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

A Phase 1, First-in-Human, Open-Label, Dose Escalation Study of Duvortuxizumab, A Humanized CD19 x CD3 Dual-Affinity Re-Targeting (DART®) Protein in Subjects With Relapsed or Refractory B-cell Malignancies

The purpose of this study is to evaluate the safety, tolerability, dose-limiting toxicities (any harmful effect of a drug) (DLT), maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D) and preliminary clinical activity of duvortuxizumab when administered intravenously to participants with relapsed or refractory B-cell malignancies [diffuse-large B cell lymphoma (DLBCL), follicular lymphoma (FL), mantle-cell lymphoma (MCL), chronic lymphocytic leukemia (CLL), and acute lymphoblastic leukemia (ALL)].

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.

Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2
• Participants must meet protocol specified hematology and chemistry lab parameters criteria
• Histological confirmation of disease with documented disease relapse after the last therapy requiring treatment per the treating physician. Participants with lymphoma must have at least 1 measurable site of disease (Part 2 only). In addition, B-cell malignancy disease-specific criteria specified in the protocol must also be met
• A woman of childbearing potential must have a negative highly sensitive serum [beta-human chorionic gonadotropin (β-hCG)] or urine pregnancy test at (minimum sensitivity 25 International units (IU)/ liter (L) or equivalent units of HCG) within 7 days prior to the first dose of study drug
• A woman must agree to use an effective method of birth control and agree not to donate eggs (ova, oocytes) for the purposes of assisted reproduction during the study and for 3 months after receiving the last dose of study drug
• A man who is sexually active with a woman of childbearing potential must agree to use a barrier method of contraception (eg, condom with spermicidal foam/gel/film/cream/suppository), man who is sexually active with a woman who is pregnant must use a condom and men must agree not to donate sperm for 90 days after the last dose of study drug
• Each participant (or their legally acceptable representative) must sign an informed consent form (ICF) indicating that he or she understands the purpose of and procedures required for the study and are willing to participate in the study. Consent is to be obtained prior to the initiation of any study related tests or procedures that are not part of standard of care for the participant's disease

Exclusion Criteria:

• History of, or known central nervous system (CNS) involvement caused by the underlying B-cell malignancy or prior history of National Cancer Institute common terminology criteria for adverse events (NCI CTCAE) Grade greater than or equal to >= 3 drug-related CNS toxicity. Participants with signs or symptoms of CNS involvement should have a computed tomography (CT) or magnetic resonance imaging (MRI)
• History of or known or suspected autoimmune disease (exception: vitiligo, resolved childhood atopic dermatitis, and history of Grave's disease that is euthyroid clinically and by laboratory testing at Screening)
• Prior allogeneic hematopoietic stem-cell transplant for participants with DLBCL, FL, MCL, and CLL only. Prior allogenic hematopoietic stem-cell transplant is permitted for participants with ALL
• Prior solid organ transplantation
• Prior treatment with a therapeutic agent targeting CD19 and/or CD3