A Phase 3 interventional study of IgPro20 in Secondary Immune Deficiency, sponsored by CSL Behring. Recruiting at 60 sites in 11 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-21.
Sponsored by CSL Behring · Phase 3, Interventional, and Treatment
This is a prospective, multicenter, open-label, single-arm study to assess the efficacy, safety, and pharmacokinetics (PK) of IgPro20 in adults with hematologic malignancies treated with B-cell targeting Chimeric antigen receptor T-cell (CAR T-cell) and T-cell redirecting therapies (such as T-cell engager bispecific antibody [TCE BsAb] therapy). The primary objective is to demonstrate that true annualized rate of serious bacterial infection (SBIs) is less than (\<) 1.0.
This study includes two cohorts:
Participants treated with Chimeric antigen receptor T-cell (CAR T-cell) therapy or TCE BsAb and are:
Documented partial or complete response to CAR T-cell or TCE BsAb therapy based on applicable response criteria at the time of Screening:
If participant has ongoing IgRT (intravenous immunoglobulin [IVIG] or subcutaneous immunoglobulin [SCIG]) for SID during Screening, then any IgG level at Screening is acceptable for enrollment. Participants with IgG less than (\<) 500 milligrams per deciliter (mg/dL) are assigned to the Loading Cohort, participants with IgG ≥ 500 mg/dL are assigned to the Maintenance-only Cohort.
If participant does not have ongoing IgRT (IVIG for > 8 weeks or SCIG for > 2 weeks) for SID during Screening and are not expected to receive IgRT during Screening, then IgG \< 500 mg/dL is required for enrollment (participant is assigned to the Loading Cohort)
Exclusion Criteria:
In the loading cohort, participants will receive a loading dose of IgPro20 subcutaneously (SC) once daily for five consecutive days during the first week (Initial Treatment Period), followed by SC infusion weekly dosing for a total treatment duration of 52 weeks. In the maintenance-only cohort, participants will receive weekly doses of IgPro20 SC infusion for a total treatment duration of 52 weeks.
Biological: IgPro20
IgPro20 infusion administered SC.
Also known as: Immune Globulin Subcutaneous (Human) 20% Liquid
Number of Serious Bacterial Infections (SBIs) per Participant
The SBIs includes: bacteremia / sepsis, bacterial meningitis, osteomyelitis / septic arthritis, bacterial pneumonia, and visceral abscess.
Time frame: Up to Month 12
Number of Infections per Participant
Time frame: Up to Month 12
Number of Common Terminology Criteria for Adverse Events (CTCAE) >= Grade 3 Infections per Participant
As per CTCAE, Grade 3 is defined as Severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self care activities of daily living (self-care activities of daily living refer to bathing, dressing and undressing, feeding self, using the toilet, taking medications, and not bedridden). Grade 4: Life-threatening consequences; urgent intervention indicated and Grade 5: Death related to adverse event. Infections of CTCAE Grade 3 or worse will be reported.
Time frame: Up to Month 12
Number of Days Hospitalized due to Infections
Time frame: Up to Month 12
Number of Days With Anti-infectives Use
Time frame: Up to Month 12
Number of Infection-related Deaths and Complications
Time frame: Up to Month 12
Number of Infection-related Requirement for Intravenous (IV) Therapy
Time frame: Up to Month 12
Number of Infection-related Requirement for Hospitalization per Participant
Time frame: Up to Month 12
Number of Participants with Treatment-emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs), Infusion Site Reaction and Other Local Reactions
In this study, thromboembolic events are treated as AESIs. The following 3 narrow standardized Medical Dictionary for Regulatory Activities (MedDRA) queries are used for TEE evaluation: * Embolic and thrombotic events, arterial * Embolic and thrombotic events, venous * Embolic and thrombotic events, vessel type unspecified, and mixed arterial and venous.
Time frame: Up to Month 12
Trough Concentrations of Serum IgG
Time frame: Up to Week 56
Area Under the Serum Concentration Time Curve (AUC) for IgG From Timepoint Zero to tau (AUC[0-t])
Time frame: Before IgPro20 dosing at Week 52 and up to Week 54 (after the last dose of IgPro20)
Maximal Serum Concentration (Cmax) of IgG
Time frame: Before IgPro20 dosing at Week 52 and up to Week 54 (after the last dose of IgPro20)
Time to Maximal Serum Concentration (Tmax) of IgG
Time frame: Before IgPro20 dosing at Week 52 and up to Week 54 (after the last dose of IgPro20)
Plan to share: Yes — CSL will consider on a case-by-case basis requests to share Individual Patient Data (IPD) with external bona-fide, qualified scientific and medical researchers. For information on the process and requirements for submitting a voluntary data sharing request for IPD, please contact CSL at clinicaltrials@cslbehring.com.
Supporting information: Study protocol, Sap
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