A collaborative research program with Alzheimer’s patients involving Thousand Oaks-based Amgen Inc., Swiss drug maker Novartis and Banner Alzheimer’s Institute in Arizona is discontinued, the companies said Thursday in a statement.

Patients were exhibiting worsening cognitive function in the second of a three-phase study, which monitored the effects of the drug BACE1 inhibitor CNP520, or umibecestat.

The Generation Program was designed to monitor the safety and efficacy of the drug in people at high risk of developing Alzheimer symptoms based on age and genetic status.

“Although the outcomes of the research program did not lead to the results we aimed for, we are committed to sharing our findings to help advance the medical and scientific community one step further toward finding a prevention for this devastating disease,” Dr. David Reese, executive vice president of research and development for Amgen, said in a statement.

Shares of Amgen (AMGN) closed Thursday down $4.27, or 2.3 percent, to $178 on the Nasdaq.