What the label lists and what reports show
Antihemophilic factor and fc-vwf-xten fusion protein-ehtl side effects
Antihemophilic factor and fc-vwf-xten fusion protein-ehtl's FDA label: “Most common adverse reactions (incidence >10%) are headache and arthralgia.” FAERS holds 1,318 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 haemorrhage (531 reports).
- No generic listed
Check it at the source: the antihemophilic factor and fc-vwf-xten fusion protein-ehtl FDA label on DailyMed (effective February 23, 2026); 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 ALTUVIIIO?You can have an allergic reaction to ALTUVIIIO. Call your healthcare provider or emergency department right away if you have any of the following symptoms: difficulty breathing, chest tightness, swelling of the face, rash or hives. Your body can also make antibodies called "inhibitors" against ALTUVIIIO. This can stop ALTUVIIIO from working properly. Your healthcare provider may give you blood tests to check for inhibitors. The common side effects of ALTUVIIIO are headache and joint pain. These are not the only possible side effects of ALTUVIIIO. Tell your healthcare provider about any side effect that bothers you or does not go away.
Source: FDA drug label, Bioverativ Therapeutics Inc., effective February 23, 2026 (SPL set 01411972-df40-4ccf-88f0-d3220e5abda9), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence >10%) are headache and arthralgia.
Table 3: Adverse Reactions with Frequency of ≥3% Reported in ALTUVIIIO Studies Pooled data from Study 1 and Study 2 including 233 patients across the adult and adolescent and pediatric studies.
| Adverse Drug Reactions | Number of Patients n (%) (N = 233) |
|---|---|
| Headache | 35 (15) |
| Arthralgia | 31 (13) |
| Pyrexia | 10 (4) |
| Vomiting | 7 (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, continuedMost common adverse reactions (incidence >10%) are headache and arthralgia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Bioverativ Therapeutics Inc. (A SANOFI COMPANY) at 1-800-633-1610 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. The safety data described in this section reflects exposure to ALTUVIIIO in two clinical studies, Study 1 and Study 2 and are pooled for analysis. In Study 1, a total of 159 previously treated patients (PTPs) (134 adults and 25 adolescents) with severe Hemophilia A) received at least one dose of ALTUVIIIO for either routine prophylaxis, on-demand treatment of bleeding episodes or perioperative management. A total of 152 (96%) patients achieved at least 25 exposure days and 115 (72%) patients achieved at least 50 exposure days with a median of 53.0 (range 2–63) for both exposure days and injections per patient. Overall exposure was monitored for a total of 151.5 patient-years [see Clinical Studies (14) ]. …
Source: FDA drug label, Bioverativ Therapeutics Inc., effective February 23, 2026 (SPL set 01411972-df40-4ccf-88f0-d3220e5abda9), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,318 reports list antihemophilic factor and fc-vwf-xten fusion protein-ehtl among the medicines taken, each a report of something that happened, not proof the medicine caused it; 3 are coded as a death and 144 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 23 reactions below, 3 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?
- Antihemophilic factor and fc-vwf-xten fusion protein-ehtl: 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