An open-label phase II study comparing two doses of MK-6482 for the treatment of advanced renal cell carcinoma (RCC) following progression on prior systemic therapy.

TPS369 Background: Treatment options for RCC in the late-line setting after immunotherapy and vascular endothelial growth factor (VEGF)-targeted therapy are limited. Hypoxia-inducible factor (HIF)-2α is a transcription factor that has been established as an oncogenic driver in clear cell RCC (ccRCC). The first-in-class small molecular HIF-2α inhibitor, MK-6482, recently showed promising antitumor activity in a cohort of heavily pretreated ccRCC patients (pts) and in pts with von Hippel-Lindau–disease-associated RCC for which the FDA granted Breakthrough Therapy Designation to MK-6482. Methods: This randomized, open-label, multicenter phase II trial will evaluate the efficacy and safety of 2 doses of MK-6482 in pts with advanced RCC who have experienced progression after prior systemic therapy (NCT04489771). Eligible pts are male or female aged ≥18 years with histologically confirmed locally advanced or metastatic ccRCC (measurable disease per RECIST v1.1) who have experienced progression after 1-3 prior systemic therapies comprising an anti-PD-1/L1 agent combined with a VEGF-targeted tyrosine kinase inhibitor (TKI) or an anti-cytotoxic T lymphocyte-associated antigen-4 agent and have undergone no more than 3 prior systemic regimens; and a Karnofsky Performance Scale ≥70. Treatment progression on anti-PD-1/L1 combination therapy was defined as pts who received at least 2 doses of anti-PD-1/L1 therapy and demonstrated radiographic disease progression as assessed by the investigator. Pts who have received prior treatment with MK-6482 or another HIF-2α inhibitor, and those requiring intermittent or chronic supplemental oxygen, or with a baseline hemoglobin less than 10 g/dL, a history of human immunodeficiency virus, hepatitis B or hepatitis C infection, or active central nervous system metastases will be excluded. Approximately 150 pts will be randomly assigned 1:1 to oral MK-6482 120 mg once daily (QD) or 200 mg QD; treatment will continue until progression, unacceptable toxicity, or withdrawal. Pts will be stratified by International Metastatic RCC Database Consortium prognostic scores (0, 1-2, 3-6) and the number of prior TKI-containing therapies (0, 1, or 2-3). Imaging with computed tomography or magnetic resonance imaging will be undertaken on Week 9 from the date of randomization, every 8 weeks through Week 49, and every 12 weeks thereafter. Adverse events will be monitored throughout the study and for 30 days after treatment (90 days for serious adverse events). The primary end point is objective response rate per RECIST v1.1 by blinded independent central review (BICR). Secondary end points are progression-free survival, duration of response and clinical benefit rate per RECIST v1.1 by BICR, overall survival, pharmacokinetics, and safety. Safety will be analyzed using a tiered approach. This study is recruiting. Clinical trial information: NCT04489771 .