A Trial to Learn How Well REGN9933 Works for Preventing Blood Clots After Knee Replacement Surgery in Adult Participants

Key Inclusion Criteria:

1. Undergoing elective unilateral TKA

2. Has a body weight ≤130 kg at screening visit

3. Is judged by the investigator to be in good health based on medical history,physical examination, vital sign measurements, and Electrocardiograms (ECG)performed at screening and/or prior to administration of initial dose of study drug

4. Is in good health based on laboratory safety testing obtained during the screeningperiod as described in the protocol

Key Exclusion Criteria:

1. History of bleeding in the past 6 months requiring hospitalization or transfusion;history of intracranial or intraocular bleeding, excessive operative orpost-operative bleeding, and traumatic spinal or epidural anesthesia; history ofbleeding diathesis.

2. History of thromboembolic disease or thrombophilia

3. History of major surgery, including brain, spinal, or ocular, within approximatelythe past 6 months.

4. History of major trauma within approximately the past 6 months.

5. Hospitalized (>24 hours) for any reason within 30 days of the screening visit

6. Using the Modification of Diet in Renal Disease equation, has an estimatedglomerular filtration rate as described in the protocol

Note: Other protocol-defined Inclusion/ Exclusion Criteria apply