Aptevo Therapeutics Doses First Patient in Phase 1/1b Clinical Trial of Lead Next-Generation Bispecific Antibody APVO436

Aptevo Therapeutics (Nasdaq:APVO), a biotechnology company focused on developing novel oncology and hematology therapeutics, announced today that the first patient has been dosed in a Phase 1/1b clinical trial of APVO436, a novel anti-CD123 by anti-CD3 bispecific antibody based on Aptevo’s ADAPTIR™ technology, which is being developed for the treatment of patients with Acute Myeloid Leukemia (AML) and High-Grade Myelodysplastic Syndrome (MDS).

As quoted in the press release:

As a novel immunotherapy, APVO436 is designed to engage the immune system to mount a targeted response against CD123-expressing hematological tumors.   Cytokine release syndrome (CRS) is a significant concern with T-cell activating therapies and has been associated with severe complications in clinical trials.  In preclinical studies, APVO436 induced lower levels of several key T-cell cytokines, including IFNg, IL-2, IL-6, and TNFa.  Aptevo believes that the improved cytokine activation profile observed in preclinical studies of APVO436 suggest that it could offer a potential safety advantage with reduced toxicities compared to other CD123 x CD3 T-cell engagers at comparable or higher doses.

“Today’s news represents an important milestone for Aptevo and for AML and MDS patients,” said Dr. Scott Stromatt, Chief Medical Officer for Aptevo.  “There is a strong unmet medical need for novel targeted biological therapies to treat patients with relapsed or refractory AML or MDS.  Chemotherapy, which is the standard of care for these patients, is generally poorly tolerated in the elderly, and patients are still confronted with high relapse rates after treatment.  Recent clinical data has demonstrated that CD123 is a validated target for AML therapy. We are particularly excited to begin clinical evaluation of APVO436 as our preclinical data suggest that it possesses best-in-class attributes and could offer benefits compared to current investigational therapies.”

Click here to read the full press release.