On April 27, 2022, 2seventy bio, Inc. entered into the First Amendment, effective as of April 25, 2022, to the License Agreement, dated August 31, 2015, between the National Institutes of Health (“NIH”) and 2seventy bio, Inc. (the “Amendment”) to amend the royalty rates payable by 2seventy to NIH on sales of licensed products by a sublicensee of 2seventy and other payments received by 2seventy from a sublicensee. The foregoing description of the material terms of the Amendment is qualified in its entirety by reference to the complete text of the Amendment, which 2seventy intends to file, with confidential terms redacted, with the Securities and Exchange Commission as an exhibit to the Company's Quarterly Report on Form 10-Q for the quarter ended March 31, 2022.