Zilucoplan is a prescription medicine (Complement Inhibitor). The sections below reproduce one FDA label for it, named under "Label". Products in other forms, strengths or from other makers have their own labels, which can differ.
- Type
- Prescription only (Rx)
- Brand names
- Zilbrysq
- Drug class
- Complement Inhibitor
- Taken
- Subcutaneous
- Label
- UCB, Inc., revised February 3, 2026 · full label on DailyMed
- Generic
- No · details
Boxed warning — the FDA's most serious warning for a medicine
WARNING: SERIOUS MENINGOCOCCAL INFECTIONS ZILBRYSQ, a complement inhibitor, increases the risk of serious infections caused by Neisseria meningitidis [see Warnings and Precautions (5.1) ] . 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. Complete or update vaccination for meningococcal bacteria (for serogroups A, C, W, Y, and B) at least 2 weeks prior to the first dose of ZILBRYSQ, unless the risks of delaying therapy outweigh the risk of developing a serious infection. Comply with the most current Advisory Committee on Immunization Practices (ACIP) recommendations for vaccination against meningococcal bacteria in patients receiving a complement inhibitor. See Warnings and Precautions (5.1) for additional guidance on the management of the risk of serious infections caused by meningococcal bacteria. Patients receiving ZILBRYSQ are at increased risk for invasive disease caused by Neisseria meningitidis , even if they develop antibodies following vaccination. Monitor patients for early signs and symptoms 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 [see Warnings and Precautions (5.2) ] . WARNING: SERIOUS MENINGOCOCCAL INFECTIONS See full prescribing information for complete boxed warning. ZILBRYSQ increases the risk of serious and life-threatening infections caused by Neisseria meningitidis . ( 5.1 ) Complete or update meningococcal vaccination at least 2 weeks prior to the first dose of ZILBRYSQ, unless the risks of delaying ZILBRYSQ outweigh the risks of developing a serious infection. Comply with the most current Advisory Committee on Immunization Practices (ACIP) recommendations for meningococcal vaccination in patients receiving a complement inhibitor. ( 5.1 ) Patients receiving ZILBRYSQ are at increased risk for invasive disease caused by N. meningitidis , even if they develop antibodies following vaccination. Monitor patients for early signs and symptoms of meningococcal infections and evaluate immediately if infection is suspected. ( 5.1 ) ZILBRYSQ is available only through a restricted program called ZILBRYSQ REMS. ( 5.2 )
What it is used for
ZILBRYSQ is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive. 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. ( 1 )
Forms and strengths
Injection: 16.6 mg/0.416 mL, 23 mg/0.574 mL, or 32.4 mg/0.81 mL of zilucoplan as a clear to slightly opalescent, colorless solution in single-dose prefilled syringes. Injection: 16.6 mg/0.416 mL, 23 mg/0.574 mL, or 32.4 mg/0.81 mL zilucoplan in single-dose prefilled syringes. ( 3 )
Who should not take it (contraindications)
ZILBRYSQ is contraindicated for initiation in patients with unresolved serious Neisseria meningitidis infection [see Warnings and Precautions (5.1) ] . ZILBRYSQ is contraindicated for initiation in patients with unresolved serious Neisseria meningitidis infection. ( 4 )
Warnings and precautions
Other Infections: Use caution when administering ZILBRYSQ to patients with any other systemic infection. ( 5.3 ) Pancreatitis and pancreatic cysts have been reported in patients treated with ZILBRYSQ. Discontinue ZILBRYSQ in patients with suspected pancreatitis and initiate appropriate management until pancreatitis is ruled out or has resolved. ( 5.4 )
5.1 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 administration of the first dose of ZILBRYSQ, according to current ACIP recommendations for patients receiving a complement inhibitor. Revaccinate patients in accordance with ACIP recommendations considering the duration of ZILBRYSQ therapy. Note that ACIP recommends an administration schedule in patients receiving complement inhibitors that differs from the administration schedule in the vaccine prescribing information. 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. Various durations and regimens of antibacterial drug prophylaxis have been considered, but the optimal durations and drug regimens for prophylaxis and their efficacy have not been studied in unvaccinated or vaccinated patients receiving complement inhibitors, including ZILBRYSQ. The benefits and risks of treatment with ZILBRYSQ, as well as the benefits and risks of antibacterial drug prophylaxis in unvaccinated or vaccinated patients, must be considered against the known risks for serious infections caused by Neisseria meningitidis . Vaccination does not eliminate the risk of meningococcal infections, despite development of antibodies following vaccination. Closely monitor patients for early signs and symptoms of meningococcal infection and evaluate patients immediately if infection is suspected. Inform patients of these signs and symptoms and instruct patients to seek immediate medical care if these signs and symptoms occur. Promptly treat known infections. Meningococcal infection may become rapidly life-threatening or fatal if not recognized and treated early. 