UCB announces U.S. FDA approval for ZILBRYSQ® (zilucoplan) autoinjector self-administration for adults living with generalized myasthenia gravis

October 16, 2026 |

18 min read

ZILBRYSQ is the first and only macrocyclic peptide C5 inhibitor approved as a self-administered once-daily, subcutaneous autoinjector for adults living with generalized myasthenia gravis (gMG) in the U.S.¹
ZILBRYSQ now offers two self-administration options for adults living with gMG who are anti-acetylcholine receptor (AChR) antibody positive.¹
The autoinjector is designed to help simplify self-administration of ZILBRYSQ, offering patients another administration option and a more convenient treatment experience.^2,3
Approval is supported by data showing ZILBRYSQ bioequivalence between the autoinjector and the existing prefilled syringe, with complete dose delivery achieved for 99.8% (n=449*) of autoinjector administrations. Patients reported high satisfaction with self-injection of ZILBRYSQ using the autoinjector device.²

ATLANTA, Oct. 20, 2026 /PRNewswire/ -- UCB (Euronext Brussels: UCB), a global biopharmaceutical company, today announced that the U.S. Food and Drug Administration (FDA) has approved the first self-administered once-daily autoinjector administration option for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive with ZILBRYSQ^® (zilucoplan).¹ The autoinjector is designed to help simplify self-administration of ZILBRYSQ, offering patients another administration option and a more convenient treatment experience.^2,3

ZILBRYSQ Logo

"This approval is the answer to a question on which we've been relentlessly focused: How do we continue to improve an already effective therapy for daily use?" said Kimberly Moran, PhD, SVP & Head, U.S. Rare Diseases at UCB. "As the first treatment to be approved as a once-daily autoinjector option for adults living with gMG in the U.S., ZILBRYSQ now provides the same therapy via another administration option. At UCB, we are committed to science and make it our point to continually help improve how people experience it."

The ZILBRYSQ autoinjector is designed to automatically deliver a pre-defined dose when activated against the skin.^1,2 Prior to the autoinjector's approval, ZILBRYSQ was available as a self-administered prefilled syringe (PFS). Patients or their care partners will now have another portable treatment solution.

"For a chronic condition like gMG, having different administration options allows patients to choose the approach that best fits their individual preferences and routines," said Donatello Crocetta, Global Head of Medical Affairs and Chief Medical Officer at UCB. "From a medical standpoint, it was essential to confirm that this added administrative option didn't come at the expense of safety and efficacy. The data supporting the autoinjector's complete dose delivery show that this option continues to offer an effective treatment for patients."

The approval of the ZILBRYSQ autoinjector for self-administration is supported by data from the following studies:

DV0012 – a Phase 1, open-label, single-center, two-period crossover study in healthy adult volunteers (n=14) which established bioequivalence of ZILBRYSQ delivered via an autoinjector compared with a PFS.²
DV0013 – a Phase 3b open-label, multi-center study in adult patients (n=31) with gMG self-administering ZILBRYSQ via autoinjector once daily. Complete dose delivery was achieved for 99.8% (n=449*) of autoinjector administrations. Patients reported high satisfaction with self-injection of ZILBRYSQ using the autoinjector device.² Self-administration was generally well tolerated. The most common TEAE was injection-site pain (n=3; 9.7%).²
A human factors validation study of 100 participants^† demonstrating that 90% successfully completed an injection with the ZILBRYSQ autoinjector on their first attempt without training.⁴

UCB expects the autoinjector to be available commercially in Q1 2027.

*Total autoinjectors used and returned.

†Participants defined as patients with gMG or those exhibiting ocular symptoms (injection-experienced and injection-naïve); caregivers (injection-experienced and injection-naïve); and healthcare professionals (HCPs).

About ZILBRYSQ^® (zilucoplan)

ZILBRYSQ (a synthetic macrocyclic peptide) is a once-daily, self-administered, subcutaneous injection that works by blocking complement component 5 (C5), a protein involved in the immune-mediated damage that occurs at the neuromuscular junction in gMG.^1,5 ZILBRYSQ is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive.¹

The precise mechanism through which ZILBRYSQ exerts therapeutic effects in gMG is unknown.

