Study of Emicizumab Prophylaxis in Participants With Hemophilia A and Inhibitors Undergoing Minor Surgical Procedures

Inclusion Criteria:

- Age ≥ 2 years

- Ability to comply with the study protocol, in the investigator's judgment

- Diagnosis of hemophilia A and current or history of high-titer inhibitor (Bethesda
titer ≥ 5 Bethesda units)

- Plan to receive at least 4 loading doses of emicizumab and been adherent to emicizumab
prophylaxis by the time of surgery

- Undergoing minor surgery within 60 days of study enrollment. Other minor surgical
procedures could be included upon consultation and approval of Medical Monitor, but
examples include central venous catheter insertion/removal/replacement, simple dental
extractions, colonoscopy, cystoscopy, or endoscopy with biopsy, excisional skin biopsy

- Must plan to continue emicizumab prophylaxis for at least 1 month after surgery

- For women of childbearing potential: agreement to remain abstinent (refrain from
heterosexual intercourse) or use contraceptive methods that result in a failure rate
of <1% per year during the study period

Exclusion Criteria:

- Diagnosis of a bleeding disorder other than hemophilia A

- Participants who have been tolerized to Factor VIII products

- Treatment with bypassing agents within 24 hours prior to surgical procedure

- Undergoing a major surgical procedure

- Previous (in the past 12 months) or current treatment for thromboembolic disease (with
the exception of previous catheter-associated thrombosis for which anti-thrombotic
treatment is not currently ongoing) or current signs of thromboembolic disease

- Other conditions (e.g., certain autoimmune diseases, including but not limited to
diseases such as systemic lupus erythematosus, inflammatory bowel disease, and
antiphospholipid syndrome) that may increase the risk of bleeding or thrombosis

- Participants who are at high risk for thrombotic microangiopathy (TMA), e.g., have a
previous medical or family history of TMA, in the investigator's judgment

- Would refuse treatment with blood or blood products, if necessary.

- Any serious medical condition or abnormality in clinical laboratory tests that, in the
investigator's judgment, precludes the participant's safe participation in and
completion of the study

- Pregnant or lactating, or intending to become pregnant during the study

- Women of childbearing potential must have a negative serum pregnancy test result
within 7 days before Study Day 1

- Treatment with any of the following: An investigational drug to treat or reduce the
risk of hemophilic bleeds within 5 half-lives of last drug administration before Study
Day 1; A non-hemophilia-related investigational drug within the last 30 days or 5
half-lives before Study Day 1 (whichever is longer); An investigational drug
concurrently

- History of clinically significant hypersensitivity associated with monoclonal antibody
therapies or components of the emicizumab injection

- Known human immunodeficiency virus (HIV) infection with CD4 count < 200
cells/microlitre within 24 weeks prior to screening