SAN DIEGO – In a 3-year Swedish study of patients with mild or moderate forms of Alzheimer’s disease who were taking cholinesterase inhibitors, varying outcomes were demonstrated in the different domains of the disease and in the scales used.
The findings show the clinical importance of functional evaluations, even in the mild stages of Alzheimer’s disease (AD), Carina Wattmo, Ph.D., said at the Clinical Trials Conference on Alzheimer’s Disease.
Some randomized trials, such as that of the anti-beta-amyloid antibody solanezumab and the medical food souvenaid, "have shown small but significant positive cognitive effects in mild AD exclusively," said Dr. Wattmo of the clinical memory research unit in the department of clinical sciences at Lund University, Malmö, Sweden.
Dr. Carina Wattmo
"Placebo-controlled trials longer than 6 months in untreated AD patients are not allowed for ethical reasons. New, longer studies are most often performed on patients who are on active treatment with cholinesterase inhibitors and/or memantine. Therapies expected to modify disease progression need to be thoroughly evaluated over many years. Knowledge on the expected longitudinal outcome in different stages of AD is scarce."
Dr. Wattmo and her associates analyzed data from the Swedish Alzheimer Treatment Study (SATS), a 3-year, prospective, open-label, nonrandomized multicenter study launched to evaluate the long-term effectiveness of cholinesterase inhibitor treatment in a routine clinical setting. Patients were diagnosed with possible or probable AD; the population included 734 patients with mild AD and 287 with moderate disease.
The patients were assessed after 2 months of therapy and every 6 months over the 3-year period, with the Mini-Mental State Examination (MMSE), the Alzheimer’s Disease Assessment Scale–cognitive subscale (ADAS-cog), the Clinician’s Interview-Based Impression of Change (CIBIC), and functional capacity based on the Instrumental Activities of Daily Living scale (IADL).
The mean age of patients was 75 years, and 64% were female. At baseline, patients in the mild AD group showed an illness duration of 2.9 years vs. 3.4 years in the moderate AD group, a difference that was statistically significant (P = .005). They also had more years of education (9.6 vs. 9.0 years; P less than .001), and a better functional capacity based on the IADL score (14.7 points vs. 19.1 points; P less than .001).
Dr. Wattmo reported 3-year results from 306 patients in the mild AD group and 79 patients in the moderate AD group. The mean change in MMSE was 3.1 points in the mild AD group vs. 4 points in the moderate AD group, a difference that did not reach statistical significance (P = .148). The mean decline in the ADAS-cog was 6.1 points in the mild AD group vs. 13.2 points in the moderate AD group, a difference that reached statistical significance (P less than .001).
In addition, 33% of patients in the mild AD group showed global CIBIC improvement or no change after 3 years of therapy, compared with 15% in the moderate AD group, a difference that was statistically significant (P = .002).
On the IADL, the mean decline was 6.3 points in the mild AD group vs. 7.5 points in the moderate AD group, a difference that was not statistically significant (P = .063).
"Varying outcomes were demonstrated in the different domains and stages of AD in this study from routine clinical practice," Dr. Wattmo concluded. "The outcome could be dependent on the scales used."
Dr. Wattmo said that she had no relevant financial conflicts to disclose.