Secondary AMLPhase 1NCT07250646
A Study of Rebecsinib for Patients With Relapsed/Refractory Secondary Acute Myeloid Leukemia or High Risk Myelofibrosis
A Phase 1 study testing rebecsinib in people with Secondary AML and Myelofibrosis, run by Aspera Biomedicines, Inc. at 3 sites in United States.
Trial 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). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Secondary AML, Myelofibrosis
- What is being tested?
- rebecsinib
- Type of treatment
- Injection or infusion
- How many people
- 28 participants
- Where
- 3 sitesUnited States
- Study dates
- 21 May 2026to Apr 2028
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
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- 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.
Who cannot join
- 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.
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- 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)
- A QT ->470 msec on ECG.
- On medication that is an inducer or inhibitor of CYP3A4, CYP2C9, CYP2C19, CYP2B6 and hepatic uptake transporters (e.g. OATP1B1/3, OAT1/2 OCT 1/2), or is metabolized by CYP2C9, 2C19, and 2B6. If they are an inducer or inhibitor or a known substrate of CYP2B6, CYP2C9, and CYP2C19 where minimal changes in drug concentration may lead to serious adverse reactions, the drug should be withdrawn for a minimum of 5 half lives or particular attention should be paid to toxicities or appropriate dose modifications to these drugs made.
- Patients who in the opinion of the investigator may be unable to comply with the safety monitoring requirements of the study.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States3 sites, 3 recruiting
- Recruiting
City of Hope Center
Duarte, California, 91010
Haris Ali, MD, 626-218-2405, harisali@coh.org
Farrah Farshidfard, 626-218-2918, ffarshidfard@coh.org
- Recruiting
UC Davis Comprehensive Cancer Center
Sacramento, California, 95817
OCR Referral Team Team, 916-382-6970, OCRReferral@health.ucdavis.edu
Brian Jonas, MD
- Recruiting
UC San Diego Moores Cancer Center
San Diego, California, 92093
Rebecca Jimenez, MD, PhD, 858-822-5377, rejimenez@health.ucsd.edu
Oliva Nolan, 858-246-5794, ocnolan@health.ucsd.edu
About this study
Official title: A Phase 1 Study of Rebecsinib, a Spliceosome Modulator That Inhibits ADAR1, in Patients With Relapsed or Refractory Secondary Acute Myeloid Leukemia or Higher-Risk Myelofibrosis
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.
Read the detailed description
The primary objective is to determine the maximum tolerated dose or biologically active dose of rebecsinib when given on days 1, 4, 8, and 11 of each 28 days cycle to patients with relapsed or refractory secondary acute myeloid leukemia (sAML), who have evolved from Myelodysplastic Syndrome (MDS) or myeloproliferative neoplasms (MPNs), or patients with higher-risk myelofibrosis. The other primary objective is to determine the safety and tolerability of rebecsinib by ongoing evaluation of adverse events (AEs), as assessed according to the NCI Common Terminology Criteria for Adverse Events (NCI CTCAE v5.0).
Study outcomes will be measured by adverse event data, response rates, progression free survival and overall survival. Pharmacodynamics and plasma pharmacokinetics of rebecsinib will be explored.
- Conditions
- Secondary AML, Myelofibrosis
- Being tested
- rebecsinib
- Keywords
- sAML, MF
- Medical subject headings
- Primary Myelofibrosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
rebecsinibDrug
Also called 17S-FD-895
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).
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 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
To assess clinical activity by evaluating overall response rate. Overall Response Rate (ORR): Percentage of patients achieving Complete Remission (CR) + Partial Remission (PR) as defined by the revised 2017 ELN response criteria for AML
Measured: From enrollment through disease assessment that shows progression, approximately 4 months.
