PARIS, Dec 19 (Reuters) - French drugmaker Sanofi and its U.S. partner Regeneron are collaborating with the American College of Cardiology (ACC) to identify patients for clinical trials on alirocumab, their new cholesterol treatment and potential blockbuster.

Under this agreement, the ACC will use its expertise in clinical research and its extensive patient registries to identify appropriate candidates for a cardiovascular outcomes clinical trial, Sanofi said in a statement on Thursday.

This is the first time that the ACC's "Pinnacle" registry will be used for clinical trial recruitment, and Sanofi hopes accessing its millions of patient records will help it fully enrol the trial, which seeks some 18,000 patients who recently suffered an acute coronary syndrome.

Alirocumab is an injectable drug from a promising new class of medicines called PCSK9 inhibitors that is also being developed by Amgen Inc and other drugmakers. It has been touted by industry analysts as a potential blockbuster that could reap annual sales of over $3 billion.

PCSK9 drugs are mainly aimed at the millions of people who either cannot tolerate statins such as Pfizer Inc's Lipitor or AstraZeneca Plc's Crestor or who cannot get their cholesterol levels under control with statins alone.

In the first of a dozen late-stage trials, alirocumab cut levels of "bad" LDL cholesterol almost in half. The drug's ultimate success will depend on longer-term studies, some of which will only give results around 2018. But Sanofi and Regeneron are hoping positive earlier data could get the drug approved for some patients before then.