AP Biosciences Begins Phase 1/2 Trials of AP402 for HER2+ Cancer

AP Biosciences, a biopharmaceutical company focused on cancer therapy innovation, has commenced a Phase 1 clinical trial for its promising new treatment, AP402. The trial, which recently dosed its first patient, is being conducted in Australia and is intended to assess the safety, tolerability, and initial effectiveness of AP402. This drug targets patients with advanced solid tumors who have not responded to traditional anti-HER2 treatments. The research may eventually expand to include sites in Taiwan, South Korea, and the United States.

The AP402 treatment is unique in its approach. It is a T cell engager that targets a specific truncated form of HER2, known as p95HER2, which is found in 30-40% of HER2-positive cancers. This variant is linked to poor prognosis and is not adequately addressed by existing therapies. AP402 is notable for being the only T-cell engager in clinical trials that connects activated T cells with p95HER2-expressing cancer cells within the tumor environment. This mechanism is designed to provide a strong immune response with minimal systemic toxicity, offering hope for patients with challenging cancers.

The Phase 1 trial, registered as AP402-101 (NCT06669975), is an open-label study across multiple centers that will enroll up to 85 participants. The trial is structured in two parts: an initial dose-escalation phase to find the maximum tolerated dose and a recommended dose for Phase 2, followed by a dose-expansion phase aimed at specific HER2-positive tumors. Primary goals of the study are to evaluate safety and tolerability, while secondary goals include assessing the objective response rate, disease control rate, and pharmacokinetic characteristics. Additionally, exploratory outcomes will investigate pharmacodynamic biomarkers and immunogenicity.

AP Biosciences plans to present preclinical data supporting AP402's therapeutic potential at the upcoming American Association of Cancer Research (AACR) conference. This presentation is expected to highlight the promise of AP402 in treating cancers that have become resistant to conventional therapies.

AP402's creation stems from AP Biosciences' innovative T-cube bispecific antibody technology, which combines targeting of the p95HER2 variant with a CD137 activation domain. This design allows T-cell activation to occur specifically within the tumor microenvironment, enhancing the immune response without causing widespread side effects like cytokine release. The antibody structure facilitates the clustering of HER2 variants, effectively triggering CD137-mediated T-cell activation. This ability to bridge HER2 variant-expressing cancer cells with CD137-expressing T-cells offers a targeted approach to recruit immune cells efficiently.

AP Biosciences is headquartered in Taiwan and is known for its commitment to developing cutting-edge antibody therapies for cancer. Utilizing its proprietary Omni-Mab and T-cube platforms, the company is at the forefront of creating bispecific antibodies that activate the immune system precisely where needed, aiming to treat both established and resistant forms of cancer.

Through its latest endeavors, AP Biosciences is paving the way for new treatments that could significantly impact the lives of patients with difficult-to-treat cancers, providing them with new therapeutic options where existing treatments are inadequate.