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# RAPT Unblinding Data in Trials on Clinical Hold
- URL: https://www.fdaweb.com/rapt-unblinding-data-in-trials-on-clinical-hold/
- Published: 2024-05-09T12:00:00.000Z
- Updated: 2026-09-14T14:30:31.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5156949

RAPT Therapeutics has decided to close and unblind two Phase 2 trials of zelnecirnon (RPT193) following FDA clinical holds due to a serious adverse event reported in February. The Phase 2b trial of zelnecirnon (RPT193) in atopic dermatitis and a Phase 2a trial in asthma were halted by FDA after a patient experienced liver failure in the atopic dermatitis (AD) trial, according to the company. The adverse event cause is currently unknown but it has been characterized as potentially related to zelnecirnon, it says ([see earlier story](https://www.fdaweb.com/clinical-hold-on-rapt-zelnecirnon-studies/)). Prior to the hold, 229 patients had been enrolled in the Phase 2b AD trial, of which about 110 had finished the 16-week dosing period.

“Although there were a significant number of patients who were unable to complete the AD trial due to the hold, we believe we will have sufficient data, even if not statistically significant, to inform our path forward and support our discussions with the FDA,” the company says in a [financial release](https://investors.rapt.com/news-releases/news-release-details/rapt-therapeutics-reports-first-quarter-2024-financial-results?ref=fdaweb.com). “We are working with the clinical trial sites to clean the data and we anticipate that our analysis of the data will be completed in the third quarter of this year. Concurrently, we are continuing our investigation and analysis of the serious adverse event that triggered the clinical hold.”