Aptevo Therapeutics Inc’s shares fell 17.3% in pre-market trading to $2.15 on Wednesday, extending a decline that has pushed the stock near its 52-week low of $2.30.
The drop follows the company’s disclosure of Phase 1b/2 trial results for its mipletamig triplet therapy in evaluable frontline acute myeloid leukemia patients with TP53 mutations. Among 14 evaluable patients, the therapy achieved a 93% clinical benefit rate, with 11 patients reaching complete remission or complete remission with incomplete hematologic recovery—a 79% remission rate. This exceeded a historical benchmark of 41%.
The company also highlighted the potential for significant share dilution. An August 2026 warrant inducement and private investment in public equity (PIPE) financing created the possibility of more than 6.4 million new shares entering the market via a resale registration statement. This figure substantially exceeds the roughly 1.8 million shares of common stock outstanding as of late August.
Aptevo’s stock has lost nearly all of its value over the past year, falling from a 52-week high of $48.78. The broader U.S. equity market showed modest gains, with the S&P 500 up 0.3%, the Dow Jones rising 0.6%, and the Nasdaq adding 0.1%.
