Acute Myeloid LeukemiaPhase 1NCT05275439
Phase 1 Study of Shattuck Labs (SL)-172154 in Subjects With MDS or AML
A Phase 1 study testing SL-172154, Azacitidine (AZA) and Venetoclax in people with Acute Myeloid Leukemia and Myelodysplastic Syndromes, run by Shattuck Labs, Inc. at 23 sites in 3 countries.
Trial summary
SL03-Old Hundred(OHD)-104 is designed as a Phase 1a/1b open label, trial to evaluate the safety, pharmacokinetics (PK), pharmacodynamic (PD), and preliminary efficacy of SL-172154 monotherapy as well as in combination with azacitidine or in combination with Azacitidine and Venetoclax. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Myeloid Leukemia, Myelodysplastic Syndromes
- What is being tested?
- SL-172154, Azacitidine (AZA) and Venetoclax
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 106 participants
- Where
- 23 sitesin 3 countries
- Study dates
- 17 Mar 2022to 6 Feb 2025
- Phase
- Phase 1
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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
- Participants are eligible to be included in the study only if all the following criteria apply.
- Subject has voluntarily agreed to participate by giving written informed consent in accordance with ICH/GCP guidelines and applicable local regulations.
- Age ≥ 18 years.
- For subjects with AML, confirmation of AML diagnosis by 2016 WHO criteria [Arber, 2016] (World Health Organization [WHO] classification, excluding acute promyelocytic leukemia [APL]).
- Subjects with MDS must have:
- morphologically confirmed diagnosis of MDS by 2016 WHO criteria [Arber, 2016] with <20% blasts in bone marrow per bone marrow biopsy/aspirate or peripheral blood.
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- confirmation of intermediate, high or very high risk category by Revised International Prognostic Scoring System (IPSS-R).
- Subjects with a diagnosis of any of the following are excluded: Atypical CML, juvenile myelomonocytic leukemia (JMML), chronic myelomonocytic leukemia (CMML), and unclassifiable MDS/ myeloproliferative neoplasm (MPN).
- [Dose Escalation Cohort - SL-172154 Monotherapy] Subjects with AML must have relapsed/refractory disease (≥5% blasts by manual aspirate differential, flow cytometry, or immunohistochemistry) following at least 1 prior line of therapy but no more than 4 prior lines of therapy. Subjects with higher-risk MDS must have relapsed/refractory disease following at least 1 prior line but no more than 4 prior lines of therapy.
- Prior hydroxyurea or other supportive care in the form of transfusions or growth factors will not be considered prior therapy.
- Subjects who have undergone allogeneic-hematopoietic cell transplantation (HCT) are eligible if they are at least 6 months post-HCT, have relapsed AML or MDS as defined above, are not on treatment or prophylaxis for graft versus host disease (GVHD) for at least 6 weeks before administration of study treatment, and have no active GVHD.
- Subjects must not be eligible for rescue chemotherapy and allogeneic-HCT per local or institutional guidelines at the time of screening.
- [Dose Escalation Cohort - SL-172154 Administered with Azacitidine] Subjects with relapsed/refractory AML and MDS (as defined in Inclusion criterion 5) following at least 1 prior line of therapy but no more than 4 prior lines of therapy.
- Treatment for MDS preceding secondary AML will not be considered as a prior line of therapy for secondary AML.
- Prior hydroxyurea or other supportive care in the form of transfusions or growth factors will not be considered prior therapy.
- Subjects who have undergone allogeneic-HCT are eligible if they are at least 6 months post-HCT, have relapsed AML or MDS as defined above, are not on treatment or prophylaxis for GVHD for at least 6 weeks before the first dose of study treatment, and have no active GVHD.
- Subjects must not be eligible for rescue chemotherapy and allogeneic-HCT per local or institutional guidelines at the time of screening.
- In addition, previously untreated subjects meeting either of the following criteria are eligible for this cohort:
- Previously untreated subjects with AML with known adverse cytogenetics who fall into the adverse ELN risk group and who are unlikely to benefit from standard intensive induction therapy or refuse intensive induction therapy at time of enrollment.
- Previously untreated subjects with MDS with documentation of at least one TP53 gene mutation or deletion based on a local test. Prior MDS therapy with lenalidomide or other supportive care in the form of transfusions or growth factors is allowed.
