The firm recently had a successful end-of-Phase II meeting with the FDA, in which the agency provided feedback into a Phase III trial design.

In a combined analysis of patients from five open-label trials, 22 percent responded to the protease activator, the first approved treatment for the rare disease.

The firm will use the funds to advance its mRNA therapies, including its lead candidate STX-001 for treating melanoma and triple-negative breast cancer.