Kura Oncology Inc. (NASDAQ: KURA) reported clinical trial results showing tumor shrinkage in 77% of response-evaluable patients treated with its experimental drug combination of darlifarnib and adagrasib for KRAS G12C-mutated solid tumors.

The Phase 1a trial included 30 patients with 26 evaluable for response. Objective response rates varied by cancer type: 67% in pancreatic ductal adenocarcinoma, 50% in non-small cell lung cancer, and 29% in colorectal cancer patients who had not previously received KRAS inhibitor treatment.

The study evaluated heavily pretreated patients, including those with prior KRAS inhibitor exposure. Among response-evaluable patients who had not previously received KRAS inhibitor treatment, 94% achieved tumor shrinkage.

Patients received darlifarnib at doses of 3 mg, 5 mg, or 8 mg once daily on specific days of each 28-day cycle, combined with adagrasib 400 mg twice daily. The company stated it will not advance the 8 mg dose for further evaluation in this combination.

At the data cutoff date of March 25, 2026, 37% of patients remained on study treatment. Median follow-up times were 6.7 months for pancreatic cancer, 6.9 months for lung cancer, and 8.9 months for colorectal cancer patients.

The company described the combination as well tolerated with a manageable safety profile, according to the press release statement.

Darlifarnib is designed as a farnesyl transferase inhibitor that targets resistance mechanisms across multiple targeted therapies by blocking mTORC1 signaling pathways.

Kura plans to present these results at the 2026 American Society of Clinical Oncology Annual Meeting on May 30, 2026, and will host an investor event on June 3, 2026.