A 67% confirmed objective response rate in pancreatic cancer — one of oncology’s most stubbornly lethal tumors — is not a number that arrives quietly. That figure comes from preliminary Phase 1a data out of Kura Oncology’s FIT-001 study, presented at ASCO 2026, pairing darlifarnib — a next-generation farnesyl transferase inhibitor — with adagrasib in KRAS G12C-mutated pancreatic ductal adenocarcinoma. Across 26 response-evaluable patients, tumor shrinkage occurred in 77% overall and in 94% of KRAS inhibitor-naïve patients, with confirmed ORRs of 50% in NSCLC and 29% in KRAS inhibitor-naïve colorectal cancer rounding out the three-tumor readout. These figures compare favorably against historical adagrasib monotherapy benchmarks — a meaningful signal that the FTI backbone is doing real pharmacological work, not just riding a partner’s efficacy.
The mechanism matters here. Darlifarnib suppresses RHEB farnesylation and sustains mTORC1 inhibition, a pathway that activates as an adaptive escape route when KRAS signaling is blocked. Preclinical data show enhanced anti-tumor activity across mutant-selective, pan-KRAS, and RAS(ON) multi-selective inhibitors, with tumor regressions even in models previously exposed to KRAS inhibitor therapy. That last point carries distinct clinical weight: 40% of the 30 FIT-001 patients carried prior KRAS inhibitor exposure, and clinical activity was still observed in that pretreated subset. In a landscape where sotorasib’s initial NSCLC approval rested on a 36% ORR from monotherapy, a combination strategy that appears to deepen and extend response — including after prior KRAS inhibitor failure — reframes what resistance management could look like.
Kura’s strategic response to these data is a platform study architecture rather than a single-indication pivot. The design allows new arms to open over time, accommodating both approved and investigational partners, with successful combinations feeding into dedicated registrational programs. The first combination queued up is darlifarnib plus daraxonrasib in second-line-plus KRAS-mutant PDAC, targeting Phase 1a entry in early 2027. This is a deliberate sequencing choice: pancreatic cancer carries the heaviest unmet need and the most dramatic early ORR signal, making it the right anchor to establish proof of concept before the platform branches into other tumor types and RAS inhibitor classes.
The trial design question that will determine how quickly this platform produces actionable data is whether the adaptive arm structure includes pre-specified response thresholds that trigger expansion without requiring separate IND submissions for each new combination. Watch the enrollment rate in the daraxonrasib arm once it opens — slow accrual in PDAC historically predicts whether a signal can be confirmed before competitive drift erodes the thesis.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
