Krystal Biotech says prioritizing inhaled KB707, pauses enrollment in OPAL-1

Krystal Biotech (KRYS) announced an update on development plans for KB707, the company’s redosable immunotherapy designed to drive sustained, localized expression of interleukin-2 and interleukin-12 in the tumor microenvironment and promote systemic immune-mediated tumor clearance following inhaled or intratumoral delivery to solid tumors. Based on “promising” early evidence of efficacy in the treatment of non-small cell lung cancer, the company was granted an End of Phase 2 meeting with the United States Food and Drug Administration in October to discuss potential development pathways to support the registration of inhaled KB707. “The acceleration of our work on inhaled KB707 is a reflection of both the clear and acute unmet need that exists for new treatments of NSCLC and the promising efficacy profile we have observed to date with inhaled KB707,” said Suma Krishnan, President of Research and Development of Krystal Biotech. Evidence supporting the prioritization of inhaled KB707, including monotherapy activity and durable responses in heavily pre-treated patients with NSCLC, was disclosed by the Company at the 2025 American Society of Clinical Oncology Annual Meeting earlier this year. As of data cut-off of April 15, 2025, the objective response rate in this heavily pre-treated NSCLC patient cohort was 36%. Median duration of response and progression free survival were not reached. Inhaled KB707 continued to be safe and generally well tolerated and amenable to administration in an outpatient setting, with no Grade 4 or 5 adverse events observed. Enrollment continues in the company’s KYANITE-1 study, a Phase 1/2 open label, multi-center, dose escalation and expansion study evaluating inhaled KB707 in patients with locally advanced or metastatic solid tumors of the lung. Details of the study can be found at www.clinicaltrials.gov under NCT identifier NCT06228326. With the prioritization of inhaled KB707, the company has paused enrollment in OPAL-1, a Phase 1/2 open label, multi-center, dose escalation and expansion study evaluating intratumoral KB707 in patients with locally advanced or metastatic solid tumor malignancies. Patients on OPAL-1 continue to be followed and based on safety and efficacy results from OPAL-1, the company may adjust development plans for intratumoral KB707.