TRIAL RESULTS · SIDE EFFECTS
Zilucoplan side effects
ANSWER
In 3 placebo-controlled trials with posted results, the most common side effects of Zilucoplan were injection site bruising 17.3% (placebo 10.9%), constipation 13.4% (placebo 5.9%), injection site pain 12.5% (placebo 3.9%). Read from ClinicalTrials.gov on 2026-10-03. Not medical advice.
Trial register
Trials with posted results
6
with an arm on Zilucoplan, of 24 registered
Against placebo
3
placebo-controlled trials
People in those trials
303
on Zilucoplan · 310 on placebo
Read
2026-10-03
ClinicalTrials.gov
VS PLACEBO
Most common side effects, Zilucoplan beside placebo
Share of people with each side effect in 3 placebo-controlled trials with posted results: 303 people on Zilucoplan (all doses), 310 on placebo, same trials. Listed only when reported for at least half of the people on Zilucoplan. Source: ClinicalTrials.gov, read 2026-10-03. Not medical advice.
ALL TRIALS
The 100 most reported of 185 side effects reported
Every trial with posted results and an arm on Zilucoplan (n ≥ 20), all phases, by people affected. Placebo is shown where placebo-controlled trials reported the same event. Comparator arms are not counted.
| Side effect | Organ system | Zilucoplan | Placebo | Trials |
|---|---|---|---|---|
| Fall | Injury, poisoning and procedural complications | 28.6% (42 of 147) | 22.5% | 2 |
| Injection site bruising | General disorders | 14.7% (38 of 259) | 10.9% | 4 |
| Injection site pain | General disorders | 11.0% (32 of 290) | 3.9% | 5 |
| Headache | Nervous system disorders | 9.5% (31 of 328) | 6.8% | 4 |
| Constipation | Gastrointestinal disorders | 12.4% (30 of 242) | 5.9% | 3 |
| Muscular weakness | Musculoskeletal and connective tissue disorders | 20.4% (30 of 147) | 20.0% | 2 |
| Diarrhoea | Gastrointestinal disorders | 8.5% (22 of 259) | 3.9% | 4 |
| Neuromyopathy | Nervous system disorders | 18.0% (22 of 122) | 12.5% | 1 |
| Fatigue | General disorders | 11.6% (17 of 147) | 12.5% | 2 |
| Nausea | Gastrointestinal disorders | 6.0% (16 of 268) | 3.6% | 4 |
| Hypertension | Vascular disorders | 6.6% (16 of 242) | 4.1% | 3 |
| Contusion | Injury, poisoning and procedural complications | 6.0% (14 of 233) | 3.9% | 3 |
| COVID-19 | Infections and infestations | 3.7% (13 of 354) | 3.5% | 5 |
| Urinary tract infection | Infections and infestations | 4.0% (13 of 328) | 2.9% | 4 |
| Hypotension | Vascular disorders | 13.7% (13 of 95) | 4.9% | 1 |
| Anaemia | Blood and lymphatic system disorders | 5.8% (12 of 206) | 1.5% | 3 |
| Rash | Skin and subcutaneous tissue disorders | 5.1% (12 of 234) | 4.7% | 3 |
| Dysphagia | Gastrointestinal disorders | 5.5% (12 of 217) | 2.3% | 2 |
| Dizziness | Nervous system disorders | 9.8% (12 of 122) | 5.0% | 1 |
| Lipase increased | Investigations | 8.0% (11 of 137) | 1.1% | 3 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 4.5% (11 of 243) | 1.8% | 3 |
| Myasthenia gravis | Nervous system disorders | 9.8% (11 of 112) | 5.7% | 2 |
| Cough | Respiratory, thoracic and mediastinal disorders | 6.8% (10 of 148) | 2.5% | 2 |
| Amylase increased | Investigations | 6.6% (9 of 137) | 2.3% | 3 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 5.2% (9 of 173) | 5.0% | 3 |
