Belzutifan in patients with advanced clear cell renal cellcarcinoma (ccRCC): Subgroup analysis of the phase 2 LITESPARK-013 study.

Abstract

4534 Background: In the randomized phase 2 LITESPARK-013 study (NCT04489771), the first-in-class HIF-2α inhibitor belzutifan showed comparable antitumor activity in patients with pretreated advanced ccRCC at 200 mg and 120 mg doses (objective response rate [ORR]: 23.1% vs 23.7%; 1-sided P= 0.5312). We present results of a post hoc analysis of the pooled population (200 mg and 120 mg arms) across patient subgroups based on prior therapy and IMDC risk group. Methods: Patients with advanced ccRCC, measurable disease per RECIST v1.1, a Karnofsky Performance Scale score of ≥70%, ≤3 prior systemic regimens for advanced ccRCC (including an anti–PD-(L)1 regimen), and disease progression during or after an anti–PD-(L)1 regimen were randomly assigned 1:1 to receive belzutifan 200 mg or 120 mg QD. End points in the pooled population and subgroups were ORR and duration of response per RECIST v1.1 by blinded independent central review. Data cutoff was February 10, 2023. Results: A total of 154 patients were enrolled (200 mg, n = 78; 120 mg, n = 76). In the pooled population, the median age was 64.0 years, 127 patients (82.5%) had intermediate/poor risk per IMDC criteria, 110 patients (71.4%) received 1-3 prior tyrosine kinase inhibitor (TKI) regimens, and 81 patients (52.6%) received 2 or 3 prior lines of therapy. As of the data cutoff date, 39 patients (25.3%) in the pooled population remained on treatment. Median follow-up was 20.1 months (range, 14.8-28.4). In the pooled population, ORR was 23.4% (95% CI, 16.9-30.9; 4 complete responses [CRs], 32 partial responses [PRs]) and median duration of response (DOR) was 16.1 months (range, 2.1+ to 23.5+). Additional efficacy analyses for subgroups are presented in the table. Conclusions: This post hoc analysis from the LITESPARK-013 study of patients with pretreated advanced ccRCC suggests that belzutifan has antitumor activity regardless of prior lines of therapies and prognostic risk category. These results further support belzutifan as a treatment option for advanced RCC. Clinical trial information: NCT04489771 . [Table: see text]