Trial Outcomes & Findings for An Open-label, Nonrandomized Study to Evaluate the Safety and Immunogenicity of Raxibacumab With Reinjection (NCT NCT02016963)

Participants who had received raxibacumab \>= 4 months in another HGS study (study # HGS1021-C1064) prior to this study were eligible for enrollment in this study.

An Open-label, Nonrandomized Study to Evaluate the Safety and Immunogenicity of Raxibacumab With Reinjection

Number of participants who developed an positive anti-raxibacumab antibody response during the study were assessed.The antibody response to raxibacumab was assessed using a screening assay (i.e. by electrochemiluminescence counts). Positive samples would be further tested in an inhibition of binding assay to confirm the specificity of binding.

An AE is defined as any untoward medical occurrence in a participant or clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. This includes worsening (eg, increase in frequency or severity) of pre-existing conditions. A serious adverse event (SAE) is defined as any untoward medical occurrence that, at any dose, results in death, is life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, or is a congenital anomaly/birth defect. Medical or scientific judgment should be exercised in deciding whether reporting is appropriate in other situations. Refer to the General Adverse AE/SAE module for a complete list of AEs and SAEs.

Clinical hematological parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable.

The number of participants with at least a 2-grade worsening from Baseline in hematological toxicities is presented. Clinical hematological parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable. Baseline is defined as the value of the variable measured at Day 0 prior to dosing.

Liver function parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable.

The number of participants with at least a 2-grade worsening from Baseline in liver toxicities is presented. Liver function parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable. Baseline is defined as the value of the variable measured at Day 0 prior to dosing.

Electrolyte function parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable.

The number of participants with at least a 2-grade worsening from Baseline in electrolyte toxicities is presented. Electrolyte function parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0.Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable. Baseline is defined as the value of the variable measured at Day 0 prior to dosing.

Other chemistry parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable.

The number of participants with at least a 2-grade worsening from Baseline in other chemistry toxicities is presented. Other clinical chemistry parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable.Baseline is defined as the value of the variable measured at Day 0 prior to dosing.

Urinaysis parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable.

Urinalysis parameters were assessed using the modified Division of Microbiology and Infectious Diseases (DMID) toxicity tables, version 2.0. Grade 1 (Mild): Transient or mild discomfort (\< 48 hours); no medical intervention or therapy required. Grade 2 (Moderate): Mild to moderate limitation in activity, some assistance may be needed; no or minimal medical intervention or therapy required. Grade 3 (Severe): Marked limitation in activity, some assistance usually required; medical intervention or therapy required, hospitalizations possible. Grade 4 (Life-threatening): Extreme limitation in activity, significant assistance required; significant medical intervention or therapy required, hospitalization or hospice care probable.Baseline is defined as the value of the variable measured at Day 0 prior to dosing.

Blood was collected from each participant at the selected times: pre-dose (Day 0), 0.00347 hours (Day 0), 0.3333 hours (Day 0), Day 1, Day 3, Day 7, Day 14, Day 21, Day 28, Day 42, and Day 56 post-dose. Serum specimens were analyzed for raxibacumab using a validated electrochemiluminescense-based assay. The individual serum raxibacumab concentration data were summarized by nominal collection time and treatment group using descriptive statistics