Trial Outcomes & Findings for Post-transplant Flotetuzumab for AML (NCT NCT05506956)

NCT ID: NCT05506956

Last Updated: 2025-09-12

Results Overview

Number of participants with dose-limiting toxicities (DLTs) at specified dose levels to determine MTD

• Recruitment status: COMPLETED
• Study phase: PHASE1
• Target enrollment: 3 participants
• Primary outcome timeframe: 6 months
• Results posted on: 2025-09-12

Participant Flow

All participants receive dose level 1 (DL1): Flotetuzumab: 500 ng/kg/day. No participants received DL-1: Flotetuzumab: 300 ng/kg/day during the study.

Participant milestones

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day All participants will receive one cycle (28 days) of flotetuzumab. After one cycle, all participants will undergo a bone marrow biopsy to assess response and based on the response, may receive additional cycles up to a total cycle of six cycles. Flotetuzumab: Patients enrolled on dose level 1 (DL1) will receive flotetuzumab by continuous infusion using multi-step lead-in dosing, and then 500 ng/kg/day on days 7-28. After one cycle, all patients will undergo a bone marrow biopsy to assess response including assessment of minimal residual disease (MRD). Patients who fail to achieve a CR, CRi, CRh (complete remission with partial hematologic recovery), or MLFS may continue with subsequent induction cycles as a continuous infusion up to a total of five cycles. If there is evidence of response (CR, CRi, CRh, or MLFS) and the toxicities of treatment are acceptable, patients will be eligible for two consolidation cycles. Additional bone marrow biopsies for response assessment will be performed after the second cycle. If there is a need to de-escalate dosing based on toxicity, then patients will be enrolled on DL-1 using multi-step lead-in dosing, and then 300 ng/kg/day on days 5-28 of the first cycle and days 1-28 of subsequent cycles.
Overall Study STARTED	3
Overall Study COMPLETED	1
Overall Study NOT COMPLETED	2

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Post-transplant Flotetuzumab for AML

Baseline characteristics by cohort

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants All participants will receive one cycle (28 days) of flotetuzumab. After one cycle, all participants will undergo a bone marrow biopsy to assess response and based on the response, may receive additional cycles up to a total cycle of six cycles. Flotetuzumab: Patients enrolled on dose level 1 (DL1) will receive flotetuzumab by continuous infusion using multi-step lead-in dosing, and then 500 ng/kg/day on days 7-28. After one cycle, all patients will undergo a bone marrow biopsy to assess response including assessment of minimal residual disease (MRD). Patients who fail to achieve a CR, CRi, CRh (complete remission with partial hematologic recovery), or MLFS may continue with subsequent induction cycles as a continuous infusion up to a total of five cycles. If there is evidence of response (CR, CRi, CRh, or MLFS) and the toxicities of treatment are acceptable, patients will be eligible for two consolidation cycles. Additional bone marrow biopsies for response assessment will be performed after the second cycle. If there is a need to de-escalate dosing based on toxicity, then patients will be enrolled on DL-1 using multi-step lead-in dosing, and then 300 ng/kg/day on days 5-28 of the first cycle and days 1-28 of subsequent cycles.
Age, Categorical <=18 years	0 Participants n=93 Participants
Age, Categorical Between 18 and 65 years	1 Participants n=93 Participants
Age, Categorical >=65 years	2 Participants n=93 Participants
Age, Continuous	69 years n=93 Participants
Sex: Female, Male Female	0 Participants n=93 Participants
Sex: Female, Male Male	3 Participants n=93 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=93 Participants
Race (NIH/OMB) Asian	1 Participants n=93 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=93 Participants
Race (NIH/OMB) Black or African American	0 Participants n=93 Participants
Race (NIH/OMB) White	2 Participants n=93 Participants
Race (NIH/OMB) More than one race	0 Participants n=93 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants
Region of Enrollment United States	3 Participants n=93 Participants

PRIMARY outcome

Timeframe: 6 months

Number of participants with dose-limiting toxicities (DLTs) at specified dose levels to determine MTD

Outcome measures

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants Multi-step lead-in dosing on days 1-7 followed by 500 ng/kg/day on days 7-28
Number of Participants With Dose-limiting Toxicities to Determine Maximum Tolerated Dose (MTD) of Flotetuzumab in Patients With Relapsed/Refractory AML Following alloHSCT	1 Participants

SECONDARY outcome

Timeframe: 6 months

Number of participants with complete response (CR) following alloHSCT.

Outcome measures

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants Multi-step lead-in dosing on days 1-7 followed by 500 ng/kg/day on days 7-28
Complete Response to Flotetuzumab in Patients With Relapsed AML Following Allogeneic Hematopoietic Stem Cell Transplant (alloHSCT)	0 Participants

SECONDARY outcome

Timeframe: 6 months

Number of participants with complete response with incomplete count recovery (CRi) following allogeneic hematopoietic stem cell transplant (alloHSCT).

