LUND, Sweden and SEATTLE, WA, USA I October 24, 2017 I Alligator Bioscience (Nasdaq Stockholm: ATORX), a biotechnology company developing antibody-based pharmaceuticals for tumor-directed immunotherapy and Aptevo Therapeutics Inc. (Nasdaq: APVO), a biotechnology company focused on developing novel immuno-oncology and hematology therapeutics, today announced further details of the companies’ collaboration on ALG.APV-526, a bispecific antibody targeting 4-1BB and a tumor antigen, now identified as 5T4, which is found on various types of cancer cells.

5T4 is a protein predominantly expressed on tumor cells.  It is present at very low levels or not at all in normal tissue. This enables the immune-activating effect of ALG.APV-527 to be targeted specifically to the tumor and not against normal tissue, the goal being effective tumor-directed immune activation with minimal side effects.  The 5T4 tumor antigen is present on a number of different solid tumors, including breast, cervical, non-small-cell-lung, prostate, renal, gastric, colorectal and bladder cancers, indicating that ALG.APV-527 may be used for the treatment of several different types of cancer.

“The fact that 5T4 is selectively expressed on tumor cells in many different cancer indications, but in very low levels in normal tissue, makes it a very attractive target for tumor-directed immunotherapy,” said Professor Peter Stern, Manchester University, UK.

By combining a tumor-binding and an immunomodulatory antibody in one molecule, Alligator and Aptevo have created a drug candidate whose effect is localized to the tumor area, activating the tumor-specific immune cells present there.   

About Dr. Peter Stern
Professor Peter Stern, University of Manchester, United Kingdom, advisor to the joint venture, discovered the 5T4 antigen in 1988. He is an expert in tumor-associated antigens and virus-associated tumors.  Professor Stern’s research has contributed substantially to the development of both cancer vaccines and antibody-based drugs for cancer treatment.

About ALG.APV-527
ALG.APV-527 is a bispecific antibody (4-1BB x 5T4) intended for tumor-directed treatment of solid cancers. The ALG.APV-527 antibody consists of two parts, one part activating tumor-specific T cells through the co-stimulatory receptor 4-1BB (CD137), the other part binding to the 5T4 protein expressed on the surface of tumor cells.

About Aptevo Therapeutics Inc.
Aptevo Therapeutics Inc. is a clinical-stage biotechnology company focused on novel oncology and hematology therapeutics to meaningfully improve patients’ lives.  Aptevo has a commercial product, IXINITY®, approved and marketed in the United States for the treatment of Hemophilia B, and a versatile core technology – the ADAPTIR™ modular protein technology platform capable of generating highly-differentiated bispecific antibodies with unique mechanisms of action to treat cancer or autoimmune diseases.  Aptevo has two ADAPTIR antibody candidates currently in clinical development and a broad pipeline of novel investigational-stage bispecific antibody candidates focused in immuno-oncology and autoimmune disease and inflammation. For more information, please visit

About Alligator Bioscience
Alligator Bioscience AB is a clinical-stage biotechnology company developing tumor-directed immuno-oncology antibody drugs. Alligator’s growing pipeline includes lead clinical and pre-clinical drug candidates (ADC-1013, ATOR-1015, ATOR-1017, and ALG.APV-527) and novel research candidates. ADC-1013 (JNJ-64457107) is licensed to Janssen Biotech, Inc., part of J&J, for global development and commercialization. Alligator’s shares are listed on Nasdaq Stockholm (ATORX). The Company is headquartered in Lund, Sweden, and has approximately 45 employees. For more information, please visit

SOURCE: Alligator Biosciences