Toxicity and outcomes of ipilimumab plus nivolumab in patients 80 years and older.

Abstract

12051 Background: The combination of ipilimumab and nivolumab (Ipi-Nivo) is a standard of care regimen in many malignancies. However, immune-related adverse events (irAE) are common and are of great concern, especially when treating the elderly population. This subgroup of patients may be at greater risk for serious irAEs and be less able to tolerate the potential treatment side effects. We sought to retrospectively evaluate our experience treating elderly patients ≥ 80 years with Ipi-Nivo to characterize adverse events. Methods: A retrospective chart review of the electronic medical records of all patients treated with Ipi-Nivo at the Mayo Clinic Health System was performed. Patients with any solid tumor who received their first dose of Ipi-Nivo at the age of ≥ 80 were included. Records were analyzed for baseline characteristics, cancer type, toxicity, and response to therapy. Differences between continuous and categorical variables were assessed using the students’ t-test and the chi-squared test, respectively. Overall survival (OS) was estimated using the Kaplan-Meier method. Cox proportional hazard models assessed the relative contribution of factors to survival after treatment. P values < 0.05 were considered statistically significant. All analyses were performed using SAS V.9.4. Results: Forty-six patients met inclusion criteria, 13 females and 33 males. Median age of first dose was 83 (Range: 80 - 94). Sixty-seven percent had an ECOG performance status (PS) 0-1 and 33% had an ECOG PS 2-3. Thirteen (28.3%) patients received 4 cycles of Ipi-Nivo. Cancers included: 18 (40%) melanomas, 10 (21%) mesothelioma, 9 (19.5%) lung cancers, and 9 (19.5%) other types. Thirty-one patients (67%) developed at least one irAE. Of the irAEs, 8 (17.4%) were grade 1, 20 (43.5%) were grade 2, 14 (30.4%) were grade 3, and 3 (6.5%) were grade 4. Systemic steroids were used in 29 (63%) patients. Twenty-six (56.5%) patients were hospitalized for any cause, and 12 (26.1%) were hospitalized due to an irAE. Of the 26 patients hospitalized during treatment, 19 (73%) died within 1 year of discharge; 11 (42%) died within < 1 month of discharge and 3 (12%) died within 1-3 months of discharge. Median OS from the date of first Ipi-Nivo dose was 14.6 months in the ECOG PS 0-1 and 6.5 months in the ECOG PS 2-3. ECOG PS of 0-1 was associated with a significantly decreased risk of mortality (HR [hazard ratio] 0.33, 95 % CI [confidence interval]: 0.15-0.70; p=0.0025) compared to ECOG PS of 2-3. Conclusions: This is the first analysis to evaluate the outcomes of Ipi-Nivo in patients ≥ 80 years. Approximately 60% of the patients required systemic steroids and a quarter were hospitalized with grade 3-4 irAEs. As expected, patients with ECOG PS 2-3 did significantly worse than ECOG PS 0-1. Ipi-Nivo should be used with caution in patients ≥ 80 years.