SAN DIEGO
— In early cuts of data, the next iteration of KRAS drugs for lung cancer appears to bear more promise than the first.
KRAS mutations drive around a quarter of all cancer cases and had been an elusive target until recently. The first two KRAS agents — Bristol Myers Squibb’s Krazati and Amgen’s Lumakras — were developed for one mutation called G12C that makes up roughly 1 in 8 non-small cell lung cancer cases. They represented a scientific breakthrough but ultimately elicited marginal benefit in lung cancer.
A bevy of drugmakers now hope to outdo those agents or capitalize on other KRAS mutations in lung cancer. Among them, Revolution Medicines, high off a stunning Phase 3 readout in pancreatic cancer, and D3 Bio reported findings from early-stage studies on their targeted drugs for certain lung cancer patients on Sunday at the annual American Association for Cancer Research meeting in San Diego.
City of Hope lung cancer physician-scientist Christine Lovly called the first iteration of KRAS G12C agents “a monumental leap forward.” But “nobody ever thought that these would be the only drugs that we have,” she said.
Shanghai-based D3 Bio is calling its drug elisrasib a next-generation option for non-small cell lung cancer patients with G12C mutations. In a Phase 1/2 study for previously-treated advanced lung cancer patients, D3 Bio tested its treatment both in patients who had tried a different KRAS G12C inhibitor and those who had not.
Among the 84 patients who hadn’t previously received a KRAS G12C inhibitor, 58.8% of patients responded to a 600 mg dose of the treatment. In these patients, the therapy staved off cancer progression for about a year, with a median duration of response of 16.5 months.
Meanwhile, in 31 patients who had received a previous KRAS G12C agent, the drug still elicited responses in roughly a third of patients, with a median progression-free survival of 8.1 months. Overall survival data were not mature for either group of patients.
Researchers from the multi-country trial reported that grade 3 treatment-related adverse events occurred in 11.5% of patients. Presenter Byoung Chul Cho of Yonsei University called the safety profile of the drug favorable, but discussant Adrian Sacher of UHN Princess Margaret Cancer Centre in Toronto pointed to some cases of elevated liver enzymes in the study, which could signal liver toxicities.
D3 Bio in December
announced a $108 million raise
to fund Phase 3 trials for elisrasib, but the company has yet to share additional details on its plans. Others, including RevMed and BridgeBio Oncology Therapeutics, are likewise developing G12C agents.
“This is a very crowded field,” said Lovly. “It’s going to come down to combinability.”
RevMed on Sunday shared new data on zoldonrasib, which is the next-furthest along asset in its pipeline after the ‘pan-RAS’ drug daraxonrasib that was part of the company’s buzzy Phase 3 pancreatic cancer readout. Zoldonrasib targets KRAS G12D, which is present in roughly 5% of lung cancer patients.
The drugmaker reported that among 27 patients with previously treated lung cancer, 14 saw their tumors shrink substantially — good for a 52% response rate. The drug helped stave off cancer progression for a median of 11.1 months in these patients, and 73% of patients were still alive at one year.
The most common adverse events included nausea, vomiting, diarrhea and rash, most of which were considered mild-to-moderate. Dose interruptions from adverse events occurred in 15% of patients, while 5% discontinued treatment.
RevMed’s chief development officer Alan Sandler called the company’s second-line pancreatic cancer data a “watershed moment” that helped validate its pipeline, and said the zoldonrasib data built on that. “We’re not done,” he said.
RevMed said in February that it plans to start a Phase 3 trial called RASolve 308 in the first half of 2026 to study a zoldonrasib combination for first-line patients with metastatic KRAS G12D-mutated lung cancer. It’s also studying daraxonrasib in second- and third-line lung cancers as part of a registrational trial called RASolve 301 that’s expected to be completed at the end of 2027.
When asked about the overlap across indications with its experimental drugs, Sandler said, “It’s a wonderful dilemma.”
“We don’t know which is going to be best in which setting, but we know that all of them have the opportunity for success,” he said, noting that the company is not only testing its agents individually and in combination with chemotherapy, but also in combination with each other.
Meanwhile, Astellas last month
shared
results on a KRAS G12D protein degrader, which is the first of its kind.
RevMed reported last week that daraxonrasib doubled survival time in patients with second-line pancreatic cancer, marking a breakthrough for the deadly cancer. On Tuesday, the company will also share highly anticipated updated results of daraxonrasib in first-line pancreatic cancer.