Moderna Inc. blamed a switcheroo by the U.S. FDA for the refusal-to-file (RTF) letter on the seasonal influenza vaccine mRNA-1010. Shares of the firm (NASDAQ:MRNA) closed Feb. 11 at $40.51, down $1.49, having traded as low as $36.66 as investors learned of the RTF letter, which Moderna said is “inconsistent with feedback” the company was given by regulators during pre-phase III as well as pre-BLA-submission talks.