Translate Bio Shares Drop After Its mRNA-Based Cystic Fibrosis Candidate Did Not Improve Lung Function

Translate Bio Inc TBIO revealed its second interim analysis from Phase 1/2 clinical trial evaluating MRT5005 in patients with cystic fibrosis (CF).

• MRT5005 is an mRNA product candidate designed to address CF's underlying cause by delivering mRNA encoding fully functional cystic fibrosis transmembrane conductance regulator (CFTR) protein to the lung epithelial cells through nebulization.
• Data from 12 patients across three cohorts demonstrated that multiple doses of inhaled cystic fibrosis treatment suggest the therapy is safe. The program also appeared safe in an additional cohort with four patients in a single-dose cohort.
• However, no improvement in lung function was observed in any of the newly reported cohorts. No pattern of increase in ppFEV1 (a key measure of lung capacity) in the multiple-dose cohorts and the single-dose cohort was observed.
• No clear pattern of new or increasing levels of immunogenicity markers (anti-CFTR antibodies, anti-PEG antibodies, or T-cell sensitization to CFTR) was observed during repeat dosing.
• As a whole, Translate is evaluating the candidate in up to 40 patients in the trial, in two portions examining single and multiple ascending doses. The single-dose portion encompassed 8, 16, and 24 mg. Later, a 20 mg dose level was added, and the 24 mg cohort was scrapped.
• Patients witnessed mild to moderate side effects on the safety front, with three of 12 individuals experiencing fever, chills, or headache after the first dose. The symptoms did not recur after the second dose.
• Translate saw one serious side effect in the 20 mg cohort as a patient developed a pulmonary exacerbation 22 days after being dosed.
• There was a single instance of a possible mild to moderate hypersensitivity reaction, but that resolved the next day after receiving medical treatment.
• Also, Truist Securities downgraded the company from Buy to Hold, with a $20 price target.
• Price Action: TBIO shares are down 24.3% at $19.46 in premarket trading on the last check Thursday.