The trials have been designed for evaluating gantenerumab in individuals with Alzheimer’s and mild Alzheimer’s dementia-caused mild cognitive impairment (MCI), together called early Alzheimer’s disease.
The double-blind, international, randomised, placebo-controlled Phase III GRADUATE I and II trials assessed the efficacy and safety of gantenerumab in study subjects for more than 27 months.
They enrolled 1,965 patients across 30 countries and categorised them into a 1:1 ratio to receive gantenerumab or a placebo.
The variation from baseline on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) at 116 weeks was the primary endpoint of the trials.
Gantenerumab was found to be well tolerated, including its subcutaneous dose.
In GRADUATE I and II studies, trial subjects in the gantenerumab arm had a slowing clinical decline of -0.31 and -0.19, respectively, from a baseline score on the CDR-SB, which was not statistically significant.
The findings indicate an 8% and 6% relative drop in clinical decline in GRADUATE I and II studies, respectively, versus a placebo.
The beta-amyloid removal level was also lesser than anticipated.
An investigational, fully human monoclonal IgG1 antibody, gantenerumab acts on and attaches to accumulated beta-amyloid forms.
Roche Global Product Development head and chief medical officer Levi Garraway said: “We are profoundly grateful to the study participants, their care partners, and study sites for their contributions to this research.
“While the GRADUATE results are not what we hoped, we are proud to have delivered a high quality, clear, and comprehensive Alzheimer’s dataset to the field, and we look forward to sharing our learnings with the community as we continue to search for new treatments for this complex disease.”
In October this year, the company reported positive data from two Phase III trials of Vabysmo (faricimab) to treat macular oedema caused by branch and central retinal vein occlusion.