- [Dose Expansion Cohort Part A: SL-172154 Administered with Azacitidine] Subjects diagnosed with MDS must be previously untreated. Prior MDS therapy with lenalidomide, luspatercept or supportive care in the form of transfusions or growth factors is allowed. Up to 1 cycle of prior therapy with a hypomethylating agent is permitted. Subjects with newly diagnosed treatment-related MDS are also eligible for enrollment.
- [Dose Escalation - Safety Run-in Cohort AND Dose Expansion Cohort Part B: SL 172154 Administered with Azacitidine and Venetoclax] Subjects with AML must be previously untreated as defined by:
- Subject must be ineligible for induction therapy with a standard cytarabine and anthracycline induction regimen due to age or co-morbidities as defined by the following:
- ≥ 75 years of age
- ≥ 60 to 74 years of age with at least one of the following co-morbidities:
- Eastern Cooperative Oncology Group (ECOG) Performance Status of 2
- History of congestive heart failure (CHF) requiring treatment
- Ejection fraction ≤ 50%
- Chronic stable angina
- DLCO ≤ 65% or FEV1 ≤ 65%
- Creatinine clearance ≥ 30 mL/min to < 45 mL/min
- Documented contraindication to anthracycline or cytarabine based therapy
- Subjects with AML with known adverse cytogenetics who fall into the adverse ELN risk group and who are unlikely to benefit from standard intensive induction therapy or refuse intensive induction therapy at time of enrollment are also eligible.
- Subjects with newly diagnosed secondary AML and who are unlikely to benefit from standard intensive induction therapy or refuse intensive induction therapy at time of enrollment are eligible for enrollment. Subjects with secondary AML after MDS must not have received prior chemotherapy or no more than 2 cycles of prior hypomethylating agent for MDS.
- [Dose Expansion Cohort Part C: SL-172154 Administered Azacitidine]: Subjects with previously untreated de novo AML or secondary AML with TP53 gene mutation or deletion who are unlikely to benefit from standard intensive induction therapy or refuse intensive induction therapy at time of enrollment are eligible. All subjects must have documentation of at least one TP53 gene mutation/deletion based on local test. Subjects with secondary AML after MDS must not have received prior chemotherapy or no more than 2 cycles of prior hypomethylating agent for MDS.
- ECOG Performance Status of 0, 1, or 2.
- Laboratory values must meet the following criteria:
- Laboratory parameter Threshold value White blood cell count (WBC) ≤ 20 x 109/L (Hydroxyurea is permitted to meet this criterion) Creatinine clearance (CrCl) ≥ 30 mL/min (using modified Cockcroft-Gault formula) ALT/AST ≤ 3 x ULN Total bilirubin ≤ 1.5 x ULN; subjects with isolated indirect hyperbilirubinemia are permitted if direct bilirubin ratio is <35% and total bilirubin is ≤ 3.0 x ULN
- Willing to provide consent for bone marrow aspirate samples at baseline and on-treatment for exploratory research as described in the Schedule of Assessments.
- For subjects with relapsed/refractory disease, recovery from prior anti-cancer treatments including surgery, radiotherapy, chemotherapy or any other anti-cancer therapy to baseline or ≤ Grade 1. (NOTE: Low-grade or controlled toxicities (e.g., alopecia) may be allowed upon agreement by the Medical Monitor)
- Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test within 72 hours of the first dose of study treatment. NOTE: females are defined as being of childbearing potential unless they are surgically sterile (i.e., have undergone a complete hysterectomy, bilateral tubal ligation/occlusion, bilateral oophorectomy, or bilateral salpingectomy), have a congenital or acquired condition that prevents childbearing or are naturally post-menopausal for at least 12 consecutive months. Documentation of post-menopausal status must be provided. To avoid pregnancy, FCBP must start using a highly effective method of contraception (i.e., <1% failure rate) at least 14 days prior to initiation of study treatment and continue use during treatment and for 30 days (which exceeds 5 half-lives) after the last dose of SL-172154, or for the duration required by local prescribing information after the last dose of azacitidine (i.e., for sites in UK and Spain, at least 6 months after the last dose of azacitidine in either combination regimen).
