Study to Assess Safety and Impact of SelG1 With or Without Hydroxyurea Therapy in Sickle Cell Disease Patients With Pain Crises (SUSTAIN)

An SCPC is defined as an acute episode of pain with no other medically determined cause than a vasoocclusive event that requires a medical facility visit and treatment with oral or parenteral narcotics, or parenteral non-steroidal anti-inflammatory drugs. The annual rate of SCPC is defined as the total number of pain crises for a patient occurring from the date of randomization to the end date multiplied by 365 divided by the number of days during that same time period. End date is defined as the last dose date plus 14 days. For participants never dosed, the end date was the end of study date. This calculation accounts for early dropouts or lost to follow-up by extrapolating the SCPC rate of every participant to one year.

An SCPC is defined as an acute episode of pain with no other medically determined cause than a vasoocclusive event that requires a medical facility visit and treatment with oral or parenteral narcotics, or parenteral non-steroidal anti-inflammatory drugs. The annual rate of SCPC is defined as the total number of pain crises for a patient occurring from the date of randomization to the end date multiplied by 365 divided by the number of days during that same time period. End date is defined as the last dose date plus 14 days. For participants never dosed, the end date was the end of study date. This calculation accounts for early dropouts or lost to follow-up by extrapolating the SCPC rate of every participant to one year.

The annual rate of days hospitalized was calculated as the number of days hospitalized multiplied by 365 divided by the end date minus the date of randomization plus one where the end date is defined as the last dose date plus 14 days (for subjects never dosed, the end date equaled the end of study date, which was the last site contact for these patients).

Time to first SCPC is defined as months from randomization to first SCPC. A participant without SCPC before withdrawal or completion of the study is considered censored at the time of the end date. End date is defined as the last dose plus 14 days. For participants never dosed, the end date is the end of study date.

Time to second SCPC is defined as months from randomization to second SCPC. A patient with less than two SCPC before withdrawal or completion of the study is considered censored at the time of the end date. End date is defined as the last dose plus 14 days. For patients never dosed, the end date is the end of study date.

Uncomplicated SCPC is defined as an acute episode of pain with no known cause for pain other than a vasoocclusive event; requiring a visit to a medical facility; and requiring treatment with a parenteral or oral narcotic (including opiates), or parenteral NSAIDs; but is NOT classified as an acute chest syndrome, hepatic sequestration, splenic sequestration or priapism.

Acute Chest Syndrome (ACS) is defined on the basis of the finding of a new pulmonary infiltrate involving at least one complete lung segment that was consistent with alveolar consolidation, but excluding atelectasis (as indicated by chest X-ray). At least one of the following additional signs or symptoms needs to be present as well: a participant had to have reported chest pain, a temperature of more than 38.5oC, tachypnea, wheezing or cough.

The BPI instrument was completed by the patients at pre-specified study visits prior to & during the Treatment & Follow-Up Evaluation Phases. Patients completed the brief pain inventory long-form, 1-week recall at the indicated pre-specified study visits. The BPI is a standardized self-reported questionnaire developed to provide information on the intensity of pain (the sensory dimension) as well as the degree to which pain interferes with function (the reactive dimension). The BPI also asks questions about pain relief, pain quality, & the patient's perception of the cause of pain. Since pain can be quite variable over a day, the BPI asks patients to rate their pain at the time of responding to the questionnaire (pain now), & also at its worst, least, & average over the previous week. The scorings for pain & interference have a range from 0 (no pain/no interference) to 10 (worst pain/complete interference). The BPI scoring manual was used to calculate scores for each domain.