OBJECTIVES

To assess treatment patterns in first-line (1L) setting among US Veterans Health Administration patients with metastatic renal cell carcinoma (mRCC).

METHODS

This retrospective study identified newly diagnosed adult patients with mRCC who initiated ≥1 line of therapy from 01Oct2013-31Dec2017 (index date=1L therapy start date) and had continuous health plan enrollment from ≥6 months prior to the mRCC diagnosis until ≥3 months post–index date. Second-line (2L) therapy was defined by switch to any non-index therapy. Duration of 1L therapy was measured from index date to the earliest of last prescription’s end date, 2L therapy start date, or follow-up end. Univariate Poisson regression was used to compare patients treated with tyrosine kinase inhibitor (TKI) therapy vs mechanistic target of rapamycin (mTOR), immuno-oncology (IO) therapy, or other therapy, separately, based on rates (in 100-person years) of continuation, permanent discontinuation, interruption, and switch to 2L therapy.

RESULTS

Of 809 patients (mean age, 68.4y; 98.4% male; 79.9% white), 85.0%, 7.7%, 4.7%, and 2.6% were treated with TKI, mTOR, IO, or other therapy in 1L, respectively. Patients in the IO cohort were more likely to have baseline COPD (31.6% vs 16.7%; p=0.022) a higher continuation rate (47.7 vs 14.5; p<0.0001) and a lower rate of switching to 2L therapy (13.0 vs 50.3; p=0.0073) vs TKI cohort. Patients received mTOR had a higher rate of permanent discontinuation (49.0 vs 31.0; p=0.0334) and interruption (221.0 vs 122.9; p=0.0002). Duration of 1L therapy (in days) was similar for TKI vs. IO (153.3 vs133.2, p=0.3372), longer for TKI vs. mTOR (153.3 vs 96.9, p=0.0055) and TKI vs. other therapy (153.3 vs 42.9, p<0.0001).

CONCLUSIONS

Among patients with mRCC, although 1L TKI therapy showed similar duration vs IO, IO therapy demonstrated higher continuation rates vs TKI. Future research should focus on understanding which patients would benefit from IO+TKI.