Kainova Therapeutics has announced encouraging topline findings from its phase 1 EPRAD study of DT-9081, an oral EP4 receptor antagonist being developed for patients with advanced, recurrent and metastatic solid tumours.

The study, carried out at four sites in France and Belgium, met all its primary objectives. According to the company, DT-9081 demonstrated a favourable safety profile alongside robust pharmacokinetic and pharmacodynamic characteristics, including dose-proportional exposure and sustained EP4 receptor engagement across all tested doses.

Investigators also observed early signs of anti-tumour activity. No dose-limiting toxicities were reported, supporting the therapy’s tolerability and mechanism of action. Full details are available under clinicaltrials.gov identifier NCT05582850.

Professor Jean-Pascal Machiels, Principal Investigator of the EPRAD study, commented: “The results of the study not only validate EP4 receptor antagonism as a powerful mechanism to counteract PGE2-driven immune suppression, but also demonstrate the clinical potential of DT-9081 across a range of tumour types.

Since chemotherapy and other standard treatments often trigger PGE2 production by cancer cells, restoring competence through selective EP4 inhibition offers a rational and versatile strategy to overcome resistance. It was my honour to contribute to the advancement of DT-9081 through the clinic.”

Dr Jean-Marie Cuillerot, Chief Medical Officer of Kainova Therapeutics, said: “The phase I EPRAD study generated a clear and coherent data set that precisely characterises DT-9081’s clinical profile. Across all dose levels, we observed consistent safety findings together with robust PK/PD readouts.

“The high-quality clinical and translational data obtained in this study are essential for understanding how EP4 antagonism behaves in patients with advanced solid tumours in a clinical setting.”

HUTCHMED has initiated a global phase 1/2a clinical trial of HMPL-A580, its second antibody-targeted therapy conjugate, in patients with unresectable, advanced or metastatic solid tumours in China and the US. The first patient received a dose on 4 March 2026.

HMPL-A580 is described as a first-in-class ATTC that links a highly selective PI3K/PIKK inhibitor payload to an anti-EGFR antibody via a cleavable linker. EGFR is widely expressed across multiple solid tumour types and is recognised as a key driver of tumour growth and progression.

Preclinical findings have shown that inhibiting the PAM pathway can work synergistically with anti-EGFR therapy to enhance anti-tumour activity, with further data due to be presented at an upcoming scientific meeting.

The first-in-human study is multicentre and open label, assessing safety, tolerability, pharmacokinetics, immunogenicity and early signs of efficacy. The phase 1 dose-escalation stage will determine the maximum tolerated dose and recommended dose for expansion.

The phase 2a expansion and optimisation stage will further characterise safety and preliminary anti-tumour activity in selected solid tumours and identify the recommended dose for the next phase. The trial is listed under identifier NCT07396584.

HUTCHMED’s ATTC platform combines monoclonal antibodies with proprietary small-molecule inhibitor payloads to deliver dual mechanisms of action. According to the company, this approach differs from traditional antibody drug conjugates by pairing targeted therapies to achieve synergistic anti-tumour effects and more durable responses in preclinical models.

The platform is designed to improve tumour accessibility, reduce off-tumour toxicity and support combinations with chemotherapy and immunotherapy.

Built on more than 20 years of targeted therapy development, the platform aims to generate candidates for a wide range of cancer types by using antibody-guided delivery and tumour-specific payload release to overcome limitations of conventional small-molecule inhibitors.