- Male subjects with female partners must have azoospermia from a prior vasectomy, an underlying medical condition, or agree to use a highly effective method of contraception (i.e., <1% failure rate) during treatment and for 30 days (which exceeds 5 half-lives) after the last dose of SL-172154, or for the duration required by local prescribing information after the last dose of azacitidine (i.e., for sites in UK and Spain, at least 3 months; for sites in Canada, at least 6 months).
- [Dose Expansion Cohort Part D: SL-172154 with Azacitidine vs Azacitidine monotherapy]: Subjects diagnosed with MDS must be previously untreated. Prior MDS therapy with lenalidomide, luspatercept or supportive care in the form of transfusions or growth factors is allowed. No prior therapy with a hypomethylating agent is permitted. Subjects with newly diagnosed treatment-related MDS are also eligible for enrollment. TP53 mutation status results based on local test must be available prior to randomization.
Who cannot join
- Participants are excluded from the study if any of the following criteria apply:
- [Monotherapy and Combination Regimen Dose Escalation Cohorts] Prior treatment with:
- CAR-T cell therapy within 3 months from the first dose of the study drug.
- Prior treatment with anti-CD47 targeting agent or CD40 agonist within 28 days prior to the first dose of study treatment.
- Prior treatment with signal-regulatory protein alpha (SIRPα)-targeting agent.
- Other experimental therapies for AML or MDS within 14 days or at least 5 half-lives (whichever is shorter) prior to the first dose of study treatment.
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- Evidence of active CNS involvement with leukemia.
- Subjects requiring agents other than hydroxyurea to control blast counts within 14 days prior to the first dose of study treatment.
- Evidence of active bleeding or bleeding diathesis or major coagulopathy (including familial).
- [Only for Cohorts Including Venetoclax in the Regimen] Subject has received strong and/or moderate CYP3A inducers within 7 days prior to the first dose of venetoclax.
- Use of systemic corticosteroids (>10 mg daily of prednisone or equivalent) or other non-steroidal immunosuppressive medication, current or within 14 days of the first dose of study treatment with the following exceptions (i.e., the following are allowed within 14 days of first dose):
- Topical, intranasal, inhaled, ocular, intraarticular corticosteroids
- Physiological doses of replacement steroid (e.g., for adrenal insufficiency)
- Steroid premedication for hypersensitivity reactions (e.g., reaction to IV contrast) or a brief course of treatment of non-autoimmune conditions (e.g., transfusion reactions, delayed-type hypersensitivity reaction caused by contact allergen).
- Receipt of live attenuated vaccine within 30 days of first dose of SL-172154 treatment.
- Subject has active, uncontrolled infection (e.g., viral, bacterial, or fungal). Subjects are eligible if infection is controlled with antibiotics, antivirals and/or antifungals.
- [Only for Cohorts Including Venetoclax in the Regimen] Subject has a malabsorption syndrome or other condition that precludes the enteral route of administration.
- Symptomatic peptic ulcer disease or gastritis, active diverticulitis, other serious gastrointestinal disease associated with diarrhea within 6 months of first dose of study treatment.
- Clinically significant or uncontrolled cardiac disease including any of the following:
- Myocarditis
- Unstable angina within 6 months from first dose of study treatment
- Acute myocardial infarction within 6 months from first dose of study treatment
- Uncontrolled hypertension
- NYHA Class III or IV congestive heart failure
- Clinically significant (symptomatic) cardiac arrhythmias (e.g., sustained ventricular tachycardia, second- or third- degree atrioventricular (AV) block without a pacemaker, circulatory collapse requiring vasopressor or inotropic support, or arrhythmia not stabilized on therapy)
- Subject has chronic respiratory disease that requires continuous oxygen, or significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, hepatic, cardiovascular disease, or any other medical condition that in the opinion of the Investigator would adversely affect his/her participation in the study.
- Subjects who have had any major surgical procedure within 14 days of first dose of study treatment.
- Subject is a woman who is pregnant or breast feeding or planning to become pregnant or breast feed while enrolled in this study.
- Psychiatric illness/social circumstances that would limit compliance with study requirements and substantially increase the risk of AEs or compromised ability to provide written informed consent.
- Presence of another malignancy that requires active therapy and that in the opinion of the Investigator and Sponsor would interfere with the monitoring of disease assessments in this study.
- Known hypersensitivity to any of the study medications including excipients of azacitidine.
- Has undergone solid organ transplantation.
