Ebb & Flow

One reason investors worry about the biotech sector is the magnitude of loss that can occur instantly on product setbacks. A reminder is Connetics' 47 percent slide on Wednesday after its gamma interferon showed no efficacy in a Phase III trial in atopic dermatitis (see BioCentury Extra, Aug. 28). CNCT was down $3.563 - 41 percent - on the week to $5.062. By comparison, 32 major biotech sell-offs that followed disappointing clinical events over the past three years clipped each stock an average of 44 percent (see chart, next page). Generally positive reports aren't immune - witness Amylin's 43 percent drop on Aug. 18 after data from two Phase III trials of AMLN's pramlintide in diabetes were tempered by unanticipated strength in the placebo group.

NOT UNNERVED: Idec (IDPH) gained 9 percent on the week, up $2.50 to $30.375, despite announcing on Friday that it had received a notice from FDA requesting additional information on manufacturing of Rituxan for non-Hodgkin's