The enthusiasm generated for a mouse study stems from the desperation for new ideas as the number of Alzheimer's cases, now at 5.4 million in the U.S., is expected to more than double by the year 2050 as the nation's demographic profile continues to gray. A better understanding of the disease process—the knowledge that pathology begins 10 or 20 years before the first symptom—has shifted focus toward earlier drug trials. New technologies that combine brain imaging and spinal fluid tests might identify at-risk patients and test new drugs. A relatively inexpensive drug that can be ingested orally, such as bexarotene, could then be prescribed to at-risk but symptom-free patients, who would take them over the course of their lifetimes, like a cholesterol-lowering drug.
As ReXceptor moves forward with its clinical trial plans, it will inevitably have to contend with the demands of the families of Alzheimer's patients. Landreth emphasizes that calling your physician after reading an article like this one is a bad idea. "Don't try this at home," he cautions, "because we don't know we what dose to give, we don't know how frequently to give it, and there are a few nuances to its administration. So one shouldn't be prescribing it off-label." It is also unclear whether a drug like bexarotene would work at a middle or advanced stage of the disease, when neurodegenerative processes have already set in.
Bexarotene's genesis as an Alzheimer's treatment comes as an outgrowth of Landreth's long-time fundamental work on cell receptors. If it succeeds, it will demonstrate that new ideas for treating this seemingly intractable disease may come from beyond the sometimes narrowly focused strategies of large pharmaceutical companies.