Biogen and Eisai have reported a new set of results from the ongoing long-term extension (LTE) Phase lb trial of aducanumab for the treatment for mild cognitive impairment (MCI) caused by Alzheimer’s disease (AD) and mild AD dementia.

The randomised, double-blind, placebo-controlled, multiple-dose trial is designed to analyse the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and clinical effects of aducanumab in the enrolled patients.

The trial evaluated aducanumab at fixed doses of 1mg/kg, 3mg/kg, 6mg/kg and 10mg/kg.

It also included an arm with a titration regimen to give the patients a gradually increased dose of aducanumab until the maximum dose of 10mg/kg.

The newly published results are based on the trial’s placebo-controlled stage, as well as LTE for patients treated with aducanumab up to 36 months in the titration cohort and up to 48 months in the fixed-dose cohorts.

According to Biogen, the results are generally consistent with previous interim analyses, and no changes were reported to the risk-benefit profile of aducanumab.

“The results for each dose arm are generally consistent with previous interim analyses.”

Biogen said in a statement said: “The results for each dose arm are generally consistent with previous interim analyses.

“Amyloid plaque levels as measured by positron emission tomography (PET) continued to decrease in a dose and time-dependent manner in patients from the titration cohort at 36 months and fixed-dose cohorts at 48 months.

“Amyloid plaque levels in the 10mg/kg fixed-dose at 48 months remained at a level considered below the quantitative cut point that discriminates between a positive and negative scan. Analyses of exploratory clinical endpoints Clinical Dementia Rating Sum of Boxes (CDR-SB) and the Mini-Mental State Examination (MMSE) suggest a continued benefit on the rate of clinical decline over 36 months and 48 months, respectively.”

During the Phase lb trial, 196 patients were treated with aducanumab or placebo, 143 of them entered the LTE.

Altogether, 185 patients received aducanumab. Of those patients, 46 patients experienced amyloid imaging abnormalities (ARIA)-E (edema), while eight patients experienced more than one episode of ARIA-E.