Data from Phase 1b dose escalation and expansion trial (n=69) shows a favorable safety profile, with manageable adverse events consistent with the known profiles of the respective drugs.Encouraging preliminary signals of efficacy for the higher dose combination cohorts of HC-7366 with belzutifan were observed. Additionally, several patients in the dose escalation and initial expansion (Expansion 1) remain on treatment. Translational analyses demonstrate clear evidence of HC-7366 pathway engagement and a pharmacodynamic profile differentiating the combination from the known effects of HC-7366 and belzutifan monotherapy.Second Dose Expansion Cohort (Expansion 2) fully enrolled, with updated results from both Expansion 1 and Expansion 2 expected in 2H 2026 and full results to be reported at a future date. ROSEVILLE, Minn., May 21, 2026 (GLOBE NEWSWIRE) -- HiberCell, Inc., a clinical-stage biotechnology company developing therapeutics targeting the integrated stress response (ISR) to address cancer relapse, metastasis, and resistance, today announced that preliminary results from its ongoing Phase 1b study (NCT06234605) of HC-7366 in combination with WELIREG® (belzutifan), Merck’s (known as MSD outside of the United States and Canada) oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor, will be presented in two poster presentations at the upcoming 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. The study is evaluating HC-7366, an activator of the ISR kinase GCN2, in patients with advanced clear cell renal cell carcinoma (ccRCC) whose disease progressed after prior PD-1/PD-L1 checkpoint inhibitor and VEGF-tyrosine kinase inhibitor (VEGF-TKI) therapy.