HUTCHMED (Stock Code: 00013) published an announcement disclosing the start of a Phase I/IIa clinical trial for HMPL-A580, its second novel Antibody-Targeted Therapy Conjugate (ATTC). The trial focuses on unresectable, advanced, or metastatic solid tumors in China and the US, where the first patient was dosed on March 4, 2026.

HMPL-A580 is a first-in-class candidate combining a selective PI3K/PIKK small-molecule inhibitor payload with an anti-EGFR antibody. According to the announcement, this dual-target approach seeks to deliver simultaneous inhibition of the PAM pathway and EGFR signaling with the goal of improving anti-tumor activity. Preclinical data indicate that inhibiting the PAM pathway may enhance the anti-tumor effects of EGFR blockade.

The Phase I/IIa trial assesses the safety, tolerability, pharmacokinetics, immunogenicity, and preliminary efficacy of HMPL-A580. The Phase I portion explores dose escalation, while the Phase IIa part evaluates safety and anti-tumor activity in selected solid tumors to inform optimization and future clinical strategy. Details of the study design and patient enrollment are available under clinical trial identifier NCT07396584.

HUTCHMED’s ATTC platform underlies this approach by combining monoclonal antibodies with small-molecule inhibitor payloads, aiming to enhance targeted delivery, reduce off-tumor toxicity, and achieve deep, durable responses in various cancer types. The company’s announcement references plans to further advance HMPL-A580 and other ATTC candidates to address unmet medical needs.

The announcement also includes forward-looking statements regarding potential outcomes, safety, and approvals, reminding readers of associated development risks and uncertainties. Additional information is provided in HUTCHMED’s regulatory filings and disclosures.