- Known or active human immunodeficiency virus (HIV) infection
- Known or active infection with hepatitis B (positive for hepatitis B surface antigen [HbsAg]) or hepatitis C virus ([HCV]; if HCV antibody (Ab) test is positive check for HCV ribonucleic acid [RNA]).
- NOTE: Hepatitis B virus (HBV): Subjects who are hepatitis B core antibody [HbcAb]-positive but HbsAg-negative are eligible for enrollment. HCV: Subjects who are HCV Ab-positive but HCV RNA-negative are eligible for enrollment.
Trial locations and contacts
23 sites in 3 countries.
23 sites in 3 countries
United States16 sites
University of Michigan
Ann Arbor, Michigan, 48109
Dana-Farber Cancer Institute
Boston, Massachusetts, 02215
Roswell Park Comprehensive Cancer Center
Buffalo, New York, 14263
University of North Carolina, Lineberger Comprehensive Cancer Center
Chapel Hill, North Carolina, 27599
The University of Chicago
Chicago, Illinois, 60637
University of Cincinnati Medical Center
Cincinnati, Ohio, 45219
Baylor Scott & White Research Institute
Dallas, Texas, 75246
City of Hope
Duarte, California, 91010
START Midwest
Grand Rapids, Michigan, 49546
MD Anderson Cancer Center
Houston, Texas, 77030
UCLA Medical Center-Bowyer Oncology Center
Los Angeles, California, 90095
Norton Cancer Institute
Louisville, Kentucky, 40202
Yale Cancer Center
New Haven, Connecticut, 06510
UPMC Hillman Cancer Center
Pittsburgh, Pennsylvania, 15232
VCU Massey Cancer Center
Richmond, Virginia, 23219
Moffitt Cancer Center
Tampa, Florida, 33612
United Kingdom4 sites
University Hospitals Plymouth NHS Trust, Derriford Hospital
Crownhill, Plymouth, PL6 8DH
King's College Hospital NHS Foundation Trust
London, Denmark Hill, SE5 9RS
Imperial College Healthcare NHS Trust
London, W12 0HS
The Christie NHS Foundation Trust
Manchester, M20 4BX
Canada3 sites
Tom Baker Cancer Centre
Calgary, Alberta, T2N 4N2
Jewish General Hospital
Montreal, Quebec, H3T 1E2
Princess Margaret Cancer Centre
Toronto, Ontario, M5G 2C1
About this study
Official title: An Open-Label Phase 1a/1b Dose Escalation and Expansion Cohort Study of SL-172154 (SIRPα-Fc-CD40L) in Combination With Azacitidine or With Azacitidine and Venetoclax for the Treatment of Subjects With Higher-Risk Myelodysplastic Syndrome (MDS) or Acute Myeloid Leukemia (AML)
SL03-Old Hundred(OHD)-104 is designed as a Phase 1a/1b open label, trial to evaluate the safety, pharmacokinetics (PK), pharmacodynamic (PD), and preliminary efficacy of SL-172154 monotherapy as well as in combination with azacitidine or in combination with Azacitidine and Venetoclax.
Read the detailed description
This Phase 1a/1b study is an open label, multicenter trial in subjects with higher-risk (i.e., intermediate, high or very high risk by IPSS-R) MDS or AML. The study is designed to evaluate the safety, PK, pharmacodynamic effects, and preliminary anti tumor activity of SL-172154 monotherapy and SL-1712154 administered with either Azacitidine or Azacitidine and Venetoclax. Subjects will receive SL-172154 as monotherapy or administered with Azacitidine with or without Venetoclax until documented disease progression, unacceptable toxicity or intolerance, withdrawal of consent, or the subject meets other criteria for discontinuation (whichever occurs first).
Part D: Safety and efficacy will be further explored in Part D. Approximately 60 subjects with previously untreated higher-risk MDS will be randomized equally into 3 groups: 3.0 mg/kg SL-172154+azacitidine, 1.0 mg/kg SL-172154+azacitidine and azacitidine monotherapy. Patients will be stratified based on the TP53 mutation status (TP53m vs TP53wt) and bone marrow blast count at study entry (<5% vs ≥5%).
