Clinical Study With Blinatumomab in Pediatric and Adolescent Patients With Relapsed/Refractory B-precursor Acute Lymphoblastic Leukemia
|Study Design:||Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||A Single-Arm Multicenter Phase II Study Preceded by Dose Evaluation to Investigate the Efficacy, Safety, and Tolerability of the BiTE® Antibody Blinatumomab (MT103) in Pediatric and Adolescent Patients With Relapsed/Refractory B-Precursor Acute Lymphoblastic Leukemia (ALL)|
- Phase I: Number of Participants With Dose-limiting Toxicities (DLTs) [ Time Frame: Cycle 1, 28 days ]
The maximum tolerated dose (MTD) was defined as one or fewer out of 6 participants experiencing a dose limiting toxicity (DLT) or the maximum administered dose (MAD).
A dose limiting toxicity is any Grade ≥ 3 adverse event related to study drug, Grade 3 fatigue, headache, insomnia, fever, hypotension or infection were not considered dose limiting toxicities. Laboratory parameters of Grade ≥ 3 but not considered as clinically relevant and/or responding to routine medical management, thrombocytopenia, leukopenia (including neutropenia and lymphopenia), and anemia were not considered dose limiting toxicities.
- Percentage of Participants With Complete Remission in the First Two Cycles [ Time Frame: Cycles 1 and 2 (12 weeks) ]
Hematological assessments were performed from bone marrow biopsy samples. All hematological assessments of bone marrow were reviewed in a central laboratory. Complete remission (CR) was defined as
- M1 bone marrow (bone marrow blasts < 5%)
- No evidence of circulating blasts or extra-medullary disease
Complete remission includes participants with incomplete recovery of peripheral blood counts.
- Number of Participants With Adverse Events [ Time Frame: From the start of the first infusion to 30 days after the end of the last infusion in the core study or from the start of the first retreatment cycle infusion to 30 days after the end of the last retreatment cycle, median treatment duration was 28 days ]
The severity (or intensity) of adverse events (AEs) was assessed according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE), v4.03 and according to the following:
Grade 1 - Mild adverse event; Grade 2 - Moderate adverse event; Grade 3 - Severe and undesirable adverse event; Grade 4 - Life-threatening or disabling adverse event; Grade 5 - Death. The investigator used medical judgment to determine if there was a causal relationship (ie, related, unrelated) between an adverse event and blinatumomab.
- Steady State Concentration of Blinatumomab [ Time Frame: Cycles 1 and 2 during the IV infusion on day 3 (at least 48 hours after start of infusion) and days 8, 15 and 22 (steady state) and day 29 at End of Infusion (EoI) and 2, 4, and 8 hours after EoI for ages ≥ 2 years. ]
Blinatumomab serum concentrations were quantified in all patients during the first 2 treatment cycles in the phase 1 part of the study only. Blinatumomab concentrations were quantified using a validated bioassay, the lower limit of quantification was 50 pg/mL. Steady state serum concentration (Css) was presumed on day 1, approximately 5 half-lives after the start of the IV infusion.
The steady state serum concentration reported is the mean of the observed concentrations collected after during cycles 1 and 2.
- Time to Hematological Relapse (Duration of Response) [ Time Frame: Up to the data cut-off date of 12 January 2015; median observation time was 23.5 months for phase 1 and 11.5 months for phase 2. ]
Time to hematological relapse was measured only for participants in remission and was measured from the time the participant first achieved remission until first documented relapse or death due to disease progression. Participants without a documented relapse (hematological or extramedullary) and who did not die were censored at the time of their last bone marrow assessment or their last survival follow-up visit confirming remission. Participants who died without having reported hematological relapse or without showing any clinical sign of disease progression were censored on their date of death.
Hematological relapse is defined as the proportion of blasts in bone marrow > 25% following documented remission, or extramedullary relapse.
Time to hematological relapse was analyzed by Kaplan-Meier methods and the median observation time was calculated by the reverse Kaplan Meier method.
- Overall Survival [ Time Frame: Up to the data cut-off date of 12 January 2015; median observation time was 23.5 months for phase 1 and 11.6 months for phase 2. ]
Overall survival (OS) was measured for all participants from the first treatment of blinatumomab until death due to any cause or the date of the last follow-up. Participants who did not die were censored on the last documented visit date or the date of the last contact when the patient was last known to have been alive. For patients who withdrew their informed consent only information until the date of withdrawal was analyzed.
Overall survival was estimated using Kaplan-Meier methods. The median follow-up time with respect to overall survival was calculated by the reverse Kaplan-Meier method.