| Oedema peripheral | General disorders | 6.1% (9 of 147) | 2.5% | 2 |
| Insomnia | Psychiatric disorders | 7.5% (9 of 120) | 2.7% | 2 |
| Dysarthria | Nervous system disorders | 7.4% (9 of 122) | 5.0% | 1 |
| Pyrexia | General disorders | 9.5% (9 of 95) | 3.3% | 1 |
| Nasopharyngitis | Infections and infestations | 5.8% (8 of 137) | 3.4% | 3 |
| Pruritus | Skin and subcutaneous tissue disorders | 5.4% (8 of 147) | 5.0% | 2 |
| Hypokalaemia | Metabolism and nutrition disorders | 3.7% (8 of 217) | 2.3% | 2 |
| Septic shock | Infections and infestations | 8.4% (8 of 95) | 5.5% | 1 |
| Respiratory failure | Respiratory, thoracic and mediastinal disorders | 8.4% (8 of 95) | 5.5% | 1 |
| Anxiety | Psychiatric disorders | 5.7% (7 of 122) | 2.5% | 1 |
| Acute kidney injury | Renal and urinary disorders | 7.4% (7 of 95) | 2.7% | 1 |
| Pulmonary embolism | Respiratory, thoracic and mediastinal disorders | 2.0% (6 of 303) | 1.6% | 3 |
| Decreased appetite | Metabolism and nutrition disorders | 4.1% (6 of 147) | 12.5% | 2 |
| Hepatic enzyme increased | Investigations | 2.8% (6 of 217) | 1.8% | 2 |
| Tension headache | Nervous system disorders | 4.9% (6 of 122) | 5.0% | 1 |
| Respiratory Failure | Respiratory, thoracic and mediastinal disorders | 4.9% (6 of 122) | 2.5% | 1 |
| Pneumonia | Infections and infestations | 1.7% (5 of 303) | 1.3% | 3 |
| Pain in extremity | Musculoskeletal and connective tissue disorders | 4.1% (5 of 122) | 5.0% | 1 |
| Hypertriglyceridaemia | Metabolism and nutrition disorders | 5.3% (5 of 95) | 3.3% | 1 |
| Oliguria | Renal and urinary disorders | 5.3% (5 of 95) | 0.5% | 1 |
| Acute respiratory failure | Respiratory, thoracic and mediastinal disorders | 5.3% (5 of 95) | 3.3% | 1 |
| Vomiting | Gastrointestinal disorders | 1.7% (4 of 233) | 5.5% | 3 |
| COVID-19 pneumonia | Infections and infestations | 1.3% (4 of 303) | 2.6% | 3 |
| Hyperglycaemia | Metabolism and nutrition disorders | 3.3% (4 of 121) | 3.8% | 2 |
| Injection site reaction | Injury, poisoning and procedural complications | 3.3% (4 of 122) | 5.0% | 1 |
| Salivary hypersecretion | Gastrointestinal disorders | 3.3% (4 of 122) | 7.5% | 1 |
| Tachycardia | Cardiac disorders | 4.2% (4 of 95) | 1.1% | 1 |
| Hypoxia | Respiratory, thoracic and mediastinal disorders | 2.1% (3 of 146) | 1.6% | 3 |
| Injection site pruritus | General disorders | 5.9% (3 of 51) | - | 2 |
| Sinusitis | Infections and infestations | 5.9% (3 of 51) | - | 2 |
| Post-traumatic pain | Injury, poisoning and procedural complications | 2.5% (3 of 122) | 5.0% | 1 |
| Pneumonia aspiration | Respiratory, thoracic and mediastinal disorders | 2.5% (3 of 122) | 0.0% | 1 |
| Atrial fibrillation | Cardiac disorders | 3.2% (3 of 95) | 2.2% | 1 |
| Troponin increased | Investigations | 3.2% (3 of 95) | 2.2% | 1 |
| Hypernatraemia | Metabolism and nutrition disorders | 3.2% (3 of 95) | 1.6% | 1 |
| Sepsis | Infections and infestations | 1.1% (2 of 181) | 1.1% | 2 |
| Deep vein thrombosis | Vascular disorders | 0.9% (2 of 217) | 0.0% | 2 |
| Generalised oedema | General disorders | 1.6% (2 of 122) | 0.0% | 1 |
| Pneumonia klebsiella | Infections and infestations | 2.1% (2 of 95) | 1.1% | 1 |
| Acute myocardial infarction | Cardiac disorders | 2.1% (2 of 95) | 0.5% | 1 |
