(ChemotherapyAdvisor) – Memantine, a drug used to treat Alzheimers’ patients, also slows cognitive decline among patients who undergo whole-brain radiation therapy (WBRT) for brain tumors, according to a randomized, placebo-controlled phase 3 study presented at the American Society for Radiation Oncology’s (ASTRO’s) 54th Annual Meeting in Boston, MA.
“Our findings suggest that memantine may prevent the changes that occur in the brain following radiation therapy, impacting future treatment practices for these patients and suggest a role for further study in other patient populations receiving radiation to the brain,” said lead author Nadia N. Laack, MD, a radiation oncologist at the Mayo Clinic in Rochester, MN.
Memantine is a N-Methyl-D-aspartate receptor antagonist.
“Even though no statistically significant difference was seen in delayed recall, patients treated with memantine had better cognitive function over time,” Dr. Laack reported. “Specifically, memantine delays time to cognitive decline and reduces the rate of decline in recognition memory, executive function and processing speed in patients receiving WBRT.”
The authors studied patients’ cognitive functioning at baseline, during, and after WBRT (37.5 Gy over 15 fractions), testing for recognition memory, global function, executive function, and cognitive processing speed. Patients were randomized to receive either placebo or 20 mg memantine per day for 24 weeks, starting within 3 days of initiating WBRT. Only 32% of patients enrolled completed the study because of poor survival and progressive disease, the authors noted.
Cognitive declines were seen after a significantly longer period of time among patients who were administered memantine than placebo-arm patients (P=0.02), the authors said.
“There was less decline on the HVLT-R (Hopkins Verbal Learning Test-Revised) Delayed Recognition in the memantine arm at 24 weeks (P=0.015),” the authors reported. “Fewer patients receiving memantine experienced decline on the Controlled Oral Word Association test at 8 (P=0.008) and 16 weeks (P=0.004).”
Grade 3 and 4 toxicities were similar between study arms, including hair loss, fatigue, headache, and nausea.
There were no survival differences among patients in the treatment arms.