in the PEG-IFN group and 34.6% in the observation group. The researchers observed no difference with regard to OS (P=.57).
Among patients with stage III microscopic ulcerated melanoma, adjuvant PEG-IFN alfa-2b was associated with improvements in RFS (HR=0.72; 99% CI, 0.46-1.13), distant metastasis-free survival (HR=0.65; 99% CI, 0.41-1.04) and OS (HR=0.59; 99% CI, 0.35-0.97).
Adjuvant PEG-IFN alfa-2b was discontinued due to toxicity in 37% of the study population.
“What is critically lacking is new insight into the optimal duration of therapy and predictors of which patients may derive the greatest benefit from therapy,” Ahmad A. Tarhini, MD, an assistant professor in the department of medicine at the University of Pittsburgh and an investigator with the University of Pittsburgh Cancer Institute’s melanoma program, wrote in an accompanying editorial. “EORTC 18991 has not shed new light on this question, which was the initial impetus for this trial.”