X0306 4 2019-03-25 0 0001300699 Athenex, Inc. ATNX 0001427110 Zuo William Wei C/O ATHENEX, INC. 1001 MAIN STREET, SUITE 600 BUFFALO NY 14203 0 1 0 0 President, China Division Common Stock 2019-03-25 4 P 0 1000 12.47 A 1118777 D Stock Option (Right to Buy) 7.50 2025-06-11 Common Stock 120000 120000 D Stock Option (Right to Buy) 11.00 2018-06-13 2027-06-13 Common Stock 1 1 D Stock Option (Right to Buy) 17.30 2028-03-27 Common Stock 25000 25000 D Stock Option (Right to Buy) 13.17 2029-02-28 Common Stock 25000 25000 D This transaction was executed in multiple trades ranging from $12.39 to $12.50. The price reported in Column 4 is a weighted average price. The reporting person hereby undertakes to provide upon request to the SEC staff, the Issuer or a security holder full information regarding the number of shares and prices at which the transactions were effected. The option vests in three equal installments beginning on June 11, 2016. This option vests in four equal annual installments beginning on March 27, 2019. The option vests in four equal annual installments beginning on February 28, 2020. /s/ Teresa Bair, Attorney-in-Fact 2019-03-26