Athena's Zanaflex Suffers Setback In USA

Athena Neurosciences' stock took a tumble last week on the news that the US Food and Drug Administration sent the company a letter saying its New Drug Application for Zanaflex (tizanidine HCl), a new treatment for spinal cord spasticity, cannot be approved in its present form. Athena licenses the drug from Sandoz of Switzerland.

According to Athena, the FDA said that it has concerns regarding the sufficiency of the clinical data supporting the efficacy of the drug and that these concerns must be resolved before the NDA can be approved. The company said that it is in negotiation with the agency regarding the issues raised. Tizanidine is already sold in more than 50 other countries by Sandoz and its affiliates under the trade names Sirdalud or Ternelin. Sales of the product in 1994 were more than $100 million.

Commenting on the development, Athena president John Groom said that the company is confident of the data which shows that tizanidine reduced the number and severity of spasms, but that the FDA had requested more data on the more subjective criterion of clinical benefit to patients. He added the agency will probably want at least one more clinical trial before considering the drug for approval, and that this would take at least a year to complete.