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Arrowhead Announces Interim Results from Ongoing Phase 1/2 Study of ARO-C3 for Treatment of Complement Mediated Diseases

- Achieved Mean Reductions of 88% in C3 and 91% in AH50

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

“ARO-C3 has achieved encouraging results in Part 1 of this Phase 1/2 clinical study, including a mean reduction of 88% in C3 and 91% in AH50 at the highest dose tested. These data in healthy volunteers provide us with further confidence as we begin Part 2 of the study, which includes patients with various complement mediated diseases,” said James Hamilton, M.D., MBA, chief of discovery and translational medicine at Arrowhead. “Substantial unmet medical need remains in the treatment of multiple complement mediated diseases, including IgA nephropathy, C3 glomerulopathy, paroxysmal nocturnal hemoglobinuria, and additional renal and hematologic indications, despite the availability of approved complement C5 inhibitors that have significantly improved treatment. In addition, we believe C3 inhibition has interesting potential, as it is upstream of C5 in the complement cascade.”

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 (PNH) or with complement-mediated renal disease (Part 2).

About Arrowhead Pharmaceuticals

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.

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Source: Arrowhead Pharmaceuticals, Inc.


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