Outcome measures

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants Multi-step lead-in dosing on days 1-7 followed by 500 ng/kg/day on days 7-28
Complete Response With Incomplete Count Recovery to Flotetuzumab in Patients With Relapsed AML Following alloHSCT	0 Participants

SECONDARY outcome

Timeframe: 6 months

Number of participants with partial response (PR) following allogeneic hematopoietic stem cell transplant (alloHSCT).

Outcome measures

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants Multi-step lead-in dosing on days 1-7 followed by 500 ng/kg/day on days 7-28
Partial Response to Flotetuzumab in Patients With Relapsed AML Following alloHSCT	0 Participants

SECONDARY outcome

Timeframe: 6 months

Number of safety events defined as CTCAE grade III-IV acute GVHD.

Outcome measures

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants Multi-step lead-in dosing on days 1-7 followed by 500 ng/kg/day on days 7-28
Acute Graft-versus-host Disease (GVHD) Incidence	0 events

SECONDARY outcome

Timeframe: 6 months

Number of events of chronic GVHD requiring systemic immune suppression

Outcome measures

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants Multi-step lead-in dosing on days 1-7 followed by 500 ng/kg/day on days 7-28
Chronic GVHD Incidence	0 events

SECONDARY outcome

Timeframe: through study completion, an average of 1 year 8 months

Number of participant deaths without recurrent or progressive disease after allo-HSCT.

Outcome measures

Measure	Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 Participants Multi-step lead-in dosing on days 1-7 followed by 500 ng/kg/day on days 7-28
Non-relapse Mortality	0 Participants

Adverse Events

Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day

Serious events: 2 serious events

Other events: 3 other events

Deaths: 3 deaths

Serious adverse events

Measure

Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 participants at risk All participants will receive one cycle (28 days) of flotetuzumab. After one cycle, all participants will undergo a bone marrow biopsy to assess response and based on the response, may receive additional cycles up to a total cycle of six cycles. Flotetuzumab: Patients enrolled on dose level 1 (DL1) will receive flotetuzumab by continuous infusion using multi-step lead-in dosing, and then 500 ng/kg/day on days 7-28. After one cycle, all patients will undergo a bone marrow biopsy to assess response including assessment of minimal residual disease (MRD). Patients who fail to achieve a CR, CRi, CRh (complete remission with partial hematologic recovery), or MLFS may continue with subsequent induction cycles as a continuous infusion up to a total of five cycles. If there is evidence of response (CR, CRi, CRh, or MLFS) and the toxicities of treatment are acceptable, patients will be eligible for two consolidation cycles. Additional bone marrow biopsies for response assessment will be performed after the second cycle. If there is a need to de-escalate dosing based on toxicity, then patients will be enrolled on DL-1 using multi-step lead-in dosing, and then 300 ng/kg/day on days 5-28 of the first cycle and days 1-28 of subsequent cycles.

Blood and lymphatic system disorders Cytokine Release Syndrome

66.7% 2/3 • From enrollment through study completion, approximately 1 year 8 months

Other adverse events

Measure

Dose Level 1 (DL1): Flotetuzumab: 500 ng/kg/Day n=3 participants at risk All participants will receive one cycle (28 days) of flotetuzumab. After one cycle, all participants will undergo a bone marrow biopsy to assess response and based on the response, may receive additional cycles up to a total cycle of six cycles. Flotetuzumab: Patients enrolled on dose level 1 (DL1) will receive flotetuzumab by continuous infusion using multi-step lead-in dosing, and then 500 ng/kg/day on days 7-28. After one cycle, all patients will undergo a bone marrow biopsy to assess response including assessment of minimal residual disease (MRD). Patients who fail to achieve a CR, CRi, CRh (complete remission with partial hematologic recovery), or MLFS may continue with subsequent induction cycles as a continuous infusion up to a total of five cycles. If there is evidence of response (CR, CRi, CRh, or MLFS) and the toxicities of treatment are acceptable, patients will be eligible for two consolidation cycles. Additional bone marrow biopsies for response assessment will be performed after the second cycle. If there is a need to de-escalate dosing based on toxicity, then patients will be enrolled on DL-1 using multi-step lead-in dosing, and then 300 ng/kg/day on days 5-28 of the first cycle and days 1-28 of subsequent cycles.

Immune system disorders Fever

100.0% 3/3 • Number of events 3 • From enrollment through study completion, approximately 1 year 8 months

Additional Information

Kristen Murray, Program Manager

Johns Hopkins University

Phone: 410-614-6707

Email: kmeckel2@jhmi.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place