| Cardio-respiratory arrest | Cardiac disorders | 2.1% (2 of 95) | 1.1% | 1 |
| Multiple organ dysfunction syndrome | General disorders | 2.1% (2 of 95) | 1.1% | 1 |
| Pneumonia bacterial | Infections and infestations | 2.1% (2 of 95) | 0.5% | 1 |
| Pain | General disorders | 7.7% (2 of 26) | - | 1 |
| Herpes zoster | Infections and infestations | 7.7% (2 of 26) | - | 1 |
| Back pain | Musculoskeletal and connective tissue disorders | 7.7% (2 of 26) | - | 1 |
| Cerebral haemorrhage | Nervous system disorders | 0.6% (1 of 181) | 0.4% | 2 |
| Cerebrovascular accident | Nervous system disorders | 0.6% (1 of 181) | 0.4% | 2 |
| Cardiac arrest | Cardiac disorders | 0.5% (1 of 217) | 1.8% | 2 |
| Cardiac failure congestive | Cardiac disorders | 0.5% (1 of 217) | 0.0% | 2 |
| Supraventricular tachycardia | Cardiac disorders | 0.5% (1 of 217) | 0.5% | 2 |
| Pyelonephritis | Infections and infestations | 0.8% (1 of 121) | 0.0% | 2 |
| Vertigo | Ear and labyrinth disorders | 4.0% (1 of 25) | - | 1 |
| Influenza like illness | General disorders | 4.0% (1 of 25) | - | 1 |
| Lymphocyte count decreased | Investigations | 4.0% (1 of 25) | - | 1 |
| White blood cell count decreased | Investigations | 4.0% (1 of 25) | - | 1 |
| Myalgia | Musculoskeletal and connective tissue disorders | 4.0% (1 of 25) | - | 1 |
| Rectal haemorrhage | Gastrointestinal disorders | 4.0% (1 of 25) | - | 1 |
| Asthenia | General disorders | 4.0% (1 of 25) | - | 1 |
| Sinusitis bacterial | Infections and infestations | 4.0% (1 of 25) | - | 1 |
| Staphylococcal sepsis | Infections and infestations | 4.0% (1 of 25) | - | 1 |
| Aphthous ulcer | Gastrointestinal disorders | 1.2% (1 of 86) | 0.0% | 1 |
| Oesophageal candidiasis | Infections and infestations | 1.2% (1 of 86) | 0.0% | 1 |
| Oral candidiasis | Infections and infestations | 1.2% (1 of 86) | 0.0% | 1 |
| Basal cell carcinoma | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1.2% (1 of 86) | 0.0% | 1 |
| Angioedema | Skin and subcutaneous tissue disorders | 1.2% (1 of 86) | 0.0% | 1 |
| Traumatic haematoma | Injury, poisoning and procedural complications | 0.8% (1 of 122) | 5.0% | 1 |
| Tinnitus | Ear and labyrinth disorders | 0.8% (1 of 122) | 5.0% | 1 |
| Increased upper airway secretion | Respiratory, thoracic and mediastinal disorders | 0.8% (1 of 122) | 0.0% | 1 |
| Faecaloma | Gastrointestinal disorders | 0.8% (1 of 122) | 0.0% | 1 |
| Pancreatitis | Gastrointestinal disorders | 0.8% (1 of 122) | 0.0% | 1 |
| Pneumoperitoneum | Gastrointestinal disorders | 0.8% (1 of 122) | 0.0% | 1 |
| Chest pain | General disorders | 0.8% (1 of 122) | 0.0% | 1 |
| Oesophageal carcinoma | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 0.8% (1 of 122) | 0.0% | 1 |
| Device malfunction | Product Issues | 0.8% (1 of 122) | 0.0% | 1 |
Source: ClinicalTrials.gov posted results, read 2026-10-03. A trial lists events above its own reporting threshold, so a rare event may be missing from some trials. Not medical advice.
FDA LABEL
What the FDA label says
ZILBRYSQ NDA216834 · label of 2026-02-03 Regulator
The most common adverse reactions (≥10%) in patients with gMG were injection site reactions, upper respiratory tract infection, and diarrhea.
