RA CAPITAL MANAGEMENT, L.P. bought MLYS

Footnotes

The stock option vests in 12 substantially equal monthly installments following the date of grant.; RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund") and RA Capital Nexus III Fund, L.P. (the "Nexus Fund III"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, the Fund, the Nexus Fund III, Dr. Kolchinsky and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein.; Derek DiRocco is a Partner of the Adviser who serves on the Issuer's board of directors. Under Dr. DiRocco's arrangement with the Adviser, Dr. DiRocco holds the RSUs and the options for the benefit of the Fund and the Nexus Fund III. Dr. DiRocco is obligated to turn over to the Adviser any net cash or stock received upon settlement of the RSUs or exercise of the options, as applicable, which will offset advisory fees owed by the Fund and the Nexus Fund III to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the option and underlying common stock.