Phase 2 Trial of Tau Antibody RO7105705 Recruiting Patients with Moderate Alzheimer’s

A Phase 2 trial is enrolling patients with moderate Alzheimer’s to test an investigational antibody known as RO7105705 that targets the Tau protein.

The Genentech-sponsored multicenter, randomized study (NCT03828747) intends to assess the efficacy, safety, and pharmacological profile of RO7105705. The company plans to recruit 260 patients in the U.S. More information on study locations and contacts can be found here.

After a screening period, patients will receive RO7105705 or placebo by intravenous infusion every two weeks for the first three doses and every four weeks thereafter in a double-blind treatment period. Participants can then undergo an optional open-label extension period which will consist of RO7105705 infusions every four weeks. The last stage will be a safety follow-up period.

The trial’s primary goal is measuring the change in cognitive function and functional abilities from baseline to week 49.

RO7105705, or MTAU9937A, is being developed by Genentech — owned by Roche — and AC Immune. The treatment candidate is a humanized monoclonal antibody, designed to stop the cell-to-cell spread of toxic forms of the Tau protein in the brain. This spread is associated with the onset and progression of cognitive decline in Alzheimer’s disease.

“Slowing the propagation of Tau pathology may therefore slow disease progression and reduce cognitive decline,” Andrea Pfeifer, AC Immune’s CEO, said in an email reply to Alzheimer’s News Today.

Adding that anti-Tau therapies have shown promise in animal models, Pfeifer mentioned that the buildup of Tau pathology in Alzheimer’s is thought to occur after the accumulation of amyloid beta, the main component of senile plaques. However, recent results with imaging tracers “suggest that Tau is already present six to 10 years before clinical symptoms occur,” she explained.

AC Immune and Genentech started their collaboration in 2012. Genentech is also conducting the Phase 2 TAURIEL trial (NCT03289143), testing the safety and impact on dementia severity of the same antibody in patients with prodromal (early) to mild Alzheimer’s. This study is also recruiting participants at 135 locations globally. More information can be found here. Treatment will last for almost 1.5 years.

“We are highly encouraged that Genentech is broadening its clinical evaluation of our anti-Tau antibody,” Pfeifer said in a press release. By starting this second Phase 2 trial, Genentech is “demonstrating potentially, a greater belief in our anti-Tau antibody, as well as Tau as a target.” If successful, she added, “we would look forward to initiation of a Phase 3 trial.”

In December 2018, AC Immune and Eli Lilly announced a partnership to develop Tau aggregation blockers for the treatment of Alzheimer’s and other neurodegenerative diseases. The research will use AC Immune’s Morphomer platform and will focus mainly on AC Immune’s lead molecule, ACI-3024. A Phase 1 trial is expected to start this year.

Other product candidates targeting Tau and being developed by AC Immune include the vaccine ACI-35, currently in a Phase 1b/2a trial in collaboration with Janssen Pharmaceuticals and a Tau imaging agent undergoing Phase 2 testing in partnership with Life Molecular Imaging.