Regenxbio's stock jumped sharply in pre-open trading, rising 11.9% after reports that the U.S. Food and Drug Administration has signaled it will revisit its earlier denial of Navsunli (RGX-121, clemidsogene lanparvovec), a gene therapy candidate for Mucopolysaccharidosis Type II, also called Hunter syndrome. The move follows a series of regulatory setbacks for the program earlier in the year.
The company has announced plans to resubmit a Biologics License Application in the third quarter of 2026. Management said a formal meeting with the FDA is expected in July, with the stated purpose of addressing the outstanding issues that led to the agency's Complete Response Letter issued in February.
Navsunli's regulatory path has been bumpy. In January 2026 the FDA placed a clinical hold on RGX-121 after a safety signal emerged in a related therapy, and the authority later issued a CRL citing insufficient evidence of effectiveness. Those developments had been material negatives for the stock and contributed to a steep drawdown that saw the shares trade near a 52-week low of $5.46.
With the FDA now indicating a willingness to reconsider its earlier position, sentiment among investors shifted rapidly in pre-market trading. The stock's move today builds on an incipient recovery that had begun from its low, reflecting a reassessment of the near-term regulatory outlook for the program.
Alongside the regulatory developments, Regenxbio has a partnered program with AbbVie for a sura-vec therapy targeting diabetic retinopathy. That collaboration includes a $100 million milestone payment tied to first patient dosing in the NAAVIGATE study. Company guidance has indicated that this dosing event would occur in the second quarter of 2026, making it a potential non-dilutive cash catalyst in the near term.
The broader market backdrop also supported risk-on positioning during the session. The NASDAQ was reported to be up 1.9% and the S&P 500 up 1.1%, an environment that typically favors small-cap biotechnology names. Peer companies operating in the gene therapy and rare disease space, such as Rocket Pharmaceuticals and uniQure, could see renewed investor attention as regulatory momentum shifts for Regenxbio.
Taken together, the FDA's willingness to reverse its rejection of Navsunli constitutes a meaningful inflection point for a program that had experienced compounding regulatory challenges earlier in the year. When combined with the potential AbbVie milestone and a favorable market tone, today's pre-market rally represents a notable repricing of the company's near-term pipeline prospects.
What to watch next
- Progress toward the July FDA meeting and the substance of discussions aimed at resolving the CRL issues.
- The timing and confirmation of the planned BLA refiling in Q3 2026.
- Confirmation that first patient dosing in the NAAVIGATE study occurs in Q2 2026, which would trigger the $100 million AbbVie milestone.