The B5201003 OLE study was terminated based on the failure of the 'parent" B5201002 study to meet its efficacy endpoints. Termination was not due to safety.

This is an open label extension study in subjects with Sickle Cell Disease (SCD) who have completed the double blind Phase 3 study (B5201002).

This is an open label extension study in subjects who are 6 years of age or older with Sickle Cell Disease (SCD) who have completed the double blind Phase 3 study (B5201002). This study is designed to evaluate the safety and describe the efficacy of rivipansel as treatment for one or more vaso-occlusive crisis (VOC) events in hospitalized subjects with SCD.

Inclusion Criteria:

• Completion of Study B5201002.
• Documented diagnosis of SCD.
• At least 6 years of age.
• Male and female subjects of childbearing potential and at risk for pregnancy must agree to use a highly effective method of contraception throughout the study.
• Diagnosis of VOC necessitating IV opioids and admission to the hospital.
• Able to receive the first dose of rivipansel within 24 hours from administration of the first dose of IV opioids for this hospitalization.

Exclusion Criteria:

• Non-compliance with study procedures in the double blind study (B5201002).
• Occurrence of any severe and/or generalized cutaneous manifestation or any other adverse event during participation in Study B5201002 that was related to study drug and which would therefore make it inappropriate for the subject to receive rivipansel in the current study.
• Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or study drug administration or may interfere with the interpretation of study results.
• Clinically significant deterioration in renal function in Study B5201002.
• Pregnant female subjects, breastfeeding female subjects and male and female subjects of childbearing potential who are unwilling or unable to use a highly effective method of contraception.
• Active use of illicit drugs and/or alcohol dependence.