Peregrine Pharma is the latest company with an immuno-oncology candidate to join forces with a big pharma partner, pairing up with AstraZeneca for a trial in solid tumours.
The two companies will look at the benefits of combining AZ’s PD-L1 checkpoint inhibitor durvalumab (MEDI4736) with Peregrine’s bavituximab, which targets a molecule called phosphatidylserine (PS) involved in processes that hide tumours from the immune system.
By blocking PS, bavituximab both removes this brake and sends the immune system an activating signal to boost its activity against tumour cells. That complements durvalumab’s mechanism of action which blocks a different signal used by tumours to evade detection by the immune system, according to the two companies.
The two drugs will be tested in a phase I/IIb trial in multiple solid tumours, providing data on the safety and dosing of the two drugs in cancer, and will be conducted by Peregrine.
Preclinical data suggests that targeting and blocking the PS-signalling pathway allows more patients to initiate a T-cell immune response, resulting in longer treatment duration when used in combination with checkpoint inhibitors that in turn results in more subjects responding to therapy.
Bavituximab is already in a phase III trial as a second-line therapy for non-small cell lung cancer (NSCLC), which is shaping up to be something of a battleground for the new immuno-oncology drugs as it combines a very high patient population with relatively few effective therapies.
The SUNRISE trial is due to complete enrolment by the end of the year, potentially setting up approval of the drug in 2016, with an additional trial in NSCLC and another in HER2-negative breast cancer due to start in the coming weeks.
Bristol-Myers Squibb’s checkpoint inhibitor Opdivo (nivolumab) is already approved to treat NSCLC while Merck & Co’s Keytruda (pembrolizumab) is in late-stage development for this indication. If bavituximab is approved, having data with durvalumab could help AstraZeneca‘s drug make headway in that market.
“Within oncology, there is a need almost across the board for new drugs that will improve existing therapies,” said Peregrine’s chief executive Steve King.