Open-Label Extension Study of Marstacimab in Hemophilia Participants With or Without Inhibitors

Inclusion Criteria: * All participants will have a minimum body weight as defined by parent studies * Participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, and other study procedures. * Participants have successfully completed participation in parent studies, defined as did not require "Early Termination" Exclusion Criteria: * Previous or current treatment for or history of coronary artery disease, venous or arterial thrombosis (CTCAE Grade \>3), or ischemic disease (except catheter-associated thrombosis) * Abnormal renal function as defined by eGFR \<30 mL.min/1.73 m(2) * Known planned surgical procedure during the planned study period * Unstable hepatic function as determined by the Investigator clinical assessment and review of the participant's most recent laboratory results, which would make the participant inappropriate for the study * For participants known to be HIV+, worsening disease status as determined by the Investigator clinical assessment and review of participant's most recent laboratory results, to include recent locally available CD4 count (if available), which would make the participant inappropriate for the study * Regular, concomitant therapy with immunomodulatory drugs (eg, IVIG, and routine systemic corticosteroids, rituximab) * Ongoing or planned use of immune tolerance induction or prophylaxis with FVIII or FIX replacement during the study * Participation in other study involving investigational drug(s) or investigational vaccine(s) within 30 days or 5 half-lives prior to or during study participation, with the exception of participation in parent studies * Investigator site staff or Pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the Investigator, and their respective family members