- Relapse-free Survival [ Time Frame: Up to the data cut-off date of 12 January 2015; median observation time was 23.5 months for phase 1 and 11.5 months for phase 2. ]
Relapse-free survival (RFS) was assessed for participants who achieved a complete remission during the core study and was measured from the time the participant first achieved remission until first documented relapse or death due to any cause. Participants without a documented relapse (hematological or extramedullary) or who did not die were censored at the time of their last bone marrow assessment or their last survival follow-up visit confirming remission.
Relapse free survival was estimated using Kaplan-Meier methods and the median observation time was calculated by the reverse Kaplan-Meier method.
- Percentage of Participants Who Received an Allogeneic Hematopoietic Stem Cell Transplant During Blinatumomab Induced Remission [ Time Frame: Up to the data cut-off date of 12 January 2015; Maximum duration on study was 24 months in phase 1 and 15 months for phase 2. ]The percentage of participants who received allogeneic hematopoietic stem cell transplantation (HSCT) while in remission due to treatment with blinatumomab during the first two cycles, and received no further anti-leukemic medication before HSCT.
- Number of Participants Who Developed Anti-blinatumomab Antibodies [ Time Frame: Predose up until 30 days after last dose of study medication; median treatment duration was 28 days. ]Antibodies to blinatumomab were detected using an electrochemiluminescence (ECL)-based assay.
- Serum Cytokine Peak Levels [ Time Frame: Cycle 1 and 2 day 1 (prior to infusion, 2 and 6 hours after infusion start), day 2 and day 3. ]The activation of immune effector cells was monitored by the measurement of peripheral blood cytokine levels including interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor-alpha (TNF-α) and interferon gamma (IFN-ɣ) using cytometric bead assays. The limit of detection of the assay (LOD) was 20 pg/mL and the lower limit of quantification (LLOQ) was 125 pg/mL. Data below LOD were set to 10 pg/mL while data < LOQ and > LOD were reported as measured.
|Study Start Date:||January 2012|
|Study Completion Date:||May 2016|
|Primary Completion Date:||August 2014 (Final data collection date for primary outcome measure)|
Blinatumomab was administered as a continuous intravenous (cIV) infusion at a constant daily flow rate over 4 weeks followed by a treatment-free interval of 2 weeks. Doses ranged between 5 and 30 µg/m²/day. Each participant received up to five cycles of treatment.
Administered by continuous intravenous infusion
Childhood acute lymphoblastic leukemia (ALL) is a type of cancer of the blood and bone marrow in which the bone marrow makes too many abnormal immature lymphocytes.
Blinatumomab is a bispecific single-chain antibody construct designed to link B cells and T cells resulting in T cell activation and a cytotoxic T cell response against cluster of differentiation (CD)19 expressing cells.
The purpose of this study is to investigate the pharmacokinetics (PK), pharmacodynamics (PD) and safety of escalating doses of blinatumomab in pediatric and adolescent patients with relapsed/refractory B-precursor ALL, to select a dose and to investigate the efficacy and safety of that dose of blinatumomab in the above-mentioned patient population.
The phase 1 part of the study included the evaluation of four dose levels of blinatumomab with comprehensive PK/PD assessments and was separated in 2 parts:
- Phase 1 dose evaluation/escalation part to define the recommended phase 2 dose of blinatumomab in patients aged 2 to 17 years
- Phase 1 PK expansion part in patients aged < 18 years to further assess PK/PD at the recommended phase 2 dose. In this part additional participants were enrolled to ensure that 6 patients in each of the 2 older age groups (2-6 and 7-17 years) were analyzed for PK before recruitment of infants < 2 years of age began.
In the phase 2 extension cohort (efficacy phase) of the study, eligible participants less than 18 years were enrolled according to a two-stage design and received blinatumomab at the recommended dose level (5/15 μg/m²/day).
The study consisted of a screening period, a treatment period, and an End of Core Study visit 30 days after last dose of study medication. A treatment cycle consisted of a continuous intravenous (cIV) infusion over 4 weeks followed by a treatment-free interval of 2 weeks. Participants who achieved complete remission (CR) within 2 cycles of treatment could receive up to 3 additional consolidation cycles of blinatumomab. Instead of consolidation cycles with blinatumomab, participants could be withdrawn from blinatumomab treatment to receive chemotherapy or allogeneic HSCT as early as the first cycle, at the discretion of the investigator.
After the last treatment cycle and End of Core Study visit, all participants were followed for efficacy and survival for up to 24 months after treatment start. Participants who suffered a hematological relapse of B-precursor ALL during their follow-up period (at least 3 months after completion of treatment) had the possibility for retreatment with blinatumomab.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01471782
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|Study Chair:||Arend von Stackelberg, MD||Charite University, Berlin, Germany|
|Study Chair:||Lia Gore, MD||Children's Hospital Denver, USA|