Oncology · Medical Literature
Adjuvant Pembrolizumab plus Belzutifan for Renal-Cell Carcinoma.
Abstract
Adjuvant pembrolizumab improves disease-free and overall survival among patients with resected clear-cell renal-cell carcinoma. The hypoxia-inducible factor 2α inhibitor belzutifan has activity in advanced disease. Adjuvant pembrolizumab with belzutifan may further improve outcomes in patients with clear-cell renal-cell carcinoma at increased risk for recurrence. In this phase 3, double-blind trial, we randomly assigned participants in a 1:1 ratio to receive intravenous pembrolizumab at a dose of 400 mg every 6 weeks (≤9 doses) and either daily oral belzutifan at a dose of 120 mg (pembrolizumab-belzutifan) or placebo (pembrolizumab-placebo) for up to 1 year. The primary end point was disease-free survival as assessed by the investigator; secondary end points included overall survival and safety. A total of 921 participants were assigned to receive pembrolizumab-belzutifan and 920 were assigned to receive pembrolizumab-placebo. The median time from randomization to the data-cutoff date (August 23, 2025) was 28.4 months (range, 15.0 to 40.1). Disease-free survival was significantly higher with pembrolizumab-belzutifan than with pembrolizumab-placebo (hazard ratio for disease recurrence or death, 0.72; 95% confidence interval [CI], 0.59 to 0.87; two-sided P<0.001); the estimated 24-month disease-free survival was 80.7% and 73.7%, respectively. At this interim analysis with 29% of the final-analysis events observed, overall survival did not differ significantly between the groups (hazard ratio for death, 0.78; 95% CI, 0.51 to 1.19; two-sided P = 0.24); the estimated 24-month overall survival was 96.2% with pembrolizumab-belzutifan and 95.7% with pembrolizumab-placebo. Adverse events of grade 3 or higher occurred in 52.1% of the participants who received pembrolizumab-belzutifan and in 30.2% of those who received pembrolizumab-placebo. Treatment with pembrolizumab-belzutifan led to significantly higher disease-free survival, with a greater risk of grade 3 or higher toxic effects, than treatment with pembrolizumab monotherapy after nephrectomy in participants with clear-cell renal-cell carcinoma at increased risk for recurrence. (Funded by Merck Sharp and Dohme, a subsidiary of Merck [Rahway, NJ]; LITESPARK-022 ClinicalTrials.gov number, NCT05239728.).
Clinical relevance
In patients with resected clear-cell renal-cell carcinoma at increased risk for recurrence, does adding the HIF-2α inhibitor belzutifan to adjuvant pembrolizumab improve disease-free survival compared with pembrolizumab plus placebo? __SNAPSHOT__ {"studyDesign":"Phase 3, multicenter, double-blind, randomized controlled trial (LITESPARK-022; NCT05239728)","setting":"Multinational; academic and community oncology centers across multiple countries","sampleSize":"n=1,841 (pembrolizumab-belzutifan: n=921; pembrolizumab-placebo: n=920)","population":"Adults with histologically confirmed clear-cell RCC at increased risk of recurrence following nephrectomy, defined as: (1) stage M0 intermediate-high risk (pT2 grade 4 or sarcomatoid N0; or pT3 any grade N0), (2) stage M0 high risk (pT4 N0, or any pT N1), or (3) M1 with no evidence of disease (NED) after resection of metastatic lesions. No prior systemic therapy; ECOG PS 0–1; surgery within 12 weeks of randomization.","intervention":"Pembrolizumab 400 mg IV every 6 weeks (≤9 doses, ~1 year) plus belzutifan 120 mg orally once daily for up to 54 weeks (~1 year)","comparator":"Pembrolizumab 400 mg IV every 6 weeks (≤9 doses) plus matching oral placebo once daily for up to 54 weeks","primaryOutcome":"Disease-free survival (DFS) by investigator assessment, defined as time from randomization to disease recurrence (locoregional or distant metastasis) or death from any cause","followUp":"Median 28.4 months from randomization to data cutoff (August 23, 2025); range 15.0–40.1 months","fundingSource":"Industry (Merck Sharp and Dohme, a subsidiary of Merck, Rahway, NJ)"}
Key findings
At the prespecified first interim analysis (IA1), pembrolizumab plus belzutifan significantly improved investigator-assessed DFS compared with pembrolizumab plus placebo (HR 0.72; 95% CI 0.59–0.87; P=0.0003), representing a 28% relative reduction in the risk of disease recurrence or death. Median DFS was not reached in either arm. The estimated 24-month DFS rate was 80.7% (95% CI 77.7–83.2) in the combination arm versus 73.7% (95% CI 70.6–76.6) in the control arm, an absolute difference of approximately 7.0 percentage points (calculated). NNT at 24 months to prevent one recurrence or death event = approximately 14 (calculated). Overall survival data were immature at IA1, with 87 total events (38 vs. 49); the OS HR numerically favored the combination (HR 0.78; 95% CI 0.51–1.19; P=0.1220) but did not reach statistical significance, representing only 29% of the events required for the final OS analysis. Treatment completion rates were similar (70% combination, 71% placebo). Grade ≥3 treatment-emergent adverse events (TEAEs) were substantially more frequent in the combination arm (52.1% vs. 30.2%). The most common high-grade toxicities unique to the combination were anemia (grade ≥3: 12.1% vs. 0.4%), elevated ALT (6.4% vs. 2.0%), and hypoxia (grade ≥3: 4.6% vs. 0%). Any-grade anemia occurred in 84.0% of the combination arm vs. 11.4% of the control arm. Anemia was managed with dose interruption (24.7%), dose reduction (17.3%), discontinuation (4.0%), and/or transfusion or erythropoiesis-stimulating agents (12.7%). Grade ≥3 hypoxia (4.6%) was managed with dose modification, supplemental oxygen, or discontinuation in 1.6% of patients. Grade 5 TEAEs occurred in 1.1% (combination) vs. 1.2% (placebo), and treatment-related deaths were reported in 0.3% of patients in each group.
