AstraZeneca and Bristol Myers Squibb have denied any ongoing merger discussions. A senior source close to the matter stated no deal was ever planned. This comes after reports of preliminary talks between the two major drugmakers. AstraZeneca shares experienced a significant decline following the initial deal speculation. Both companies declined to comment on the reported discussions.

U.K. pharmaceutical giant AstraZeneca is considering a deal to merge with its U.S. rival Bristol Myers Squibb.

AstraZeneca in talks to merge with Bristol Myers Squibb, creating $400B pharma giant, while talks ongoing for months, antitrust scrutiny is expected.