This phase II trial studies how well flotetuzumab works in treating patients with CD123 positive blood cancer that has come back or does not respond to treatment. Immunotherapy with monoclonal antibodies, such as flotetuzumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread.
PRIMARY OBJECTIVES: I. Evaluate the anti-tumor activity of flotetuzumab in CD123-positive advanced acute lymphoblastic leukemia (ALL) (Cohort A) and other hematological malignancies (Cohort B), as assessed by complete remission (complete remission \[CR\]/complete remission with incomplete count recovery \[CRi\]/complete remission with partial hematological recovery \[CRh\]) rate. SECONDARY OBJECTIVES: I. Evaluate toxicity profile of flotetuzumab. II. Evaluate remission duration among responders. III. Estimate 1-year overall survival. IV. Evaluate minimal residual disease (MRD) status in responders in the ALL cohort. V. Evaluate the percentage of patients who receive subsequent allogeneic transplantation. EXPLORATORY OBJECTIVES: I. Examine immune profile pre- and post-treatment with flotetuzumab. II. Assess the association between CD123 expression and tumor response. III. Assess the association between alterations in tumor genetic or microenvironment with response. IV. Assess cytokine levels during therapy. OUTLINE: Patients receive flotetuzumab intravenously (IV) continuously for 28 days. Patients who achieve partial response or stable disease or any clinical benefit (partial remission \[PR\], stable disease \[SD\]) that did not meet CR, CRi, CRh or morphologic leukemia free state (MLFS) criteria receive a second 28-day continuous flotetuzumab IV infusion. Patients who achieve CR/CRi/CRh/MLFS after course 1 or course 2 receive flotetuzumab IV at a 4 days on-3 days off schedule. Treatment repeats every 28 days for up to 6 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days and then up to 1 year.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Given IV
Best response of complete remission (complete remission [CR], complete remission with incomplete count recovery [CRi], complete remission with partial hematological recovery [CRh])
Rates and 95% Clopper Pearson binomial confidence interval (CI) will be calculated for complete remission/response rate (confirmed CR/CRi/CRh).
Time frame: Within the first 4 courses (112 days)
Incidence of adverse events
Will be assessed by National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0. Observed toxicities will be summarized in terms of type (organ affected or laboratory determination), severity, attribution, time of onset, duration, probable association with the study treatment and reversibility or outcome.
Time frame: Up to 1 year
Minimal residual disease (MRD) as assessed by multi-color flow cytometry
Time frame: Up to 1 year
Duration of remission
Time frame: Up to 1 year
Number who bridge to allogeneic hematopoietic cell transplantation
Some of the patients treated on this trial will go on to receive a hematopoietic stem cell transplant. The electronic data capture system will capture those who go on (bridge) to receive a transplant (yes, no). Total number will be based on those patients coded as 'yes'.
Time frame: Up to 1 year
Percent who bridge to allogeneic hematopoietic cell transplantation
Some of the patients treated on this trial will go on to receive a hematopoietic stem cell transplant. The electronic data capture system will capture those who go on (bridge) to receive a transplant (yes, no). Total number will be based on those patients coded as 'yes'. Percent who bridge will be calculated as follows: number of patients who bridge to transplant divided by total number of patients treated on this trial.
Time frame: Up to 1 year
Overall survival
Will be estimated using the product-limit method of Kaplan and Meier.
Time frame: Up to 1 year
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