In addition to ZILBRYSQ, UCB's gMG portfolio includes RYSTIGGO^® (rozanolixizumab-noli), a subcutaneously infused monoclonal antibody targeting the neonatal Fc receptor (FcRn) approved by the FDA for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.⁶ With two approved medicines with distinct mechanisms of action, UCB continues to offer physicians and the U.S. gMG community a choice of targeted therapies from a single company.

The precise mechanism through which RYSTIGGO exerts therapeutic effects in gMG is unknown.

About generalized myasthenia gravis (gMG)

gMG is a rare neuromuscular autoimmune disease that has a global prevalence of 150–350 cases per 1 million people.⁷ People living with gMG can experience a variety of symptoms, including severe muscle weakness that can result in double vision, drooping eyelids, difficulty with swallowing, chewing and talking, as well as life-threatening weakness of the muscles of respiration.^8,9

In gMG, pathogenic autoantibodies can impair synaptic transmission at the neuromuscular junction (NMJ) by targeting specific proteins on the post-synaptic membrane.¹⁰ This disrupts the ability of the nerves to stimulate the skeletal muscle and results in a weaker contraction.¹⁰ gMG can occur in any race, gender or age.^8,9,11

Important Safety Information about ZILBRYSQ® (zilucoplan) in the U.S.¹

ZILBRYSQ is a complement inhibitor indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive.

IMPORTANT SAFETY INFORMATION INCLUDING BOXED WARNING

WARNING: SERIOUS MENINGOCOCCAL INFECTIONS

Life-threatening and fatal meningococcal infections have occurred in patients treated with complement inhibitors. These infections may become rapidly life-threatening or fatal if not recognized and treated early. ZILBRYSQ, a complement inhibitor, increases the risk of serious infections caused by Neisseria meningitidis.

Complete or update meningococcal vaccination (for serogroups A, C, W, Y, and B) at least 2 weeks prior to the first dose of ZILBRYSQ, unless the risk of delaying therapy outweigh the risks of developing a meningococcal infection. Comply with the most current Advisory Committee on Immunization Practices (ACIP) recommendations for vaccination against meningococcal bacteria in patients receiving a complement inhibitor.
Persons receiving ZILBRYSQ are at increased risk for invasive disease caused by Neisseria meningitidis, even if they develop antibodies following vaccination. Monitor patients for signs of serious meningococcal infections and evaluate immediately if infection is suspected.

Because of the risk of serious meningococcal infections, ZILBRYSQ is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called ZILBRYSQ REMS.

CONTRAINDICATIONS

ZILBRYSQ is contraindicated for initiation in patients with unresolved Neisseria meningitidis infection.

WARNINGS AND PRECAUTIONS

Serious Meningococcal Infections

ZILBRYSQ, a complement inhibitor, increases a patient's susceptibility to serious, life-threatening, or fatal infections caused by meningococcal bacteria (septicemia and/or meningitis) in any serogroup, including non-groupable strains. Life-threatening and fatal meningococcal infections have occurred in both vaccinated and unvaccinated patients treated with complement inhibitors. The initiation of ZILBRYSQ treatment is contraindicated in patients with unresolved serious Neisseria meningitidis infection. Complete or update meningococcal vaccination (for serogroups A, C, W, Y and B) at least 2 weeks prior to administering the first dose of ZILBRYSQ, according to current ACIP recommendations for patients receiving a complement inhibitor. If urgent ZILBRYSQ therapy is indicated in a patient who is not up to date with meningococcal vaccines according to ACIP recommendations, provide the patient with antibacterial drug prophylaxis and administer meningococcal vaccines as soon as possible. Closely monitor patients for early signs and symptoms of meningococcal infection and evaluate patients immediately if infection is suspected. Consider interruption of ZILBRYSQ in patients who are undergoing treatment for serious meningococcal infection, depending on the risks of interrupting treatment in the disease being treated.

ZILBRYSQ REMS

Due to the risk of meningococcal infections, ZILBRYSQ is available only through a restricted program under a REMS called ZILBRYSQ REMS. Under the ZILBRYSQ REMS, prescribers must enroll in the program. Prescribers must counsel patients about the risk of meningococcal infection, provide the patients with the REMS educational materials, and ensure patients are vaccinated with meningococcal vaccines. Additional information on the REMS requirements is available at www.ZILBRYSQREMS.com or 1-877-414-8353.

