Endeavor BioMedicines has acquired exclusive global rights to the HER3-targeted antibody-drug conjugate (ADC) from Hummingbird Bio, HMBD-501.

The next-generation ADC HMBD-501 is generated by Hummingbird Bio’s antibody discovery and engineering platform using ADC technologies for an improved safety and efficacy profile.

HMBD-501 binds to an epitope on the HER3 receptor with the binding unaffected by NRG1 (HER3 ligand) levels. This allows attachment to HER3-expressing tumours even in high ligand contexts.

Endeavor BioMedicines co-founder, CEO and chairman John Hood stated: “This exclusive licence with Hummingbird Bio provides Endeavor with a potential best-in-class HER3-ADC, with the opportunity to treat a large number of patients in multiple tumour types.

“HER3 is more broadly expressed on tumours than HER2 and is expressed on tumours that do not express HER2.

“This next-generation ADC has the potential to address significant unmet clinical needs in areas left behind by HER2 agents.”

Endeavor BioMedicines will make upfront and milestone payments of $430m to Hummingbird, which is also entitled to receive royalties on net sales.

Hummingbird Bio co-founder and CEO Piers Ingram said: “Hummingbird Bio has designed HMBD-501 to have a wider therapeutic index than current HER3 ADCs, maximising the potential clinical benefit for patients, and we are delighted that Endeavor has recognised the potential of this ADC built with our proprietary antibody technology.

“We are pleased to license HMBD-501 to the experienced Endeavor team to bring the molecule into the clinic and a step closer to benefiting patients.”