Commitments and Contingencies	6 Months Ended
Jun. 30, 2026
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Agreements with Contract Manufacturing Organizations and Contract Research Organizations The Company enters into various agreements in the normal course of business with Contract Manufacturing Organizations (“CMOs”), Contract Research Organizations (“CROs”) and other third parties for preclinical research studies, clinical trials and testing and manufacturing services. The agreements with CMOs primarily relate to the manufacturing of our sterile gel that is mixed with in-house produced vectors as part of the final drug product for VYJUVEK. Agreements with third parties may also include research and development consulting activities, clinical-trial agreements, testing of our clinical-stage, pre-commercial and commercial stage products and/or storage, packaging and labeling. The Company is obligated to make milestone payments under certain of these contracts. The Company incurred research and development expenses related to commitments under these agreements of $2.4 million and $2.2 million for the three months ended June 30, 2026 and June 30, 2025, respectively, and $4.9 million and $4.3 million for the six months ended June 30, 2026 and June 30, 2025, respectively. Legal Proceedings In the ordinary course of business, the Company is subject from time to time to various proceedings, lawsuits, disputes, or claims. In accordance with FASB ASC Topic 450, Contingencies (“ASC 450”), the Company accrues a liability for legal contingencies when it is probable that a liability has been incurred, and the amount of the loss can be reasonably estimated. If there is at least a reasonable possibility that a loss may be incurred, ASC 450 requires disclosure of a loss contingency. In the first quarter of 2025, the Company and certain of its employees received subpoenas from the U.S. Department of Justice requesting that the Company produce certain documents regarding its sponsored genetic testing program relating to VYJUVEK and commercial practices relating thereto. The Company is cooperating and providing information in response to the subpoenas. It is not possible to estimate the amount of any loss or range of possible loss that might result from this inquiry, and because the final outcome cannot be predicted with certainty, unfavorable or unexpected developments or outcomes could result in a material impact to the Company’s results of operations. On September 18, 2025, a stockholder filed a derivative complaint in the Court of Chancery of the State of Delaware, naming the Company’s directors as defendants and the Company as a nominal defendant. The complaint alleged claims for breach of fiduciary duty, unjust enrichment, and waste of corporate assets based on allegedly excessive non-employee director compensation in each of 2021 through 2024. The parties have entered into a settlement agreement, which was filed with the Court and is subject to Court approval following a fairness hearing scheduled for September 14, 2026. If the Court approves the settlement, the Company will adopt, implement, and maintain certain corporate governance reforms for a period of five (5) years. The Company has recorded a liability for the plaintiff’s attorneys fees and expenses (i.e., the settlement amount), which is not material to the condensed consolidated financial statements. On May 29, 2026, Jonathan Forman filed a lawsuit against the Company in the United States District Court for the District of Delaware (Docket No. 1:26-cv-00628) asserting claims for correction of inventorship, under 35 U.S.C. § 256, of U.S. Patent No. 10,829,529 and U.S. Patent No. 12,522,636 (together, the “Patents”), which relate to compositions and methods for delivering CFTR polypeptides and which the plaintiff alleges are embodied in the Company’s KB407 product candidate for the treatment of cystic fibrosis. The plaintiff alleges that he conceived of, and contributed to, the inventions claimed in the Patents and that he was erroneously omitted as a named inventor on the Patents. In addition to the correction of inventorship, the plaintiff is seeking his attorneys’ fees and his cost and expenses. The Company believes the plaintiff’s claims are without merit and intends to defend the matter vigorously. The Company is unable to estimate the possible loss or range of losses, if any, that may result from the matter.

The Company enters into various agreements in the normal course of business with Contract Manufacturing Organizations (“CMOs”), Contract Research Organizations (“CROs”) and other third parties for preclinical research studies, clinical trials and testing and manufacturing services. The agreements with CMOs primarily relate to the manufacturing of our sterile gel that is mixed with in-house produced vectors as part of the final drug product for VYJUVEK. Agreements with third parties may also include research and development consulting activities, clinical-trial agreements, testing of our clinical-stage, pre-commercial and commercial stage products and/or storage, packaging and labeling. The Company is obligated to make milestone payments under certain of these contracts. The Company incurred research and development expenses related to commitments under these agreements of $2.4 million and $2.2 million for the three months ended June 30, 2026 and June 30, 2025, respectively, and $4.9 million and $4.3 million for the six months ended June 30, 2026 and June 30, 2025, respectively.

In the ordinary course of business, the Company is subject from time to time to various proceedings, lawsuits, disputes, or claims. In accordance with FASB ASC Topic 450, Contingencies (“ASC 450”), the Company accrues a liability for legal contingencies when it is probable that a liability has been incurred, and the amount of the loss can be reasonably estimated. If there is at least a reasonable possibility that a loss may be incurred, ASC 450 requires disclosure of a loss contingency.

In the first quarter of 2025, the Company and certain of its employees received subpoenas from the U.S. Department of Justice requesting that the Company produce certain documents regarding its sponsored genetic testing program relating to VYJUVEK and commercial practices relating thereto. The Company is cooperating and providing information in response to the subpoenas. It is not possible to estimate the amount of any loss or range of possible loss that might result from this inquiry, and because the final outcome cannot be predicted with certainty, unfavorable or unexpected developments or outcomes could result in a material impact to the Company’s results of operations.

On September 18, 2025, a stockholder filed a derivative complaint in the Court of Chancery of the State of Delaware, naming the Company’s directors as defendants and the Company as a nominal defendant. The complaint alleged claims for breach of fiduciary duty, unjust enrichment, and waste of corporate assets based on allegedly excessive non-employee director compensation in each of 2021 through 2024. The parties have entered into a settlement agreement, which was filed with the Court and is subject to Court approval following a fairness hearing scheduled for September 14, 2026. If the Court approves the settlement, the Company will adopt, implement, and maintain certain corporate governance reforms for a period of five (5) years. The Company has recorded a liability for the plaintiff’s attorneys fees and expenses (i.e., the settlement amount), which is not material to the condensed consolidated financial statements.

On May 29, 2026, Jonathan Forman filed a lawsuit against the Company in the United States District Court for the District of Delaware (Docket No. 1:26-cv-00628) asserting claims for correction of inventorship, under 35 U.S.C. § 256, of U.S. Patent No. 10,829,529 and U.S. Patent No. 12,522,636 (together, the “Patents”), which relate to compositions and methods for delivering CFTR polypeptides and which the plaintiff alleges are embodied in the Company’s KB407 product candidate for the treatment of cystic fibrosis. The plaintiff alleges that he conceived of, and contributed to, the inventions claimed in the Patents and that he was erroneously omitted as a named inventor on the Patents. In addition to the correction of inventorship, the plaintiff is seeking his attorneys’ fees and his cost and expenses. The Company believes the plaintiff’s claims are without merit and intends to defend the matter vigorously. The Company is unable to estimate the possible loss or range of losses, if any, that may result from the matter.