September 4, 2025 — Leads & Copy — Aptevo Therapeutics Inc. (NASDAQ:APVO) has announced the expansion of its anti-cancer pipeline with two provisional patents for trispecific candidates, APVO452 and APVO451. These candidates target prostate and multiple solid tumor cancers by engaging tumor antigens, T cells, and immunosuppressive cells.
The new programs build on Aptevo’s suite of CRIS-7-derived, CD3-directed molecules, supported by clinical validation from mipletamig, which has shown safety and efficacy in treating acute myeloid leukemia (AML).
Aptevo’s CD3-engaging portfolio includes mipletamig, a CD123 x CD3 bispecific in a Phase 1b/2 trial for frontline AML. Mipletamig has been evaluated in over 100 patients across three trials, demonstrating high remission rates and a favorable safety profile.
The expansion includes tumor-directed bispecifics APVO442 (prostate, PSMA x CD3) and APVO455 (solid tumors, Nectin-4 x CD3), all sharing the CRIS-7-derived CD3 binding domain.
According to Peter Pavlik, PhD, Senior Director of Protein Engineering at Aptevo, these trispecific molecules, powered by the ADAPTIR-FLEX platform, activate T cells in a tumor-specific manner and modulate the immunosuppressive tumor microenvironment.
APVO452 targets PSMA, CD3, and CD40 for prostate cancers, while APVO451 targets Nectin-4, CD3, and CD40 for a range of solid tumors. Early data indicate potent, anti-cancer activity that attacks cancer in multiple ways.
Lynn Bonham, PhD, Senior Director of Translational Pharmacology at Aptevo, noted that these molecules lock onto the tumor, activate T cells, and reprogram suppressive immune cells.
With the addition of APVO452 and APVO451, Aptevo has eight bispecific and trispecific therapeutic candidates, positioning the company at the forefront of next-generation T cell engagers.
Miriam Weber Miller, Head of Investor Relations & Corporate Communications, Email: IR@apvo.com or Millerm@apvo.com, Phone: 206-859-6628
Source: Aptevo Therapeutics
