Pembrolizumab Plus Belzutifan Improves DFS in Clear Cell RCC Trial

The combination of pembrolizumab and belzutifan has demonstrated a significant improvement in disease-free survival (DFS) for patients with clear cell renal cell carcinoma at increased risk of recurrence following surgery, according to data presented at the 2026 ASCO Genitourinary Cancers Symposium. The findings suggest a potential new standard of care for this patient population, building upon the established role of pembrolizumab as a single agent in the adjuvant setting.

Building on Existing Treatment Strategies

Adjuvant pembrolizumab, an immunotherapy drug, has already been shown to reduce the risk of mortality by 38% compared to placebo in patients with clear cell renal cell carcinoma who are at high risk of recurrence after nephrectomy, a surgical procedure to remove the kidney. However, approximately 40% of patients treated with pembrolizumab alone still experience disease progression or death within five years of surgery, highlighting the need for additional therapeutic options.

Belzutifan, an oral medication that inhibits HIF-2alpha, has previously shown promise in treating advanced renal cell carcinoma, particularly in patients who have progressed on prior immunotherapy and VEGFR-TKI therapies. The LITESPARK-005 trial demonstrated that belzutifan significantly improved progression-free survival (PFS) and objective response rates compared to everolimus in this setting.

LITESPARK-022 Trial Results

The LITESPARK-022 trial, a randomized, double-blind study, investigated the efficacy of adding belzutifan to adjuvant pembrolizumab. The trial enrolled 1,841 patients with clear cell renal cell carcinoma who had undergone surgery within the previous 12 weeks and were identified as being at increased risk of recurrence. Participants were randomly assigned to receive either pembrolizumab (400 mg every 6 weeks for approximately one year) plus belzutifan (120 mg daily for up to 54 weeks) or pembrolizumab plus placebo.

After a median follow-up of 28.4 months, the results showed a statistically significant improvement in DFS for the group receiving the combination therapy (HR = 0.72; 95% CI, 0.59-0.87). So that the risk of disease recurrence or death was 28% lower in the pembrolizumab plus belzutifan arm compared to the pembrolizumab monotherapy arm. The benefit was observed across various subgroups, including those stratified by PD-L1 status, age, and gender.

Preliminary overall survival (OS) data also favored the combination arm, with a numerical difference in death rates (4.1% vs. 5.3%). While these OS results are not yet statistically significant, researchers noted that the curves continued to separate even after treatment with pembrolizumab was discontinued, suggesting a potential long-term benefit.

Safety Considerations

As with any combination therapy, the addition of belzutifan was associated with a higher incidence of adverse events. The most common grade 3 or worse adverse events observed in the belzutifan arm included anemia (12% vs. 0.5%) and hypoxia (4.6% vs. 0%). However, most adverse events were grade 1 or 2 in severity. Discontinuation rates due to treatment-related adverse events were also higher in the belzutifan arm (10.2% vs. 7.3%).

Implications for Clinical Practice

“Pembrolizumab plus belzutifan showed a statistically significant and clinically meaningful DFS improvement vs. Pembrolizumab monotherapy,” stated Dr. Toni K. Choueiri, director of the Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute, during a press briefing. “LITESPARK-022 is the first adjuvant phase 3 trial in renal cell carcinoma to reveal a significant benefit for a combination treatment vs. An active immunotherapy comparator.”

Dr. Brian I. Rini, chief of clinical trials at Vanderbilt-Ingram Cancer Center, described the data as “practice-changing” and emphasized the need for further research to understand the underlying biology driving the observed benefits. He suggested that the combination may be particularly effective in delaying or potentially curing micrometastatic disease.

Next Steps and Ongoing Research

The findings from the LITESPARK-022 trial are expected to prompt discussions regarding the potential integration of belzutifan into adjuvant treatment regimens for patients with clear cell renal cell carcinoma at increased risk of recurrence. Further research will be crucial to identify biomarkers that can predict which patients are most likely to benefit from this combination therapy and to optimize treatment strategies. Continued follow-up of the LITESPARK-022 trial will also be essential to assess the long-term impact of the combination on overall survival and quality of life. The U.S. Food and Drug Administration (FDA) will likely review the data and consider whether to expand the approved indications for belzutifan and pembrolizumab based on these findings. Regulatory updates and potential changes to clinical guidelines will be closely monitored by healthcare professionals.

researchers are exploring other potential combinations and novel therapeutic approaches to further improve outcomes for patients with renal cell carcinoma. Personalized vaccine strategies are also under investigation as a means of harnessing the power of the immune system to fight this disease.