UCB S.A. (OTC: UCBJY) (OTC: UCBJF) dropped some encouraging news on Wednesday at the International Congress on Neuromuscular Diseases 2026. The company presented data showing that its two drugs for generalized myasthenia gravis (gMG) — rozanolixizumab and zilucoplan — keep working over the long haul, helping patients manage a broad range of symptoms.
gMG is a chronic autoimmune disorder where the body's immune system attacks the communication between nerves and muscles. Think of it as a glitch in the wiring: signals don't get through, and muscles get weak. It can affect everything from double vision to breathing. UCB also shared findings that its newly approved zilucoplan pre-filled pen is easy for patients to use on their own.
Rozanolixizumab: Consistent Relief, Cycle After Cycle
A pooled analysis of the Phase 3 MycarinG study and its open-label extensions looked at 129 adults with gMG who received at least two symptom-driven treatment cycles of rozanolixizumab. The results showed consistent improvements in both clinician- and patient-reported measures of double vision and eyelid drooping across up to 13 cycles. Patients also reported better eye-related quality of life — fewer problems using their eyes.
Another analysis of the same studies found sustained improvements in the Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores. Benefits showed up in symptoms like double vision, eyelid droop, speech, chewing, swallowing, facial muscle function, breathing, and limb strength. Basically, the drug helped across the board.
Safety-wise, 93.1% of patients who got at least one cycle had treatment-emergent adverse events (TEAEs), but most were mild or moderate. The most common were headache, diarrhea, and COVID-19. Importantly, there was no increase in TEAEs with repeated cycles — so the drug didn't become harder to tolerate over time.
MuSK-Positive Patients: A Tough Subgroup Gets Consistent Benefit
UCB also reported results from 12 adults with MuSK antibody-positive gMG — a rarer and often more severe form of the disease. These patients received repeated symptom-driven rozanolixizumab treatment. Patient-reported MG-ADL scores improved from a weighted mean of 10.4 at baseline to 5.2 by Day 43 across up to 13 cycles. QMG scores dropped from 16.8 to 9.4. The findings suggested consistent clinical benefit with an acceptable safety profile. Among 18 MuSK-positive patients who got at least one cycle, 77.8% reported TEAEs, again mostly mild or moderate.
Zilucoplan: Sustained Benefit and a User-Friendly Pen
A separate analysis of the Phase 3 RAISE study and its ongoing RAISE-XT extension looked at zilucoplan in adults with anti-acetylcholine receptor antibody-positive gMG. By Week 12, patients on zilucoplan had greater improvements than placebo across multiple MG-ADL measures, including chewing, talking, eyelid droop, and rising from chairs. Those improvements increased further and stayed durable through Week 120 in the extension study. QMG and quality-of-life assessments showed similarly positive results.
UCB also presented results from a human factors validation study of the newly approved zilucoplan pre-filled pen. One hundred participants tried it without any prior training. Ninety percent completed an injection on their first attempt. The study found no new use-related safety risks, supporting the device as a solid self-administration option. That's a big deal for patients who want to manage their condition at home without frequent clinic visits.
Overall, UCB's data reinforce that both drugs can deliver long-term symptom control, and the new pen makes zilucoplan even more convenient. For patients with gMG, that's a hopeful message.
