X0508 4 2026-02-09 0 0001711279 Krystal Biotech, Inc. KRYS 0001801385 ROMANO KATHRYN C/O KRYSTAL BIOTECH, INC. 2100 WHARTON STREET, SUITE 701 PITTSBURGH PA 15203 0 1 0 0 Chief Accounting Officer 1 Common Stock 2026-02-09 4 M 0 12500 63.55 A 31818 D Common Stock 2026-02-09 4 S 0 2000 270.5579 D 29818 D Common Stock 2026-02-09 4 S 0 5700 271.6627 D 24118 D Common Stock 2026-02-09 4 S 0 2824 272.5079 D 21294 D Common Stock 2026-02-09 4 S 0 928 273.7075 D 20366 D Common Stock 2026-02-09 4 S 0 552 274.6388 D 19814 D Common Stock 2026-02-09 4 S 0 400 275.68 D 19414 D Common Stock 2026-02-09 4 S 0 96 277.88 D 19318 D Common Stock 2026-02-09 4 G 0 750 0 D 18568 D Stock Option (Right to Buy) 63.55 2026-02-09 4 M 0 12500 0 D 2032-02-27 Common Stock 12500 12500 D The option exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. The Rule 10b5-1 trading plan started on November 6, 2025, and will terminate on August 31, 2026, subject to early termination in accordance with the terms of the Rule 10b5-1 trading plan, including upon completion of the sale of all of the shares of the Company's common stock subject to the Rule 10b5-1 trading plan. The transaction was executed in multiple trades ranging from $270.010 to $270.950. 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. The transaction was executed in multiple trades ranging from $271.105 to $272.095. 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. The transaction was executed in multiple trades ranging from $272.1275 to $273.070. 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. The transaction was executed in multiple trades ranging from $273.160 to $274.095. 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. The transaction was executed in multiple trades ranging from $274.305 to $274.815. 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. The transaction was executed in multiple trades ranging from $275.445 to $275.930. 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. The transaction was executed in a single trade. Represents a bona fide gift of the Company's common stock to a charitable donor-advised fund. The options vested ratably over a four-year period beginning on February 28, 2022. /s/ Kathryn Romano 2026-02-11