MedImmune Inc. said that Wall Street misinterpreted its decision to end its clinical program for the treatment of respiratory syncytial virus, after investors drove the company's stock down 47 percent to $4.875 last week.

The company announced it was ending the program after reviewing the results of two treatment trials using its RespiGam polyclonal antibody. One Phase III study was in about 100 high-risk infants and the other Phase III study was in a similar number of non-high risk infants. The subjects received one dose intravenously of 1500 mg/kg of drug.