Study of SANGUINATE™ In the Treatment of Sickle Cell Disease Patients With Vaso-Occlusive Crisis

Patients who are experiencing a vaso-occlusive crisis will report to the clinic for treatment
and screening into the SGSC-005 study. Patients who meet all inclusion/exclusion criteria
will be randomized to receive either SANGUINATE 320 mg/kg or placebo (saline) over a 2 hour
infusion period. Assessments of vital signs, ECGs, safety labs, adverse events as well as
patient and physician questionnaires will be completed up to 6 hours after the start of the
infusion. Patients will then be assessed for discharge either to home or admitted to the
hospital for further treatment depending on their disease severity. Follow-up phone calls
will be completed 24 hours and 7 days after initiation of treatment . A follow-up visit will
be completed in the clinic at 72 hours after initiation of treatment.

Inclusion Criteria:

1. Age ≥ 18 years,

2. Sickle Cell Disease (all genotypes),

3. Diagnosis of a severe vaso-occlusive crisis (VOC), based on the clinical judgement of
the Investigator,

4. Participant needs to be admitted to the ambulatory site for treatment of VOC requiring
IV pain medication,

5. Able to provide written consent,

6. Able to receive IV infusion of study drug.

Exclusion Criteria:

1. In the judgment of the Investigator, the participant is not a good candidate for the
study,

2. An acute severe complication of SCD beyond VOC,

3. Pregnant or actively trying to become pregnant, or breastfeeding,

4. Participant had > 6 urgent visits for SCD complications in the prior 3 months,

5. Fewer than 30 days since any prior treatment with IV pain medication for VOC,

6. Onset of current acute painful crisis > 3 days prior to dosing,

7. Evidence of moderate to severe renal insufficiency (CrCl < 50 mL/min) or chronic
kidney disease, or of moderate to severe hepatic disease (LFTs > 2 x ULN) based on
past medical history,

8. Concurrent or prior treatment within 90 days with an investigational medication,

9. Abnormal ECG due to cardiac ischemia and/or atrial fibrillation of acute onset, in the
opinion of the Investigator.