Arena Pharmaceuticals Inc. claim that their experimental new weight-loss drug, Lorcaserin, helps adults lose weight and keep it off. Unlike many similar failed drugs of the past, side effects mostly include a quite manageable headache, dizziness, and nausea. The FDA is set to review Lorcaserin on September 16, and if approved, it would become the company’s first marketed product.

Daily Finance references a two-year study published in the New England Journal of Medicine called BLOOM (Behavioral modification and Lorcaserin for Overweight and Obesity Management). The resulting data shows that 47.5% of the patients taking Lorcaserin lost at least 5% of their body weight, with 22.6% of these patients losing at least 10% of their body weight. This involved continual, twice daily doses of the pill for a year. Those who continued to take Lorcaserin in the second year of the study were found to maintain their weight loss much better too. Impatient types who find this wait too lengthy should consider an early 12 week clinical test where different doses were administered. The results showed that the group who took the largest dose (20mg/day) lost the most weight with an average of 7.9lbs, compared to 4.0 lbs for a 10mg dosage and 5.7lbs for a 15mg dosage.

Lorcaserin is essentially an appetite surpressant, and eliminates the feeling of hunger. By acting on serotonin, a chemical associated with feelings of well-being and feeling full, it works by binding to a receptor in an area of the brain involved with appetite control and metabolism. Despite this, there was no evidence of raised blood pressure or cholesterol levels, such as was the case of the similar yet dreaded "Fen-Phen" (Fenfluramine) drug which stirred up controversy in the 1990's. In fact, Lorcaserin has been found in some cases to marginally improve blood pressure, heart rate, and cholesterol.

Where the side effect of past drugs have been frightening and sometimes fatal, Lorcaserin side effects are minor nuisances in comparison: nausea, dry mouth, fatigue, headache, dizziness, vomiting and urinary tract infections. Headaches were the most common, with 18% of the study group being affected.

News of this “miracle pill” sent shares of Arena Pharmaceuticals (ARNA) skyrocketing over twenty percent to a daytime high of $5.68 per share on July 15th. Also excited about this prospect is Japan’s Eisai Pharmaceuticals, who have entered into to a licensing deal, whereby Arena will receive $50 million dollars upfront and up to an additional $90 million if the FDA decides it is safe for sale and distribution. Once approved, Eisai will have exclusive marketing rights for this drug that could be worth more than $1.3 billion and be in the medicine cabinets of more than half of American homes. Understandably, there is a great eagerness to get the drug to the public, and the hope is to start selling Lorcaserin 12 weeks after the approval date.