BMS to pay big to enter KRAS field

Bristol Myers Squibb (BMS) has announced it will buy the oncology drug developer Mirati Therapeutics, setting it up to gain Krazati (adagrasib), a KRAS inhibitor that received approval from the US Food and Drug Administration in December 2022. It also gets molecules such as MRTX1719, which is expected to enter Phase 2 clinical trials in the first half of 2024.

“With multiple targeted oncology assets including Krazati, Mirati is another important step forward in our efforts to grow our diversified oncology portfolio,” BMS chief operating officer Chris Boerner says in a statement.

BMS will pay $4.8 billion for Mirati, plus another $1 billion if and when the FDA accepts an application for MRTX1719. That valuation represents a 52% premium on the 30-day average of Mirati’s stock price before reports of a potential takeover began to emerge.

The KRAS protein helps regulate how cells grow and proliferate, but when mutated it has the potential to turn normal cells into cancerous ones. KRAS has thus become a target of interest for drug makers. The first KRAS inhibitor, Lumakras, was developed by Amgen and approved by the FDA in 2021. Krazati is the only other to win approval so far. Both are used to treat non-small-cell lung cancer.

BMS clearly has high hopes for Krazati, though it brought in only $6.3 million during the first three months of 2023, its first quarter on the market. Studies have shown that Krazati has an edge over Amgen’s drug when it comes to efficacy, but Lumakras has the advantage on durability of patient response.

MRTX1719, which is still in trials at Mirati, doesn’t target the KRAS protein. Instead, it deals with the PRMT5 protein—but previous research has detailed the potential for crosstalk between these two proteins.

Although Lumakras and Krazati are the only KRAS inhibitors currently on the market, analysts expect that won’t be the case much longer.

Six other pharmaceutical firms have similar small-molecule drugs at varying stages of clinical trials. This is “the major risk to Krazati’s ability to reach blockbuster status,” wrote Matt Phipps, a research analyst at William Blair, in an Oct. 9 report. Phipps notes that the addition of MRTX1719 to BMS’s product line is promising, but he cautions that Amgen is developing a similar drug, and initial data is expected as soon as Oct. 13.