HER2 Positive Cancer

TAIPEI, Taiwan I April 29, 2025 I AP Biosciences, a clinical-stage biopharmaceutical company dedicated to transforming cancer therapy through innovative bispecific antibodies, today announced the presentation of new preclinical data for its lead asset, AP402, at the 2025 American Association for Cancer Research (AACR) Annual Meeting in San Diego, California. The data, presented in a poster titled “AP402, a bispecific antibody targeting p95HER2 and CD137, shows potent antitumor activity,” highlight the therapeutic potential of AP402 to address treatment-resistant HER2-positive cancers through conditional T-cell engagement. “The findings presented at AACR reinforce the rationale for advancing AP402 into clinical studies,” said Jeng Her, Ph.D., Founder and Chief Executive Officer of AP Biosciences. “By selectively targeting p95HER2—a truncated HER2 isoform implicated in therapeutic resistance—and conditionally activating CD137, AP402 offers a unique mechanism to recruit and stimulate immune effector cells while minimizing the risk of systemic toxicity. These data demonstrate the strength of our T-cube platform in delivering targeted immune activation precisely within the tumor microenvironment.” Results Summary In conclusion, the preclinical data show that AP402 effectively engages innate and adaptive immune responses, demonstrates robust antitumor activity in p95HER2-expressing tumor models, and is well tolerated in non-human primates. These findings support the continued development of AP402, which recently entered clinical evaluation in Australia ( NCT06669975 ). About AP402 AP402 is a first-in-class bispecific antibody developed by AP Biosciences to target p95HER2, a truncated variant of HER2 associated with resistance to Herceptin and poorer prognosis. This variant is present in approximately 30–40% of HER2-positive breast cancer patients. By leveraging p95HER2 recognition to cluster CD137, the design enables localized T-cell activation within the tumor microenvironment, helping to minimize systemic cytokine-related toxicity. The binding domains for p95HER2 and CD137 are strategically positioned on opposite ends to enhance bridging between HER2 variant-expressing cancer cells and CD137-expressing T-cells, ensuring efficient immune cell recruitment without spatial hindrance. This novel mechanism has positioned AP402 as a promising therapeutic approach to addressing tumors that have developed resistance to traditional anti-HER2 therapies, offering potential new hope for patients with refractory/recurrent cancers. About AP Biosciences AP Biosciences is a Taiwan-based clinical-stage biopharmaceutical company committed to developing innovative antibody-based therapies for cancer and other diseases. Applying its proprietary Omni-Mab and T-cube platforms, AP Biosciences is pioneering next generation bispecific antibodies that activate the immune system precisely where it’s needed, for both established and treatment-resistant cancers. SOURCE: AP Biosciences

AstraZeneca (AZ) and Daiichi Sankyo have shared positive results from a late-stage study of their antibody drug conjugate (ADC) Enhertu (trastuzumab deruxtecan) in patients with HER2-positive metastatic breast cancer. The phase 3 DESTINY-Breast09 study has been evaluating the drug in combination with pertuzumab as a first-line treatment for this patient population. Up to 20% of patients with metastatic breast cancer are affected by HER2-positive disease. Despite HER2-targeted therapies improving outcomes, prognosis remains poor, with the majority of patients experiencing disease progression within two years of first-line treatment with standard-of-care taxane, trastuzumab and pertuzumab (THP). Enhertu, which targets HER2 on cancer cells, is already approved in more than 75 countries globally to treat adults with pre-treated unresectable or metastatic HER2-positive breast cancer. In DESTINY-Breast09, Enhertu plus pertuzumab demonstrated a highly statistically significant and clinically meaningful improvement in progression-free survival compared to THP, with this benefit seen across all pre-specified patient subgroups. Interim overall survival data also showed an early trend favouring Enhertu plus pertuzumab compared to THP, but this was not mature at the time of the planned interim analysis. The safety profile of the Enhertu combination was consistent with the known profiles of the individual therapies. The results make DESTINY-Breast09 the first trial in more than a decade to demonstrate superior efficacy across a broad HER2-positive metastatic breast cancer patient population compared to the current first-line standard of care, according to the companies. Susan Galbraith, executive vice president, oncology haematology research and development, AZ, said the results mark a “significant milestone for patients and [set] the foundation for Enhertu in combination with pertuzumab as an important treatment option in the first-line HER2-positive setting.” Ken Takeshita, global head, research and development, Daiichi Sankyo, added: “The results from DESTINY-Breast09 reinforce the importance of effectively targeting HER2 to achieve durable disease control early in the treatment of HER2-positive metastatic breast cancer. “Building on the positive results seen with Enhertu in the second-line setting, these new findings suggest that starting treatment with Enhertu in combination with pertuzumab at the time of metastatic diagnosis delays disease progression, postponing the time until additional treatment may be needed.” Data from the combination arm of DESTINY-Breast09 will be shared with regulatory authorities, the companies outlined, adding that the second arm evaluating Enhertu monotherapy versus THP remains blinded to patients.

