Regenxbio, Inc. Class Action Lawsuit – RGNX
Introduction to Regenxbio, Inc. (RGNX) Securities Class Action Lawsuit
A securities fraud class action has been filed against Regenxbio, Inc. (NASDAQ: RGNX), asserting claims under the Securities Exchange Act of 1934, including Sections 10(b) and 20(a) and Rule 10b-5, covering investors who purchased the Company's securities between February 9, 2022 and January 27, 2026, inclusive. According to the complaint, investors allege the Company and senior executives misrepresented the safety and efficacy profile of RGX-111, an AAV gene therapy product candidate for severe MPS I, which received Fast Track designation from the FDA in 2018, by repeatedly highlighting positive biomarker, tolerability, and neurodevelopment results.
Behind those assurances, the complaint alleges serious safety concerns existed, including the potential for a central nervous system neoplasm, and the program was later de-prioritized. The story culminated on January 28, 2026, when REGENXBIO announced the FDA had placed a clinical hold on RGX-111 after a CNS tumor was identified in a trial participant, and the FDA also placed a hold on RGX-121, a related MPS II product candidate due to shared risk. As the truth surfaced, REGENXBIO's stock fell 17.8% in a single day, harming investors who bought at inflated prices.
“Most RGNX shareholders never file or join the class action, which means they miss out on potential recovery funds,” said Attorney Joseph Levi.
Regenxbio, Inc. (RGNX) Securities Lawsuit Case Details
Case Name: Kuik v. Regenxbio, Inc. et al.
Case No.: 8:26-cv-00611-DKC
Jurisdiction: U.S. District Court, District of Maryland (Southern Division)
Filed on: February 13, 2026
Regenxbio, Inc. (RGNX) Company Profile
Regenxbio is a clinical-stage biotechnology company listed on the NASDAQ as RGNX developing gene therapies that deliver functional genes to cells with genetic defects, including rare lysosomal storage disorders such as Mucopolysaccharidosis Type I (MPS I). Its product candidates use the Company's NAV Technology Platform, featuring the NAV AAV9 vector, a proprietary adeno-associated virus (AAV) gene delivery system designed for one-time administration.
Regenxbio, Inc. (RGNX) Securities Lawsuit Class Period
February 9, 2022 - January 27, 2026, inclusive (the Class Period).
All investors who purchased or otherwise acquired Regenxbio securities (NASDAQ: RGNX) between February 9, 2022 and January 27, 2026, inclusive, are within the alleged class.
Allegations in the Regenxbio, Inc. (RGNX) Securities Class Action Lawsuit
The lawsuit targets REGENXBIO, INC. and three executives: former CEO Kenneth T. Mills, current CEO Curran Simpson, and Executive Vice President and Chief Medical Officer Stephen Pakola, alleging they disseminated false and misleading statements. The complaint alleges they told investors RGX-111 was progressing well, emphasizing safety, biomarker improvements, and neurodevelopmental gains, overstated efficacy based on interim biomarker data, and positioning it as a key program in the Company's pipeline while concealing material safety data.
The narrative begins on February 9, 2022, when Dr. Pakola announced early data from a Phase I/II clinical trial and said "RGX-111 has been well-tolerated with emerging evidence of CNS biomarker activity and improvements in neurodevelopmental function," while planning to enroll more patients.
The message continued on February 24, 2023, as CEO Mills called RGX-111 the Company's second-most advanced neurodegenerative candidate and part of the "5x'25" strategy, touting overwhelmingly positive results, stating the therapy "continues to demonstrate compelling evidence of CNS biomarker activity" and that most trial patients showed "continued skill acquisition across multiple neurodevelopmental assessments."
The optimism persisted into January 14, 2025, when CEO Curran Simpson, announcing a partnership with Nippon Shinyaku, asserted that "RGX-111 has demonstrated very promising results in Phase 1/2 study" for Hurler syndrome. According to the complaint, these upbeat statements concealed material adverse facts about RGX-111's safety, including the potential for a CNS neoplasm, a serious adverse event risk. The pleading further alleges that, despite the public positivity, the Company abruptly decided in November 2023 to de-prioritize RGX-111 and pursue "strategic alternatives" for the program, a corporate strategic pivot.
The Truth Emerges
The picture shifted on November 8, 2023, when management acknowledged a change in course, signaling de-prioritization of the RGX-111 program. Dr. Pakola stated the Company was "no longer moving forward with our RGX-111...rare neurodegenerative programs," and CEO Mills added there would be a "discontinuation of any clinical development work," effectively de-prioritizing the product candidate with only short-term partnering efforts anticipated and no meaningful contribution to operating plans going forward.
Then, on January 28, 2026, REGENXBIO issued a press release announcing the FDA had placed a clinical hold on RGX-111 after a routine MRI revealed an intraventricular CNS tumor in a five-year-old participant in the Phase I/II study who had received intracisternal RGX-111 four years earlier. The Company reported preliminary genetic analysis of the resected tumor detected an AAV vector genome integration event associated with overexpression of a proto-oncogene (PLAG1), an oncogenic safety signal, and noted the investigation into causality was ongoing. The FDA simultaneously placed a clinical hold on RGX-121, an investigational treatment for MPS II due to "the similarities in products, study populations, and shared risk between the clinical studies." These disclosures addressed earlier representations that RGX-111 was well tolerated with no drug-related serious adverse events, contradicting prior safety and tolerability claims.
