France’s Sanofi is paying $462 million to exit the immuno-oncology pact it established with US biotech Regeneron in 2015 half a year earlier than planned.

With the severance agreement, which restructures the original deal originally scheduled to end in mid-2019, the French drugmaker will cover its share of drug discovery costs from the last quarter of 2018 as well as a termination fee and provide development support for two clinical-stage assets. 

As part of the 2015 arrangement four years ago, the Paris-based player paid Regeneron $640 million up front and committed to spending $750 million to take programs up to clinical proof of concept.

In addition increased flexibility to advance its early-stage immuno-oncology pipeline, the new arrangement gives Sanofi the right to opt in to two bispecific programs for two clinical assets as well as increased flexibility to advance its early-stage immuno-oncology pipeline.

Regeneron will retain all rights to its other immuno-oncology discovery and development programs. At the same time, it will commit up to $120 million to fund new developments in the field.

The US biotech will spend up to $70 million to develop the BCMAxCD3 drug in multiple myeloma and as much as $50 million on the MUC16xCD3 bispecific in mucin-16 expressing cancers.  If Sanofi exercises its option on the multiple myeloma asset, it will lead development and fully cover the costs. Regeneron will refund up to 50% of the costs out of its equal split of any profits.