Shares of NMT Medical ( NMTI) were among the worst-performing health-related stocks Monday, plunging 32% after the medical device maker said a study designed to test the company's StarFlex technology on migraine headaches failed to meet its primary endpoints. The company's MIST study was designed for patients with a heart defect called patent foramen ovale, which is a risk factor for migraines. The company sought to use its StarFlex technology, which is a patent foramen ovale closure, to reduce migraine headaches by 40% at six months. MIST results indicated a 37% reduction in migraine burden for those using the technology and a 17% reduction in those who received the sham procedure and no implant. "Although we were disappointed that MIST did not satisfy its endpoints, the study was designed to help demonstrate clinical relevancy and not to obtain a specific regulatory approval," the company said in a statement. "The study has provided us with significant data that we intend to incorporate into our MIST II and MIST III studies." Shares were trading down $6.71 to $14.21. Andrx ( ADRX) jumped 10% after the company agreed to be acquired by fellow generic-drug maker Watson Pharmaceuticals ( WPI) for $1.9 billion in cash, or $25 a share. The price represents a 16% premium to Friday's closing price of $21.59. The deal, which should close within six months, is expected to be accretive to Watson's 2007 earnings. After the acquisition, Watson will become the third largest generic-pharmaceutical company in the U.S., based on the number of dispensed prescriptions, and have more than 60 abbreviated new drug applications in its pipeline. Shares of Andrx were trading up $2.19 to $23.78, while shares of Watson fell 82 cents, or 3%, to $28.73. Tutogen Medical ( TTG) soared 19% after the maker of tissue products said Zimmer Holdings ( ZMH) approached the company about possible strategic transactions. Potential deals include a further investment by Zimmer in Tutogen shares, or an acquisition of some or all of Tutgen's stock. "We have made a great deal of progress in the past year in positioning the company for improved performance," Tutogen said. "We believe this approach by Zimmer is indicative of that progress." Shares were trading up 75 cents to $4.60.