Bristol-Myers Squibb has bought itself the chance of snapping up rights to Bavarian Nordic’s experimental prostate cancer immunotherapy Prostvac in a deal that could net the latter more up to $975 million.

The US drug giant is paying the Danish biotech an initial $60 million for the option to license rights to the drug - a prostate-specific antigen-targeting cancer immunotherapy being developed for metastatic castration-resistant prostate cancer - and then further upfront and milestone payments up to $915 million if it decides to proceed.

BMS has been given an undisclosed time-frame to exercise its option following completion of the ongoing Phase III trial of Prostvac, with results reportedly expected late 2016, early 2017, according to media reports.

The company is planning a further combination study of Prostvac and its checkpoint inhibitor Yervoy (ipilimumab) on the back of promising early-stage results, and is also considering other immunotherapies that might be paired with Bavarian Nordic’s drug in exploratory trials.