Page updated ·next FDA decision on the calendar·Data as of Oct 11, 2026 9:31 PM ET
The FDA's own letter · Complete Response Letter, BL 125840 (PDF), dated February 7, 2026, released under FDA's CRL transparency program. The company announced the decision on February 9, 2026; the FDA acted on February 7, 2026.
✕ COMPLETE RESPONSE LETTER
REGENXBIO Inc., clemidsogene lanparvovec (RGX-121) · MPS II (Hunter Syndrome).
Run-up into the decision (T-120 → T+5)
Daily close, T-120 (8/25/25) through T+5. Run-up high $15.98 on 1/22/26, low $8.03 on 8/26/25 (T-120 to T-1). FDA decision 2/9/26. Historical price action, not a forecast.
13F reports list long positions in common stock at quarter end, are due 45 days later, and show no short positions or later trades. Notes, warrants and other instruments are not counted as shares.
Questions
Was clemidsogene lanparvovec (RGX-121) approved by the FDA?
Not in this review cycle. A Complete Response Letter, declining to approve the application for clemidsogene lanparvovec (RGX-121) in its current form, was announced on February 9, 2026. A CRL is not final; the primary source is linked on this page.
Which company is behind clemidsogene lanparvovec (RGX-121)?
clemidsogene lanparvovec (RGX-121) is a REGENXBIO Inc. (RGNX) program. The company announced the FDA decision on February 9, 2026; the FDA's own record of the decision is linked on this page.
How did RGNX stock trade into the FDA decision?
Measured over the 120 trading days before the decision (T-120 to T-1), RGNX moved +18.6%. That is the recorded price path into this specific event. Historical measurement, not a prediction, and not investment advice.
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