* Sanofi to file drug for US and EU approval by year-end
* Nine Phase III ODYSSEY trials meet primary endpoint
* Alirocumab "generally well tolerated" in trials
PARIS, July 30 (Reuters) - A new drug being developed by French drugmaker Sanofi and U.S. partner Regeneron cut "bad" LDL cholesterol more than placebo and existing treatments in nine late-stage clinical trials, the companies said on Wednesday.
The injectable drug, called alirocumab, is from a promising new class of medicines, called PCSK9 inhibitors, also being developed by Amgen Inc and other drugmakers. If approved, these drugs could reap annual sales of $3 billion or more, according to some industry analysts.
The Phase III ODYSSEY trials showed that after 24 weeks, the mean percentage reduction in LDL cholesterol with alirocumab was consistent with results seen in previous trials, the companies said in a statement.
The trials involved patients whose high LDL cholesterol levels are not sufficiently controlled by existing treatments such as statins, who cannot tolerate these or who present a high or very high cardiovascular risk.
"The robust data from these studies in more than 5,000 patients is the basis of our global regulatory submissions, which we expect in the U.S. and EU by year-end," said Sanofi R&D chief Elias Zerhouni.
PCSK9 inhibitors block a protein that prevents the body from eliminating LDL cholesterol from the bloodstream and offer a new way of fighting the build-up of artery-clogging fat that puts patients at risk of heart attacks.
These 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 earlier mid-stage studies, when combined with statins, alirocumab and Amgen's own PCSK9 drug cut levels of LDL cholesterol by close to 70 percent, more than statins alone.
The drug was "generally well tolerated" in the trials, with most common adverse events being nasopharyngitis, upper respiratory tract infections and injection site reactions.
Serious adverse events and deaths were "generally balanced" between treatment groups as were musculoskeletal, neurocognitive and liver-related events, the companies added.
An interim safety analysis showed that after 18 months of treatment, patients on alirocumab were less prone to cardiovascular events (cardiac death, myocardial infarction, stroke, and unstable angina requiring hospitalization) compared with those on placebo.
Alirocumab's potential to cut cardiovascular risk is being assessed in an ongoing 18,000-patient long-term outcomes trial.
(Editing by Mark Potter)