TAIPEI, Taiwan, April 22, 2025 (GLOBE NEWSWIRE) -- AP Biosciences, a clinical-stage biopharmaceutical company dedicated to transforming cancer therapy through development of innovative bispecific antibodies, today announced that it has dosed the first patient in its Phase 1 study evaluating AP402, a potential first-in-class, next generation T cell engager targeting CD137 and p95HER2 in patients relapsed/refractory to anti-HER2 treatment. The Phase 1 clinical trial, currently taking place in Australia, is designed to evaluate the safety, tolerability, and preliminary efficacy of AP402 in HER2+ patients with advanced solid tumors, including breast cancer. The following dose expansion phase of the study may include clinical sites in Taiwan, South Korea and the United States. “AP402 targets p95HER2, a truncated form of HER2 present in 30-40% of HER2-positive cancers, which is associated with exceptionally poor prognosis, and not addressable by conventional anti-HER2 therapies,” said Dr. Jeng Her, Ph.D., Founder and Chief Executive Officer of AP Biosciences. “AP402 represents the only T-cell engager in human trials which bridges activated T cells and p95HER2-expressing cancer cells in the tumor – a differentiated mechanism that could deliver a powerful immune response while minimizing systemic toxicity. AP402 thus offers promise as a potential therapeutic option for patients with difficult-to-treat cancers that could enhance efficacy and safety where other treatments fall short.” AP402-101 (NCT06669975), is a multi-center, open-label Phase 1 trial, enrolling up to 85 patients divided in two parts: a dose-escalation phase to determine the maximum tolerated dose and recommended Phase 2 dose (RP2D), followed by a dose-expansion phase targeting specific HER2-positive tumor types. Primary endpoints of the study include safety and tolerability, while secondary endpoints will evaluate objective response rate (ORR), disease control rate (DCR), and pharmacokinetic (PK) parameters. Exploratory endpoints will assess pharmacodynamic biomarkers and immunogenicity. The Company has announced that preclinical data supporting the therapeutic potential of AP402 will be presented in a poster at this year’s American Association of Cancer Research (AACR) conference. Visit https://www.apbioinc.com/en/ for more information about AP Biosciences and its pipeline of next-generation cancer therapies. About AP402AP402 is a first-in-class bispecific antibody originated and developed by AP Biosciences to target p95HER2, a truncated variant of HER2 that is expressed in 30-40% of treatment-resistant HER2-positive cancers. AP402 is constructed using T-cube bispecific antibody technology which combines p95HER2 targeting with a CD137 activation domain to enable target-dependent T-cell activation exclusively in the tumor microenvironment. The antibody design facilitates clustering of HER2 variants to effectively trigger CD137-mediated T-cell activation, while minimizing potential side effects related to systemic cytokine release. The binding domains for p95HER2 and CD137 are designed to enhance bridging between HER2 variant-expressing cancer cells and CD137-expressing T-cells, ensuring efficient immune cell recruitment without spatial hindrance. This novel mechanism has positioned AP402 as a promising potential therapeutic approach to addressing tumors that have developed resistance to traditional anti-HER2 therapies, offering new hope for patients with refractory/recurrent cancers. About AP Biosciences AP Biosciences is a Taiwan-based clinical-stage biopharmaceutical company committed to developing innovative antibody-based therapies for cancer and other diseases. Applying its proprietary Omni-Mab and T-cube platforms, AP Biosciences is pioneering next generation bispecific antibodies that activate the immune system precisely where it’s needed, for both established and treatment-resistant cancers. AP Biosciences ContactSpike LoAP Biosciencespr@apbioinc.com+886-2-2653-2886 Media ContactJason Braco, PhDLifeSci Communicationsjbraco@lifescicomms.com(908)-432-4243