05:10 PM EDT, 08/29/2024 (MT Newswires) -- NuCana ( NCNA ) sank 47% in extended trading Thursday, after saying it is discontinuing phase 2 testing of its NUC-3373 drug candidate for the potential colorectal cancer treatment.

The company made the decision after determining that a combination of NUC-3373 with three different chemotherapies would unlikely meet the primary endpoint of superior progression-free survival compared with a control arm.

All three active arms of the trial demonstrated a favorable safety profile and NUC-3373 also was generally well tolerated, the company said, with only 12 of the 175 patients enrolled in the study discontinuing treatment because of adverse events.

NuCana ( NCNA ) expects to discuss data from another trial combining NUC-7738 with Merck's (MRK) Keytruda in patients with melanoma next month at an industry conference.

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