Heptares Therapeutics has achieved an important milestone in its immuno-oncology collaboration with AstraZeneca, which is focused on the development of AZD4635 (HTL-1071) as a potential new treatment for a range of cancers. As a result, Heptares has been notified today that the achievement has triggered a $12 million payment from AstraZeneca.

AZD4635 is a potent and selective, orally available, small molecule adenosine A2A receptor antagonist discovered by Heptares and licensed to AstraZeneca in 2015.

The milestone was triggered by the successful completion of a preclinical program that demonstrated a clear effect of AZD4635 in reversing adenosine-mediated T-cell suppression and enhancing anti-tumor immunity. Blockade of A2A signaling with AZD4635 was found to reduce tumor growth when used alone and in combination with anti-PD-L1 checkpoint inhibitors.

AZD4635 is currently in a Phase 1 clinical trial as a single agent and in combination with AstraZeneca’s durvalumab (anti-PD-1L antibody) in patients with solid malignancies.

“The preclinical study results are very exciting and confirm that inhibition of A2A signaling offers an attractive mechanism to treat cancers by preventing tumors from evading the immune system and making them susceptible to checkpoint inhibitors,” said Fiona Marshall, chief science officer, Heptares. “We now look forward to the results from the first clinical study with AZD4635 around the end of the year.”