- Conditions
- Acute Myeloid Leukemia, Myelodysplastic Syndromes
- Being tested
- SL-172154, Azacitidine (AZA), Venetoclax
- Medical subject headings
- Leukemia, Myeloid, Acute, Myelodysplastic Syndromes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SL-172154Drug
The investigational product (IP), SL-172154, is a novel fusion protein consisting of human SIRPα and CD40L (SIRPα -Fc-CD40L) linked via a human Fc.
Azacitidine (AZA)Drug
Chemotherapy drug approved for use in MDS and AML.
VenetoclaxDrug
Drug approved for use in AML.
| Study group | Role | What they receive |
|---|---|---|
| SL-172154 | Experimental | Patients will receive intravenous administration Receives: Drug: SL-172154 |
| SL-172154 + Azacitidine | Experimental | Patients will receive intravenous administration of SL-172154 and Azacitidine. Receives: Drug: SL-172154; Drug: Azacitidine (AZA) |
| SL-172154 + Azacitidine + Venetoclax | Experimental | Patients will receive intravenous administration of SL-172154 and Azacitidine plus oral venetoclax. Receives: Drug: SL-172154; Drug: Azacitidine (AZA); Drug: Venetoclax |
| Part D-Previously untreated HR-MDS 1:1:1 Randomization | Experimental | Patients will randomized to receive intravenous administration of the following:
* 3 mg/kg SL-172154 + Azacitidine
* 1 mg/kg SL-172154 + Azacitidine
* Azacitidine Monotherapy Receives: Drug: SL-172154; Drug: Azacitidine (AZA) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety Profile of SL-172154 Monotherapy or in Combination With Azacitidine
Number of participants with treatment emergent adverse events from dose escalation and dose expansion cohorts
Measured: From Day 1 to study completion, an average of 2-5 months depending on the treatment arm
Recommended Phase 2 Dose of SL-172154 Administered With Azacitidine
Based on review of all data, including safety, tolerability, PK, antitumor activity, and PD effects
Measured: From Day 1 to study completion, an average of 2-5 months depending on the treatment arm
Safety Profile of SL-172154 in Combination With Azacitidine or Azacitidine Monotherapy
Number of participants with treatment emergent adverse events from Part D cohorts
Measured: From Day 1 to study completion, an average of 2-5 months depending on the treatment arm
Secondary outcomes (8)
Preliminary Evidence of Anti-tumor Activity of SL-172154 Administered Alone or With Azacitidine
International Working Group (IWG) 2006 criteria (MDS): Response for subjects with MDS will be evaluated based on guidelines by the IWG 2006 MDS response criteria [Cheson, 2006]. Subject's response is based on the most recent bone marrow results and recent hematology values. Hematology values for up to 2 weeks from the bone marrow evaluation can be used to determine the IWG response.
European LeukemiaNet (ELN) 2017 criteria (AML): Response will be evaluated based on guidelines by the 2017 ELN Response Criteria in AML [Dohner, 2017]. Subject's response is based on the most recent bone marrow results and recent hematology values. Hematology values for up to 2 weeks from the bone marrow evaluation can be used to determine the response.
Measured: Approximately 24 months
Immunogenicity to SL-172154 During and After Treatment of SL-172154 Alone or With Azacitidine
Number of participants with positive anti-drug antibody (ADA) titer, of those who were ADA negative at baseline
Measured: Approximately 24 months
Maximum Serum Concentration (Cmax) of SL-172154
The Cmax is the maximum observed serum concentration of SL-172154 following single and multiple doses
Measured: Cycle 1 Day 1/2, Cycle 1 Day 15/16, and Cycle 2 Day 1/2 (cycle = 28 days)
Time at Which Maximum Concentration of SL-172154 is Observed (Tmax)
The Tmax is the time at which the maximum concentration of SL-172154 is observed following single and multiple doses
Measured: Cycle 1 Day 1/2, Cycle 1 Day 15/16, and Cycle 2 Day 1/2 (cycle = 28 days)
Area Under the Serum Concentration-time Curve (AUC)
The AUC is the area under the serum concentration time curve following single and multiple doses of SL-172154
Measured: Cycle 1 Day 1, Cycle 1 Day 15/16, and Cycle 2 Day 1 (cycle = 28 days)
Terminal Elimination Half-life (t1/2)
Terminal elimination half-life (t1/2) of SL-172154
Measured: Approximately 24 months
Clearance (CL)
Clearance of Sl-172154
