A Study of Rebecsinib for Patients With Relapsed/Refractory Secondary Acute Myeloid Leukemia or High Risk Myelofibrosis

NCT07250646 | Not Yet Recruiting Phase 1 DMC FDA Drug

• 1 other identifier: ASPE-01-01
• Study Type: interventional
• Target: 28
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to test the safest and most effective dose of a new investigational drug, rebecsinib. Participants in this study will have either Secondary Acute Myeloid Leukemia (sAML) that has either returned (relapsed) or not responded to treatment (refractory) or have higher risk Myelofibrosis (MF). Participants will receive a study drug infusion on Day 1, Day 4, Day 8 and Day 11 of each 28-day cycle for a total of 6 cycles.

Conditions

Secondary AML; Myelofibrosis

Keywords

sAML; MF

Outcome Measures

Primary Outcomes (2)

• Determine the Maximum Tolerated Dose

  Find the rate of dose limiting toxicities (DLTs) to establish the maximum tolerated dose (MTD) or biologically active dose of rebecsinib when given on days 1, 4, 8, and 11 of each 28 days cycle.

  From first dose through 28 days after initial dose for dose all finding cohorts, approximately 2 years.

• Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]

  To determine the safety and tolerability of rebecsinib by ongoing evaluation of treatment-emergent adverse events (AEs) by collecting description, timing, grade \[CTCAE v5.0\], severity, seriousness, and relatedness of all events.

  From enrollment to initiation of new therapy for each subject, approximately 4 months.

Secondary Outcomes (4)

• Assess Clinical Activity through Overall Response Rate using 2017 ELN Response Criteria

  From enrollment through disease assessment that shows progression, approximately 4 months.

• Assess Clinical Activity through Duration of Response

  From enrollment through disease assessment that shows progression, approximately 4 months

• Assess Clinical Activity through Progression Free Survival Using 2017 ELN Response Criteria

  From enrollment through disease assessment that shows progression, approximately 4 months

• Assess Clinical Activity through Overall Survival using the revised 2017 ELN response criteria for AML

  From enrollment through disease assessment that shows progression, approximately 4 months

Interventions

rebecsinib DRUG

Rebecsinib is administered by intravenous infusion on Days 1, 4, 8, and 11 of the 28 day cycle. Doses to be tested are 0.2, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, and 8.0 mg/kg based in ideal body weight (IBW).

Also known as: 17S-FD-895

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Ability to understand and the willingness to sign a written informed consent.
• Must have a refractory myeloid neoplasm (5th Edition WHO Classification of Tumors) consisting of secondary AML (sAML), which has evolved from antecedent MDS, MPN, MDS/MPN, or have higher-risk MF defined by DIPSS Plus or MIPSS70+ version 2.0, and excess bone marrow blasts (\> 5%). Patients with sAML, defined as AML with an antecedent history of MDS or MPN or WHO AML with myelodysplasia related genetic changes or WHO AML with myelodysplasia related cytogenetic abnormalities. Must be ineligible for bone marrow transplantation at the time of enrollment and have relapsed or be refractory or intolerant to available therapies, such as anthracycline chemotherapy, epigenetic modifier therapy (azacytidine or decitabine) or venetoclax including any treatment that is active in specific mutations if relevant (e.g., FLT3 inhibitors for patients with FLT3 mutations). If the patient has not received intensive induction chemotherapy in the past as a result of being unfit for chemotherapy, then the patient must have undergone at least one line of epigenetic modifier or other available therapy. If the patient has received intensive induction therapy, then the patient must have undergone at least two lines of therapy. If a patient has a FLT3 or IDH mutation, prior therapy must include a FLT3 or an IDH inhibitor. Relapse is defined as the recurrence of excess leukemic blasts in the marrow after previously achieving a complete remission, or complete remission with incomplete count recovery. Refractory refers to persistent excess leukemic blasts after two cycles of standard anthracycline containing induction, or one cycle of a high dose cytarabine containing regimen, or one cycle of a non-intensive regimen.
• Calculated Creatinine clearance (CrCl) \> 60 mL/min (based upon the Cockcroft- Gault Equation \[CrCl = (140-age) \* ideal body wt (in kg) \* (0.85 if female) / (72 \* Cr)\]. Estimate Ideal body weight in (kg) Males: IBW = 50 kg + 2.3 kg for each inch over 5 feet. Females: IBW = 45.5 kg + 2.3 kg for each inch over 5 feet.
• Has recovered from the toxic effects of prior therapy to their clinical baseline.
• Subjects must be aged 18 years or older.
• Both men and women of all races and ethnic groups are eligible for this trial.
• Women of childbearing potential (not postmenopausal for at least one year or not surgically incapable of bearing children) must agree not to become pregnant for the duration of the study. Both men and women must agree to use a barrier method of contraception for the duration of the study and until 10 weeks after the final dose of rebecsinib.
• Women of child-bearing potentialmust have a negative serum or urine pregnancy test.
• For sAML and high risk MF, at relapse must have ≥5% leukemic bone marrow blasts.
• Subjects must have an ECOG performance status of 0-2.
• Hemoglobin ≥ 8.0 g/dL. This is to alleviate immediate concomitant need for transfusion via institutional guidelines for transfusion for symptomatic anemia.
• Total bilirubin ≤ 1.5 times upper limit of normal.
• ALT and AST ≤ 1.5 times upper limit of normal
• Prothrombin time international normalized ratio (INR) ≤ 2; AND Partial thromboplastin time ≤ 1.66 times upper limit of normal.

