BMS, Mirati's Krazati cements lead over Amgen's Lumakras with FDA approval in colorectal cancer

Despite coming to market second, Bristol Myers Squibb’s Mirati Therapeutics-inherited cancer med Krazati has gained the lead on its Amgen rival Lumakras in a heated KRAS race.

Late Friday, the U.S. FDA granted an accelerated approval for BMS’ KRAS inhibitor Krazati plus Eli Lilly’s Erbitux (cetuximab) to treat certain chemotherapy-experienced adults with KRAS-mutated locally advanced or metastatic colorectal cancer (CRC). Given that the approval is accelerated, BMS may have to further prove Krazati’s merit in CRC in a confirmatory trial to keep hold of the green light.

The new nod comes after Krazati’s initial approval in previously treated KRAS G12C-mutated non-small cell lung cancer (NSCLC) in Dec. 2022. Krazati, also known as adagrasib, was the second KRAS-targeting drug to hit the U.S. market behind Lumakras, which snagged its initial approval in NSCLC in May 2021.

BMS got its hands on Krazati when it agreed to buy out Mirati for around $4.8 billion last fall. Bristol closed the transaction in late January.

CRC with a KRAS G12C mutation occurs in approximately 3% to 4% of colorectal cancer patients and has historically proven difficult to treat, according to Rona Yaeger, M.D., gastrointestinal oncologist and early drug development specialist at Memorial Sloan Kettering Cancer Center.

The FDA based its approval on early results from Krazati’s 94-patient, phase 1/2 KRYSTAL-1 open-label study, in which the drug was administered in 600mg tablets twice a day along with Erbitux either weekly or biweekly, the FDA explained in a separate release.

In the trial, the Krazati combo reached a confirmed objective response rate (ORR) of 34%--meeting its primary endpoint—and charted a median duration of response (DOR) of 5.8 months. Thirty-one percent of patients who responded to Krazati had a DOR of at least half-a-year, the FDA noted.

Current late-line standard-of-care medicines in CRC yield limited objective response rates of around 1% to 6% after progression on chemotherapy, BMS pointed out.

Aside from moving into a second indication to Lumakras’ one, Krazati further cemented its lead in the KRAS race this past March when BMS unveiled confirmatory results from the late-stage KRYSTAL-12 study that found the med significantly reduced the risk of tumor progression or death versus chemotherapy in certain NSCLC patients.

Krazati’s confirmatory win marked another blow to Lumakras after Amgen recently applied for a full approval of its rival KRAS inhibitor leveraging progression-free survival data from the phase 3 CodeBreaK 200 trial. Problem was, the FDA figured the study’s results couldn’t be reliably interpreted, and a group of external advisers agreed.

Despite this, the FDA has let Lumakras stay on the market while Amgen runs another confirmatory study. The California-based company expects that to be done no later than Feb. 2028.

Meanwhile, Amgen is also gunning for a Lumakras approval in CRC. The company in October reported results from its phase 3 CodeBreaK 300 trial showing that 960mg Lumakras plus Vectibix extended patients' median progression-free survival to 5.6 months versus 2.2 months for standard treatments in chemo-refractory KRAS G12C colorectal cancer.

Krazati, during its first earnings quarter under BMS’ wing, snared $21 million over the first three months of 2024.