Belzutifan Offers Longer TTD, Better PRO Results Versus Everolimus

New patient-reported outcomes (PROs) from the phase 3 LITESPARK-005 study have further confirmed the benefit of belzutifan against everolimus in patients with metastatic clear cell renal cell carcinoma (ccRCC) who experienced progression after prior treatment with immune checkpoint and anti-angiogenic therapies.

Previous results of the phase 3 LITESPARK-005 study demonstrated superior progression-free survival (PFS) and overall response rate (ORR) from belztuifan monotherapy versus everolimus in this patient group.

At the 2024 American Society of Clinical Oncology Genitourinary Cancers Symposium, Thomas Powles, MD, PhD, FCRP, presented the results of the PROs related to belzutifan and how the treatment compares to everolimus.

The PRO analysis population consisted of 366 patients who received belzutifan treatment as part of the study, and 354 patients who received everolimus. The Functional Assessment of Cancer Therapy–Kidney Symptom Index Disease-Related Symptoms (FKSI-DRS) and European Organisation for Research and Treatment of Cancer’s Quality of Life 30-item core questionnaire (QLQ-C30) were administered on day 1 of treatment, as well as week 1, 3, 5, and 9, and then every 4 weeks.

Secondary endpoints included time to deterioration (TTD) and least square (LS) mean change from baseline as determined by FKSI-DRS and QLQ-C30 global health status/quality of life and physical functioning scales.

The median follow-up was 25.7 months, and median duration of treatment was 7.6 months with belzutifan versus 3.9 months with everolimus. Completion rates of the FKSI-DRS and QLQ-C30 were >90% at baseline and >55% at week 17 in each arm.

Significantly longer TTD was noted in the belzutifan arm versus the everolimus treatment arm, and mean changes in FKSI-DRS and QLQ-C30 scores suggested stability from baseline to week 17 with belzutifan, while it worsened in the everolimus treatment arm. A potential greater worsening in physical functioning scale scores were also noted with everolimus treatment versus belzutifan.

While belzutifan offers beneficial PFS and ORR rates, it also offers longer TTD and better PRO results when compared with everolimus for the treatment of patients with metastatic ccRCC who experienced prior progression.