Oral Belzutifan Plus Lenvatinib For Renal Cell Carcinoma
- In the phase III LITESPARK-011 trial, the HIF-2α inhibitor belzutifan combined with the VEGF-targeted TKI lenvatinib demonstrated longer progression-free survival compared with cabozantinib, suggesting a meaningful advancement for second-line therapy.
- By targeting complementary hypoxia-driven tumor pathways, the regimen represents one of the first successful combinations of these drug classes in renal cell carcinoma, potentially expanding the therapeutic framework beyond sequential monotherapy.
- Anemia and hypoxemia associated with belzutifan and VEGF-inhibitor-related adverse effects such as diarrhea, fatigue, and hand-foot syndrome were observed, reinforcing the need for proactive monitoring and close clinician-patient communication to balance efficacy with quality of life.
Following first-line immune checkpoint inhibitor (ICI)-based combinations, sequencing therapy in advanced clear-cell renal cell carcinoma (ccRCC) is still unsettled. VEGFR-targeted TKIs remain a common pattern, and European Association of Urology (EAU) guidance notes cabozantinib monotherapy has particularly robust data after PD-1-based combinations, making it a clinically relevant comparator for modern trials.
Belzutifan is an oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor and is approved by the U.S. Food and Drug Administration (FDA) for adults with advanced RCC with a clear-cell component after prior PD-1/PD-L1 therapy and a VEGF-TKI.
What LITESPARK-011 Shows
LITESPARK-011 is an open-label, randomized phase 3 trial evaluating oral belzutifan plus lenvatinib versus cabozantinib in unresectable, locally-advanced or metastatic ccRCC that progressed on or after anti-PD-(L)1 therapy. Results were presented as a late-breaking abstract at the 2026 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium.
Dr. Alexandra Drakiki, a medical oncologist at University of California Los Angeles, tells SurvivorNet Connect the trial results are quite promising for the field.
“We’re going to have, even in the second-line setting, combinations of two different classes of drugs that are now given together and can improve improve progression-free survival,” she says.
A total of 747 patients were randomized 1:1 to belzutifan 120 mg daily plus lenvatinib 20 mg daily (n=371) or cabozantinib 60 mg daily (n=376). The co-primary endpoints were progression-free survival (PFS) by blinded independent central review and overall survival (OS). Objective response rate (ORR) and duration of response (DOR) were key secondary endpoints.
- At the second interim analysis (median follow-up 29.0 months), belzutifan plus lenvatinib reduced the risk of progression or death by 30% versus cabozantinib (PFS HR 0.70; 95% CI, 0.59–0.84; P=.00007).
- Median PFS was 14.8 months versus 10.7 months, respectively.
- Response depth and durability also favored the combination. ORR was 52.6% with belzutifan/lenvatinib versus 40.2% with cabozantinib, with more complete responses reported (20 vs 4; 5.4% vs 1.1%).
- Among responders, median DOR was 23.0 months versus 12.3 months; at 24 months, 49.5% versus 25.5% of responses were ongoing.
OS was numerically improved but did not cross the interim statistical boundary. Median OS was 34.9 months versus 27.6 months (HR 0.85; 95% CI, 0.68–1.05; P=.06075), and the final OS analysis is pending.
Safety Profile & What Changes In-Clinic
The adverse-event pattern largely matched known class effects, but belzutifan-specific toxicities shift supportive care priorities. Anemia occurred in 69.2% with the combination versus 25.6% with cabozantinib, and hypoxia occurred in 15.4% versus 0%.
Despite dual therapy, discontinuation due to adverse events was similar between arms (~11%), and grade ≥3 treatment-related adverse events were reported in 71.6% versus 65.8% (combination vs cabozantinib). Patient-reported outcomes (kidney symptom index and global health/quality-of-life) showed similar time to deterioration between arms in interim reporting.
From a practical standpoint, this aligns with belzutifan labeling: monitor hemoglobin and oxygenation and withhold/reduce therapy for clinically significant anemia or hypoxia.
Dr. Drakiki says that combinations of two different classes of drugs, given together, can extend disease control, but toxicity management depends on “daily communication with our patients” to catch and address adverse effects early.
Perspective For The Field
LITESPARK-011 is consequential because it shows a statistically significant PFS advantage and improved response durability versus a widely used post-ICI standard (cabozantinib) in a phase 3 trial tailored to the modern sequencing era.
Regulatory review is already underway. Merck & Co., Inc. and Eisai Co., Ltd. report that the FDA has accepted supplemental applications for belzutifan plus lenvatinib in this setting, with a target action date of October 4, 2026.
Until OS matures and regulatory and guideline decisions land, the near-term message for medical professionals is clear: an all-oral HIF-2α inhibitor/VEGFR-TKI combination can outperform cabozantinib on PFS (14.8 vs 10.7 months; HR 0.70) with higher ORR (52.6% vs 40.2%) and longer DOR (23.0 vs 12.3 months), at the cost of more belzutifan-typical anemia and hypoxia that require proactive monitoring and patient engagement.
