Compass Therapeutics (CMPX) said Tuesday topline data from an ongoing phase 2/3 trial of tovecimig combined with paclitaxel in biliary tract cancer showed 'statistically significant' improvement in overall response rate, indicating it has met the trial's primary efficacy endpoint.

The drug combination achieved a 17.1% ORR, including one complete response, versus 5.3% for paclitaxel alone.

The secondary endpoints including progression-free survival, overall survival, and duration of response-could not be analyzed yet due to insufficient events, with data expected in Q4, the company said.

Shares rose 11% in recent premarket trading.