AstraZeneca developing reversal agent for heart drug Brilinta

* Antibody to reverse blood-thinning effect in emergencies

* Currently no products to reverse anti-platelet drugs

* Move (NasdaqGS: MOVE - news) may give Brilinta an edge in competitive market (Adds more detail on Brilinta and competition)

By Ben Hirschler

LONDON, Nov 13 (Reuters) - AstraZeneca (NYSE: AZN - news) is developing an antibody treatment to reverse the blood-thinning effect of its heart drug Brilinta in rare emergency situations, such as urgent surgery or in the event of major bleeding.

The move could give Brilinta an edge among drugs that block platelets in the blood, since there are no approved products to counteract their effects. Because they reduce clotting, the drugs can cause problems if doctors need to operate suddenly.

AstraZeneca said on Thursday the experimental antibody product, MEDI2452, was in pre-clinical tests at its MedImmune biotech unit.

Brilinta has struggled so far to gain traction in a competitive market, where Plavix - developed by Sanofi (NasdaqGM: GCVRZ - news) and Bristol-Myers Squibb - is now available as a cheap generic.

However, prospects for the drug brightened in August when the U.S. Department of Justice dropped an investigation into the original clinical trial used to win marketing approval, lifting a shadow hanging over the product.

Brilinta has also won preferred status from two U.S. medical associations.

An AstraZeneca spokeswoman said Brilinta demand was now picking up, with U.S. new prescription volume overtaking Eli Lilly's rival Effient in the week commencing Oct. 27.

AstraZeneca flagged up the promise of Brilinta in its defence against an abortive $118 billion takeover bid by Pfizer earlier this year, forecasting annual sales of $3.5 billion for the drug by 2023.

That number assumes it works more widely in heart conditions, and a series of large clinical trials are now under way to prove the case. AstraZeneca hopes to report headline results from one study, known as PEGASUS, in December or early in January.

AstraZeneca, which is determined to prove the value of its drug pipeline, will hold an investor day focused on new medicines on Nov. 18, eight days before Pfizer (NYSE: PFE - news) is allowed to return with a new public offer under British takeover rules.

In another move to bolster its long-term drug prospects, AstraZeneca also signed a drug technology deal on Thursday with Isis Pharmaceuticals (Stuttgart: 881866 - news) . (Editing by Jon Boyle)