Thursday's Health Winners & Losers

Updated from 2:25 p.m. EDT

Study updates launched and sank a few biotech stocks Thursday while the overall mood was grim.

Corcept Therapeutics(CORT Quote) closed up 23.2% after saying preliminary top-line results showed a statistically significant reduction in weight gain in patients who took olanzapine plus corlux compared to those who took olanzapine alone in a two-week, male-only, proof-of-concept study. The announcement managed to pump the stock 33 cents to $1.75.

Pharmaceutical company Vivus(VVUS Quote) said it finished a meeting with the Food and Drug Administration, following the completion of its phase II program for investigative obesity treatment Qnexa. As a result of the meeting, the company said it will dose 4,500 patients in a pivotal 56-week phase III program studying obese patients and obese patients with associated comorbidities, or conditions that exist in addition to obesity such as type 2 diabetes, hypertension and dislipidemia.

It intends to initiate enrollment this fall and is preparing an application for special protocol assessment for the drug as a treatment for obesity in the U.S. After rising 16 cents to $5.17 in premarket trading, the company was hugging the flat line, down 5 cents to $4.96.

Vivus is part of the Nasdaq biotechnology index, which was up less than 1 point at 812.61.