Biotechnology firm Alector has announced initial positive results from the Phase I/Ib INFRONT clinical trial of AL001 to treat frontotemporal dementia patients with a granulin mutation (FTD-GRN).

A loss of function mutation in the progranulin gene is known to be one of the primary drivers of FTD, a progressive and severe form of dementia.

The ongoing Phase I/Ib trial is evaluating the safety, tolerability, pharmacokinetics, and pharmacodynamics of intravenously AL001 in healthy volunteers and subjects with FTD-GRN.

It involves single and multiple AL001 doses and will measure the plasma and cerebrospinal fluid (CSF) levels of progranulin, a disease-specific biomarker.

Results from 50 healthy volunteers and four patients showed AL001 to be generally safe and well-tolerated up to the highest dose level.

In addition, the drug candidate led to a dose-dependent rise in PGRN levels in plasma, as well as CSF of healthy volunteers and also FTD-GRN patients.

It was observed that AL001 led to a three-fold increase in plasma PGRN and doubled the level in the CSF of asymptomatic and symptomatic FTD-GRN patients, restoring it to the normal range.

Alector chief medical officer Robert Paul said: “Our initial findings in this study show that treatment with AL001 is able to restore the level of progranulin in FTD-GRN patients back to the normal range.

“The good tolerability and safety observed, and promising progranulin response in the first four patients, support advancing AL001 to a Phase II study in the second half of this year for the treatment of FTD-GRN patients.”

The trial is expected to be completed in December.