Assess Clinical Activity through Duration of Response
To assess clinical activity by evaluating duration of response. Duration of response is defined as number of days from day of complete or partial remission to day of relapse
Measured: From enrollment through disease assessment that shows progression, approximately 4 months
Assess Clinical Activity through Progression Free Survival Using 2017 ELN Response Criteria
To assess clinical activity by evaluating progression free survival, defined by the revised 2017 ELN response criteria for AML
Measured: 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
To assess clinical activity by evaluating overall survival, defined by the revised 2017 ELN response criteria for AML
Measured: From enrollment through disease assessment that shows progression, approximately 4 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Nov 2025
- Study start21 May 2026
- Primary completionOct 2027 (estimated)
- Study completionApr 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Secondary AMLStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Model description
- 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.
- Masking
- None (open label)
- Enrolment
- 28 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Aspera Biomedicines, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Tempus AI
- Responsible party
- Sponsor
- Investigators
- James Mangan, MD, PhD, Principal investigator, UC San Diego Moores Cancer Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07250646
- Sponsor's protocol ID
- ASPE-01-01
- Status last verified
- Jun 2026
- First submitted
- 1 Aug 2025
- Last updated
- 20 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1 Study of Rebecsinib, a Spliceosome Modulator That Inhibits ADAR1, in Patients With Relapsed or Refractory Secondary Acute Myeloid Leukemia or Higher-Risk Myelofibrosis
- ClinicalTrials.gov ID
- NCT07250646
- Acronym / sponsor ID
- ASPE-01-01
- Conditions
- Secondary AML, Myelofibrosis
- Keywords
- sAML, MF
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 28 participants (estimated)
- Lead sponsor
- Aspera Biomedicines, Inc.Industry (pharma, biotech, devices)
- Collaborators
- Tempus AI
- Study start
- 21 May 2026 (actual)
- Primary completion
- Oct 2027 (estimated)
- Study completion
- Apr 2028 (estimated)
- First posted
- 26 Nov 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
The primary objective is to determine the maximum tolerated dose or biologically active dose of rebecsinib when given on days 1, 4, 8, and 11 of each 28 days cycle to patients with relapsed or refractory secondary acute myeloid leukemia (sAML), who have evolved from Myelodysplastic Syndrome (MDS) or myeloproliferative neoplasms (MPNs), or patients with higher-risk myelofibrosis. The other primary objective is to determine the safety and tolerability of rebecsinib by ongoing evaluation of adverse events (AEs), as assessed according to the NCI Common Terminology Criteria for Adverse Events (NCI CTCAE v5.0).
Study outcomes will be measured by adverse event data, response rates, progression free survival and overall survival. Pharmacodynamics and plasma pharmacokinetics of rebecsinib will be explored.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Model description
- 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.
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (14 listed)
- 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.
Key exclusion criteria (18 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| rebecsinibAlso: 17S-FD-895Rebecsinib 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). | Drug | – |
Primary outcome
Determine the Maximum Tolerated Dose
Time frame: From first dose through 28 days after initial dose for dose all finding cohorts, approximately 2 years.
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.
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]
Time frame: From enrollment to initiation of new therapy for each subject, approximately 4 months.
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.
4 secondary outcomes
Assess Clinical Activity through Overall Response Rate using 2017 ELN Response Criteria
Time frame: From enrollment through disease assessment that shows progression, approximately 4 months.
Assess Clinical Activity through Duration of Response
Time frame: From enrollment through disease assessment that shows progression, approximately 4 months
Assess Clinical Activity through Progression Free Survival Using 2017 ELN Response Criteria
Time frame: 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
Time frame: From enrollment through disease assessment that shows progression, approximately 4 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jul 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
James Mangan, MD, PhD principal investigator
UC San Diego Moores Cancer Center
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing rebecsinib in people with Secondary AML and Myelofibrosis, run by Aspera Biomedicines, Inc. at 3 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 20 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Curis L Scribner, MD (510-914-8368, cscribner@asperabio.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Determine the Maximum Tolerated Dose (time frame: From first dose through 28 days after initial dose for dose all finding cohorts, approximately 2 years.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jul 2026.