Measured: Cycle 2 Day 1 (monotherapy) or 2 (combination) (cycle = 28 days)
Volume of Distribution
Volume of distribution of SL-172154
Measured: Cycle 2 Day 1 (monotherapy) or 2 (combination) (cycle = 28 days)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Mar 2022
- Study start17 Mar 2022
- Primary completion6 Feb 2025
- Study completion6 Feb 2025
Why it stopped: Development discontinued
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Acute Myeloid LeukemiaStudies 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
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 106 participants (actual)
Sponsor and investigators
- Lead sponsor
- Shattuck Labs, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Shattuck Labs, Study director, Shattuck Labs
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05275439
- Sponsor's protocol ID
- SL03-OHD-104
- Status last verified
- Feb 2026
- First submitted
- 15 Feb 2022
- Last updated
- 18 Mar 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label Phase 1a/1b Dose Escalation and Expansion Cohort Study of SL-172154 (SIRPα-Fc-CD40L) in Combination With Azacitidine or With Azacitidine and Venetoclax for the Treatment of Subjects With Higher-Risk Myelodysplastic Syndrome (MDS) or Acute Myeloid Leukemia (AML)
- ClinicalTrials.gov ID
- NCT05275439
- Acronym / sponsor ID
- SL03-OHD-104
- Conditions
- Acute Myeloid Leukemia, Myelodysplastic Syndromes
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Development discontinued
- Enrolment
- 106 participants (actual)
- Lead sponsor
- Shattuck Labs, Inc.Industry (pharma, biotech, devices)
- Study start
- 17 Mar 2022 (actual)
- Primary completion
- 6 Feb 2025 (actual)
- Study completion
- 6 Feb 2025 (actual)
- First posted
- 11 Mar 2022 (actual)
- Results
- Posted 18 Mar 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
SL03-Old Hundred(OHD)-104 is designed as a Phase 1a/1b open label, trial to evaluate the safety, pharmacokinetics (PK), pharmacodynamic (PD), and preliminary efficacy of SL-172154 monotherapy as well as in combination with azacitidine or in combination with Azacitidine and Venetoclax.
Detailed description
This Phase 1a/1b study is an open label, multicenter trial in subjects with higher-risk (i.e., intermediate, high or very high risk by IPSS-R) MDS or AML. The study is designed to evaluate the safety, PK, pharmacodynamic effects, and preliminary anti tumor activity of SL-172154 monotherapy and SL-1712154 administered with either Azacitidine or Azacitidine and Venetoclax. Subjects will receive SL-172154 as monotherapy or administered with Azacitidine with or without Venetoclax until documented disease progression, unacceptable toxicity or intolerance, withdrawal of consent, or the subject meets other criteria for discontinuation (whichever occurs first).
Part D: Safety and efficacy will be further explored in Part D. Approximately 60 subjects with previously untreated higher-risk MDS will be randomized equally into 3 groups: 3.0 mg/kg SL-172154+azacitidine, 1.0 mg/kg SL-172154+azacitidine and azacitidine monotherapy. Patients will be stratified based on the TP53 mutation status (TP53m vs TP53wt) and bone marrow blast count at study entry (<5% vs ≥5%).
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| SL-172154 | Experimental | Drug: SL-172154Patients will receive intravenous administration |
| SL-172154 + Azacitidine | Experimental | Drug: SL-172154, Drug: Azacitidine (AZA)Patients will receive intravenous administration of SL-172154 and Azacitidine. |
| SL-172154 + Azacitidine + Venetoclax | Experimental | Drug: SL-172154, Drug: Azacitidine (AZA), Drug: VenetoclaxPatients will receive intravenous administration of SL-172154 and Azacitidine plus oral venetoclax. |
| Part D-Previously untreated HR-MDS 1:1:1 Randomization | Experimental | Drug: SL-172154, Drug: Azacitidine (AZA)Patients will randomized to receive intravenous administration of the following: * 3 mg/kg SL-172154 + Azacitidine * 1 mg/kg SL-172154 + Azacitidine * Azacitidine Monotherapy |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (43 listed)
- Participants are eligible to be included in the study only if all the following criteria apply.
- Subject has voluntarily agreed to participate by giving written informed consent in accordance with ICH/GCP guidelines and applicable local regulations.
- Age ≥ 18 years.
