Kura Oncology Announces Robust Activity of Darlifarnib Plus Cabozantinib in Clear Cell Renal Cell Carcinoma Patients

Published: 2026-04-17 07:35:59 ET KURA

Published on 04/17/2026 at 07:35 am EDT

Kura Oncology, Inc. announced new preliminary data from a subset analysis of patients with clear cell renal cell carcinoma (ccRCC) previously treated with cabozantinib in the ongoing FIT-001 clinical trial of darlifarnib (KO-2806) in combination with cabozantinib. The analysis specifically evaluated patients with ccRCC who had previously received cabozantinib, a population that typically derives limited benefit from subsequent therapy. In this setting, the combination of darlifarnib and cabozantinib demonstrated robust antitumor activity along with a manageable safety profile as demonstrated in all RCC patients across multiple dose levels, including full dose cabozantinib.

These findings are consistent with clinical and preclinical data presented at the 2025 European Society for Medical Oncology and in earlier data disclosures supporting the potential of darlifarnib to enhance the activity of VEGFR-targeted therapies and to address mechanisms of resistance. Clinical Activity in Cabozantinib-Pretreated Patients (N=16): Objective response rate (ORR) was 44%, with a disease control rate (DCR) of 94% across all doses tested in this population. Tumor shrinkage observed in 75% of patients, with reductions ranging from 32% to 47% among responders.

Antitumor activity observed in a heavily pre-treated, cabozantinib-exposed population, including patients whose best response to prior cabozantinib was stable disease. Responses observed in patients previously treated with cabozantinib in the immediate prior line as well as those who had received other TKIs in addition to cabozantinib. Treatment durations ranged from 8 to 56 weeks, with six patients remaining on therapy at the time of data cutoff.

These findings are notable given that patients who progress on cabozantinib are generally considered unlikely to respond to subsequent cabozantinib therapy. The FIT-001 study is evaluating darlifarnib in patients with RCC at once-daily doses of 3 mg, 5 mg or 8 mg alternating 7 days on and off in combination with cabozantinib at once-daily doses of 60 mg or 40 mg. All patients must have received prior immunotherapy.

The study has advanced into Phase 1b dose expansion to assess an optimal biologically active dose for the combination. The presentation from 2026 IKCS: Europe is available on Kura?s website under the Posters and Presentations tab in the Farnesyl Transferase Inhibition section. Kura will host a webcast and conference call featuring management and Adanma Ayanambakkam, M.D., M.S., Assistant Professor of Hematology Oncology and Director of Genitourinary Medical Oncology Research, Stephenson Cancer Center, University of Oklahoma Health Sciences Center.