QUESTIONS
Does zilucoplan cause injection site bruising?
In 3 placebo-controlled trials with posted results, 17.3% of people on zilucoplan reported injection site bruising, against 10.9% on placebo. Source: ClinicalTrials.gov, read 2026-10-03. Not medical advice.
Does zilucoplan cause constipation?
In 3 placebo-controlled trials with posted results, 13.4% of people on zilucoplan reported constipation, against 5.9% on placebo. Source: ClinicalTrials.gov, read 2026-10-03. Not medical advice.
Does zilucoplan cause injection site pain?
In 3 placebo-controlled trials with posted results, 12.5% of people on zilucoplan reported injection site pain, against 3.9% on placebo. Source: ClinicalTrials.gov, read 2026-10-03. Not medical advice.
Does zilucoplan cause headache?
In 3 placebo-controlled trials with posted results, 9.6% of people on zilucoplan reported headache, against 6.8% on placebo. Source: ClinicalTrials.gov, read 2026-10-03. Not medical advice.
Does zilucoplan cause diarrhoea?
In 3 placebo-controlled trials with posted results, 8.2% of people on zilucoplan reported diarrhoea, against 3.9% on placebo. Source: ClinicalTrials.gov, read 2026-10-03. Not medical advice.
REGISTERED STUDIES
24 registered clinical trials of Zilucoplan
The 10 most recently updated are listed.
| NCT06055959 | A Study to Evaluate Subcutaneous Zilucoplan in Pediatric Participants With Generalized Myasthenia Gravis Status: RECRUITING · Updated 2026-10-02 |
|---|---|
| NCT06435312 | An Open-label Extension Study to Evaluate Subcutaneous Zilucoplan in Pediatric Participants With Generalized Myasthenia Gravis Status: ENROLLING_BY_INVITATION · Updated 2026-10-02 |
| NCT07215949 | Zilucoplan for Severe gMG Exacerbations Status: RECRUITING · Updated 2026-08-28 |
| NCT06961747 | A Study to Assess Zilucoplan Concentration in Breast Milk of Healthy Lactating Women Status: RECRUITING · Updated 2026-08-27 |
| NCT04225871 | Open-Label Extension of Zilucoplan in Subjects With Generalized Myasthenia Gravis Status: COMPLETED · Updated 2026-08-12 |
| NCT04297683 | HEALEY ALS Platform Trial - Master Protocol Status: ACTIVE_NOT_RECRUITING · Updated 2026-07-21 |
| 2022-502072-23-00 | A MULTICENTER OPEN-LABEL, UNCONTROLLED STUDY TO EVALUATE THE PHARMACOKINETICS, PHARMACODYNAMICS, SAFETY, TOLERABILITY, AND ACTIVITY OF ZILUCOPLAN IN PEDIATRIC STUDY PARTICIPANTS FROM 2 TO LESS THAN 18 YEARS OF AGE WITH ACETYLCHOLINE RECEPTOR ANTIBODY POSITIVE GENERALIZED MYASTHENIA GRAVIS Status: UNKNOWN · Updated 2026-06-05 |
| 2022-502073-42-00 | AN OPEN-LABEL EXTENSION STUDY TO EVALUATE THE LONG-TERM SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS, AND ACTIVITY OF ZILUCOPLAN IN PEDIATRIC STUDY PARTICIPANTS WITH ACETYLCHOLINE RECEPTOR ANTIBODY POSITIVE GENERALIZED MYASTHENIA GRAVIS Status: UNKNOWN · Updated 2026-06-05 |
| NCT06471361 | A Study to Evaluate the Safe and Effective Use of a Zilucoplan Auto-injector by Study Participants With Generalized Myasthenia Gravis Status: COMPLETED · Updated 2026-03-27 |
| NCT06511076 | A Study to Evaluate Zilucoplan Injected Subcutaneously Either by a Prefilled Syringe or an Auto-injector in Healthy Adult Participants Status: COMPLETED · Updated 2026-01-06 |
WEEKLY
Register Watch, weekly
New trials, approvals and enforcement actions. One email a week.