Other Infections

Serious infections with Neisseria species (other than Neisseria meningitidis), including disseminated gonococcal infections, have been reported in patients treated with complement inhibitors. ZILBRYSQ blocks terminal complement activation; therefore, patients may have increased susceptibility to infections, especially with encapsulated bacteria, such as infections caused by Neisseria meningitidis but also Streptococcus pneumoniae, Haemophilus influenzae, and to a lesser extent, Neisseria gonorrhoeae. Administer vaccinations for the prevention of Streptococcus pneumoniae infection according to ACIP recommendations. Patients receiving ZILBRYSQ are at increased risk for infections due to these organisms, even if they develop antibodies following vaccination.

Pancreatitis And Other Pancreatic Conditions

Pancreatitis and pancreatic cysts have been reported in patients treated with ZILBRYSQ. Patients should be informed of this risk before starting ZILBRYSQ. Obtain lipase and amylase levels at baseline before starting treatment with ZILBRYSQ. Discontinue ZILBRYSQ in patients with suspected pancreatitis and initiate appropriate management until pancreatitis is ruled out or has resolved.

ADVERSE REACTIONS

In a placebo-controlled study, the most common adverse reactions (reported in at least 10% of gMG patients treated with ZILBRYSQ) were injection site reactions, upper respiratory tract infections, and diarrhea.

Please see Important Safety Information below and full U.S. Prescribing Information at ZILBRYSQ | UCB.

Important Safety Information about RYSTIGGO^® (rozanolixizumab-noli) in the US⁷

RYSTIGGO (rozanolixizumab-noli) is a neonatal Fc receptor blocker indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.¹³

IMPORTANT SAFETY INFORMATION

WARNINGS AND PRECAUTIONS

Infections: RYSTIGGO may increase the risk of infection. Delay RYSTIGGO administration in patients with an active infection until the infection is resolved. During treatment with RYSTIGGO, monitor for clinical signs and symptoms of infection. If serious infection occurs, administer appropriate treatment and consider withholding RYSTIGGO until the infection has resolved.

Immunization

Immunization with vaccines during RYSTIGGO treatment has not been studied. The safety of immunization with live or live-attenuated vaccines and the response to immunization with any vaccine are unknown. Because RYSTIGGO causes a reduction in IgG levels, vaccination with live-attenuated or live vaccines is not recommended during treatment with RYSTIGGO. Evaluate the need to administer age-appropriate vaccines according to immunization guidelines before initiation of a new treatment cycle with RYSTIGGO.

Aseptic Meningitis: Serious adverse reactions of aseptic meningitis (also called drug-induced aseptic meningitis) have been reported in patients treated with RYSTIGGO. If symptoms consistent with aseptic meningitis develop, diagnostic workup and treatment should be initiated according to the standard of care.

Hypersensitivity Reactions: Hypersensitivity reactions, including angioedema and rash, were observed in patients treated with RYSTIGGO. Management of hypersensitivity reactions depends on the type and severity of the reaction. Monitor patients during treatment with RYSTIGGO and for 15 minutes after for clinical signs and symptoms of hypersensitivity reactions. If a reaction occurs, institute appropriate measures if needed.

ADVERSE REACTIONS

In a placebo-controlled study, the most common adverse reactions (reported in at least 10% of RYSTIGGO-treated patients) were headache, infections, diarrhea, pyrexia, hypersensitivity reactions, and nausea. Serious infections were reported in 4% of patients treated with RYSTIGGO. Three fatal cases of pneumonia were identified, caused by COVID-19 infection in two patients and an unknown pathogen in one patient. Six cases of infections led to discontinuation of RYSTIGGO.

Please refer to the full Prescribing Information for additional Important Safety Information.

For further information, contact UCB:

U.S. Communications

Becky Malone

T +1.919.605.9600

becky.malone@ucb.com

Corporate Communications, Media Relations

Laurent Schots

T +32.2.559.92.64

laurent.schots@ucb.com

Investor Relations

Yvonne Naughton

T +44.175.344.7521

yvonne.naughton@ucb.com

Sahar Yazdian

T +32.2.559.91.37

sahar.yazdian@ucb.com

About UCB

UCB, Brussels, Belgium (www.ucb.com) is a global biopharmaceutical company focused on the discovery and development of innovative medicines and solutions to transform the lives of people living with severe diseases of the immune system or of the central nervous system. With more than 9,000 people in approximately 40 countries, the company generated revenue of €7.7 billion in 2025. UCB is listed on Euronext Brussels (symbol: UCB).

