X0206 3/A 2017-07-20 2017-07-20 0 0001705843 Calyxt, Inc. CLXT 0001712240 Corkal Bryan W.J. 600 COUNTY ROAD D WEST SUITE 8 NEW BRIGHTON MN 55112 1 Chief Financial Officer Common Stock 98000 D Common Stock 500 I Spouse Stock Option (Right to Buy) 13.29 2027-06-14 Common Stock 147000 D Includes 98,000 restricted stock units with respect to Calyxt, Inc. common stock, which were granted on June 14, 2017. Due to a clerical error, the vesting of this award was incorrectly described in the original Report. The correct description is that the restricted stock units vested 20% on the date of grant and vest 10% on the first anniversary of the grant, with the remainder vesting quarterly in equal installments over the following 42 months. This amended Report is also being filed to include these shares that are indirectly held by the Reporting Person and which were inadvertently omitted from the original Report. Due to a clerical error, the vesting of this award was incorrectly described in the original Report. The correct description is that the award vested 20% on the date of grant, June 14, 2017, and vests 10% on the first anniversary of the grant, with the remainder vesting quarterly in equal installments over the following 42 months. /s/ David M. Vander Haar, attorney-in-fact for Mr. Corkal 2018-04-16