The main objective of this prospective, observational, long-term follow-up (LTFU) study is to evaluate the long-term safety profile of the gene therapy products evaluated by Krystal Biotech, Inc. which have a shared backbone of HSV-1, in participants who received at least one dose of investigational product (IP).
All adult and pediatric participants who received at least one gene therapy treatment in a previous Krystal Biotech, Inc. sponsored study, and have discontinued or completed the parent treatment protocol (which do not have the LTFU embedded into the parent protocol), as applicable.
Consent/Assent must be obtained by the participants (and, parental/legal representative, when applicable) prior to any study-related data being collected.
Participant is willing and able to adhere to the protocol requirements.
Participants who enroll into a non-Krystal Biotech, Inc. interventional gene therapy clinical trial will be excluded from the study.