This was a multicenter, Phase 1, standard 3+3 dose-escalation study to evaluate the safety and anti-neoplastic activity of moxetumomab pasudotox in relapsed or refractory participants with chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL) or Small Lymphocytic Lymphoma (SLL).
This was a multicenter, Phase 1, standard 3+3 dose-escalation study to evaluate the safety and anti-neoplastic activity of CAT-8015 in relapsed or refractory participants with CLL, PLL, or SLL. Participants in the initial dose cohort were to receive CAT-8015 at a dose of 5 microgram per kilogram (mcg/kg) CAT-8015, increasing to 10 mcg/kg in the second dose cohort, and then increasing by 10 mcg/kg increments in subsequent cohorts (that is, to doses of 20, 30, 40, 50, 60 mcg/kg, etc) until a maximum tolerated dose (MTD) was identified. Following identification of the MTD, the MTD cohort was to be expanded to 16 participants.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
11
Participants received a single intravenous infusion of 5 mcg/kg moxetumomab pasudotox (CAT-8015) on Days 1, 3, and 5 of every 28-day cycle and continued cycles of therapy until progressive disease (PD) or until otherwise they become ineligible.
Participants received a single intravenous infusion of 10 mcg/kg moxetumomab pasudotox (CAT-8015) on Days 1, 3, and 5 of every 28-day cycle and continued cycles of therapy until progressive disease (PD) or until otherwise they become ineligible.
Participants received a single intravenous infusion of 20 mcg/kg moxetumomab pasudotox (CAT-8015) on Days 1, 3, and 5 of every 28-day cycle and continued cycles of therapy until progressive disease (PD) or until otherwise they become ineligible.
Research Site
Indianapolis, Indiana, United States
Research Site
Bethesda, Maryland, United States
Research Site
Lodz, Poland
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious Adverse Events (TESAEs)
An adverse event (AE) events present at baseline that worsened in intensity after administration of investigational product or events absent at baseline that emerged after administration of study drug, for the period extending to 30 days after the last dose of study drug. A serious adverse event (SAE) is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening situation (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect in the offspring of a participant who received moxetumomab pasudotox. Treatment-emergent were events between administration of investigational product and Day 28 that were absent before treatment or that worsened relative to pretreatment state.
Time frame: From start of study drug administration until 30 days after the last dose of study drug
Number of Participants With Vital Signs Abnormalities Recorded as Treatment-Emergent Adverse Events (TEAEs)
The vital sign abnormalities which require an action or intervention by the investigator, or a finding judged by the investigator were reported as an adverse event. TEAEs were events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug, for the period extending to 30 days after the last dose of study drug.
Time frame: From start of study drug administration until 30 days after the last dose of study drug
Number of Participants With Clinically Relevant Electrocardiogram (ECG) Abnormalities Recorded as Adverse Events (AEs)
AEs observed in participants with clinically significant ECG abnormalities were assessed.
Time frame: From start of study drug administration until 30 days after the last dose of study drug
Number of Participants With Clinically Significant Laboratory Abnormalities Recorded as Treatment-Emergent Adverse Events (TEAEs)
An abnormal laboratory finding which required an action or intervention by the investigator, or a finding judged by the investigator to represent a change beyond the range of normal physiologic fluctuation were reported as an adverse event. Treatment-emergent were events between first dose of study drug and 30 days after the last dose that were absent before treatment or that worsened relative to pretreatment state. Number of participants with grade 3 or higher treatment-emergent adverse events for laboratory abnormalities were reported as clinically relevant laboratory changes.
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Time frame: From start of study drug administration until 30 days after the last dose of study drug
Number of Participants With Objective Response Rate (ORR): Complete Response (CR) or Partial Response (PR)
Objective response rate defined as the proportion of participants with confirmed complete response (CR) or confirmed partial response (PR) according to Response Evaluation Criteria.
Time frame: Up to 2 years of post-treatment follow-up
Best Overall Objective Tumor Response
Antitumor activity was assessed by best overall objective tumor response.
Time frame: Up to 2 years of post-treatment follow-up
Time to Reach Maximum Observed Plasma Concentration (Tmax) of Moxetumomab Pasudotox
The Tmax is the time to reach maximum observed plasma concentration of Moxetumomab Pasudotox.
Time frame: Predose, 0.25 (During Infusion), 0.5 (End of Infusion), 1, 1.5, 2, 4, 8 and 12 hours postdose on Day 1 and 5; Predose and End of Infusion on Day 3
Maximum Observed Serum Concentration (Cmax) for Moxetumomab Pasudotox
The Cmax is the maximum observed plasma concentration of Moxetumomab Pasudotox.
Time frame: Predose, 0.25 (During Infusion), 0.5 (End of Infusion), 1, 1.5, 2, 4, 8 and 12 hours postdose on Day 1 and 5; Predose and End of Infusion on Day 3
Number of Participants With Positive Neutralizing Antibodies
Participants tested for immunogenicity to moxetumomab pasudotox prior to enrollment, before each cycle and at end of study. The neutralization assay measures the capacity of participant's plasma (antibodies) to inhibit the binding of moxetumomab pasudotox to its target, cluster of differentiation 22 (CD22), coated onto enzyme linked immunosorbent assay (ELISA) plates. It was used as a direct surrogate for biological activity based on the mechanism of action of this drug. Significant level of neutralizing antibody activity defined as the capacity of test plasma to inhibit greater than (\>)50 percentage (%) of the binding of CAT-8015 to CD22 using an ELISA-based method.
Time frame: Up to end of treatment (4-6 weeks after the last dose)
Percentage Change From Baseline in Cluster of Differentiation 22 (CD22) Expression
Participants demonstrated CD22 expression on malignant cells at Screening and CD22 is a regulatory molecule that prevents the over activation of the immune system and the development of autoimmune diseases.
Time frame: End of treatment (4-6 weeks after the last dose)