X0306 4 2019-11-15 0 0001711279 Krystal Biotech, Inc. KRYS 0001298709 Krishnan Krish S C/O KRYSTAL BIOTECH, INC. 2100 WHARTON STREET, SUITE 701 PITTSBURGH PA 15203 1 1 1 0 President and CEO Common Stock 2019-11-15 4 S 0 11895 49.7242 D 2024567 D Common Stock 2019-11-15 4 S 0 11386 50.6903 D 2013181 D Common Stock 2019-11-15 4 S 0 4598 51.4696 D 2008583 D Common Stock 2019-11-18 4 S 0 1046 50.9768 D 2007537 D Common Stock 2019-11-18 4 S 0 10513 51.8162 D 1997024 D Common Stock 2019-11-18 4 S 0 8080 52.6787 D 1988944 D Common Stock 2019-11-18 4 S 0 2082 53.8618 D 1986862 D Common Stock 2019-11-18 4 S 0 400 54.38 D 1986462 D Common Stock 112162 I By trust Common Stock 2001462 I By spouse The sales reported were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person following discussions with the Compensation Committee and the Board of Directors. This transaction was executed in multiple trades ranging from $49.16 to $50.13. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. This transaction was executed in multiple trades ranging from $50.16 to $51.14. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. This transaction was executed in multiple trades ranging from $51.235 to $51.65. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. This transaction was executed in multiple trades ranging from $50.29 to $51.27. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. This transaction was executed in multiple trades ranging from $51.31 to $52.28. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. This transaction was executed in multiple trades ranging from $52.31 to $53.215. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. This transaction was executed in multiple trades ranging from $53.35 to $54.33. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. This transaction was executed in multiple trades ranging from $54.35 to $54.42. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. Directly beneficially owned by the Krishnan Family Trust. The reporting person and her spouse are each joint beneficial owners of the trust with joint voting and investment control. Directly beneficially owned by Suma S. Krishnan, the spouse of the reporting person. /s/ Krish S. Krishnan 2019-11-19