Magenta Therapeutics, Inc. entered into a Sublease Termination and Release Agreement with Novartis Institutes for Biomedical Research, Inc. pursuant to which, effective as of the Termination Date, the parties terminated that certain Sublease, as amended, by and between the Company and Novartis, dated as of May 4, 2018. Under the Sublease, the Company had leased approximately 69,000 square feet of research and development, laboratory and office space located at 100 Technology Square in Cambridge, Massachusetts. The Sublease was previously scheduled to terminate, in accordance with its terms, on the earlier of (i) February 28, 2028 or (ii) the date upon which the Sublease may otherwise be terminated or expire (a) pursuant to its terms, (b) pursuant to the terms of the Overlease or (c) pursuant to law.

In exchange for the early termination of the Sublease pursuant to the Termination Agreement, the Company agreed to make a one-time termination payment to Novartis in the amount of $14,780,188.00. Following the Termination Date, the Company's principal executive offices will be located at 300 Technology Square in Cambridge, Massachusetts.