Practice implications
LITESPARK-022 establishes that adding belzutifan to adjuvant pembrolizumab significantly improves investigator-assessed DFS compared with pembrolizumab monotherapy in patients with resected ccRCC at intermediate-high risk, high risk, or M1 NED. This is the first phase 3 adjuvant trial in RCC to demonstrate a statistically significant benefit for any combination regimen over an active immunotherapy comparator. The FDA granted approval to belzutifan plus pembrolizumab in June 2026 based on these data. However, several important caveats apply. First, overall survival remains immature; the DFS benefit has not yet translated to a demonstrated survival advantage, and OS results were not statistically significant at this interim analysis — the OS analysis is ongoing and will be essential to confirm the durability and magnitude of clinical benefit. Second, the toxicity burden of the combination is substantial: grade ≥3 TEAEs nearly doubled compared with pembrolizumab alone (52.1% vs. 30.2%), with anemia and hypoxia being the signature belzutifan-associated toxicities requiring proactive monitoring, dose adjustments, and occasionally supportive interventions. Third, a prespecified subgroup observation suggests that the DFS benefit from the combination may be preferentially concentrated in the intermediate-high-risk group, with less apparent incremental benefit in high-risk and M1 NED populations who already derive substantial benefit from pembrolizumab monotherapy — though the trial was not powered to confirm subgroup differences. No validated predictive biomarker currently guides patient selection. Results are applicable specifically to patients with clear-cell histology; those with non-clear-cell RCC or poor performance status were not included. Clinicians should engage in shared decision-making, particularly for patients who may tolerate the added toxicity poorly (e.g., those with baseline anemia, pulmonary compromise, or anticipated adherence challenges). Because only the full journal article abstract was available for this summary, specific subgroup data, quality-of-life results, and exploratory endpoints from the NEJM publication may contain additional nuance not captured here. __LIMITATIONS__ Overall survival data are immature at IA1 (only 29% of required OS events observed; HR 0.78, not statistically significant); DFS is a surrogate endpoint and its translation to OS benefit remains unproven at this follow-up.,Median follow-up of only 28.4 months is relatively short for an adjuvant RCC trial in which late recurrences are well recognized; longer follow-up is required.,Entirely industry-funded (Merck Sharp and Dohme), introducing potential for publication bias and selective outcome reporting.,Trial was not powered to definitively assess subgroup differences; apparent heterogeneity of DFS benefit across risk strata (intermediate-high vs. high risk vs. M1 NED) is exploratory and hypothesis-generating only.,No validated predictive biomarker exists to identify which patients derive the greatest benefit, limiting precision in patient selection.,The double-blind design is a strength for DFS assessment, but investigator-assessed DFS (rather than blinded independent central review as the primary analysis) introduces potential bias.,The 52.1% rate of grade ≥3 TEAEs in the combination arm raises concerns about real-world tolerability and may limit generalizability to patients with comorbidities (e.g., baseline anemia, chronic pulmonary disease) who were underrepresented.,Treatment duration was limited to approximately one year; optimal duration of the combination and whether shorter or longer courses would differ in efficacy or safety is unknown.,Quality-of-life impact of significantly increased toxicity burden has not been fully reported and is a critical consideration for patients receiving adjuvant (not palliative) therapy. __BOTTOM_LINE_CATEGORY__ practice_changing __BOTTOM_LINE__ In resected high-risk clear-cell RCC, adding belzutifan to adjuvant pembrolizumab produced a statistically significant and clinically meaningful improvement in disease-free survival (HR 0.72; 95% CI 0.59–0.87; 24-month DFS 80.7% vs. 73.7%) compared with pembrolizumab alone, and the FDA approved this combination in June 2026. However, grade ≥3 toxicities were substantially higher with the combination (52.1% vs. 30.2%), OS remains immature and non-significant, and there are signals that benefit may be concentrated in the intermediate-high-risk subgroup. Clinicians should discuss this combination as an emerging standard-of-care option for eligible patients while emphasizing the need for proactive anemia and hypoxia monitoring, the absence of mature OS data, and individualized risk-benefit assessment.