Two new drugs designed to treat Alzheimer's were in trial stages when they began showing disappointingly ineffective results for slowing the progression of the crippling cognitive disease.

According to the Los Angeles Times, the biological therapies were meant to wipe out plaques in the brain that cause the slow cognitive degeneration brought on by Alzheimer's. In late-stage clinical trials, both solanezumab and bapineuzumab were not able to slow the brain disease's effects.

The researchers' study was published Thursday in the New England Journal of Medicine.

"Overall, I think these studies suggest that anti-amyloid interventions may need to be administered early in the disease," study co-author Dr. Paul Aisen, a UC San Diego Alzheimer's researcher, told the LAT.

Previous studies have pinpointed buildup of the amyloid protein to cause Alzheimer's slow-progressing effects. These two new drugs had promising early trials and appeared to be on the way to the FDA for evaluation and approval.

Backed by Johnson and Johnson and Pfizer, bapineuzumab seems to be done for as the two companies abandoned the drug after trials were made public in 2012. Developed by pharmaceutical company Eli Lilly, solanezumab will get another go in trials aimed at treating early-stage Alzheimer's patients.

Dr. Steven Salloway, lead researcher on the bapineuzumab study, told HealthDay News said future trials may focus more on combining therapies, similar to how HIV is treated.

"This will involve a little more creativity in drug development. Companies will have to cooperate and share data," he said. "We also need to have drugs that will lower amyloid more dramatically than they did in this trial."

Heather Snyder, director of medical and scientific operations for the Alzheimer's Association, said amyloid remains an important focus for studying, but it should not be the only point of research.

"It's really important to continue to research a number of different mechanisms that could explain Alzheimer's," she told HealthDay. "We can understand more about how the immune system is involved, for example. It's important to understand what is happening during Alzheimer's."