Translate Bio announced that it has completed enrollment and dosing in the dose cohorts comprising the second interim data analysis from its Phase 1/2 clinical trial for MRT5005 in cystic fibrosis (CF). These include multiple-ascending dose (MAD) groups (8, 12 and 16 mg), and a 20 mg single-ascending dose (SAD) group. The Company anticipates reporting interim clinical data from these cohorts early in the second quarter of 2021. MRT5005, the first mRNA therapeutic with delivery to the lung, is designed to address the underlying cause of CF, regardless of genetic mutation, by delivering mRNA encoding fully functional cystic fibrosis transmembrane conductance regulator (CFTR) protein to cells in the lung through nebulization. Currently approved CFTR modulator treatments are specific to a patient’s genetic mutation; therefore, there remains a significant unmet medical need for patients with CF who have genetic mutations non-amenable to these treatments or for patients who derive little therapeutic benefit from or are unable to tolerate these treatments. Translate Bio previously reported the first interim analysis data from the Phase 1/2 clinical trial which included 8, 16 and 24 mg single-ascending dose groups. MRT5005 is the first clinical-stage mRNA product candidate designed to address the underlying cause of CF by delivering mRNA encoding fully functional cystic fibrosis transmembrane conductance regulator (CFTR) protein to the lung epithelial cells through nebulization. MRT5005 is being developed to treat all patients with CF, regardless of the underlying genetic mutation, including those with limited or no CFTR protein. The United Stated Food and Drug Administration (FDA) has granted MRT5005 Orphan Drug, Fast Track and Rare Pediatric Disease designation. The randomized, double-blind, placebo-controlled Phase 1/2 clinical trial of MRT5005 is designed to enroll at least 40 adult patients with CF who have two Class I and/or Class II mutations. The primary endpoint of the trial will be the safety and tolerability of single and multiple escalating doses of MRT5005 administered by nebulization. Percent predicted forced expiratory volume in one second (ppFEV1), which is a well-defined and accepted endpoint measuring lung function, will also be measured at pre-defined timepoints throughout the trial. The Phase 1/2 clinical trial of MRT5005 for the treatment of CF is being conducted in collaboration with the Cystic Fibrosis Foundation Therapeutics Development Network and the Emily’s Entourage Patient Registry. In July 2019, the Company announced interim results from the 8, 16 and 24 mg SAD groups of the Phase 1/2 clinical trial. A second interim analysis is anticipated early in the second quarter of 2021 and will include 8, 12 and 16 mg MAD groups and a 20 mg SAD group. The clinical trial continues to enroll and dose in the remaining dose groups, including a 20 mg MAD group and a daily dosing cohort.