Arena Pharmaceuticals (Nasdaq: ARNA) is best known for its weight-loss drug, Belviq, which is slated to hit the U.S. market soon. Its main competition will be VIVUS' (Nasdaq: VVUS) Qsymia, and a third biotech -- Orexigen Therapeutics (Nasdaq: OREX) -- continues to work toward approval from the Food and Drug Administration for its obesity drug, Contrave.

Arena struck a deal last quarter with South Korean company Ildong to commercialize Belviq in South Korea. Arena is getting $5 million for the deal and will be entitled to more payouts if further milestones are reached.

Recently, Arena expanded its relationship with Ildong to include temanogrel, a drug in the early phases of development that will be aimed at treating arterial thrombosis. In this video, Motley Fool health care analysts Max Macaluso and David Williamson break down this news and discuss why it's too early for investors to start celebrating this deal.