Efficacy of immune-checkpoint inhibitors (ICI) in the treatment of older adults with metastatic renal cell carcinoma (mRCC) - an International mRCC Database Consortium (IMDC) analysis.

Objective: Older adults with metastatic renal cell carcinoma(mRCC) are underrepresented in immune-checkpoint inhibitor(ICI) registration trials. Here we compare the efficacy of ICI treatments in older vs. younger adults with mRCC.

Methods: Using the International mRCC Database Consortium(IMDC), patients treated with a PD(L)-1 based ICI were identified. Older adult was defined as ≥70-years at the time of treatment. Descriptive statistics were summarized in means, medians, and proportions. Effectiveness endpoints included overall survival (OS), time-to-treatment failure(TTF), time-to-next treatment(TNT), and overall response rate(ORR). Hazards ratios were adjusted(aHR) for IMDC risk factors, histology, line of treatment and older age.

Results: Of 1427 included patients, 397(28%) were older adults. ICI was used as 1st line(1 L) in 40%, 2nd line(2 L) in 49% and 3rd line(3 L) in 11% of patients. In univariable analysis, older adults had inferior OS compared to younger adults(25.1 m vs. 30.8 m, p < 0.01). There were no significant differences in TTF (6.9 m vs. 6.9 m, p = 0.4) or TNT(9.1 m vs 10 m, p = 0.3) between groups. In multivariable analyses, older age was not independently associated with worse OS(aHR = 1.02, p = 0.8), TTF(aHR = 0.95, p = 0.6) or TNT(aHR = 0.93, p = 0.5). Older adults had a lower ORR compared to younger adults(24% vs. 31%, p = 0.01), which was mainly driven by responses in 1 L(31% vs. 44%, p = 0.02) and not observed in 2 L/3 L.

Conclusions: After multivariable analyses, older adults with mRCC treated with ICI had no difference in OS, TTF or TNT when compared to younger adults. Our data support that chronological older age should not preclude patients from receiving ICI based therapies.