Market Reaction
Investors reacted immediately to the January 28, 2026 disclosure. REGENXBIO's stock on NASDAQ: RGNX fell $2.40, or 17.8%, from a prior close of $13.41 on January 27, 2026 to close at $11.01 on January 28, 2026, reflecting a significant stock price decline.
Next Steps
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The Court will issue its order for lead plaintiff and counsel in the weeks after submissions are due.
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The Court will then consider motion for class certification.
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The Court will later consider a Motion to Dismiss.
Disclaimer: This shareholder alert is for informational purposes only and does not constitute legal advice. Consult a qualified attorney for personalized guidance. No specific outcomes are guaranteed.
Frequently Asked Questions
What is the REGENXBIO securities class action lawsuit about?
The lawsuit alleges that REGENXBIO, Inc. (NASDAQ: RGNX) and certain executives violated federal securities laws by making materially false and misleading statements about the company's RGX-111 gene therapy candidate for treating severe Mucopolysaccharidosis Type I (MPS I). According to the complaint, defendants repeatedly touted positive safety and biomarker data from the Phase I/II study while allegedly concealing serious safety risks, including the potential for CNS tumors. The lawsuit claims these misrepresentations artificially inflated REGENXBIO's stock price during the class period.
What is the class period for the REGENXBIO lawsuit?
The class period spans from February 9, 2022 through January 27, 2026. Investors who purchased or acquired REGENXBIO securities during this timeframe may be eligible to participate in the class action. The complaint was filed on February 13, 2026 in the United States District Court for the District of Maryland.
What event triggered the REGENXBIO stock decline?
According to the complaint, on January 28, 2026, REGENXBIO announced that the FDA placed a clinical hold on its RGX-111 gene therapy after an intraventricular CNS tumor was discovered in a participant treated in the Phase I/II study four years earlier. Preliminary genetic analysis reportedly detected AAV vector genome integration associated with overexpression of a proto-oncogene. Following this disclosure, REGENXBIO's stock price allegedly fell from $13.41 to $11.01 per share, a decline of approximately 17.8% in a single trading day.
Who are the defendants in the REGENXBIO class action?
The defendants named in the complaint include:
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REGENXBIO, Inc., the biotechnology company
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Kenneth T. Mills, former President and CEO (September 2015 to July 2024)
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Curran Simpson, current President and CEO (from July 2024)
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Stephen Pakola, M.D., Executive Vice President and Chief Medical Officer
The complaint alleges these individual defendants had the power and authority to control the company's public statements and SEC filings.
What specific claims does the lawsuit make against REGENXBIO?
The complaint asserts claims under Section 10(b) of the Securities Exchange Act and Rule 10b-5 against all defendants, alleging they made false and misleading statements about RGX-111's safety profile. Additionally, the lawsuit brings Section 20(a) claims against the individual defendants as alleged "controlling persons" of the company. Plaintiffs allege defendants knew or recklessly disregarded the safety risks associated with the AAV-based gene therapy while publicly describing the trial results as demonstrating "very promising" outcomes.
What statements does the lawsuit allege were misleading?
The complaint alleges that between 2022 and 2026, defendants repeatedly stated that RGX-111 was "well tolerated" with "no drug-related serious adverse events" in press releases and earnings calls. According to the lawsuit, defendants described the Phase I/II trial data as showing an "encouraging CNS profile" and "very promising results" while allegedly failing to disclose material safety concerns, including the potential for CNS neoplasm that the complaint claims defendants were aware of when they de-prioritized the program in November 2023.
What damages are plaintiffs seeking in the REGENXBIO lawsuit?
The complaint seeks damages on behalf of class members who purchased REGENXBIO securities at allegedly artificially inflated prices during the class period. Plaintiffs are requesting compensation for economic losses sustained when the stock price declined following the January 28, 2026 disclosure. The lawsuit also seeks pre-judgment and post-judgment interest, reasonable attorneys' fees, expert fees, and other costs. A jury trial has been demanded.
What is the REGENXBIO class action about?
The lawsuit alleges REGENXBIO (NASDAQ: RGNX) and executives made false statements about the safety of its RGX-111 gene therapy for MPS I. According to the complaint, defendants concealed serious risks including potential CNS tumors while publicly touting positive trial results.
What is the class period for this lawsuit?
The class period is February 9, 2022 through January 27, 2026. Investors who purchased REGENXBIO securities during this time may be eligible to participate in the class action filed in the District of Maryland.
What caused the REGENXBIO stock drop?
According to the complaint, on January 28, 2026, REGENXBIO disclosed an FDA clinical hold on RGX-111 after a CNS tumor was found in a trial participant. The stock allegedly fell approximately 17.8% in one day following this announcement.
Who are the defendants?
The defendants include REGENXBIO, Inc., former CEO Kenneth T. Mills, current CEO Curran Simpson, and Chief Medical Officer Stephen Pakola. The complaint alleges these individuals controlled the company's public statements.
What legal claims are alleged?
The complaint asserts violations of Section 10(b) and Rule 10b-5 of the Securities Exchange Act against all defendants, plus Section 20(a) "controlling person" claims against individual defendants.
What relief is being sought?
Plaintiffs seek damages for investors who purchased REGENXBIO stock at allegedly inflated prices, plus interest and attorneys' fees. A jury trial has been demanded.
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