Early data from ARCT-032 clinical trial for CF expected next month
Study still recruiting patients not eligible for CFTR modulators and others
Interim results from the first nine participants in a Phase 2 clinical trial testing Arcturus Therapeutics’ experimental inhaled therapy ARCT-032 in adults with cystic fibrosis (CF) are expected next month.
The U.S.-based study, called LunairCF (NCT06747858), is still recruiting CF patients who aren’t eligible for CFTR modulators or who have been off these standard treatments for at least 60 days. The trial’s enrollment, which has a target of 12 participants, is expected to be completed by year’s end.
“We … look forward to sharing two [patient groups] of Phase 2 CF data in September,” Joseph Payne, Arcturus’ president and CEO, said in a company press release.
The company hopes to meet with the U.S. Food and Drug Administration in the first half of next year to discuss LunairCF results and plans for Phase 3 trial testing, which may include pediatric and adolescent CF patients. Arcturus expects to start such late-stage testing in 2026.
ARCT-032 uses different approach to boost CFTR function
CF is caused by mutations in the CFTR gene, which contains instructions for cells to manufacture a protein of the same name. Without a working protein, certain cells are less able to regulate fluid levels, resulting in unusually thick, sticky mucus. As this mucus builds up in organs and tissues, including the lungs, it causes respiratory and other CF symptoms.
CFTR modulators, one class of available CF therapies, aim to correct CFTR protein defects to allow for more normal function. However, these typically only work for people with specific CFTR mutations.
ARCT-032 uses a different approach to boost CFTR function by targeting an earlier step in protein production. Cells manufacture proteins by copying genetic instructions in DNA to another type of molecule, called messenger RNA (mRNA). The therapy uses fat-coated particles to deliver a healthy CFTR gene’s mRNA to cells in the lungs.
Arcturus expects this to result in the production of a healthy, working CFTR protein without the need for protein correction. This would mean that the therapy could benefit a broad range of people with CF, regardless of mutation type.
ARCT-032 received rare pediatric disease designation in the U.S. and orphan drug designation in both the U.S. and the European Union for the treatment of CF. These statuses are meant to accelerate the therapy’ clinical development and regulatory review.
Data from Phase 1/1b show therapy was safe at several dose levels
Interim data from a prior Phase 1/1b trial (NCT05712538) showed that ARCT-032 was safe and well tolerated at several dose levels in both healthy volunteers and CF participants. After two doses, there was a trend toward improved lung function in four people with CF who had distinct mutation and treatment statuses.
In LunairCF, where participant dosing started earlier this year, investigators are testing three ascending doses of ARCT-032 in adults with CF who are not eligible for CFTR modulators or who are not taking this type of treatment due to intolerance, poor response, or lack of access.
Participants are inhaling their assigned dosage of ARCT-032 each day for 28 days, or about a month.
The trial’s primary goals are to assess the incidence and severity of adverse events for a total of 16 weeks, or about four months. Secondary goals include the assessment of the therapy’s movement into, through, and out of the body at up to six weeks. Some efficacy measures will be assessed after four weeks, including changes in lung function and the Cystic Fibrosis Quality of Life Questionnaire-Revised.
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