Positive CHMP opinion brings us closer to offering WELIREG, a first-in-class HIF-2α inhibitor, to certain patients in the European Union, in order to help address critical gaps in care for these patients,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “We are committed to providing innovative treatment options that address serious unmet needs for patients globally and look forward to the European Commission’s decision.”

The CHMP recommendation in VHL disease-associated tumors is based on objective response rate (ORR) and duration of response (DOR) results from the LITESPARK-004 trial. If approved, WELIREG would be the first and only systemic treatment for patients with VHL disease-associated tumors in the EU.

In August 2021, WELIREG was approved in the U.S. for the treatment of adult patients with VHL disease who require therapy for associated RCC, CNS hemangioblastomas or pNET not requiring immediate surgery based on the results from LITESPARK-004, an open-label clinical trial in 61 patients with VHL-associated RCC. In the LITESPARK-004 trial, WELIREG showed an ORR of 49% (95% CI, 36-62) in patients with VHL-associated RCC (n=30/61); all responses were partial responses (PR). Median DOR for these patients was not reached, with ongoing responses ranging from 2.8+ to 22+ months; among responders, 56% (n=17/30) maintained a response for at least 12 months.

Patients enrolled in LITESPARK-004 had other VHL-associated tumors, including CNS hemangioblastomas and pNET. In patients with VHL-associated CNS hemangioblastomas (n=24) in this trial, WELIREG showed an ORR of 63% (95% CI, 41-81) (n=15/24), with a complete response (CR) rate of 4% (n=1/24) and a PR rate of 58% (n=14/24). Median DOR for these patients was not reached, with ongoing responses ranging from 3.7+ to 22+ months; among responders, 73% (n=11/15) maintained a response for at least 12 months. In patients with VHL-associated pNET (n=12) in this trial, WELIREG showed an ORR of 83% (95% CI, 52-98) (n=10/12), with a CR rate of 17% (n=2/12) and a PR rate of 67% (n=8/12). Median DOR for these patients was not reached, with ongoing responses ranging from 11+ to 19+ months; among responders, 50% (n=5/10) maintained a response for at least 12 months.

The CHMP recommendation in advanced clear cell RCC that progressed following two or more lines of therapy that included a PD-(L)1 inhibitor and at least two VEGF targeted therapies, is based on PFS and ORR results from the LITESPARK-005 trial, the first positive Phase 3 trial in these patients.

In December 2023, WELIREG was approved in the U.S. for the treatment of adult patients with advanced RCC following a PD-1 or PD-L1 inhibitor and a VEGF-TKI based on the results from LITESPARK-005, an open-label clinical trial in 746 patients with unresectable, locally advanced or metastatic clear cell RCC that progressed following PD-1 or PD-L1 checkpoint inhibitor and VEGF receptor targeted therapies either in sequence or in combination. In the trial, WELIREG reduced the risk of disease progression or death by 25% (HR=0.75 [95% CI, 0.63-0.90]; p=0.0008) versus everolimus in these patients. Median PFS was 5.6 months (95% CI, 3.9-7.0) for WELIREG versus 5.6 months (95% CI, 4.8-5.8) for everolimus. The ORR for WELIREG was 22% (n=82) (95% CI, 18-27), with a CR rate of 3% (n=10) and a PR rate of 19% (n=72), and the ORR for everolimus was 4% (n=13) (95% CI, 2-6), with no patients achieving a CR and a PR rate of 4% (n=13).