Innovent Biologics has dosed the first subject in the Phase Ia/Ib clinical trial of its antibody, IBI325, to treat advanced solid tumours.

The open-label, first-in-human, dose-escalation trial will analyse the safety, tolerability, pharmacokinetics, pharmacodynamics and initial efficacy of IBI325 as monotherapy and along with sintilimab in advanced solid tumour patients. 

It will also determine the recommended dose intended for further studies.

A differentiated, humanised antibody against CD73, IBI325 is designed to offer relief in the immunosuppressive tumour microenvironment and could work along with various other cancer treatments such as PD-1 or PD-L1 antibodies. 

An ecto-enzyme found on stromal cells and tumours, CD73 converts extracellular adenosine monophosphate (AMP) to adenosine. 

Adenosine attaches to the adenosine A2A andA2B receptors present on immune cells and hinders anti-tumour immune responses.

In preclinical studies, IBI325 demonstrated to fully hinder CD73 on both soluble and cell surfaces. Furthermore, the therapy showed anti-tumour activities in several tumour models.

Innovent senior vice-president Dr Zhou hui said: “Our preclinical data suggested that IBI325 could completely inhibit the activity of CD73 molecule with no ‘hook effect’ compared with the other candidates in the same class. 

“The new combination therapy of IBI325 and sintilimab would potentially address the existing unmet medical needs left by current immunotherapies.”

The latest development comes after the company dosed the first participant in an investigator-initiated-trial of its chimeric antigen receptor T cell product called IBI345, for the advanced Claudin18.2-positive solid tumour treatment. 

Subject enrolment in the trial is currently underway. It will assess the safety, tolerability, pharmacokinetics and initial efficacy of IBI345 for Claudin18.2-positive solid tumour as the primary goal.