Aptevo Therapeutics (NASDAQ:APVO) saw its stock jump 57% on Tuesday after announcing that Cohort 3 of its Phase 1b/2 RAINIER trial for acute myeloid leukemia (AML) achieved a 100% remission rate.
The study is testing mipletamig, Aptevo’s CD123 x CD3 bispecific antibody, alongside venetoclax and azacitidine in newly diagnosed AML patients who are ineligible for intensive chemotherapy. The company reported no dose-limiting toxicities or cytokine release syndrome during the trial.
The complete remission observed at the highest dose underscores mipletamig’s potential to enhance frontline AML therapy. Additionally, 40% of patients achieved minimal residual disease (MRD)-negative status, an indicator associated with improved long-term outcomes.
“Cohort 3 demonstrates the kind of progress that changes expectations for frontline AML therapy,” said Marvin White, President and CEO of Aptevo. “Delivering a 100% remission rate reinforces our conviction that mipletamig is more than an active agent—it’s a differentiated medicine designed to integrate with the venetoclax and azacitidine backbone and elevate outcomes for patients who have had too few options for too long.”
The company emphasized that the frontline AML market is worth billions globally, and current standard treatments yield lower remission rates than those seen in the RAINIER trial. Cohort 3 enrollment is now complete, and Cohort 4 is underway at the next dose level. Aptevo plans to share the latest results at a major medical conference in Q4.
Aptevo Therapeutics stock price
This content is for informational purposes only and does not constitute financial, investment, or other professional advice. It should not be considered a recommendation to buy or sell any securities or financial instruments. All investments involve risk, including the potential loss of principal. Past performance is not indicative of future results. You should conduct your own research and consult with a qualified financial advisor before making any investment decisions.