Aptevo Therapeutics and Alligator Bioscience to Present Positive Interim Phase 1 Data Evaluating ALG.APV-527 Monotherapy in Multiple Solid Tumor Types, at ESMO Congress 2024

SEATTLE WA and LUND, SWEDEN / ACCESSWIRE / September 13, 2024 / Aptevo Therapeutics ("Aptevo") (NASDAQ:APVO) and Alligator Bioscience AB ("Alligator") (ATORX) today announced that positive interim data from the dose escalation phase of their Phase 1 trial evaluating ALG.APV-527 will be presented in a poster session on Saturday, September 14, 2024, at the European Society for Medical Oncology (ESMO) Annual Congress 2024, taking place September 13 th - 17 th , 2024 in Barcelona, Spain.

Presentation Details

Poster number: #668P

Title: First-in-Human Phase I Dose Escalation Study of ALG.APV-527, a 5T4 Tumor Antigen-Conditional 4-1BB Bispecific Antibody, in Patients with Advanced Solid Tumors, Demonstrates Positive Safety, Signals of Biological Activity and Patients with Lasting Stable Disease

Presenter: Thomas Marron, MD, PhD

Date/Time: Saturday, September 14 th

About the Trial

The ALG.APV-527 Phase 1 trial is a multi-center, multi-cohort, open-label dose-escalation trial that will include administration of ALG.APV-527 up to sixescalating dose levels in a 3+3 design*. The trial will be conducted at up to 10 sites in the U.S. and will enroll adult patients with multiple solid tumor types/histologies likely to express the 5T4 antigen. ALG.APV-527 will be given intravenously once every two weeks. The trial will assess the safety and tolerability, pharmacokinetics, pharmacodynamics and preliminary anti-tumor activity of ALG.APV-527.

*The 3+3 design proceeds in cohorts of three patients treated at increasing dose levels. Dose escalation stops when at least two out of three or six patients experience dose limiting toxicities (DLTs) at that dose level.

About ALG.APV-527

ALG.APV-527 is a bispecific conditional 4-1BB agonist, only active upon simultaneous binding to 4-1BB and 5T4. This has the potential to be clinically important because 4-1BB can stimulate the immune cells (antitumor-specific T cells and NK cells) involved in tumor control, making 4-1BB a particularly compelling target for cancer immunotherapy. 5T4 is an oncofetal tumor associated antigen overexpressed on numerous solid tumors including non-small-cell lung carcinoma (NSCLC), breast, head and neck, cervical, renal, gastric, and colorectal cancer.

Preclinical studies, highlighting the differentiated design of the molecule that minimizes systemic immune activation, allowing for highly efficacious tumor-specific responses as demonstrated by potent activity in preclinical models, has been published in the peer-reviewed publication, Molecular Cancer Therapeutics , a journal of the American Association for Cancer Research (AACR).

About Aptevo Therapeutics

Aptevo Therapeutics Inc. is a clinical-stage biotechnology company focused on developing novel bispecific immunotherapies for the treatment of cancer. Aptevo is seeking to improve treatment outcomes and transform the lives of cancer patients. For more information, please visit www.aptevotherapeutics.com.

About Alligator Bioscience

Alligator Bioscience AB is a clinical-stage biotechnology company developing tumor-directed immuno-oncology antibody drugs. Alligator's portfolio includes several promising drug candidates, with the CD40 agonist mitazalimab as its key asset. Furthermore, Alligator is co-developing ALG.APV-527 with Aptevo Therapeutics Inc., several undisclosed molecules based on its proprietary technology platform, Neo-X-Prime™, and novel drug candidates based on the RUBY™ bispecific platform with Orion Corporation. Out-licensed programs include AC101/HLX22, in Phase 2 development, by Shanghai Henlius Biotech Inc. and an undisclosed target to Biotheus Inc.

Alligator Bioscience's shares are listed on Nasdaq Stockholm (ATORX) and is headquartered in Lund, Sweden. For more information, please visit alligatorbioscience.com.

For additional information, please contact:

Aptevo Therapeutics Miriam Weber Miller Aptevo Therapeutics [email protected] or [email protected] +1 (206) 859 6629

Alligator Bioscience

Corporate Søren Bregenholt, CEO [email protected] +46 46-540 82 00

Media

Sam Cage Cohesion Bureau [email protected] +45 24 37 63 42

Investors

Frank Hoerning Andersen Cohesion Bureau [email protected] +45 25 66 86 02