SAN DIEGO and PARIS, April 17, 2026

Kura Oncology, Inc. reported encouraging clinical data from its ongoing FIT-001 trial, demonstrating that the combination of darlifarnib (KO-2806) and cabozantinib delivers robust anti-tumor activity in patients with clear cell renal cell carcinoma (ccRCC) who were previously treated with cabozantinib. Presented at the 2026 International Kidney Cancer Symposium (IKCS): Europe, the findings highlight the potential of this novel combination to overcome resistance and re-sensitize tumors to VEGF-targeted therapies, addressing a major unmet need in advanced kidney cancer.

Strong Clinical Responses in Resistant RCC Patients

Data from the subset analysis showed a 44% objective response rate (ORR) and an impressive 94% disease control rate (DCR) in patients who had previously received cabozantinib, a group typically associated with limited treatment options and poor outcomes. Notably, tumor shrinkage was observed in 75% of patients, with reductions ranging between 32% and 47% among responders, indicating meaningful clinical benefit even in heavily pretreated populations.

The combination therapy demonstrated activity across patients regardless of prior response to cabozantinib, including those whose disease had progressed or remained stable during earlier treatment. Additionally, treatment durations extended up to 56 weeks, with approximately one-third of patients continuing therapy at the time of data cutoff, suggesting durable responses and sustained disease control.

Importantly, the regimen maintained a manageable safety and tolerability profile across multiple dose levels, including full-dose cabozantinib, reinforcing its feasibility for continued clinical development.

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Mechanism Targets Resistance Pathways in Kidney Cancer

Darlifarnib is a farnesyl transferase inhibitor (FTI) designed to enhance the efficacy of VEGF receptor tyrosine kinase inhibitors (TKIs) such as cabozantinib by targeting key resistance pathways in tumor cells. This mechanism enables the therapy to restore sensitivity to VEGF-targeted treatments, a critical advantage in patients whose disease has progressed on standard therapies.

The findings are consistent with earlier preclinical and clinical data, which demonstrated that darlifarnib can modulate tumor signaling pathways and improve therapeutic response when combined with VEGF inhibitors. This positions the drug as a promising component of next-generation combination strategies in oncology, particularly for tumors that develop resistance to conventional therapies.

The FIT-001 study is currently evaluating multiple dosing regimens to determine the optimal biologically active dose, supporting further expansion into later-stage trials.

Advancing Precision Oncology Pipeline in RCC

Kura Oncology continues to advance its precision medicine pipeline, focusing on therapies that target specific molecular drivers of cancer progression and resistance. The success of the darlifarnib combination underscores the company’s strategy of developing targeted therapies that enhance existing treatment modalities, improving outcomes for patients with difficult-to-treat cancers.

Clear cell renal cell carcinoma remains one of the most common forms of kidney cancer, and while VEGF-targeted therapies have improved survival, treatment resistance remains a major challenge. The ability of darlifarnib to re-sensitize tumors to cabozantinib could represent a significant advancement in treatment sequencing and disease management.

As the study progresses into Phase 1b dose expansion, Kura aims to further validate these findings and explore the broader clinical potential of this combination in advanced RCC and potentially other solid tumors.

The latest clinical data from Kura Oncology highlight the potential of darlifarnib in combination with cabozantinib to address resistance and improve outcomes in advanced kidney cancer. With strong response rates, durable activity, and a favorable safety profile, this combination therapy represents a promising step forward in precision oncology and targeted treatment strategies.

Source: Kura Oncology press release