|The following article features coverage from the American Society of Clinical Oncology 2019 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Administering adjuvant ipilimumab may improve overall survival in patients with resected high-risk melanoma, according to the findings of a randomized phase 3 trial presented at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois.
In the study (ClinicalTrials.gov identifier: NCT01274338), 523 patients were randomized to receive ipilimumab 3 mg/kg, 636 were randomized to receive high-dose interferon-α2b, and 511 were randomized to receive ipilimumab 10 mg/kg. Patients in the first group received induction low-dose ipilimumab every 3 weeks for a total of 4 courses followed by maintenance low-dose ipilimumab every three months for a maximum of 4 courses. Patients in the second group received high-dose interferon-α2b for 1 month followed by maintenance high-dose interferon-α2b, 3 times per week for 11 months. Patients in the third group received induction high-dose ipilimumab every 3 weeks for a total of 4 courses followed by maintenance high-dose ipilimumab every 3 months for a maximum of 4 courses. The researchers evaluated each type of treatment for safety and efficacy. Primary end points were overall survival and relapse-free survival.
When the researchers compared overall survival in ipilimumab 3 mg/kg group with the high-dose interferon-α2b group, they found that ipilimumab 3 mg/kg yielded better results; 5-year overall survival was 0.72 (95% CI, 0.68-0.76) in the low-dose ipilimumab group compared with 0.67 (95% CI, 0.62-0.72) in the other group.
When the investigators compared overall survival in the ipilimumab 10mg/kg group with the high-dose interferon-α2b group, they identified a trend toward improvement in overall survival in the ipilimumab 10 mg/kg group but those trends were not statistically significant.
When the researchers compared relapse-free survival (RFS) in the ipilimumab 3 mg/kg group with the high-dose interferon-α2b group, they found that median RFS in the ipilimumab group was 4.5 years compared with 2.5 years in the other group. In a comparison between higher-dose ipilimumab and high-dose interferon-α2b group, there was a trend toward improvement in the ipilimumab group but it was not statistically significant.
The researchers found that 37% of patients who received ipilimumab 3 mg/kg experienced grade 3 or higher adverse events compared with 79% of patients who received high-dose interferon-α2b and 58% of patients who received ipilimumab 10 mg/kg. In addition, 35% of patients who received ipilimumab 3 mg/kg experienced adverse events of any grade that led to discontinuation of treatment compared with 20% of patients who received high-dose interferon-α2b and 54% of those who received ipilimumab 10 mg/kg. Of all grade 5 adverse events that were at least possibly related to treatment, 3 occurred in the ipilimumab 3 mg/kg (ipi3) group, 2 occurred in the high-dose interferon-α2b group, and 8 occurred in the ipilimumab 10 mg/kg group.
“For the first time in the adjuvant therapy of melanoma, E1609 has demonstrated significant improvement of overall survival with ipi3 against an active control regimen previously shown to have both [overall survival] and [relapse-free survival] benefits,” said lead study author Ahmad A. Tarhini, MD, PhD, acting professor in the department of hematology and medical oncology at Emory University School of Medicine, Atlanta.
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Tarhini AA, Lee SJ, Hodi FS, et al. United States Intergroup E1609: A phase III randomized study of adjuvant ipilimumab (3 or 10 mg/kg) versus high-dose interferon-α2b for resected high-risk melanoma. Presented at: 2019 American Society of Clinical Oncology (ASCO) Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract 9504.