Krystal Biotech has announced results from the highest dose cohort of its Phase 1 CORAL-1 trial of KB407 gene therapy that confirm CFTR expression in 6 of 7 cystic fibrosis patients who received 4 administrations of nebulized KB407 over 4 days. Investigators were unable to obtain a successful biopsy for the 7th patient. The CORAL-1 dose escalation study was initiated in 2023 and included arms for 1, 2, or 4 administrations of KB407.
Of the 7 CF patients included in the cohort, 4 were ineligible for CFTR modulator therapy, the company said, noting that successful transduction in the 6 patients evaluated was independent of modulator status. According to the announcement the percentage of airway cells that were positive for CFTR or for viral marker expression ranged from 29.4% to 42.1%.
Study design for the Phase 3 CORAL-3 study of KB407 in CF patients was recently submitted to the FDA, Krystal said, with initiation of that trial expected by mid-2026.
Krystal Biotech President, Research & Development, Suma Krishnan commented, “Today’s update has profound implications for Krystal and for the many CF patients unable to benefit from modulator therapy. With clear evidence of CFTR protein expression in patients with Class 1 mutations and reproducible KB407 transduction across a diverse CF population, we are moving forward with conviction into our repeat dosing study with registrational intent, CORAL-3. We are excited to be working with the Cystic Fibrosis Foundation to accelerate clinical development and potential registrational timelines.”
In addition to KB407 for CF, Krystal’s pipeline includes inhaled gene therapies for the treatment of non-small cell lung cancer (KB707) and for alpha-1 antitrypsin deficiency (KB408).
Read the Krystal Biotech press release
