Data from subset analysis of cabozantinib-pretreated patients support potential to overcome resistance and resensitize tumors to VEGF TKI therapy

44% ORR and 94% DCR in ccRCC patients previously treated with cabozantinib, with tumor shrinkage observed in 75% of patients

Responses observed in heavily pretreated patients, including those with stable disease on prior cabozantinib

Durable treatment durations reaching 56 weeks, with one-third of patients remaining on therapy at time of data cut-off

Manageable safety and tolerability profile in all RCC patients across multiple dose levels

Virtual investor event today, April 17, 2026, at 7:30 a.m. PT / 10:30 a.m. ET / 4:30 p.m. CEST

SAN DIEGO and PARIS, April 17, 2026 (GLOBE NEWSWIRE) -- Kura Oncology, Inc. (NASDAQ:KURA), a biopharmaceutical company focused on precision medicines for the treatment of cancer, today 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 (NCT06026410) of darlifarnib (KO-2806) in combination with cabozantinib. Results were presented at the 2026 International Kidney Cancer Symposium (IKCS): Europe in Paris, France.

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 (ESMO) 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.

"Patients with advanced ccRCC whose disease progresses on cabozantinib have limited treatment options," said Adanma Ayanambakkam, M.D., M.S., Assistant Professor of Hematology Oncology Director of Genitourinary Medical Oncology Research, Stephenson Cancer Center, University of Oklahoma Health Sciences Center. "The tumor shrinkage and high disease control rate observed with darlifarnib in combination with cabozantinib suggest this approach may offer meaningful clinical benefit in a refractory setting or in patients with disease progression after 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.

"These data highlight the potential of darlifarnib to overcome resistance to prior cabozantinib and enhance the activity of VEGF TKIs in patients with advanced RCC," said Mollie Leoni, M.D., Chief Medical Officer of Kura Oncology. "We are highly encouraged by these results and are committed to advancing this combination to evaluate further its potential to deliver meaningful benefit for RCC patients."

2026 IKCS: Europe Presentation

The presentation from 2026 IKCS: Europe is available on Kura's website at www.kuraoncology.com under the Posters and Presentations tab in the Farnesyl Transferase Inhibition section.

Virtual Investor Event

Kura will host a webcast and conference call today, April 17, 2026, at 7:30 a.m. PT / 10:30 a.m. ET / 4:30 p.m. CEST 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. The live webcast and replay will be available on the Company's website at www.kuraoncology.com under the Investors tab in the Events and Presentations section.

About Kura Oncology

Kura Oncology is a biopharmaceutical company committed to realizing the promise of precision medicines for the treatment of cancer. Kura's pipeline of small molecule drug candidates is designed to target cancer signaling pathways and address high-need hematologic malignancies and solid tumors. Kura developed and is commercializing KOMZIFTI™ (ziftomenib), the FDA-approved once-daily, oral menin inhibitor for the treatment of adults with relapsed or refractory NPM1-mutated acute myeloid leukemia, and continues to pioneer advancements in menin inhibition and farnesyl transferase inhibition. For additional information, please visit the Kura website at https://kuraoncology.com/ and follow us on X and LinkedIn.

Forward-Looking Statements

This news release contains certain forward-looking statements that involve risks and uncertainties that could cause actual results to be materially different from historical results or from any future results expressed or implied by such forward-looking statements. Such forward-looking statements include, among other things, statements regarding the potential of darlifarnib to enhance the activity of cabozantinib and other VEGFR-targeted therapies and to address mechanisms of resistance, and the potential of darlifarnib in combination with cabozantinib to offer meaningful clinical benefit to patients with RCC. Factors that may cause actual results to differ materially include the risk that compounds that appeared promising in early research or clinical trials do not demonstrate safety and/or efficacy in later preclinical studies or clinical trials, the risk that Kura may not obtain approval to market its product candidates, uncertainties associated with performing clinical trials, regulatory filings, and other interactions with regulatory bodies, and other risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such drugs. You are urged to consider statements that include the words "may," "will," "would," "could," "should," "believes," "estimates," "projects," "promise," "potential," "expects," "plans," "anticipates," "intends," "continues," "designed," "goal," or the negative of those words or other comparable words to be uncertain and forward-looking. For a further list and description of the risks and uncertainties Kura faces, please refer to Kura's periodic and other filings with the Securities and Exchange Commission, which are available at www.sec.gov. Such forward-looking statements are current only as of the date they are made, and Kura assumes no obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise.

Conflict of Interest Disclosure

Dr. Ayanambakkam's disclosures include consulting or advisory roles with Regeneron, Pfizer Oncology, Astellas Pharma, Bristol Myer Squibb – WINN CDA, Pharmacosmos Therapeutics, Natera Oncology, Foundation Medicine,National Cancer Institute, Native American Center of Cancer Health Excellence, AVEO, Johnson & Johnson, Kura Oncology.

Kura Contact

Investors and Media:

Greg Mann

858-987-4046

gmann@kuraoncology.com

Kura Oncology Reports Darlifarnib Plus Cabozantinib Demonstrates Robust Activity in Patients With Clear Cell Renal Cell Carcinoma Previously Treated With Cabozantinib