In a post-hoc analysis of the previously completed phase 3 MyacarinG study (NCT03971422), results showed that treatment with rozanolixizumab (Rystiggo; UCB), an FDA-approved medication, may enhance ocular symptoms in patients with generalized myasthenia gravis (gMG).1
These findings were presented as a poster at the 2025 Muscular Dystrophy Association (MDA) Clinical & Scientific conference, held March 16-19, in Dallas Texas, as well as at the ICNMD, held October 26-29, 2024. Overall, the analysis comprised 200 patients from the study, testing changes of Ocular Muscle Weakness scores on the Myasthenia Gravis Symptoms Patient-Reported Outcomes (MGSPRO) over a 7-day treatment period. Additionally, the study also used Myasthenia Gravis Impairment Index (MGII) ocular subdomain, an 8-item assessment, as an optional outcome over a 14-day period.
Led by Ali Habib, MD, a neurologist at the ALS & Neuromuscular Center, University of California, Irvine, improvements in MGSPRO Ocular Muscle Weakness score were observed in both those on both dosed rozanolixizumab groups (7 mg/kg [n = 66]; 10 mg/kg [n = 67]) vs placebo (n = 67). At day 43, investigators reported mean changes from baseline of –9.6 (SD, 16.8), –11.9 (SD, 14.0), and –3.4 (SD, 18.2) for the rozanolixizumab 7 mg/kg, 10 mg/kg, and placebo groups, respectively.
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In the post-hoc analysis, mean change from baseline in MGII ocular score was –2.9 (SD, 5.4), –5.2 (SD, 4.9), and –1.0 (SD, 4.3), respectively, for the rozanolixizumab groups and placebo. Furthermore, mean change from baseline in the Myasthenia Gravis-Activities of Daily Living ocular subdomain score was –0.8 (SD, 1.3) for the rozanolixizumab 7 mg/kg group, –1.0 (SD, 1.2) for the 10 mg/kg cohort, and –0.1 (SD, 0.9) for those on placebo. Above all, the therapy was considered safe and well tolerated, with most treatment-emergent adverse events (TEAEs) either mild or moderate in nature.
Top Clinical Takeaways
1. Rozanolixizumab improved ocular muscle weakness scores significantly in patients with generalized myasthenia gravis (gMG) compared to placebo during a 7-day treatment period.
2. The post-hoc analysis revealed the 10 mg/kg dose of rozanolixizumab showed the greatest improvement in MGII ocular subdomain scores, reducing symptoms by 5.2 points on average.
3. Rozanolixizumab was well-tolerated, with most treatment-emergent adverse events (TEAEs) reported as mild or moderate, reinforcing its safety profile.
Ocular symptoms are among the most common initial manifestations of MG, frequently presenting as ptosis (drooping eyes) and diplopia (double vision) due to weakness of the levator palpebrae superioris and extraocular muscles. These symptoms are typically asymmetric, intermittent, and worsen with fatigue or prolonged activity. Unlike cranial nerve palsies, the patterns of muscle involvement are variable, and alignment can shift throughout the day. While some patients remain in the ocular stage, up to 50% progress to gMG within 2 years.
Rozanolixizumab, a humanized IgG4 monoclonal antibody that binds to the neonatal Fc receptor, was approved in the U.S. in late 2023, becoming the first and only medication for anti-acetylcholine receptor (AChR) and anti-muscle-specific tyrosine kinase (MuSK) antibody positive gMG, the most common subtypes of the disease. Its approval was based on data from MycarinG, where findings showed that rozanolixizumab-treated patients outperformed placebo on the primary end point of MG-ADL scores over a 43-day treatment period.2,3
In the original study, those in the rozanolixizumab 7 mg/kg and 10 mg/kg groups demonstrated least-square (LS) mean changes of –3.370 and –3.403, respectively, on MG-ADL compared with –0.784 for those on placebo. The therapy also performed well on Quantitative Myasthenia Gravis (QMG) score, a secondary outcome, with point changes of –5.4 and –6.7 in the 7 and 10 mg/kg groups, respectively, vs changes of –1.9 points in the placebo-treated group (P <.001).
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REFERENCES
1. Habib A, Pascuzzi R, Vu T, et al. Ocular symptoms in patients with generalized myasthenia gravis receiving rozanolixizumab: Post hoc analysis of MycarinG. Presented at: 2025 MDA Clinical & Scientific conference. March 16-19; Dallas, TX. ABSTRACT P353.
2. UCB announces US FDA approval of Rystiggo (rozanolixizumab-noli) for the treatment of adults with generalized myasthenia gravis. News release. June 27, 2023. Accessed June 27, 2023. https://www.prnewswire.com/news-releases/ucb-announces-us-fda-approval-of-rystiggo-rozanolixizumab-noli-for-the-treatment-of-adults-with-generalized-myasthenia-gravis-301864023.html
3. Bril V, Druzdz A, Grosskreutz J, et al. Safety and efficacy of rozanolixizumab in patients with generalized myasthenia gravis (MycarinG): a randomized, double-blind, placebo-controlled, adaptive phase 3 study. Lancet Neurol. 2023;22(5):383-394. doi:10.1016/S1474-4422(23)00077-7.
