Retail traders cooled on Bayer shares Tuesday after the company unveiled a big-ticket partnership with Kumquat Biosciences to develop a new cancer drug aimed at one of oncology’s toughest genetic targets.

Bayer will pay up to $1.3 billion under an exclusive global licensing and collaboration agreement for Kumquat’s KRAS G12D inhibitor, a precision medicine candidate for pancreatic, colorectal, and lung cancers. 

The San Diego biotech, founded by scientists known for pioneering KRAS research, has recently received FDA clearance to initiate human trials, with the first Phase Ia study scheduled to launch under Kumquat’s watch. Bayer will step in to handle later development and commercialization.

The financial terms include upfront and milestone payments, as well as tiered royalties on sales if the drug reaches the market. Kumquat also holds an option to negotiate a U.S. profit-sharing arrangement.

Bayer’s Head of Business Development and Licensing, Juergen Eckhardt, said the tie-up is part of the company’s push into high-need cancer areas, noting that Kumquat’s expertise could help fill a major treatment gap. 

Roughly one in four cancers involve KRAS mutations, but the G12D variant, which is the most common and aggressive of them all, still has no approved drug to target it.

Its biggest footprint is in pancreatic ductal adenocarcinoma (PDAC), where it shows up in more than a third of patients. 

PDAC makes up about 85% of all pancreatic cancers and is hard to treat, with fewer than one in ten people surviving beyond five years. Cases are expected to nearly double worldwide by 2050, the company stated in a press release. 

Kumquat CEO Yi Liu said the deal validates the company’s approach and will provide it with the resources to advance its KRAS G12D program while accelerating other projects in its pipeline. 

On Stocktwits, retail sentiment for Bayer was ‘bearish’ amid ‘normal’ message volume.

Bayer’s U.S.-listed stock has risen 53% so far in 2025.

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