Biopharmaceutical company Sosei Group Corporation (TSE:4565) said on Monday that it has triggered a USD15m payment by the end of the first quarter ended 31 March 2019 for next generation immuno-oncology candidate AZD4635 from its strategic alliance partner AstraZeneca (LSE:AZN) .

AstraZeneca has reached a clinical development milestone for its next generation immuno-oncology candidate AZD4635 under its partnership with Sosei.

According to Sosei, AZD4635 is its potent and selective, orally available, small molecule adenosine 2A receptor antagonist. By stimulating A2A receptors, adenosine prevents T-cells within the immune system from being activated and reduces their ability to destroy cancer cells. Blocking A2A receptors can therefore promote the anti-cancer response of T-cells within the tumour microenvironment.

To date, AstraZeneca's clinical study has established the maximum-tolerated dose of AZD4635 as a single agent and in combination with durvalumab. The study has progressed successfully to the point where the therapeutic potential of AZD4635 is being explored in multiple solid tumours. It is moving the trial towards Phase 2, thereby triggering the milestone payment to Sosei Heptares. Headline data from the Phase 1 study is planned to be presented at a scientific congress in 2019.

In addition, Sosei's AZD4635 is in a Phase 1 open-label, multicentre study as a single agent and in combination with a PD-L1 antibody, durvalumab in solid malignancies; in Phase 1/2a open-label, multicenter, study in combination with oleclumab in previously treated advanced EGFR-driven non-small cell lung cancer (NSCLC); as well as advancing through a Phase 1 clinical programme as a single agent and in combination with anti-PD-L1 antibody durvalumab (IMFINZI) in solid tumours.