A Dose Escalation Study of Duvortuxizumab in Participants With Relapsed or Refractory B-cell Malignancies

This first in human study consists of 2 parts: a) The dose escalation part and b) The dose expansion part. This is an openlabel (all participants know the identity of the intervention), multicenter (more than one study site) study to evaluate the safety, establish a recommended Phase 2 dose (RP2D), and to determine the preliminary efficacy of duvortuxizumab in participants with relapsed or refractory B cell malignancies. The dose escalation part of the trial (Part 1) will be comprised of 3 different patient groups based on disease indication: Group 1 (DLBCL, FL, MCL); Group 2 (CLL); Group 3 (ALL). The duvortuxizumab dosing will be done on biweekly and weekly basis. Duvortuxizumab weekly escalating dosing will be investigated. Dose escalation will begin with Group 1 and will initially follow an accelerated dose titration design, followed by a traditional 3+3 design. At each dose escalation level the treatment of the second participant should be initiated after at least 72 hours of observation after the start of the first duvortuxizumab dose of the first participant. Dose escalation in Groups 2 and 3 will follow a 3+3 design and will begin after the initial dose level in Group 1 is deemed safe. Participants \[Group 1 (DLBCL, FL, MCL), Group 2 (CLL) Group 3 (ALL)\] are enrolled into cohorts of increasing dose levels of duvortuxizumab administered in 28 day treatment cycles. Up to 3 RP2Ds may be determined in Part 1 (one RP2D for Group 1, one RP2D for Group 2, and one RP2D for Group 3). In the cohort expansion part of the trial (Part 2), participants with relapsed or refractory B cell malignancies (DLBCL, FL, MCL, CLL and ALL) will be enrolled according to tumor type in up to 5 cohorts and receive duvortuxizumab at the RP2D determined in Part 1 for their disease type. The study consists of 3 periods: Screening period (up to 28 days prior to the first dose of study drug); Treatment period \[first dose of study drug until the End of Treatment Visit (within 30 days after the last dose)\]; and follow up period \[End of Treatment Visit and continue until death, lost to follow up, consent withdrawal, or study end (as determined by the sponsor), whichever occurs first\]. Number of participants who achieve an overall response in each Dose Expansion cohort will be evaluated primarily. Participants' safety will be monitored throughout the study.