There is a particular reason that oncologists have long considered KRAS-mutated cancers to be among the most difficult to treat. The gene mutation, which appears across pancreatic, lung, and colorectal cancers, has historically been resistant to targeted drug therapies, and even when newer KRAS inhibitors arrive on the market, patients frequently develop resistance to those too. A small biopharmaceutical company in San Diego may have found a meaningful way around that problem.
Kura Oncology, Inc. (NASDAQ: KURA) reported Phase 1 clinical data this week showing that its experimental drug darlifarnib, when combined with adagrasib, a KRAS inhibitor marketed as Krazati and owned by Bristol-Myers Squibb Company (NYSE: BMY), produced tumor shrinkage in 77% of evaluable patients with KRAS G12C-mutated solid tumors. The trial, called FIT-001, enrolled 30 patients across three tumor types, with 26 considered evaluable for response.
The objective response rates across those tumor types were notable: 67% in pancreatic ductal adenocarcinoma, 50% in non-small cell lung cancer, and 29% in colorectal cancer among KRAS inhibitor-naive patients. For context, adagrasib as a monotherapy typically produces response rates in the range of roughly 20% to 45% depending on the tumor type and line of therapy, which makes the combination numbers stand out. Responses were also observed in patients who had already been treated with a prior KRAS inhibitor, which addresses one of the central challenges in this category: what to do when first-line targeted therapy stops working.
The mechanism behind this is worth understanding. Darlifarnib belongs to a class of drugs called farnesyl transferase inhibitors, or FTIs. It works by blocking a protein called RHEB from activating a cellular signaling pathway known as mTORC1, which tumors use as an escape route when KRAS inhibitors are applied. By shutting down that escape route, darlifarnib appears to resensitize tumors to the KRAS inhibitor, rather than allowing the cancer to reroute around it. In one notable example from the NSCLC cohort, a patient who had already failed a prior KRAS inhibitor achieved an 84% reduction in target lesions on the combination regimen.
The results are scheduled to be presented formally at the American Society of Clinical Oncology Annual Meeting on May 30, 2026, one of the highest-profile gatherings in oncology and a closely watched event for biotech investors.
The morning after the data release, analysts at three major financial institutions reiterated their buy ratings on Kura’s stock. Jefferies Financial Group, Inc. (NYSE: JEF) maintained its Buy rating with a $28 price target, while a separate firm reaffirmed a Buy rating with a $40 target, citing the data’s favorable risk-reward profile. Bank of America Corporation (NYSE: BAC) also stuck with its Buy rating following the release. Truist Financial Corporation (NYSE: TFC) was among the institutions that had also previously carried a Buy-equivalent rating on the stock.
For investors evaluating Kura’s broader picture, the financial position adds context to the clinical story. For the quarter ending March 31st, the company reported $580.8 million in cash, cash equivalents and short-term investments, with an additional $180 million in anticipated collaboration payments expected from a partnership with Kyowa Kirin. That runway, management has said, is expected to carry the company through topline results from its Phase 3 KOMET-017 trial in acute myeloid leukemia, anticipated in 2028.
It is also worth noting that Kura is no longer purely a clinical-stage company. Its first approved product, KOMZIFTI (ziftomenib), received FDA approval for relapsed or refractory NPM1-mutant acute myeloid leukemia and generated $5.8 million in net product revenue in its first full quarter of commercial availability. The commercial launch provides a real-world operating baseline even as the darlifarnib pipeline continues to advance through early trials.
The darlifarnib data, while still early and based on a small Phase 1 cohort, represents what the company calls a third consecutive proof of mechanism for its FTI platform, following earlier positive combinations with other targeted therapy classes. Whether these results hold up in larger trials is the question that will define Kura’s next few years. What is clear heading into ASCO is that the combination produced results compelling enough to put a small-cap oncology company on a much larger stage.
