- Shares in Biogen rose by nearly 5% in early Friday morning trading as markets digested data released last night from an early trial of the Cambridge biotech's closely watched Alzheimer's drug aducanumab.
- Results from the Phase 1b study showed titration dosing of aducanumab helped control the incidence of ARIA, a side effect typically seen in response to Alzheimer's drugs designed to reduce amyloid plaques in the brain.
- Buildup of amyloid plaques is a hallmark characteristic of the neurodegenerative disease and targeting those plaques remains a leading hypothesis for treating the disease, even after the high-profile failure of Eli Lilly's solanezumab last month.
In the wake of Eli Lilly's setback, Biogen's aducanumab is considered one of the most promising clinical candidates for a disease-modifying Alzheimer's treatment.
Biogen currently has two Phase 3 studies underway testing aducanumab in patients with early Alzheimer's. Both aren't expected to readout until early 2020 but the data released Thursday help to bolster confidence in Biogen's clinical approach.
Patients in the Phase 1b study were randomized to receive either aducanumab or placebo. Those receiving the drug were further divided into four fixed-dose cohorts and one titration cohort. Patients who were carriers of apoplipoprotein E4 gene— a group known to experience certain side effects more frequently — were titrated, or progressively dosed, with aducanumab in hopes of improving safety even at higher doses.
On this mark, Biogen appeared to hit its target. Titration dosing limited the incidence of amyloid-related imaging abnormalities, or ARIA, to 35% of the 23 patients in that cohort. This compared favorably to the 43% and 55% rates seen in the two highest fixed-dose arms, although it was significantly higher than the 5% mark seen in the low-dose cohorts.
Furthermore, the data suggested titration was effective in both reducing amyloid plaque and slowing cognitive decline, compared to placebo.
"Titration dosing of aducanumab up to 10 mg/kg resulted in significant reductions in amyloid plaque burden during 12 months of treatment in ApoE E4-positive patients with prodromal or mild AD compared with placebo," said the abstract presented at the Clinical Trials on Alzheimer's Disease 2016 meeting.
Brian Abrahams, an equity analyst at Jefferies, believes the data helps to confirm Biogen's approach and choice of clinical endpoint in its Phase 3 testing. Yet he cautioned the reduction in ARIA risk may not be enough to fully alleviate safety concerns.
So far, investors and analysts are chalking the data up as a positive, but there has been plenty of positive data in early AD trials only to lead to epic failures in later stages.