Arrowhead Pharmaceuticals has dosed the first participants in a Phase I/II clinical trial of ARO-C3 as a potential therapy for various complement-mediated diseases.

ARO-C3 is an investigational ribonucleic acid interference (RNAi) treatment intended to lower the complement component 3 (C3) production.

The dose-escalating, placebo-controlled trial will analyse the safety, tolerability, pharmacokinetics and pharmacodynamics of ARO-C3. 

It will enrol up to 24 adult healthy subjects, up to 24 adult paroxysmal nocturnal haemoglobinuria (PNH) patients as well as up to 14 adults with complement-mediated renal disease. 

Part 1 of the trial will have healthy subjects enrolled into four arms to assess four escalating doses of the investigational treatment. 

Each arm will have six participants who will be randomised to receive either one subcutaneous dose of ARO-C3 or a placebo. 

The open-label Part 2 of the trial will enrol patients with PNH or complement-mediated renal disease to receive ARO-C3 on the first and 85th day at one of two dose levels selected in Part 1. 

Analysing the safety, tolerability, pharmacokinetics and pharmacodynamics of single doses of the treatment in healthy subjects will be the primary goal of the trial.

Furthermore, the primary objective will include assessment of the safety, tolerability, pharmacokinetics and pharmacodynamics of varying doses of ARO-C3 in PNH and complement-mediated renal disease patients.

Arrowhead Pharmaceuticals discovery and translational medicine senior vice-president James Hamilton said: “We believe a C3 targeted drug has the potential to address multiple complement mediated and complement associated diseases, where significant unmet medical need exists. 

“ARO-C3 has progressed rapidly, and our preclinical data have been very encouraging. We are eager to continue this progress as we evaluate ARO-C3 in clinical studies.”

In July last year, the company voluntarily halted Phase I/II AROENaC1001 trial of its investigational RNAi therapy, ARO-ENaC, to treat cystic fibrosis.