Pharmacokinetics and Pharmacodynamics Study of SEG101 (Crizanlizumab) in Sickle Cell Disease (SCD) Patients With Vaso- Occlusive Crisis (VOC)

The purpose of the CSEG101A2202 study was to characterize the Pharmacokinetic (PK) and Pharmacodynamic (PD) of SEG101/crizanlizumab and to evaluate the safety and efficacy of SEG101/crizanlizumab in sickle cell disease (SCD) patients.

Study CSEG101A2202 was designed as a Phase II, multicenter, open-label study. The first 45 patients (to identify 27 evaluable patients) were enrolled to the treatment group crizanlizumab 5.0 mg/kg to complete full Pharmacokinetic/Pharmacodynamic (PK/PD) sampling at week 1 and week 15. In all patients, trough PK/PD samples were collected prior to each dose. In addition, throughout the study (and when possible), all patients had blood drawn for serum to assess PK and PD drawn at times of onset and resolution of each VOC event, fever, or infection. Once the up to 45 patients were enrolled, 12 additional patients were enrolled to the exploratory treatment group and began at 7.5 mg/kg of crizanlizumab.

The study was initiated on 19-Dec-2017. This study provides five years follow up data that fully characterizes the safety, tolerability and treatment effect of the 5.0 mg/kg and 7.5 mg/kg doses of crizanlizumab along with the initially planned PK and PD data.

At the time of study closure, crizanlizumab 5.0 mg/kg was an FDA approved treatment in the United States (US) for patients with sickle-cell disease. Therefore, the patients treated with crizanlizumab 5.0 mg/kg dose were encouraged to transition to commercial supply of crizanlizumab. The patients treated with the not currently approved dose of crizanlizumab 7.5 mg/kg were allowed to join a multi-center, multi-national, rollover clinical trial (Study SEG101A2401B), for continued access to treatment with crizanlizumab.

Eligibility Criteria:
Inclusion Criteria:

* Male and non-pregnant female patients 16-70 years of age (inclusive)
* Confirmed diagnosis of sickle cell disease by hemoglobin electrophoresis or high-performance liquid chromatography (HPLC) \[performed locally\]. All sickle cell disease genotypes are eligible.
* Experienced at least 1 VOC within the preceding 12 months prior to Screening, as determined by medical history.
* If receiving HU/HC or erythropoietin stimulating agent, must have been receiving the drug for at least 6 months prior to Screening
* Hemoglobin ≥4.0 g/dL. Absolute neutrophil count ≥1.0 x 109/L and platelet count ≥75 x 109/L
* Adequate renal and hepatic function as defined:
* GFR ≥45 mL/min/1.73 m2 calculated by CKD-EPI
* ALT ≤3 x ULN
* Direct (conjugated) bilirubin ≤2 x ULN
* ECOG performance status ≤2
* Written informed consent (or assent/ parental consent for minor subjects) prior to any screening procedures

Exclusion Criteria:

* History of stem cell transplant.
* Acute VOC ending 7 days prior to first dosing
* Ongoing hospitalization prior to Screening
* Received blood products within 30 days to first dosing
* Participating in a chronic transfusion program (pre-planned series of transfusions for prophylactic purposes)
* History of severe hypersensitivity reactions to other monoclonal antibodies
* Received a monoclonal antibody or immunoglobulin -based agent within 1 year of Screening, or has documented immunogenicity to a prior biologic.
* Received active treatment on another investigational trial within 30 days (or 5 half-lives of that agent, whichever is greater) prior to Screening
* Significant active infection or immune deficiency (including chronic use of immunosuppressive drugs)
* Resting QTcF ≥470 msec at pretreatment (baseline) or other cardiac or cardiac repolarization abnormality