Gantenerumab Continues to Show Promise in Reduction of Amyloid Plaques

Latest findings from the open-label extension (OLE) Phase 3 clinical trials Scarlet RoAD (NCT01224106) and Marguerite RoAD (NCT02051608) on gantenerumab (RG1450, RO4909832) continue to show significant reductions in the accumulation of amyloid plaques in patients with Alzheimer’s disease with and without amyloid-related imaging abnormalities-edema (ARIA-E).

The findings were presented during the AD/PD 2019 14th​ International Conference on Alzheimer’s and Parkinson’s Diseases, held March 26–31 in Lisbon, Portugal.

Alzheimer’s disease is a progressive neurodegenerative disorder characterized by the formation of plaques made of a protein called beta-amyloid that accumulate between nerve cells in the brain, disrupting their function.

Gantenerumab is an investigational fully human antibody that has been designed to bind to beta-amyloid and prevent the formation and accumulation of plaques between brain cells. The therapy had initially been developed by Chugai Pharmaceutical, but is now part of a collaboration between Hoffmann-La Roche and MorphoSys.

The OLE studies Scarlet RoAD and Marguerite RoAD are assessing the safety and efficacy of gantenerumab administered by a subcutaneous (under the skin) injection at a maximum dose of 1,200 mg per month in patients with Alzheimer’s disease.

Previous findings from both studies have shown that gantenerumab reduced the accumulation of amyloid plaques in the brains of patients with Alzheimer’s disease, seen in positron emission tomography (PET) scans. The most common adverse events associated with the administration of high doses of gantenerumab were ARIA-E (accumulation of fluid inside the brain) and injection-site reactions.

Now, trial data have been re-analyzed to assess whether gantenerumab can preven the accumulation of amyloid plaques in patients with and without ARIA-E.

The findings from the re-analysis included data from all patients who had undergone PET scans at week 52 and week 104 of Scarlet RoAD and Marguerite RoAD OLE studies.

ARIA-E had an overall incidence rate of 30.6% in the group of 373 patients analyzed. However, no significant differences were found in the total amount of amyloid plaques observed at baseline in patients with and without ARIA-E.

At week 52, 41.7% of the patients who underwent PET scans had ARIA-E, and from these, one in four reported symptoms.

Between week 104 and week 52, gantenerumab significantly reduced the accumulation of amyloid plaques in the brains of all patients, regardless of the presence of ARIA-E. In addition, no significant differences were found between patients with and without ARIA-E at weeks 52 or 104.

These 2019 American Academy of Neurology (AAN) Annual Meeting, May 4-10 in Philadelphia, Pennsylvania.