Calico Life Sciences has dosed the first patient in a Phase lb trial of the investigational eIF2B activator, ABBV-CLS-7262, to treat Vanishing White Matter (VWM) disease.

The firm, in partnership with AbbVie, is currently developing ABBV-CLS-7262.

The therapy is capable of targeting eIF2B, a guanine nucleotide exchange factor that is vital for protein synthesis and a major integrated stress response (ISR) regulator.

This Phase lb, 96-week open-label, single arm study will assess the safety, tolerability, and pharmacokinetics of ABBV-CLS-7262 in patients with VWM disease.

Primary outcomes of the trial are the evaluation of adverse events over the first seven weeks and drug concentrations in plasma in the first four weeks of dosing.

VWM disease is an ultra-rare progressive leukoencephalopathy, an ailment of the brain’s white matter.

It is caused by differences in any of the five subunits of an essential enzyme in eIF2B cells.

VWM variations in eIF2B trigger a decrease in its enzymatic activity that could cause chronic activation of the ISR, which plays a crucial role in protein homeostasis and organismal resilience.

Calico founder and CEO Arthur Levinson said: “Since our founding, Calico has been focused on generating new scientific insights on biology relevant to aging and translating those insights to develop drug candidates for potential patient benefit.

“ABBV-CLS-7262 is an encouraging outcome of this approach and we are pleased to advance this clinical study in vanishing white matter disease.”