Inclusion Criteria:  Participant must be male and 18 to <75 years of age with a minimum body weight of 30 kg at screening. Participants with a diagnosis of severe hemophilia A or B (FVIII or FIX activity <1%, respectively)  Participants without inhibitor must also meet the following criteria:  No detectable or documented history of inhibitors Participants with on-demand treatment regimen with ≥6 acute bleeding episodes (spontaneous or traumatic) that required coagulation factor infusion during the 4 months period prior to enrollment and willing to continue to receive on demand treatment during the study.  Participants with Inhibitor must also meet the following criteria:  Documentation of current high titer inhibitor (≥5 BU/mL) or current low titer inhibitor (<5 BU/mL) refractory to FVIII or FIX replacement and with FVIII or FIX recovery <60% of expected within previous 4 months prior to screening. Participants with on-demand treatment regimen with ≥6 bleeding episodes (spontaneous and/or traumatic) necessitating treatment with bypass factor for at least 4 months prior to screening and willing to continue to receive on-demand treatment during the study.  Exclusion Criteria:  Previous or current treatment for and/or history of coronary artery diseases, venous or arterial thrombosis or ischemic disease Known planned surgical procedure during the planned study period. Known hemostatic defect other than hemophilia A or B. Abnormal renal or hepatic function Current unstable liver or biliary disease Abnormal hematologic parameters Abnormal coagulation activity Other acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator. Corrected QT interval (QTc) >450 msec for male participants or QTc >480 msec in participants with bundle branch block. Individuals with hypersensitivity or an allergic reaction to hamster protein or other components of the study intervention. A positive urine drug screen Current routine prophylaxis with bypassing agent or non coagulation factor-replacement therapy (eg, emicizumab) Regular, concomitant therapy with immunomodulatory drugs Ongoing or planned use of immune tolerance induction or prophylaxis with FVIII or FIX replacement during the study. Participation in other studies involving investigational drug(s) within 30 days (or as determined by local requirements) or 5 half-lives prior to study entry and/or during study participation. CD4 cell count ≤200/uL if human immunodeficiency virus (HIV)-positive Baseline ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results. Investigator site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, or participants who are Pfizer employees, including their family members, directly involved in the conduct of the study