What the label lists and what reports show
Pegcetacoplan side effects
Pegcetacoplan's FDA label: “The most common adverse reactions in patients with PNH (incidence ≥10%) were injection site reactions, infections, diarrhea, abdominal pain, respiratory tract infection, pain in extremity, hypokalemia, fatigue, viral infection, cough, arthralgia, dizziness …” FAERS holds 1,779 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fatigue (159 reports).
- No generic listed
- Boxed warning
Check it at the source: the pegcetacoplan FDA label on DailyMed (effective August 21, 2026, Apellis Pharmaceuticals, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of EMPAVELI?EMPAVELI can cause serious side effects including: See " What is the most important information I should know about EMPAVELI? " Allergic reactions. Allergic reactions can happen during your EMPAVELI infusion and can be life-threatening. […]
Source: FDA drug label, Apellis Pharmaceuticals, Inc., effective August 21, 2026 (SPL set c23d89e9-b00b-4520-e053-2995a90a95af), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions in patients with PNH (incidence ≥10%) were injection site reactions, infections, diarrhea, abdominal pain, respiratory tract infection, pain in extremity, hypokalemia, fatigue, viral infection, cough, arthralgia, dizziness, headache, and rash.
Table 2: Adverse Reactions Reported in ≥5% of Patients Treated with EMPAVELI in Study APL2-302
| Adverse Reaction | EMPAVELI (N=41) n (%) | Eculizumab (N=39) n (%) |
|---|---|---|
| Injection-site reaction Grouped terms Term includes injection-site erythema,… | 16 (39) | 2 (5) |
| Fatigue | 5 (12) | 9 (23) |
| Chest pain | 3 (7) | 1 (3) |
| Infections | 12 (29) | 10 (26) |
| Respiratory tract infection | 6 (15) | 5 (13) |
| Viral Infection | 5 (12) | 3 (8) |
| Diarrhea | 9 (22) | 1 (3) |
| Abdominal pain | 8 (20) | 4 (10) |
| Back pain | 3 (7) | 4 (10) |
| Headache | 3 (7) | 9 (23) |
| Systemic hypertension | 3 (7) | 1 (3) |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Serious Infections Caused by Encapsulated Bacteria [see Warnings and Precautions (5.1) ] Infusion-Related Reactions [see Warnings and Precautions (5.3) ] The most common adverse reactions in patients with PNH (incidence ≥10%) were injection site reactions, infections, diarrhea, abdominal pain, respiratory tract infection, pain in extremity, hypokalemia, fatigue, viral infection, cough, arthralgia, dizziness, headache, and rash. ( 6.1 ) The most common adverse reactions in patients with C3G or primary IC-MPGN (incidence ≥10%) were infusion site reactions, pyrexia, nasopharyngitis, influenza, cough, and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Apellis Pharmaceuticals, Inc. at 1-833-866-3346 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. …
Source: FDA drug label, Apellis Pharmaceuticals, Inc., effective August 21, 2026 (SPL set c23d89e9-b00b-4520-e053-2995a90a95af), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,779 reports list pegcetacoplan among the medicines taken, each a report of something that happened, not proof the medicine caused it; 103 are coded as a death and 324 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 20 reactions below, 6 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Pegcetacoplan: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions