RecruitingPhase 1

A Study of CBX-250 in Participants With Relapsed or Refractory Myeloid Leukemias

United States72 participantsStarted 2025-07-16

Plain-language summary

Study CBX-250-001 is a Phase 1, open-label, dose-escalation study of CBX-250 in participants with relapsed/refractory AML, HR-MDS, CMML, and CML. Participants aged ≥ 12 years are planned to be enrolled. CBX-250 will initially be investigated on a fixed step-up dosing schedule. CBX-250 will be administered subcutaneously in 28-day cycles, with the first study drug dose administered on Cycle 1, Day 1. Cycle 1 will consist of a priming phase over 7 days, and a target phase over 28 days. Participants will continue CBX-250 until progressive disease (PD) or unacceptable toxicity. All subsequent treatment cycles will be 28 days.

Who can participate

Age range12 Years

SexALL

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

✓. Dose Escalation: Male or female participants aged ≥18 years.
✓. Backfill Cohorts: Male or female participants aged ≥12 years for whom no curative treatment options, including transplantation, are available.
✓. Participants with histological confirmation of advanced hematologic malignancy including:
✓. R/R AML, as defined by standardized criteria (e.g., European LeukemiaNet criteria \[Dohner 2022\]; after standard of care therapy. Participants with persistent leukemia after initial therapy or with recurrence of leukemia at any time after achieving a response during or after the course of treatment (including HSCT) are eligible.
✓. R/R HR-MDS or very high risk MDS as per the Revised International Prognostic Scoring System (IPSS-R; Greenberg 2012) or Molecular International Prognostic Scoring System (IPPS-M, Bernard 2022) who are resistant or refractory to 4-6 cycles of hypomethylating agents (HMA; decitabine or azacitidine).
✓. R/R CMML who are resistant or refractory to 4-6 cycles of hypomethylating agents (HMA; decitabine or azacitidine).
✓. White blood cells must be below 25,000/µL at time of enrollment. Participants may receive cytoreduction prior to enrollment.
✓. Historical documented evidence of HLA-A\*02:01 allele positivity.

What they're measuring

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

Trial details

NCT IDNCT06994676

SponsorCrossbow Therapeutics, Inc.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2027-01

Contact for this trial

Rachel Ghiraldi

857-301-6432 rachel.ghiraldi@crossbowtx.com

View on ClinicalTrials.gov More High-risk Myelodysplastic Syndrome trials

Plain-language summary

Who can participate

Age range12 Years

SexALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

✓. Dose Escalation: Male or female participants aged ≥18 years.
✓. Backfill Cohorts: Male or female participants aged ≥12 years for whom no curative treatment options, including transplantation, are available.
✓. Participants with histological confirmation of advanced hematologic malignancy including:
✓. R/R AML, as defined by standardized criteria (e.g., European LeukemiaNet criteria \[Dohner 2022\]; after standard of care therapy. Participants with persistent leukemia after initial therapy or with recurrence of leukemia at any time after achieving a response during or after the course of treatment (including HSCT) are eligible.
✓. R/R HR-MDS or very high risk MDS as per the Revised International Prognostic Scoring System (IPSS-R; Greenberg 2012) or Molecular International Prognostic Scoring System (IPPS-M, Bernard 2022) who are resistant or refractory to 4-6 cycles of hypomethylating agents (HMA; decitabine or azacitidine).
✓. R/R CMML who are resistant or refractory to 4-6 cycles of hypomethylating agents (HMA; decitabine or azacitidine).
✓. White blood cells must be below 25,000/µL at time of enrollment. Participants may receive cytoreduction prior to enrollment.
✓. Historical documented evidence of HLA-A\*02:01 allele positivity.

What they're measuring

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

To determine the safety, tolerability, RP2D, or MTD if different, and dosing regimen of CBX-250.

Timeframe: Until the end of study (approximately 24 months)

A Study of CBX-250 in Participants With Relapsed or Refractory Myeloid Leukemias

Plain-language summary

Who can participate

Inclusion criteria

What they're measuring

Trial details

Contact for this trial

A Study of CBX-250 in Participants With Relapsed or Refractory Myeloid Leukemias

Plain-language summary

Who can participate

Inclusion criteria

What they're measuring

Trial details

Contact for this trial

Exclusion criteria