Nastech Pharmaceutical's ( NSTK) shares plummeted after the Food and Drug Administration rejected its application for calcitonin-salmon nasal spray. Regulators said the drug isn't approvable because of concerns that a possible interaction between its ingredients could harm the immune system. Nastech plans to discuss its application further with the FDA to see whether additional data could be submitted to support the drug's approval. Shares sank 12.8% to $13.31. Shares of Epix Pharmaceuticals ( EPIX), a maker of drugs used in medical imaging, fell 7.4% to $4.49 after the company said Schering ( SHR) won't exercise its option on the development of a drug intended to help doctors find blood clots using an MRI. Schering is merging with another German drug company, Bayer ( BAY). Epix says it intends to seek another collaborator for the development of the drug, dubbed EP-2104R. Johnson & Johnson's ( JNJ) shares dipped 8 cents to $60.54 after the company's Cordis medical-device division acquired the privately held wound-closure firm Ensure Medical. Terms of the deal weren't disclosed, but J&J expects to take a charge of $52 million after taxes, or 2 cents a share, for acquired research and development. Following the close of trading Wednesday, J&J announced positive efficacy results from a trial of its schizophrenia drug Paliperidone ER, saying it significantly delayed the recurrence of symptoms. Diagnostics-device maker Biosite ( BSTE) said the FDA cleared its Triage TOX drug screen as a way to identify patients on methadone, a drug that's known to interact with a number of other medications. Shares fell 0.7% to $45.60. Biopharmaceutical company Corautus Genetics ( VEGF) was up 3.6% to 87 cents after the company said the FDA lifted the clinical hold imposed in March on trials of its drug Genasis. The drug is intended to increase the length of time patients with severe angina can exercise. Corautus says a product application submitted to the FDA will remain on a partial hold as the company expected, until remaining issues, all of which are associated with the results of certain tests related to the delivery-catheter system and injection procedures, are completed.