Alzheimer's disease is the sixth leading cause of death in the United States and affects 5.4 million Americans. And, according
to the Alzheimer's Association, it is the only top 10 leading cause of death in the United States without a cure or means
of prevention. Thus, it is unsurprising that many drug companies are focused on finding a treatment to Alzheimer's.
Two such companies, Pfizer and Medivation, ended their efforts with Alzheimer's drug Dimebon this past January after it failed
to meet two endpoints in a Phase III trial.
Caregivers often have to help Alzheimer's patients take their medication.
The failure of this trial is especially disconcerting based on the difficulties companies face when conducting Alzheimer's
trials in the first place. According to William Thies, PhD, Chief Medical and Scientific Officer at the Alzheimer's Association,
one of the biggest challenges drug company's face, besides proper research funding, is subject recruitment and retention.
Although websites such as Alzheimer's Association TrialMatch offers easy access to clinical trials information for potential
subjects, there is still a need for at least 50,000 volunteers today.
Besides the problems faced during recruitment for all clinical trials (such as wanting to be on the receiving end of the experimental
drug), Alzheimer's trials face added difficulties due to the nature of the disease. For instance, because of the effect Alzheimer's
has on a person's decision-making ability, it can be difficult to follow specific regulatory guidelines.
"Many people with Alzheimer's also have other serious medical conditions, such as heart disease, diabetes, and cancer, which
may disqualify them for certain clinical studies and make it hard or impossible for them to continue in a study," Thies said.
Another challenge for Alzheimer's trials is that of the caretaker. Since those affected with Alzheimer's disease progressively
lose more and more of their memory, they become increasingly reliant on a caretaker to take care of them for their daily needs
such as reminders to take their medication and helping with transportation. Hence, recruiters are faced with the task of enlisting
both the patient and his or her provider.
Caretakers have to handle getting subjects "physically to and from the study along with the time-consuming nature of Alzheimer's
disease clinical trials—which now often include imaging or lumbar puncture," Thies said.
On top of this, Thies noted, "There is a lack of a clear regulatory path for Alzheimer's disease modifying drugs. Thus, Alzheimer's
disease trials are real research for the course and onset of the disease and not only drug development."
So what can companies do to combat this plethora of obstacles? Overall, recruiters and researchers should make participants
feel at ease and assure them that they are receiving quality care. Companies can let them know about the strict regulatory
guidelines in place by the US Food and Drug Administration and institutional review boards.
"Research shows that people involved in studies tend to do somewhat better than people in a similar stage of their disease
who are not enrolled, regardless of whether the experimental treatment works," said Thies. "It is important for companies
to make sure volunteers are aware that they can withdraw from a research study at any time if they or their physician feels
it is in their best interest."
Additionally, it is vital to let subjects know the impact they are making by participating in a clinical trial.
"It is important for volunteers to remember improved treatments can never become a reality without testing in human volunteers
and that these studies may have a measurable impact on current and future people with Alzheimer's. Every clinical study contributes
valuable knowledge, whether or not the tested treatment works as hoped," Thies said.