A Study to Evaluate the Safety and Efficacy of Crizanlizumab in Sickle Cell Disease Related Priapism

A Prospective Phase II, Open-Label, Single-arm, Multicenter, Study to Assess Efficacy and Safety of SEG101 (Crizanlizumab), in Sickle Cell Disease Patients With Priapism (SPARTAN)

The goal of the study was to evaluate the efficacy and safety of crizanlizumab in sickle cell disease (SCD) patients with priapism.

Before participating in this study, information to determine key eligibility criteria was collected as a part of a 14-week Pre-Screening period. The study included a 12-week Screening period and a 52-week (1 year) Treatment period. Eligible participants received crizanlizumab 5 mg/kg by intravenous infusion (IV). Study treatment was received at clinic visits on Week 1 Day 1, Week 3 Day 1, and then on Day 1 of every 4-week cycle. Efficacy assessments included evaluation of priapic and vaso-occlusive (VOC) events. Safety assessments included laboratory tests, electrocardiograms (ECGs), vital signs and physical examinations. Participants had a safety follow-up for up to 15 weeks after the last dose.

Inclusion criteria

• Male patients aged 12 years and above
• Confirmed diagnosis of SCD by hemoglobin electrophoresis or high-performance liquid chromatography. All SCD genotypes were eligible (HbSS, HbSβ0, HbSC, HbSβ+, and others)
• Experienced 4 or more priapic events (unwanted erection lasting at least 60 minutes) over the 14 weeks preceding study participation
• Experienced at least 3 priapic events (unwanted erection lasting at least 60 minutes) during the 12-week Screening period with at least 1 event occurring within 4 weeks prior to the first treatment
• If receiving hydroxyurea/hydroxycarbamide or L-glutamine or erythropoietin stimulating agent or voxelotor, must have been receiving the drug for at least 14 weeks prior to screening and planned to continue taking the drug at the same dose and schedule during the trial
• If receiving prophylactic treatment for priapism, must have been receiving the drug for at least 14 weeks prior to screening and planned to continue taking the drug at the same dose and schedule during the trial
• Written informed consent (or assent/parental consent for minor participants) prior to any screening procedures

Exclusion criteria:

• Had penile prosthetic implants or shunts or any other surgical procedure on the penis performed within 12 months prior to consenting was not allowed
• Took drugs/medications that may induce priapism over the 14 weeks preceding study entry
• Received leuprolide acetate (Lupron) or any other gonadotropin releasing hormone receptor agonist agent within 3 months before pre-screening
• Had an erection lasting more than 12 hours over the 14 weeks preceding study entry
• Had an erection lasting more than 12 hours during the 12 weeks of the Screening period