Baxter shares dip as Alzheimer's drug fails to meet Ph III endpoints

Shares of US drugmaker Baxter International (NYSE: BAX) fell 2.5% to $68.58 in New York trading on May 7, having fallen as much as 3.3% in the morning, after it said that the Phase III clinical study of immunoglobulin (IG), Gammagard, did not meet its co-primary endpoints of reducing cognitive decline and preserving functional abilities in patients with mild to moderate Alzheimer’s disease, marking another disappointment in finding improved treatment of the condition.

Top-line analyses from the randomized, double-blind, placebo-controlled, multi-center trial found that, after 18 months of treatment, patients with mild to moderate Alzheimer's disease taking Baxter's IG treatment at either the 400mg/kg or the 200mg/kg dose did not demonstrate a statistically significant difference in the rate of cognitive decline compared to placebo (mean 7.4 in the 400mg/kg group, 8.9 in the 200mg/kg group, and 8.4 in the placebo group). Results also did not indicate a statistically significant change in functional ability as compared to placebo (mean -11.4 in the 400mg/kg group, -12.4 in the 200mg/kg group, and -11.4 in the placebo group).

While the study was not powered to show statistical significance among the sub-groups, in the pre-specified sub-group analysis, the 400mg/kg treatment arm showed a positive, numerical difference in change from baseline versus placebo in cognition as measured by the Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-Cog) and Modified Mini-Mental State (3MS) Examination among both moderate patients and carriers of the ApoE4 genetic marker. These differences ranged between 16% and 29%.