The two major pharmaceutical firms have signed an agreement in "strategic collaboration" to develop and commercialise cancer drugs.
Pharmaceutical giants AstraZeneca and Merck said on Thursday they had agreed on a multi-billion-dollar deal to jointly develop key cancer drugs.
"The strategic collaboration is expected to further increase the number of treatment options available to patients," British company AstraZeneca and its US peer said in a statement.
Merck will pay AstraZeneca up to $8.5 billion under the deal struck to develop and commercialise the drugs.
Central to the agreement is "a global strategic oncology collaboration to co-develop and co-commercialise AstraZeneca's Lynparza (olaparib) for multiple cancer types," the pair said.
Lynparza is currently approved for the treatment of ovarian cancer but it is hoped that this can be stretched to help fight breast, prostate and pancreatic cancers thanks to the tie-up announced on Thursday, the statement added.
"By bringing together the expertise of two leading oncology innovators, we will accelerate Lynparza's potential," said AstraZeneca chief executive Pascal Soriot.
"This is a truly exciting step, and we are pleased to work with Merck, a company that shares our passion for science to deliver new medicines for cancer patients."
Merck chief executive Kenneth C Frazier added, "We look forward to working with AstraZeneca to create greater value for patients and shareholders than if both companies worked independently."
Merck will pay AstraZeneca an initial $1.6 billion, $750 million for licence options and up to $6.15 billion "upon successful achievement of future regulatory and sales milestones."