Krystal Biotech, Inc. (NASDAQ: KRYS) released clinical data from a pilot study of KB113, an investigational intratumoral immunotherapy, showing that over 80% of assessed basal cell carcinoma (BCC) lesions regressed across three patients with Gorlin syndrome.

According to the company's press release, 69 of 83 assessed landmark lesions showed any clinical regression at the final assessment, conducted 30 days after the last dose. Of those, 42 of 83 lesions demonstrated greater than 50% regression, and 8 of 83 showed at least 90% regression. One injected lesion per patient that reached at least 90% clinical regression was biopsied, and all three showed histologically confirmed complete response with no residual tumor tissue.

Regression was observed in both injected and non-injected lesions. Of the 47 non-injected landmark lesions assessed, 40 showed some degree of regression, which the company characterizes as consistent with an abscopal effect. Regression was first observed as early as two weeks after treatment initiation.

KB113 is derived from the low dose of KB707 studied in the company's OPAL-1 Phase 1/2 trial. The Gorlin Syndrome Pilot Study enrolled three adult patients, each receiving six doses over 14 weeks. All reported adverse events were described as mild to moderate and transient.

Gorlin syndrome is a genetic condition associated with an elevated risk of developing BCCs, sometimes beginning in infancy. Available data suggest the U.S. patient population may exceed 10,000.

Krystal Biotech said it has initiated discussions with the U.S. Food and Drug Administration regarding advanced clinical development of KB113 for Gorlin syndrome. The company said it will provide an update on development plans following alignment with the FDA.

Study investigator Dr. Shireen Guide is presenting the pilot study data at the 14th Pediatric Dermatology Research Alliance Annual Conference, held October 15–17, 2026, in Alexandria, Virginia. KB113 has not been approved by the FDA or any other regulatory authority.