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 [ see Contraindications (4) ] . ZILBRYSQ is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) [see Warnings and Precautions (5.2) ] . 5.2 ZILBRYSQ REMS ZILBRYSQ is available only through a restricted program under a REMS called ZILBRYSQ REMS, because of the risk of serious meningococcal infections [see Warnings and Precautions (5.1) ] . Notable requirements of the ZILBRYSQ REMS include the following: Prescribers must enroll in the REMS. Prescribers must counsel patients about the risk of serious meningococcal infection. Prescribers must provide the patients with the REMS educational materials. Prescribers must assess patient vaccination status for meningococcal vaccines (against serogroups A, C, W, Y, and B) and vaccinate if needed according to current ACIP recommendations two weeks prior to the first dose of ZILBRYSQ. Prescribers must provide a prescription for antibacterial drug prophylaxis if treatment must be started urgently and the patient is not up to date with meningococcal vaccines according to current ACIP recommendations at least two weeks prior to the first dose of ZILBRYSQ. Pharmacies that dispense ZILBRYSQ must be certified in the REMS and must verify prescribers are certified. Patients must receive counseling from the prescriber about the need to receive meningococcal vaccines per ACIP recommendations, the need to take antibiotics as directed by the prescriber, and the signs and symptoms of meningococcal infection. Patients must be instructed to carry the Patient Safety Card with them at all times during and for 2 months following treatment discontinuation with ZILBRYSQ. Further information is available at www.ZILBRYSQREMS.com or 1-877-414-8353.
5.3 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.
5.4 Pancreatitis and Other Pancreatic Conditions Pancreatitis and pancreatic cysts have been reported in patients treated with ZILBRYSQ. During the open-label extension studies, seven (3.3%) patients experienced pancreatic events, including 4 (1.9%) patients with pancreatitis and 3 (1.4%) with pancreatic cysts. In the 3-month, double-blind Study 1, adverse reactions of increased lipase were reported in six (6.9%) patients treated with ZILBRYSQ compared to no patients on placebo, and adverse reactions of increased amylase were reported in four (4.7%) patients treated with ZILBRYSQ compared to one (1.1%) patient on placebo. Lipase levels exceeded three times the upper limit of normal in six (7%) patients after being started on ZILBRYSQ compared to no patients on placebo. 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.
Side effects (adverse reactions)
The following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Serious Meningococcal Infections [see Warnings and Precautions (5.1) ] Other Infections [see Warnings and Precautions (5.3) ] Pancreatitis and Other Pancreatic Conditions [see Warnings and Precautions (5.4) ] The most common adverse reactions (≥10%) in patients with gMG were injection site reactions, upper respiratory tract infection, and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact UCB, Inc. at 844-599-2273 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. A total of 212 patients were treated with ZILBRYSQ 0.3 mg/kg in clinical studies in gMG. Of these, 137 patients were exposed for at least 6 months, and 87 were exposed for at least 1 year. In a placebo-controlled study (Study 1) in patients with gMG, 86 patients received ZILBRYSQ 0.3 mg/kg [see Clinical Studies (14) ] . Of these 86 patients, approximately 61% were female, 77% were White, 8% were Asian, and 8% were of Hispanic or Latino ethnicity. The mean age at study entry was 52.6 years (range 21 to 75 years). Table 2 summarizes the adverse reactions reported in at least 5% of patients treated with ZILBRYSQ and more frequently than placebo. The most common adverse reactions (reported in at least 10% of patients treated with ZILBRYSQ) were injection site reactions, upper respiratory tract infections, and diarrhea. Table 2: Adverse Reactions in at least 5% of Patients Treated with ZILBRYSQ and More Frequently than in Patients who Received Placebo in Study 1 Adverse Reaction ZILBRYSQ 0.3 mg/kg (n=86) % Placebo (n=88) % Injection site reactions 29 16 Upper respiratory tract infections 14 7 Diarrhea 11 2 Urinary tract infection 8 5 Nausea or vomiting 8 7 Lipase increased 7 0 Amylase increased 5 1 Pancreatic Events In addition to increases in amylase and lipase observed in Study 1, pancreatic events, including pancreatitis and pancreatic cysts have been observed in patients taking ZILBRYSQ [see Warnings and Precautions (5.4) ] . Adverse Laboratory Changes in Clinical Trials Additional laboratory abnormalities included transient elevations of blood eosinophils, which were of uncertain clinical significance.
