Sanofi and Regeneron are now officially on the clock. The partners announced Monday that they have filed PCSK9 alirocumab with the FDA for Priority Review, giving the regulator until July 24 to approve or reject the drug. Regeneron confirmed with MM&M that the duo scored the expedited priority review status by attaching the $67.5-million voucher they purchased from BioMarin.

The announcement is a critical step in the fight for first-in-class and first-in-mind status that has been building between Amgen and Sanofi/Regeneron. Amgen has a filing lead — it sent its PCSK9 evolocumab to the FDA last August — but both are stuck with the dual challenges of regulatory approval and new-drug awareness among potential prescribers. (The are also embroiled in a patent-infringement lawsuit in which Amgen seeks an injunction against alirocumab.)

Sanofi and Regeneron have supported their filing on the regulatory front using clinical research that includes data from 10 Phase-III studies and January news that a monthly shot and bimonthly shots were equally effective in keeping down LDL cholesterol levels. They have also begun an unofficial market push, as seen by the December non-branded cholesterol IQ test that doubles as an awareness trigger and a data pool the companies plan to use as a “digital representation” about just how much patients know about cholesterol.

Despite investor focus on these three manufacturers, they do not have the new drug class to themselves. Pfizer has an oral and a bimonthly PCSK9 injection in development, and cholesteryl ester transfer protein inhibitors, known as CETPs, may be making a comeback. These drugs focus on raising HDLs, which are also referred to as “good” cholesterol, as opposed to suppressing LDL (“bad cholesterol”) levels, a target that statins and PCSK9s share.

Death doomed Pfizer’s CETP torcetrapib in 2007. A lack of efficacy prompted Roche to stop developing its CETP dalcetrapib in 2012, but a study published last week in Circulation: Cardiovascular Genetics indicates the drug may work among patients with a specific genetic profile.