The US Food and Drug Administration (FDA) has cleared the Investigational New Drug (IND) application for VX-522, an experimental messenger RNA (mRNA) therapy being developed by Vertex Pharmaceuticals and Moderna to treat the underlying cause of cystic fibrosis (CF) in patients who cannot benefit from a CF transmembrane conductance regulator (CFTR) modulator.

“Clearance of the IND represents a pivotal turning point in reaching the remaining ~5,000 people with CF who are still waiting for a medicine to treat the underlying cause of their disease,” Reshma Kewalramani, MD, chief executive officer and president of Vertex, said in a press release.

VX-522 is composed of a CFTR mRNA encapsulated by a lipid nanoparticle. It is delivered to lung cells via inhalation, where the mRNA is used to produce functional copies of the CFTR protein.

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“Moderna’s development of a proprietary inhalable lipid nanoparticle to deliver a functional cystic fibrosis treatment to the lungs could lead to a transformational medical achievement,” Stéphane Bancel, chief executive officer of Moderna, said.

Vertex plans to initiate a single ascending dose clinical trial to evaluate the safety and tolerability of VX-522 in patients with CF, aged 18 years and above, who do not respond to CFTR modulator therapy.


Vertex announces investigational new drug (IND) application for VX-522, mRNA therapy for people with cystic fibrosis, cleared by FDA. News release. Vertex Pharmaceuticals Inc; December 12, 2022.