Baxter, Medivation See Positive Test Results

Baxter researchers revealed positive mid-stage test results on an intravenous drug, Gammagard, that's already in late-stage development in a very small number of patients.

According to test reports, the plasma-based drug appears to improve memory and quality of life—or at the very least, stabilize and stop the rate of loss of memory.

Baxter's stock rose almost 2 percent when the data was released. (See the accompanying video for more.)

Meanwhile, Elan and Wyeth’s shares plunged Wednesday after word that mid-stage test results on a potentially first-of-its-kind Alzheimer’s drug, Bapineuzumab, raised safety issues.

However, Elan CEO Kelly Martin told CNBC he was confident in Bapineuzumab.

"There are obviously some gaps between the market interpretation and what we know,” Martin said.

Additionally, a small biofirm, Medivation , showed new data on an anti-histamine that in a large study appears to preserve memory in mild to moderate Alzheimer’s patients.