6.2 Postmarketing Experience Adverse Reactions from Observational Studies Morphea In the open-label extension studies, which included 213 patients, morphea was observed in 10 (5%) patients; most cases had a time to onset longer than one year after start of treatment and were mild to moderate in severity. One patient discontinued ZILBRYSQ because of morphea.
Pregnancy, breastfeeding, children and older adults
Pregnancy: Based on animal data, may cause fetal harm. ( 8.1 )
8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to ZILBRYSQ during pregnancy. Patients or healthcare providers may contact UCBCares at 1-844-599-CARE (2273) or email ucbcares@ucb.com, so that information about the exposure of ZILBRYSQ during pregnancy and/or breastfeeding can be collected. Risk Summary There are no available data on ZILBRYSQ use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Administration of zilucoplan to pregnant monkeys resulted in increases in embryofetal death at maternal exposures similar to those in humans at therapeutic doses (see Animal Data ) . All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The background rate of major birth defects and miscarriage in the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data Subcutaneous administration of zilucoplan (0, 1, 2, or 4 mg/kg/day) to pregnant monkeys throughout gestation resulted in an increase in embryofetal death at all doses, in the absence of maternal toxicity. A no effect dose for adverse developmental effects in monkeys was not identified. The lowest dose tested was associated with maternal exposures (AUC) similar to that in humans at the maximum recommended human dose of 32.4 mg/day. Data from an ex vivo human placental transfer model demonstrated transfer of zilucoplan into the fetal compartment at a rate of 0.5% at a steady state plasma concentration of 10 µg/mL zilucoplan, which corresponds to a therapeutic dose of 0.3 mg/kg. The clinical significance of these data in human pregnancies is unknown.
8.2 Lactation Risk Summary There are no data on the presence of zilucoplan in human milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for ZILBRYSQ and any potential adverse effects on the breastfed infant from ZILBRYSQ or from the underlying maternal condition.
8.4 Pediatric Use Safety and effectiveness in pediatric patients have not been established.
8.5 Geriatric Use Clinical studies of ZILBRYSQ did not include sufficient numbers of patients aged 65 and older to determine whether they respond differently from younger adult patients.
How it works
Zilucoplan binds to the complement protein C5 and inhibits its cleavage to C5a and C5b, preventing the generation of the terminal complement complex, C5b-9. The precise mechanism by which zilucoplan exerts its therapeutic effect in generalized myasthenia gravis is unknown but is presumed to involve reduction of C5b-9 deposition at the neuromuscular junction.
Is there a generic Zilucoplan?
No. The FDA has not approved a generic version yet.
Brand-name versions
- Zilbrysq Ucb Inc, approved 2023
Source: Drugs@FDA (via openFDA), checked October 29, 2026. Marketing status is what companies report to the FDA; whether a pharmacy stocks a product, and what your insurance covers, can differ.
Dosage:
we do not reproduce dosing instructions. The right dose depends on the person and the condition and is set by the prescriber or pharmacist. Dosage section of the full label.
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Source: FDA structured product labeling, retrieved through openFDA. Label text is shown as published by the FDA, without editing; long sections are shortened, marked […]. openFDA data are not validated for clinical use — always check the current label and ask a doctor or pharmacist about your own treatment. Set ID 9f1d53d6-e495-4a3a-8bb9-680a15d25034.