What happened

Matinas BioPharma's (NYSEMKT:MTNB) shares slipped 13.4% on Monday. This came after Amarin Corp. (NASDAQ:AMRN) secured approval from the Food and Drug Administration to include a cardiovascular outcomes benefit on the prescription label for Amarin's purified omega-3 drug, Vascepa.

So what

Amarin's Vascepa has been FDA-approved since 2012 for use in patients with extraordinarily high levels of triglycerides (fat in the bloodstream). However, its use has been limited by the absence of data proving that lowering triglycerides reduces the risk of major cardiovascular events, including heart attack and stroke.

A man with a surprised expression listens through a wall using a paper cup.

IMAGE SOURCE: GETTY IMAGES.

That changed on Friday night, when the FDA approved including information from Amarin's Reduce-It trial on Vascepa's label. In Reduce-It, Vascepa improved outcomes in patients with triglyceride levels above 150 mg/dL by at least 20%. Previously, Vascepa was only approved for use in patients with levels above 499 mg/dL.

The FDA's decision gives Amarin a big head start over its biotech competitors, including Matinas BioPharma, which is developing MAT9001, a specially formulated omega-3 drug for lowering triglycerides. A 100-person phase 2 trial of MAT9001 in patients with triglyceride levels between 150 mg/dL and 499 mg/dL is planned to enroll early in 2020.

Now what

Amarin's head start puts it in a good position to capture a significant share of an estimated $2 billion market, but investors might not want to count Matinas BioPharma out of the race yet. MAT9001's unique formulation may offer advantages over Vascepa in terms of bioavailability, and because it includes docosapentaenoic acid (DPA), an omega-3 acid that isn't found in Vascepa, it may work better. A head-to-head, phase 2 study of MAT9001 versus Vascepa should have results available by the end of 2020.

The potential for Matinas BioPharma to have a best-in-class omega-3 drug on the market someday makes buying its shares on sale intriguing. However, it's anyone's guess whether MAT9001's trial will be successful, so only risk-tolerant investors should consider owning it.