AstraZeneca and Peregrine are expanding their ongoing onco-immunotherapy pact to allow for a Phase II trial of an experimental lung cancer combination treatment.

The companies said they will test a combination of Peregrine’s phosphatidylserine-targeted immune-activator bavituximab and AZ’ anti-PD-L1 immune checkpoint inhibitor durvalumab (MEDI4736) in a global Phase II study in patients with previously treated squamous or non-squamous non-small cell lung cancer. 

As part of the trial, which will be conducted by Peregrine, patients will be assessed retrospectively for the correlation between their PD-L1 levels and clinical outcomes. 

The new study builds on the non-exclusive collaboration sealed by the companies in August to carry out a Phase I/Ib trial evaluating the bavituximab/durvalumab combo with chemotherapy in multiple solid tumours. Peregrine had initially been planning to test bavituximab with Bristol Myers Squibb’s Opdivo in the same lung cancer population, but says the combination with durvalumab will allow “a much more cost-effective and time-efficient trial”.

“This Phase II study offers several key advantages including a supply of durvalumab that will enable us to conduct a global trial that can enroll patients more rapidly,” said Joseph Shan, who heads up clinical and regulatory affairs at Peregrine. “In addition, the expanded collaboration provides for a more cohesive clinical program utilising the same PD-L1 and other biomarker analysis across both the new Phase II trial and the already planned Phase I/Ib study combining durvalumab and bavituximab in multiple indications”.

Bavituximab and durvalumab are investigational immunotherapies with different mechanisms that assist the body's immune system in fighting cancer; bavituximab targets and modulates the activity of phosphatidylserine, a highly immune-suppressive molecule expressed broadly on the surface of cells in the tumour microenvironment, while durvalumab is a monoclonal antibody directed against PD-L1, signals from which help tumours avoid detection by the immune system.