Krystal Biotech

Krystal Biotech is a commercial-stage biotechnology company built around a deceptively simple idea: most gene therapies are one-time, irreversible treatments, but they do not have to be. The company engineers a modified herpes simplex virus type 1 (HSV-1) to carry a working copy of a gene into a patient's cells without permanently editing the genome. Because the delivery does not integrate, it can be given again - and again.

That approach produced VYJUVEK, approved by the U.S. Food and Drug Administration in 2023 as the first topical and first redosable gene therapy, and the first gene therapy to use an HSV-1 vector. It treats wounds caused by dystrophic epidermolysis bullosa (DEB), a rare and painful genetic skin disease sometimes called "butterfly skin disease" because patients' skin blisters and tears at the slightest friction.

Krystal develops its candidates in-house and manufactures them at its own good-manufacturing-practice (GMP) facilities in Pittsburgh - an unusual degree of vertical integration for a company of its size, and a deliberate one. Owning the hardest part of gene therapy, the manufacturing, is central to how the company operates.

Dystrophic epidermolysis bullosa is caused by mutations in the COL7A1 gene, which the body needs to make type VII collagen - the protein that anchors the outer layer of skin to the layers beneath. Without it, skin shears off and wounds struggle to heal. Before VYJUVEK, care was mostly bandaging and pain management.

Conventional gene therapies typically use viral vectors that can only be administered once, because the immune system learns to neutralize them and because integration into the genome carries long-term risks. A chronic, ongoing condition like DEB does not fit that model well. Krystal's HSV-1 vector was chosen for a different profile: high payload capacity, broad ability to enter skin cells, immune evasion, and no genomic integration - together making repeat dosing practical. Applied as a gel directly to wounds, it delivers functional COL7A1 to the cells that need it, then can be reapplied as new wounds appear.

That is the core of how Krystal differs from much of the gene-therapy field: it is engineered around redosing and topical or localized delivery rather than a single systemic injection.

Krystal earns revenue from prescription sales of VYJUVEK, reimbursed through specialty pharmacy and payer channels, initially in the United States and increasingly through international approvals. Product revenue funds a pipeline that spans dermatology, respiratory disease, oncology and ophthalmology - all drawing on the same delivery platform.

The company sits within the rare-disease and gene-therapy segment of biopharma, competing for attention and capital with developers such as Ultragenyx, Sarepta, Regenxbio and Abeona, as well as the symptomatic and wound-care approaches that preceded an approved DEB therapy. Its differentiation is less about a single molecule and more about a repeatable method: a platform designed for redosing, paired with in-house manufacturing.

Its customers are patients with serious genetic conditions and the clinicians who treat them - dermatologists and specialty centers for VYJUVEK today, with future programs aimed at pulmonologists, oncologists and ophthalmologists. Having reached roughly $290 million in revenue in its first full commercial year, profitably, Krystal is one of the clearer examples that rare-disease gene therapy can also stand up as a business.