** Shares of Agenus AGEN.O soar 22.4% to $4.07 premarket

** The biotech firm says it secured up to $340 mln in private financing led by Commodore Capital and backed by RA Capital Management and other investors

** Funding will support a late-stage trial of experimental cancer drug combination botensilimab and balstilimab in high-risk colon cancer patients

** AGEN says study targets microsatellite-stable colon cancer, the most common form of the disease

** Adds that financing includes $85 mln upfront and up to $255 mln from warrant exercises, which can fund operations through 2031

** Says it would stop funding a separate study in advanced colon cancer to focus resources on the new trial

** Expects to begin enrolling patients in early 2027 and report initial results later that year

** As of last close, stock up ~7% YTD