A Study of Marstacimab to Compare Prefilled Pen (PFP) Device to Prefilled Syringe (PFS) Device

Inclusion Criteria: * Male participants who are overtly healthy as determined by medical evaluation * Participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. * BMI of 17.5 to 30.5 kg/m2; and a total body weight ≥ 50 kg (110 lb). * Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the ICD and in this protocol. Exclusion Criteria: * Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, dermatological, or allergic disease * Any condition possibly affecting drug absorption (eg, conditions affecting SC administration) * Previous or current treatment for and/or history of coronary artery diseases, venous or arterial thrombosis, or ischemic disease. * History of HIV infection, hepatitis B, or hepatitis C; positive testing for HIV, HBsAg, HBcAb or HCVAb * Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior, laboratory abnormality or COVID-19 related condition that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study * Use of prescription or nonprescription drugs and dietary and herbal supplements within 7 days or 5 half-lives (whichever is longer) prior to the first dose of study intervention * Previous administration with an investigational drug within 30 days (or as determined by the local requirement) or 5 half-lives preceding the first dose of study intervention used in this study (whichever is longer). * A positive urine drug test at screening and/or admission * Screening supine BP ≥140 mm Hg (systolic) or ≥90 mm Hg (diastolic) * Baseline 12 lead ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results * Participants with ANY of the following abnormalities in clinical laboratory tests at screening: * AST or ALT level ≥1.5 × ULN; * Total bilirubin level ≥1.5 × ULN. * An estimated glomerular filtration rate (eGFR) of \<60 mL/min/1.73m2 based on the CKD-EPI equation. * Resistance to activated protein C (or Factor V Leiden mutation), prothrombin 20210 mutation, antithrombin III deficiency, protein C deficiency, or protein S deficiency. * Presence of Lupus anticoagulant anti-cardiolipin antibodies (IgG, IgM or IgA) * High sensitivity C-reactive protein (hsCRP) above the upper limits of normal * Abnormal hematology values as defined by the following laboratory tests at Screening and/or admission: * Platelet count \<100,000/uL * Hemoglobin level \<10 g/dL * A positive COVID-19 test. * History of alcohol abuse or binge drinking and/or any other illicit drug use or dependence within 6 months of Screening * Use of tobacco/nicotine containing products in excess of the equivalent of 5 cigarettes/day * Blood donation (excluding plasma donations) of approximately 1 pint (500 mL) or more within 60 days prior to dosing. * Unwilling or unable to comply with the criteria in the Lifestyle Considerations section of the protocol * 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