2 March 2023 - - US-based Arrowhead Pharmaceuticals Inc. (NASDAQ: ARWR) has posted interim results from Part 1 of AROC3-1001, an ongoing Phase 1/2 clinical study of ARO-C3, the company's investigational RNA interference therapeutic designed to reduce production of complement component 3 as a potential therapy for various complement mediated diseases, the company said.

The company plans to present additional results at an upcoming complement-focused medical meeting.

Dosing in Part 2 of the Phase 1/2 study is expected to begin in the first half of 2023.

In Part 1 of AROC3-1001, ARO-C3 interim results included:

A dose-dependent reduction in serum C3, with 88% mean reduction at highest dose tested

A dose-dependent reduction in AH50, a marker of alternative complement pathway hemolytic activity, with 91% mean reduction at highest dose tested

Duration of pharmacologic effect supportive of quarterly or less frequent subcutaneous dose administration

Safety and tolerability

Overall, no clinically significant laboratory findings or patterns of adverse changes in any clinical laboratory parameters

No dose limiting toxicity, serious or severe adverse events, or study discontinuation due to adverse events

Most common adverse events include headache, COVID-19, generally mild injection site reactions, and seasonal allergy

AROC3-1001 (NCT05083364) is a Phase 1/2, placebo controlled, dose-escalating study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of ARO-C3 in up to 42 adult healthy volunteers (Part 1), and up to 42 adult patients with paroxysmal nocturnal hemoglobinuria or with complement-mediated renal disease (Part 2).

Arrowhead Pharmaceuticals develops medicines that treat intractable diseases by silencing the genes that cause them.

Using a broad portfolio of RNA chemistries and efficient modes of delivery, Arrowhead therapies trigger the RNA interference mechanism to induce rapid, deep, and durable knockdown of target genes.

RNA interference, or RNAi, is a mechanism present in living cells that inhibits the expression of a specific gene, thereby affecting the production of a specific protein. Arrowhead's RNAi-based therapeutics leverage this natural pathway of gene silencing.