You may not qualify if:

• Pregnant or breast feeding females are excluded.
• Previous hematopoietic cell transplant.
• Patients who are currently receiving another investigational agent are excluded.
• Patients who have had chemotherapy (e.g., HMA therapy, chemotherapy, immunotherapy) or participation in any investigational drug treatment within 2 weeks or 5-half lives, whichever is more, of initiation of rebecsinib or at any time during the study.
• Current infection requiring systemic antibiotics.
• Active infection with HIV, HBV, or HCV.
• Concurrent malignancy or prior malignancy within the previous 3 years (other than completely resected carcinoma in situ or localized non-melanoma skin cancer).
• Known central nervous system (CNS) involvement by malignancy.
• Untreated autoimmunity such as autoimmune hemolytic anemia or immune thrombocytopenia.
• Known uncompensated hypothyroidism (defined as TSH greater than 2x upper limit of normal not treated with replacement hormone).
• Insufficient recovery from surgery-related wound healing.
• Impaired cardiac function including any of the following:
• Myocardial infarction within 6 months of starting study drug;
• A past medical history of clinically significant ECG abnormalities, including QTc 470 msec or greater.
• Other clinically significant heart disease (e.g. congestive heart failure, uncontrolled hypertension, history of labile hypertension, or history of poor compliance with an antihypertensive regimen)

Sponsors & Collaborators

• Aspera Biomedicines, Inc.: lead
• Tempus AI: collaborator

Study Sites (1)

UC San Diego Moores Cancer Center

San Diego, California, 92093, United States

Location

MeSH Terms

Conditions

Primary Myelofibrosis

Condition Hierarchy (Ancestors)

Myeloproliferative Disorders; Bone Marrow Diseases; Hematologic Diseases; Hemic and Lymphatic Diseases

Study Officials

• James Mangan, MD, PhD

  UC San Diego Moores Cancer Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Curis L Scribner, MD

CONTACT

510-914-8368; cscribner@asperabio.com

Karla Mack

CONTACT

443-253-0645; kmack@asperabio.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: This study includes a Modified Fibonacci design of up to 11- dose cohorts until an MTD or biologically active dose is reached or any participant experiences a ≥Grade 2 AE. An accelerated dose escalation with 1 patient per dose will be performed at doses of 0.2, 0.4, 0.6, and 0.8 mg/kg. At a dose level of 1.0 mg/kg or at a dose where a grade 2 or greater adverse event occurs, a 3+3 design escalation will be performed with doses of 1.0, 1.5, 2.0, 3.0, 4.0, 6.0 and 8.0 mg/kg with an expansion cohort of 3 patients at the MTD, so that a total of 6 patients will be evaluable at the MTD with an extra 3 patients added if RP2D is lower than MTD.

Study Record Dates

• First Submitted: August 1, 2025
• First Posted: November 26, 2025
• Study Start: April 1, 2026
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): April 1, 2028
• Last Updated: January 27, 2026

Record last verified: 2025-08

Locations

US (1)