REGENXBIO Faces Class Action Over Alleged Misleading Safety Claims for Gene Therapy
A securities class action lawsuit alleges REGENXBIO misled investors about the safety of its gene therapy RGX-111. Following an FDA clinical hold due to a patient tumor, the stock fell 17.8% in one day. Affected shareholders have until April 14, 2026 to seek lead plaintiff status.
A class action lawsuit has been filed against REGENXBIO, Inc. on behalf of investors who purchased the company’s securities between February 9, 2022 and January 27, 2026. The lawsuit alleges that REGENXBIO misled investors about the viability and safety of its gene therapy candidate RGX-111, leading to a sharp stock decline after the FDA placed a clinical hold on the program.
REGENXBIO is a clinical-stage biotechnology company developing gene therapies using its proprietary AAV platform. The company had repeatedly characterized RGX-111 as a lead clinical-stage candidate for the treatment of MPS I, highlighting FDA Fast Track designation and consistently positive interim safety, tolerability, and biomarker data from its Phase I/II studies.
The complaint alleges that, despite these public statements, the company was aware of serious safety issues related to the RGX-111 study, including the potential for central nervous system neoplasms. In November 2023, REGENXBIO abruptly de-prioritized RGX-111 and announced it was seeking “strategic alternatives” for the program.
On January 28, 2026, REGENXBIO disclosed that the FDA had placed a clinical hold on RGX-111 following a preliminary analysis of a single case of neoplasm (an intraventricular CNS tumor) in a participant treated in the Phase I trial. The FDA also placed a clinical hold on another gene therapy, RGX-121, citing “the similarities in products, study populations, and shared risk between the clinical studies.”
Following this announcement, the company’s stock price fell from a closing price of $13.41 per share to $11.01, a decline of 17.8% in a single day. Shareholders who suffered losses have until April 14, 2026 to file a motion to be appointed lead plaintiff in the class action, which was filed in the U.S. District Court for Maryland.