“This is the first time a patient with PCD has received a targeted mRNA-based therapeutic,” said Shehnaaz Suliman, M.D., MBA, M.Phil., chief executive officer of ReCode Therapeutics. “This study will evaluate RCT1100 as a potential novel treatment option for patients who do not have any approved therapies. We are especially grateful to the PCD community for the continued support and collaboration as we continue our efforts to develop a treatment for PCD patients.”

PCD is a rare and progressive genetic disease that causes cilia, the microscopic hairlike structures that line the respiratory tract, to be dysfunctional and, therefore, unable to move mucus out of the body. Bacteria and viruses become trapped in the airways, which leads to chronic infections and impaired respiratory function. Approximately 10% of PCD cases result from mutations in the DNAI1 gene.

ReCode’s proprietary Selective Organ Targeting (SORT) lipid nanoparticle (LNP) delivery platform was used to develop RCT1100, an inhaled mRNA therapy designed to deliver and express DNAI1 mRNA in target cells. The DNAI1 mRNA is intended to establish or restore proper ciliary function by addressing the underlying cause of the disease. In preclinical studies, the company’s DNAI1 mRNA led to efficient production of the DNAI1 protein and rescue of ciliary function in a relevant model of PCD.

“As the presenting symptoms of PCD can imitate common and less serious disorders, an accurate diagnosis is critical but often elusive for patients. There are currently no FDA-approved therapies that help directly rescue impaired cilia, so current treatment for PCD typically focuses on improving lung function and delaying disease progression,” said Michele Manion, president and executive director of the PCD Foundation. “The initiation of the Phase 1 study of RCT1100 marks an important milestone for our patient community and will support our ongoing efforts to change the course of treatment for PCD.”

In August 2023, ReCode completed Part A of the Phase 1 study, a double-blind, placebo-controlled study that evaluated the safety and tolerability of RCT1100 in 40 healthy adult volunteers. No serious side effects were observed in that study. Part B of the study is open-label and designed to assess the safety and tolerability of a single ascending dose of inhaled RCT1100 administered with a nebulizer in patients with PCD caused by pathogenic mutations in the DNAI1 gene. ReCode anticipates enrolling up to nine PCD patients across sites in the U.S. and internationally. For more information, please visit clinicaltrials.gov.

“With no approved therapeutics to treat the underlying cause of PCD, we are excited to bring our inhaled mRNA-based therapy forward into the clinic and to patients,” said David Lockhart, Ph.D., president and chief scientific officer of ReCode Therapeutics. “RCT1100 is currently the only treatment in clinical development for PCD. This study brings us one step closer to improving the respiratory health and quality of life of people living with this disease.”