Amberstone Biosciences has signed a partnership and licence agreement with Shanghai Henlius Biotech for conditionally activated T-cell engager candidates to treat solid tumours.

The preclinical T-cell engagers will be developed using Amberstone’s Tumor Microenvironment Activated ThErapeutics (T-MATE) platform.

Henlius will select up to two targets under the agreement. The company will oversee their global research, development, manufacturing and commercialisation.

The agreement provides Amberstone with an upfront payment and research funding. The company is also eligible for up to $440m in development, regulatory and sales milestones for each target, along with tiered royalties on net sales.

T-cell engagers redirect the T cells of a patient to destroy cancer cells. Their development in solid tumours has been limited by cytokine release syndrome and on-target, off-tumour toxicity.

Amberstone’s platform uses reversible potential of hydrogen (pH) gating and addresses these limitations.

The approach is intended to reduce T-cell activation in the bloodstream and healthy tissue while maintaining activity across the pH range found in solid tumours.

Amberstone said preclinical studies showed potent tumour-cell killing under tumour-like pH conditions while activity was markedly lower at physiological pH.

Its lead T-MATE T-cell engager is expected to enter clinical development in the first half of 2027.

The asset is currently in investigational new drug (IND)-enabling development, with other internal programmes at the discovery stage.

Amberstone is developing pH-gated, tumour-activated T-cell engagers and other antibody therapeutics through internal programmes and partnerships.

Henlius has operations spanning clinical operations, research and development, manufacturing, commercialisation and regulatory affairs.

Ten of its products have secured regulatory approvals in more than 60 countries and regions. Four have been approved by the US Food and Drug Administration and five by the European Commission.