AstraZeneca has taken another step down the acquisition pathway, this time shelling out up to $500 million to acquire privately-held, US group Amplimmune.

AZ's biologics research and development arm MedImmune has now entered into a definitive agreement to acquire the firm, which is focused on developing novel therapeutics in cancer immunology, in a bid to bolster the Anglo-Swedish drug giant's pipeline.

While Amplimmune, which spun out from John Hopkins University in 2007, has no marketed products on its books, it does offer AZ access to a swathe of early-stage assets within the immune-mediated cancer therapy arena to boost its oncology portfolio.

Most notable of these is AMP-514, an anti-programmed cell death monoclonal antibody currently in late-stage preclinical development and on track for an investigational new drug filing before the end of this year. 

“MedImmune’s focus on harnessing the power of the patient’s own immune system to fight cancer will be complemented by Amplimmune’s innovative work in this area," noted MedImmune's executive vice president Bahija Jallal. "[The deal] will allow us to strengthen our arsenal of potential cancer therapies," he said, explaining the decision.

The move comes hot on the heels of other purchases by MedImmune under a strategic drive to strengthen its research pipeline, which has recently seen it pay out $1.15 billion for respiratory group Pearl Therapeutics (in June) and $443 million for lipid-lowering specialist Omthera Pharmaceuticals (in May).

Industry observers do however seem a little wary that such deals will weigh heavy on AZ's operating costs, at a time when sales are under pressure from the loss of patent protection for key drugs such as antipsychotic Seroquel (quetiapine) and the cholesterol blockbuster Crestor (rosuvastatin).

Under the deal for Amplimmune, AZ will pay an initial purchase price of $225 million as well as up to $275 million based on reaching predetermined development milestones. The deal is expected to close in the third quarter.