Forward-looking statements

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Important factors that could result in such differences include but are not limited to: global spread and impacts of wars, pandemics and terrorism, the general geopolitical environment, climate change, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues, supply chain disruption and business continuity risks; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars or disruptive technologies/business models, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring, retention and compliance of its employees. There is no guarantee that new product candidates will be discovered or identified in the pipeline, or that new indications for existing products will be developed and approved. Movement from concept to commercial product is uncertain; preclinical results do not guarantee safety and efficacy of product candidates in humans. So far, the complexity of the human body cannot be reproduced in computer models, cell culture systems or animal models. The length of the timing to complete clinical trials and to get regulatory approval for product marketing has varied in the past and UCB expects similar unpredictability going forward. Products or potential products which are the subject of partnerships, joint ventures or licensing collaborations may be subject to disputes between the partners or may prove to be not as safe, effective or commercially successful as UCB may have believed at the start of such partnership. UCB's efforts to acquire other products or companies and to integrate the operations of such acquired companies may not be as successful as UCB may have believed at the moment of acquisition. Also, UCB or others could discover safety, side effects or manufacturing problems with its products and/or devices after they are marketed. The discovery of significant problems with a product similar to one of UCB's products that implicate an entire class of products may have a material adverse effect on sales of the entire class of affected products. Moreover, sales may be impacted by international and domestic trends toward managed care and health care cost containment, including pricing pressure, political and public scrutiny, customer and prescriber patterns or practices, and the reimbursement policies imposed by third-party payers as well as legislation affecting biopharmaceutical pricing and reimbursement activities and outcomes. Finally, a breakdown, cyberattack or information security breach could compromise the confidentiality, integrity and availability of UCB's data and systems.

Given these uncertainties, the public is cautioned not to place any undue reliance on such forward-looking statements. These forward-looking statements are made only as of the date of this document, and do not reflect any potential impacts from the evolving event or risk as mentioned above as well as any other adversity, unless indicated otherwise. The company continues to follow the development diligently to assess the financial significance of these events, as the case may be, to UCB.

UCB expressly disclaims any obligation to update any forward-looking statements in this document, either to confirm the actual results or to report or reflect any change in its forward-looking statements with regard thereto or any change in events, conditions or circumstances on which any such statement is based, unless such statement is required pursuant to applicable laws and regulations.

References:

ZILBRYSQ^® US PI.
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van den Bemt BJF, Gettings L, Domańska B, et al. A portfolio of biologic self-injection devices in rheumatology: how patient involvement in device design can improve treatment experience. Drug Deliv. 2019;26(1):384-392.
Karali S, Domanska B, Savic N, et al. Usability of zilucoplan auto-injector in generalised myasthenia gravis: a human factors validation study. Poster presented at: International Congress on Neuromuscular Diseases (ICNMD) 2026; July 7-11, 2026; Florence, Italy. Poster PP01.229.
Howard JF Jr, et al. Myasthenia gravis: The role of complement at the neuromuscular junction. Ann N Y Acad Sci. 2018.
RYSTIGGO^® US PI. https://www.ucb-usa.com/RYSTIGGO-prescribing-information.pdf. Accessed September 2026.
Punga AR, Maddison P, Heckmann JM, et al. Epidemiology, diagnostics, and biomarkers of autoimmune neuromuscular junction disorders. Lancet Neurol. 2022;21(2):176-88.
Overview of MG. Myasthenia Gravis Foundation of America. https://myasthenia.org/understanding-mg/overview-mg. Date accessed September 2026.
Myasthenia Gravis Fact Sheet. National Institute of Neurological Disorders and Stroke. 2022. https://www.ninds.nih.gov/myasthenia-gravis-fact-sheet. Accessed September 2026.
Phillips WD, Vincent A. Pathogenesis of myasthenia gravis: update on disease types, models, and mechanisms. F1000Res. 2016;5:F1000 Faculty Rev-1513.
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