- For subjects with AML, confirmation of AML diagnosis by 2016 WHO criteria [Arber, 2016] (World Health Organization [WHO] classification, excluding acute promyelocytic leukemia [APL]).
- Subjects with MDS must have:
Key exclusion criteria (35 listed)
- [Monotherapy and Combination Regimen Dose Escalation Cohorts] Prior treatment with:
- Evidence of active CNS involvement with leukemia.
- Subjects requiring agents other than hydroxyurea to control blast counts within 14 days prior to the first dose of study treatment.
- Evidence of active bleeding or bleeding diathesis or major coagulopathy (including familial).
- [Only for Cohorts Including Venetoclax in the Regimen] Subject has received strong and/or moderate CYP3A inducers within 7 days prior to the first dose of venetoclax.
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 |
|---|---|---|
| SL-172154The investigational product (IP), SL-172154, is a novel fusion protein consisting of human SIRPα and CD40L (SIRPα -Fc-CD40L) linked via a human Fc. | Drug | Part D-Previously untreated HR-MDS 1:1:1 Randomization, SL-172154, SL-172154 + Azacitidine, SL-172154 + Azacitidine + Venetoclax |
| Azacitidine (AZA)Chemotherapy drug approved for use in MDS and AML. | Drug | Part D-Previously untreated HR-MDS 1:1:1 Randomization, SL-172154 + Azacitidine, SL-172154 + Azacitidine + Venetoclax |
| VenetoclaxDrug approved for use in AML. | Drug | SL-172154 + Azacitidine + Venetoclax |
Primary outcome
Safety Profile of SL-172154 Monotherapy or in Combination With Azacitidine
Time frame: From Day 1 to study completion, an average of 2-5 months depending on the treatment arm
Number of participants with treatment emergent adverse events from dose escalation and dose expansion cohorts
Recommended Phase 2 Dose of SL-172154 Administered With Azacitidine
Time frame: From Day 1 to study completion, an average of 2-5 months depending on the treatment arm
Based on review of all data, including safety, tolerability, PK, antitumor activity, and PD effects
Safety Profile of SL-172154 in Combination With Azacitidine or Azacitidine Monotherapy
Time frame: From Day 1 to study completion, an average of 2-5 months depending on the treatment arm
Number of participants with treatment emergent adverse events from Part D cohorts
8 secondary outcomes
Preliminary Evidence of Anti-tumor Activity of SL-172154 Administered Alone or With Azacitidine
Time frame: Approximately 24 months
Immunogenicity to SL-172154 During and After Treatment of SL-172154 Alone or With Azacitidine
Time frame: Approximately 24 months
Maximum Serum Concentration (Cmax) of SL-172154
Time frame: Cycle 1 Day 1/2, Cycle 1 Day 15/16, and Cycle 2 Day 1/2 (cycle = 28 days)
Time at Which Maximum Concentration of SL-172154 is Observed (Tmax)
Time frame: Cycle 1 Day 1/2, Cycle 1 Day 15/16, and Cycle 2 Day 1/2 (cycle = 28 days)
Area Under the Serum Concentration-time Curve (AUC)
Time frame: Cycle 1 Day 1, Cycle 1 Day 15/16, and Cycle 2 Day 1 (cycle = 28 days)
Terminal Elimination Half-life (t1/2)
Time frame: Approximately 24 months
Clearance (CL)
Time frame: Cycle 2 Day 1 (monotherapy) or 2 (combination) (cycle = 28 days)
Volume of Distribution
Time frame: Cycle 2 Day 1 (monotherapy) or 2 (combination) (cycle = 28 days)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Mar 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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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. This study is not recruiting at the moment.
Shattuck Labs study director
Shattuck Labs
23 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing SL-172154, Azacitidine (AZA) and Venetoclax in people with Acute Myeloid Leukemia and Myelodysplastic Syndromes, run by Shattuck Labs, Inc. at 23 sites in 3 countries.
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 43 inclusion and 35 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: stopped early, as of the sponsor's last update on 18 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 23 sites in United States, United Kingdom, Canada. 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?
Yes. Results are posted in the registry (first posted 18 Mar 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety Profile of SL-172154 Monotherapy or in Combination With Azacitidine (time frame: From Day 1 to study completion, an average of 2-5 months depending on the treatment arm). The study lists 3 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 18 Mar 2026.