The Medicines Company (NASDAQ:MDCO) wants in on Alnylam's (NASDAQ:ALNY) early-stage cholesterol treatment ALN-PCS. A new deal requires Medicines Company to make an initial $25 million payment followed by $180 in potential milestones, and double-digit global royalties upon release.

ALN-PCS belongs to the rising class of PCSK9 inhibitors hoping to find a place in the statin-dominated market. Other contenders include late-stage projects from Amgen (NASDAQ:AMGN) and the partnership of Sanofi (NYSE:SNY) and Regeneron (NASDAQ:REGN). Will Alnylam's drug secure a place in this crowding market?

Same end, different means
PCSK9 inhibitors block a protein that would lead to an abundance of LDL, or "bad" cholesterol, if left unchecked. Amgen's AMG 145 and Sanofi-Regeneron's REGN727 stop the existing protein from doing its damage. Alnylam's drug stops things at the gene that would produce those proteins.

As I've written before, PCSK9 drugs won't dominate high-cholesterol treatments because statins remain well tolerated and offer oral dosage at a low price. But Alnylam hopes their approach will better treat patients who don't respond well to statins.

Early data on the intravenous form of ALN-PCS seem promising. Alnylam presented phase 1 data last year showing the drug reduced LDL levels up to 50% on its own. A subcutaneous injection is in preclinical trials.

The dealmakers
The terms of the new agreement mean that Medicines Company will take over both versions of ALN-PCS when they hit the phase 2 stage. The company has three products approved in the U.S., but the majority of its revenues come from the anticoagulant Angiomax, which had net sales of $360.5 million in the first nine months of last year.

Alnylam is a development-stage company. Its pipeline features projects using technologies based on RNA interface, or RNAi. The treatments include a wide range of conditions that include hemophilia and liver cancers.  

Foolish final thoughts
If it makes it to market, Alnylam's medication will arrive far later than its competitors. Sanofi hopes to push REGN727 to approval in 2015 after the phase 3 initiated last year. Amgen's on the verge of launching the final trials for AMG 145.

But if Alnylam shows a vast efficacy improvement in statin-resistant patients, it could still get a place. I want to wait for mid- and late-stage data to better evaluate ALN-PCS's potential.

Brandy Betz and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.