Roche’s Enspryng wins FDA Priority Review for at‑home subcutaneous TED treatment
- FDA accepted Roche’s supplemental BLA for Enspryng (satralizumab) and granted Priority Review, with a decision due 15 October 2026.
- Filing is based on global phase III SatraGO‑1 and SatraGO‑2 data presented at ASOPRS in October 2025.
- SatraGO‑2 met the primary proptosis endpoint: 53% response with Enspryng vs 23% with placebo at week 24; SatraGO‑1 showed 49% vs 31% (numerical, not statistically significant).
- Enspryng targets the IL‑6 receptor using recycling antibody technology and is already approved for NMOSD in ~90 countries with safety data in >10,000 patients.
Regulatory update
The US Food and Drug Administration has accepted Roche’s supplemental Biologics License Application for Enspryng (satralizumab) in thyroid eye disease (TED) and granted Priority Review. The FDA is expected to issue a decision by 15 October 2026. The filing draws on results from the SatraGO phase III programme presented at ASOPRS in October 2025.
Pivotal SatraGO data
SatraGO‑1 and SatraGO‑2 were identically designed, randomised, placebo‑controlled phase III studies enrolling 258 patients across 19 countries with active, moderate‑to‑severe and chronic inactive TED. The primary endpoint was the proportion of participants achieving ≥2 mm reduction in proptosis at week 24. In SatraGO‑2, 53% of patients on Enspryng achieved a proptosis response versus 23% on placebo (statistically significant); SatraGO‑1 showed a numerical improvement (49% vs 31%) that did not reach statistical significance. Secondary outcomes showed clinical activity score reductions in 78%–90% of patients with active TED and diplopia improvements in 44%–61% of affected patients across the two trials.
Safety and trial design
No new safety signals emerged in the SatraGO studies; safety was consistent with Enspryng’s established profile in neuromyelitis optica spectrum disorder (NMOSD). Participants were randomised 1:1 to Enspryng or placebo to assess efficacy, durability and tolerability.
Product profile and next steps
Enspryng is a humanised monoclonal antibody that targets the IL‑6 receptor using recycling antibody technology to sustain IL‑6 inhibition. It is positioned as a potential at‑home subcutaneous disease‑modifying option for TED and is already approved for NMOSD in about 90 countries with safety data from over 10,000 patients. Roche also reported positive phase III results for Enspryng in MOGAD, with regulatory submissions planned this year.
Source: Roche