FDA Alignment Reached on MPS II Resubmission

Research evidence excerpt

FDA Alignment Reached on MPS II Resubmission

Update

June 22, 2026 12:32 PM GMT

Morgan Stanley & Co. LLCMRegenxbio Inc | North America Judah C. Frommer, CFA

Equity Analyst

FDA Alignment Reached on Judah.Frommer@morganstanley.comNicholas D Japhet +1 212 761-1270

Research Associate

Nick.Japhet@morganstanley.com +1 212 761-2721

MPS II Resubmission Parth Patel

Parth.Patel@morganstanley.com +1 212 761-5065

Key Takeaways

Regenxbio Inc (RGNX.O, RGNX US)

RGNX expects to resubmit the BLA for Navsunli (RGX-121) in 3Q26 Biotechnology | United States of America

FDA confirmed no additional studies are required Stock Rating Overweight

Industry View Attractive

Reversal another sign of FDA flexibility with respect to rare disease gene Price target $16.00

Shr price, close (Jun 18, 2026) $7.80

therapies Mkt cap, curr (mm) $409

52-Week Range $16.19-5.46

Following a string of announced realignments with FDA by drug developers,

RGNX has announced that it has reached alignment with the agency on next

steps with respect to the potential BLA resubmission for Navsunli (RGX-121) for

MPS II. In a discussion that followed the recent CRL, the FDA acknowledged that

the existing data for Navsunli is sufficient to be considered for the accelerated

approval pathway and that RGNX does not need to enroll additional patients or

conduct additional studies, including the FDA's previously recommended

incorporation of an untreated control arm. The FDA has asked RGNX to request a

Type A meeting to review longer-term biomarker and clinical data and to resubmit

the BLA following the meeting. The Type A meeting is expected to take place in July

with the BLA resubmission to follow in 3Q26. The FDA stated that it would review

the resubmission on an expedited basis, with labeling discussions to begin shortly