Merck & Co.’s Welireg Notches Wins in Kidney Cancer Combo Studies

Welireg, Merck & Co.'s HIF-2α inhibitor, succeeded in two large Phase 3 trials for kidney cancer, enhancing hope for expanded use in less-advanced disease1 3 6.

In the Litespark-022 adjuvant trial, adding Welireg to Keytruda after surgical removal of cancer kept patients disease-free longer compared to Keytruda alone, achieving statistically significant and clinically meaningful improvement in disease-free survival1 5 4.

In the Litespark-011 trial for patients relapsed after Keytruda, Welireg combined with Eisai’s Lenvima delayed cancer progression more than Exelixis’ Cabometyx; however, improvement in overall survival showed a positive trend but did not reach statistical significance at interim analysis3 5 7.

These results significantly strengthen Merck’s renal cell carcinoma pipeline ahead of Keytruda’s patent expiry, with Welireg posited to potentially triple expected revenue in the adjuvant setting to more than $6 billion if approved1 5.

Welireg’s current FDA label covers renal cell carcinoma after progression on PD-(L)1 and VEGF inhibitors and generated $300 million in sales in the first half of 20251 5.

Further regulatory submissions and presentations of these data are planned, with additional Phase 3 studies, including triplet therapy, reading out next year5.