Regeneron posts late-stage trial win for myasthenia gravis drug developed with Alnylam

[Myasthenia gravis is shown using the text]
Andrii Dodonov

Regeneron Pharmaceuticals (NASDAQ:REGN [https://seekingalpha.com/symbol/REGN]) announced on Tuesday that a Phase 3 trial for its RNA-based therapy cemdisiran, developed with Alnylam Pharmaceuticals (NASDAQ:ALNY [https://seekingalpha.com/symbol/ALNY]), succeeded in a late-stage trial for generalized myasthenia gravis, a rare autoimmune disorder.

According to the company, cemdisiran, as a monotherapy and as part of a combination regimen with its FDA-approved complement inhibitor Veopoz (pozelimab), reached the primary and key secondary endpoints in its Phase 3 NIMBLE trial.

MG is a chronic disorder characterized by muscle weakness due to antibody-mediated activation of the body’s complement system, including the pro-inflammatory protein complement factor 5 (C5).

Citing 24-week data, Regeneron (NASDAQ:REGN [https://seekingalpha.com/symbol/REGN]) noted that cemdisiran, as a single agent dosed subcutaneously every three months, hit the primary and key secondary endpoints in NIMBLE.

While the experimental therapy with pozelimab also met the primary and key secondary endpoints, data for the monotherapy regimen were superior, the company said.

As for the trial's main goal, cemdisiran and cemdi-poze led to a 2.30-point and 1.74-point placebo-adjusted improvement in Myasthenia Gravis Activities of Daily Living Total Score, according to Regeneron (NASDAQ:REGN [https://seekingalpha.com/symbol/REGN]).

As for safety, the company noted that 69% of those on cemdisiran experienced treatment-emergent adverse events compared to 81% and 77% on cemdi-poze and placebo, respectively. While there were no mortalities in the 24-week placebo-controlled period, one patient in the monotherapy arm and another in the cemdi-poze arm died due to pneumonia and septic shock, respectively.

However, plans to seek regulatory approval for cemdisiran monotherapy in Q1 2026, subject to FDA feedback. [https://seekingalpha.com/pr/20211152-regeneron-announces-positive-results-from-phase-3-trial-in-generalized-myasthenia-gravis]

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