Ascidian Therapeutics Announces Leadership Transition

Daniel Rosan Appointed President

Michael Ehlers to Continue as Board Chair

BOSTON, July 21, 2026 /PRNewswire/ -- Ascidian Therapeutics, a biotechnology company seeking to treat human diseases by rewriting RNA, today announced a planned leadership transition as Ascidian heads into the next chapter.

Michael Ehlers, M.D., Ph.D., has stepped down as President and Chief Executive Officer and will continue to serve as Chair of the Board of Directors, where he will guide scientific and company strategy. Daniel Rosan, who currently serves as Chief Financial Officer and Chief Business Officer, has been appointed President while retaining his existing responsibilities to advance the company's strategic priorities. As President, Dan will work closely with Ascidian's executive leadership team and Board during the CEO succession process.

"Ascidian was built around a bold idea: that RNA editing could unlock new possibilities for patients with serious genetic diseases," said Michael Ehlers, M.D., Ph.D., Chair of the Board. "Today, we have a first-in-class RNA exon editing platform and a clear path forward. It has been a privilege to serve as Founding CEO, and I am proud of what we have built. I look forward to continuing to support Ascidian's success as Board Chair."

"Ascidian has the science, the team, the partners, and the strategy to realize the full potential of RNA exon editing," said Daniel Rosan, M.B.A., President, Chief Financial and Business Officer. "Our focus now is on execution — advancing our pipeline, delivering for our partners, and developing transformative RNA medicines. We will continue to build on the strong foundation we've created."

The leadership transition comes as Ascidian continues to progress its wholly owned and partnered pipeline, including lead program ACDN-01 for the treatment of Stargardt disease, through clinical development.

About Ascidian Therapeutics

Ascidian Therapeutics is redefining the treatment of disease by rewriting RNA. By editing exons at the RNA level, Ascidian therapies enable precise post-transcriptional editing of genes, resulting in full-length, functional proteins at the right levels, in the right cells, at the right time. With partnered and wholly owned programs in retinal, renal, neurological, neuromuscular, and genetically defined diseases, Ascidian's approach has the potential to treat patients with one dose of an RNA exon editor, opening new therapeutic possibilities for patients and their families who are seeking breakthroughs.

Learn more at Ascidian.com, or for Ascidian's currently enrolling clinical trials in Stargardt disease, visit AscidianClinicalTrials.com. 

SOURCE Ascidian Therapeutics