🧪 1,841 ccRCC: belzutifan+Keytruda vs control

In the Phase III LITESPARK-022 trial in earlier-stage clear cell Renal Cell Carcinoma (RCC), 1,841 post-nephrectomy patients randomized to belzutifan (Welireg) + pembrolizumab (Keytruda) had a 28% lower risk of recurrence or death vs Keytruda + placebo at a median 28.4 months’ follow-up (24-month DFS: 80.7% vs 73.7%). The interim readout, presented at ASCO GU, supported FDA priority review with a June 19 action date; OS remains under evaluation.

Why It Matters To Oncology

• Positions HIF-2α inhibition as a credible adjuvant strategy when layered onto PD-1 therapy in ccRCC, with an absolute ~7-point DFS separation at 24 months.

• Could reshape post-nephrectomy risk-reduction discussions if DFS benefit holds and safety/tolerability are acceptable for ~1 year of therapy.

• Represents the first positive Phase III signal for a HIF-2α inhibitor + immunotherapy combination in earlier-stage disease, per Merck.

The Financials

• Welireg already has approvals in multiple regions for advanced RCC after prior PD-(L)1 and VEGF-targeted therapy, de-risking commercialization if the adjuvant label expands.

• Keytruda is already authorized in the adjuvant RCC setting across the U.S., EU, Canada and Japan, potentially accelerating uptake if the combo is approved.

• Regulatory timelines to watch: LITESPARK-022 (PDUFA June 19) and Welireg+lenvatinib expansion filing acceptance with an FDA target date of Oct. 4.

What They're Saying

• Merck’s M. Catherine Pietanza: “These findings represent the first positive Phase III data for Welireg in earlier stages of disease, as well as the first positive Phase III results for a HIF‑2α inhibitor and immunotherapy combination.”

• Investigators highlighted that median DFS was not reached in either arm at this follow-up, underscoring the need for longer observation and OS maturity.

What's Next

• Await continued follow-up for overall survival (key secondary endpoint) and durability of DFS separation in LITESPARK-022.

• Track broader Welireg-in-RCC readouts: LITESPARK-011 (belzutifan+lenvatinib) showed PFS benefit vs cabozantinib (median 14.8 vs 10.7 months; HR risk reduction 30%) with an OS trend (34.9 vs 27.6 months).

• Look ahead to LITESPARK-012 (later this year), testing belzutifan added to Keytruda+lenvatinib in 1L advanced RCC—an important signal for triplet sequencing/combination strategy.