MENLO PARK, Calif. (AP) — Depomed Inc.'s hot flash treatment candidate Serada missed several of its goals in a pair of late-stage clinical trials, the company said Monday. Shares of Depomed plunged in early trading on the report. Depomed tested two doses of Serada, and while the drug was generally successful after four weeks of testing, it missed most of its key goals after 12 weeks. Combined, the studies included 1,100 women. They were given either 1200 milligrams or 1800 milligrams of Serada or a placebo. The study was designed to measure Serada's effectiveness in reducing the frequency and severity of moderate to severe hot flashes, compared to placebo, after four and 12 weeks of treatment. The higher dose met its four main goals after four weeks, but missed three of the four goals after 12 weeks, Depomed said. The lower dose met three of the four primary goals after four weeks, and met only one of the goals after 12 weeks. Depomed said patients who took the placebo in one of the studies did surprisingly well, and said it will continue analyzing the study data as it decides whether or not it will continue development, and how it would do so. Serada is an extended release version of the drug gabapentin, which is used to treat epilepsy and pain disorders. A week ago, Depomed reported results from a successful late-stage study of extended-release gabapentin as a treatment for pain caused by the viral infection shingles. In morning trading, Depomed shares dropped $2.38, or 37 percent, to $3.98. The stock has traded in a 52-week range of $1.01 to $6.40.