Pfizer has decided to cancel study C4181006 due to strategic considerations. This decision is not due to any specific reasons or requests from any regulatory authorities. No participants have been enrolled in this study.

The purpose of this study is to evaluate the pharmacokinetic (PK), safety, tolerability and immunogenicity of a single subcutaneous (SC) dose of the lyophilized formulation of recifercept in healthy Chinese participants.

Inclusion Criteria:

• Chinese male and female participants of nonchildbearing potential must be 21 to 55 years of age, inclusive at the time of signing the ICD.
• Chinese male and female 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.
• Participants must be of Chinese ethnicity (individuals currently residing in mainland China who were born in China and have both parents of Chinese descent).
• Body mass index (BMI) of 19.0 to 27.5 kg/m2; and a total body weight >50 kg and ≤ 120 kg.
• 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, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing).

• Any condition possibly affecting drug absorption (eg, skin inflammation at infusion site, acne, rash, scarring, tattoos, erythema, sunburn, deep tanning, etc).

• History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C; positive testing for HIV, hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCVAb), or serological reaction of syphilis. Prior hepatitis B vaccination is allowed.

• Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality 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 dose of study intervention.

• Previous administration with an investigational drug/medical device within 30 days (or as determined by the local requirement) or 5 half lives preceding the dose of study intervention used in this study (whichever is longer).

• A positive urine drug test.

• Screening supine blood pressure (BP) ≥140 mm Hg (systolic) or ≥90 mm Hg (diastolic), following at least 5 minutes of supine rest. Pulse rate > 100 beats/minute. Oral temperature (or ear temperature) > 37.5 ℃.

• Baseline 12 lead ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results (eg, baseline corrected QT (QTc) interval >450 msec, complete LBBB, signs of an acute or indeterminate age myocardial infarction, ST T interval changes suggestive of myocardial ischemia, second or third degree AV block, or serious bradyarrhythmias or tachyarrhythmias).

• Participants with ANY of the following abnormalities in clinical laboratory tests at Screening, as assessed by the study specific laboratory and confirmed by a single repeat test, if deemed necessary:

  • aspartate aminotransferase (AST) or aspartate aminotransferase (ALT) level ≥ 1.5 × upper limit of normal (ULN);
  • Total bilirubin level ≥1.5 × ULN; participants with a history of Gilbert's syndrome may have direct bilirubin measured and would be eligible for this study provided the direct bilirubin level is≤ ULN.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.