This is a 2 part study designed to provide an initial assessment on the safety, tolerability, and PK of rivipansel, following single ascending (Part 1) and multiple ascending dosing (Part 2) given subcutaneously with rHuPH20, in healthy subjects. Part 1 of the study will be conducted using a cross-over design while Part 2 of the study will be conducted using a parallel design.

Inclusion Criteria:

• Healthy male and/or female subjects of non-childbearing potential between the ages of 18 and 55 years, inclusive.
• Body Mass Index 17.5 - 30.5 kg/m2 and body weight >50 kg at Screening.
• Normal skin without potentially obscuring features in the area intended for infusion.
• Subjects willing to defer receiving prophylactic immunizations (eg, influenza or pneumococcal vaccines) during the study.
• Evidence of a personally signed and dated informed consent document indicating that the subject or a legally acceptable representative has been informed of all pertinent aspects of the study

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at time of dosing).
• History of a recent major surgery (within 3 months of screening).
• Serious infection within 1 month of screening.
• Subjects with chronic skin condition that may interfere in the assessment of emergent safety data.
• A positive urine drug screen.
• Known sensitivity to hyaluronidases.
• History of hepatitis or positive testing for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb) or hepatitis C antibodies (HCV).
• Unwilling or unable to comply with the Lifestyle Guidelines described in this protocol.
• Subjects who are investigational site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the Investigator, or subjects who are Pfizer employees directly involved in the conduct of the study.