X0306 4 2020-08-10 0 0001735438 MeiraGTx Holdings plc MGTX 0001216955 MARCUS JOEL S 450 E. 29TH STREET, 14TH FLOOR NEW YORK NY 10016 1 0 0 0 Ordinary Shares 2020-08-10 4 M 0 15459 5.63 A 15459 D Ordinary Shares 2020-08-11 4 S 0 7500 13.86 D 7959 D Ordinary Shares 2020-08-12 4 S 0 7959 14.15 D 0 D Ordinary Shares 75000 I By Third Amended and Restated Joel and Barbara Marcus Family Trust Ordinary Shares 1982726 I See Footnote Stock Option (right to buy) 5.63 2020-08-10 4 M 0 15459 0.00 D 2028-01-10 Ordinary Shares 15459 0 D The price reported reflects the weighted average sales price. The shares were sold in multiple transactions at prices ranging from $13.535 to $14.18, inclusive. The reporting person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price. The price reported reflects the weighted average sales price. The shares were sold in multiple transactions at prices ranging from $13.93 to $14.32, inclusive. Represents securities held of record by Alexandria Venture Investments, LLC ("Alexandria"). Alexandria Real Estate Equities, Inc. is the managing member of Alexandria. Each of Alexandria and Alexandria Real Estate Equities, Inc. has shared voting and investment power with respect to the shares owned by Alexandria. The reporting person is the Executive Chairman of Alexandria Real Estate Equities, Inc. and may therefore be deemed to have voting and investment power with respect to the shares owned by Alexandria. Each of the reporting person and Alexandria Real Estate Equities, Inc. disclaims beneficial ownership of such shares except to the extent of any pecuniary interest therein. The option vested and became exercisable on January 10, 2019. /s/ Richard Giroux, Attorney-in-Fact for Joel S. Marcus 2020-08-12