What the label lists and what reports show
Caplacizumab side effects
Caplacizumab's FDA label: “In adults, the most common adverse reactions (incidence >15%) are epistaxis, headache, and gingival bleeding.” FAERS holds 1,709 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 adamts13 activity decreased (156 reports).
- No generic listed
Check it at the source: the caplacizumab FDA label on DailyMed (effective April 24, 2026); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsIn adults, the most common adverse reactions (incidence >15%) are epistaxis, headache, and gingival bleeding.
Table 1: Adverse Reactions in ≥2% of Patients Treated with CABLIVI and More Frequent than Placebo During the Blinded Periods of aTTP Studies (HERCULES and TITAN)
| Adverse Reaction by Body System | CABLIVI (N=106) n (%) | Placebo (N=110) n (%) |
|---|---|---|
| Gingival bleeding | 17 (16) | 3 (3) |
| Rectal hemorrhage | 4 (4) | 0 (0) |
| Abdominal wall hematoma | 3 (3) | 1 (1) |
| Fatigue | 16 (15) | 10 (9) |
| Pyrexia | 14 (13) | 12 (11) |
| Injection site hemorrhage | 6 (6) | 1 (1) |
| Catheter site hemorrhage | 6 (6) | 5 (5) |
| Injection site pruritus | 3 (3) | 0 (0) |
| Back pain | 7 (7) | 4 (4) |
| Myalgia | 6 (6) | 2 (2) |
| Headache | 22 (21) | 15 (14) |
| Paresthesia | 13 (12) | 11 (10) |
| Urinary tract infection | 6 (6) | 4 (4) |
| Hematuria | 4 (4) | 3 (3) |
| Vaginal hemorrhage | 5 (5) | 2 (2) |
| Menorrhagia | 4 (4) | 1 (1) |
| Epistaxis | 31 (29) | 6 (6) |
| Dyspnea | 10 (9) | 5 (5) |
| Urticaria | 15 (14) | 7 (6) |
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 also discussed in other sections of the labeling: Hemorrhage [see Warnings and Precautions (5.1) ] In adults, the most common adverse reactions (incidence >15%) are epistaxis, headache, and gingival bleeding. In pediatric patients, the most frequently reported adverse reactions are epistaxis and tachycardia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ablynx US at 1-800-745-4447 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. TITAN and HERCULES The safety of CABLIVI was evaluated in two placebo-controlled clinical studies (HERCULES, in which 71 patients received CABLIVI; and TITAN, in which 35 patients received CABLIVI). The data described below and in the Warnings and Precautions reflect exposure to CABLIVI during the blinded periods of both studies, which include 106 patients with aTTP who received at least one dose, age 18 to 79 years, of whom 69% were female and 73% were White. The median treatment duration with CABLIVI was 35 days (range 1–77 days). …
Source: FDA drug label, Genzyme Corporation, effective April 24, 2026 (SPL set 2348f06e-8004-4040-832e-e9e86a39f905), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,709 reports list caplacizumab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 105 are coded as a death and 347 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, 9 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?
- Caplacizumab: 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