8-K/A: Abpro & Celltrion Advance HER2 T-Cell Engager CT-P72/ABP-102

Abpro and Celltrion announced new preclinical data for their bispecific antibody CT-P72/ABP-102, demonstrating potent anti-tumor activity in HER2-high and Enhertu-resistant models with a favorable safety profile, supporting its clinical advancement.

Summary

• Abpro Corporation and Celltrion, Inc. will present new preclinical data for CT-P72/ABP-102, a tetravalent bispecific antibody targeting HER2 and CD3, at the SITC 2025 Annual Meeting.
• The CT-P72/ABP-102 poster was selected as one of the Top 150 abstracts out of more than 1,300 submissions at SITC 2025.
• Preclinical data showed CT-P72/ABP-102 has potent and selective anti-tumor activity in HER2-high models, including those resistant to Enhertu.
• Dual-affinity engineering in CT-P72/ABP-102 reduces on-target, off-tumor activity, contributing to a favorable preclinical safety profile.
• The data supports the advancement of CT-P72/ABP-102 toward clinical development for HER2-positive cancers.
• Abpro and Celltrion plan to assemble a robust Investigational New Drug (IND) submission package and initiate the first-in-human trial for CT-P72/ABP-102 next year.

Sentiment

Score: 9

Explanation: The filing presents very strong positive preclinical data for a lead therapeutic candidate, including efficacy in drug-resistant models and a favorable safety profile. The recognition by SITC as a top abstract further enhances the positive sentiment, indicating significant progress towards clinical development.

Positives

• CT-P72/ABP-102 poster was selected as one of the Top 150 abstracts out of over 1,300 submissions at SITC 2025, indicating high scientific merit.
• The molecule demonstrated potent and selective anti-tumor activity in HER2-high models.
• Efficacy was observed in Enhertu-resistant gastric cancer models (NCI-N87/hABCG2), addressing a significant unmet medical need.
• A GLP repeated-dose toxicity study in cynomolgus monkeys showed good tolerability at all tested doses, including the highest dose (80 mg/kg), supporting a favorable safety profile.
• The dual-affinity engineering reduces binding to HER2-expressing normal tissues and CD3 on T cells with reduced affinity, aiming to minimize off-tumor effects and cytokine-related toxicity.
• The data provides a strong foundation for advancing the program to first-in-human clinical trials next year.

Risks

• The timing and advancement of development programs, including the timing and availability of additional data, may differ from expectations.
• Actual therapeutic benefits of Abpro's programs may differ from expectations.
• Final data from preclinical studies and completed clinical trials may differ materially from reported interim data from ongoing studies and trials.
• Abpro's ability to continue as a going concern and achieve compliance with Nasdaq listing standards is subject to risks.
• Risks are associated with Abpro's ability to efficiently discover and develop product candidates, obtain and maintain regulatory approval, and maintain intellectual property.
• The implementation of Abpro's business model, including strategic plans and product candidates, involves inherent risks.

Future Outlook

Abpro and Celltrion are highly encouraged by the preclinical data for CT-P72/ABP-102 and plan to build upon this foundation to assemble a robust IND submission package. They anticipate initiating the first-in-human trial for CT-P72/ABP-102 next year, aiming to develop safer, more precise treatments for patients with HER2-driven cancers worldwide.

Management Comments

• Miles Suk, CEO & Chairman of Abpro: "We are highly encouraged by the preclinical data emerging from our collaboration with Celltrion. CT-P72/ABP-102 has shown highly selective binding and compelling anti-tumor activity across HER2-high models, including Enhertu-resistant settings, while maintaining a favorable safety profile in non-human primates. These findings highlight the strength of our DiversImmune platform and reinforce our confidence in the program's clinical potential. We look forward to working with Celltrion to build upon this strong foundation to assemble a robust IND submission package and initiate the first-in-human trial for CT-P72/ABP-102 next year."
• Soo Young Lee, EVP and Head of New Drug Division at Celltrion: "CT-P72/ABP-102 represents a significant advance in the field of bispecific antibodies for targeting solid tumors. By combining dual-affinity engineering with tetravalent design, we've achieved a molecule that maintains potent anti-tumor activity in HER2-high models, including those resistant to current therapies, while minimizing off-tumor effects. These preclinical results validate our approach and underscore the potential for CT-P72/ABP-102 to set a new standard for safety and selectivity in HER2-targeted immunotherapy."
• Miles Suk: "We deeply value our partnership with Celltrion, a global leader in biologics and a trusted collaborator in advancing antibody-based therapeutics. Together, we are working to develop safer, more precise treatments for patients with HER2-driven cancers worldwide."

Industry Context

This announcement highlights the ongoing innovation in oncology, particularly in the development of bispecific antibodies and T-cell engagers for solid tumors. The focus on HER2-positive cancers, including those resistant to existing therapies like Enhertu, positions CT-P72/ABP-102 in a high-need area. The dual-affinity engineering approach aims to overcome common challenges in T-cell engager therapies, such as off-tumor activation and cytokine-related toxicity, which is a key trend in improving the safety profile of these potent agents.

Comparison to Industry Standards

• CT-P72/ABP-102 demonstrated efficacy in Enhertu-resistant gastric cancer models, suggesting a potential advantage over established antibody-drug conjugates (ADCs) like Enhertu (trastuzumab deruxtecan) in certain patient populations.
• The selection of the CT-P72/ABP-102 poster as one of the Top 150 abstracts out of more than 1,300 submissions at SITC 2025 indicates strong peer recognition and scientific merit within the immunotherapy field.
• The dual-affinity engineering and tetravalent design aim to set a new standard for safety and selectivity in HER2-targeted immunotherapy, addressing a critical limitation of some current T-cell engager therapies that struggle with on-target, off-tumor toxicity.

Stakeholder Impact

• Shareholders: Positive impact due to strong preclinical data for a key pipeline asset, potentially increasing company valuation and investor confidence.
• Patients: Potential for a new, safer, and more effective treatment option for HER2-positive cancers, especially those resistant to current therapies.
• Employees: Continued progress in drug development supports job security and potential for future growth.
• Regulatory Authorities: Will review the IND submission, potentially leading to clinical trial approval.

Next Steps

• Presentation of new preclinical data for CT-P72/ABP-102 at the SITC 2025 Annual Meeting (November 6-10, 2025).
• Assembly of a robust Investigational New Drug (IND) submission package.
• Initiation of the first-in-human trial for CT-P72/ABP-102 next year.

Key Dates

Recommendation

The robust preclinical data for CT-P72/ABP-102, demonstrating potent anti-tumor activity in HER2-high and Enhertu-resistant models with a favorable safety profile, significantly de-risks the program's early development. The recognition as a top abstract at a major scientific conference further validates its potential. The clear path to an IND submission and first-in-human trial next year indicates strong progress. For a biotech company, such positive preclinical results for a lead candidate addressing an unmet medical need are highly indicative of future value creation, warranting a 'strong buy' recommendation.

Keywords

HER2, CD3, Bispecific Antibody, T-Cell Engager, CT-P72/ABP-102, Abpro, Celltrion, Preclinical Data, Immunotherapy, Cancer, Oncology, Enhertu-resistant, DiversImmune platform, SITC 2025