Low-risk Myelodysplastic SyndromesPhase 1NCT06670222
Oral Arsenic (ATO) in Low-risk Myelodysplastic Syndromes (MDS)
A Phase 1 study testing Arsenic Trioxide (ATO) in people with Low-risk Myelodysplastic Syndromes, run by Groupe Francophone des Myelodysplasies at 3 sites in France.
Trial summary
Phase I study with dose-escalation and expansion evaluating the safety and efficacy of oral Arsenic (ATO) in low-risk Myelodysplastic Syndromes having failed to Erythropoiesis Stimulating Agents and Luspatercept (or ineligible for the latter). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Low-risk Myelodysplastic Syndromes
- What is being tested?
- Arsenic Trioxide (ATO)
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 3 sitesFrance
- Study dates
- 22 Jul 2025to Jul 2027
- 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
- Patients must meet all the following criteria to participate in the study:
- Myelodysplastic syndrome according to WHO (World Health Organization) 2022 classification
- Age ≥ 18 years
- Patient with low-risk Myelodysplastic Syndromes according to Revised International Prognostic Scoring System (IPSS-R) classification (very low, low, intermediate):
- non-sideroblastic who failed to achieved a response or who subsequently relapse after Erythropoiesis Stimulating Agents (ESA) (at Epoetin alfa 60000UI or equivalent over at least 12 weeks) without disease progression or ineligible to ESA (defined by Erythopoietine (EPO) > 500UI/L)
- sideroblastic who failed to achieved a response or who subsequently relapse after ESA (at Epoetin alfa 60000UI or equivalent over at least 12 weeks) or ineligible for ESA (defined by EPO >500UI/L) and who failed to achieved a response or who subsequently relapse after Luspatercept
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- del (5q) who failed to achieved a response or who subsequently relapse after ESA (at Epoetin alfa 60000IU or equivalent over at least 12 weeks) and who failed to achieved a response or who subsequently relapse after Lenalidomide
- Transfusion dependence (at least 3 RBC (Red Blood Cell) within a 16-week period and at least 2 transfusion episodes during this period)
- Patient not eligible for another clinical trial
- Adequate renal function defined by creatinine level less than 1.5 times the upper limit of normal and creatinine clearance ≥ 40mL/min (according to MDRD (Modification of Diet in Renal Disease) formula)
- Adequate liver function defined by total bilirubin and transaminases less than 1.5 times the upper limit of normal
- Patient not refractory to platelet transfusions
- Written consent
- Patient must understand and voluntarily sign informed consent form
- Patient must be able to adhere to the visit schedule as outlined in the study and follow protocol requirements
- Performance status 0-2 at the time of screening
- A FCBP (female of childbearing potential) for this study was defined as a sexually mature woman who: (1) had not undergone a hysterectomy or bilateral oophorectomy; or (2) had not been naturally postmenopausal (amenorrhea following cancer therapy did not rule out childbearing potential) for at least 24 consecutive months (ie, has had menses at any time in the preceding 24 consecutive months).
- A FCBP participating in the study must:
- Have had 2 negative pregnancy tests as verified by the investigator prior to starting IP (unless the screening pregnancy test was done within 72 hours of Cycle 1 Day 1). She must have had agreed to ongoing a monthly pregnancy testing during the course of the study and after end of treatment.
- If sexually active, agreed to have used, and been able to comply with, highly effective contraception** without interruption, 5 weeks prior to starting treatment, during treatment (including dose interruptions), and for 24 weeks after discontinuation of treatment.
- Highly effective contraception was defined in this protocol as the following (information also appeared in the Informed Consent Form): Hormonal contraception (eg, birth control pills, injection, implant, transdermal patch, vaginal ring), intrauterine device, tubal ligation (tying your tubes), or a partner with a vasectomy.
- Male subjects must: Have agreed to use a condom, defined as a male latex condom or nonlatex condom NOT made out of natural (animal) membrane (eg, polyurethane), during sexual contact with a pregnant female or a FCBP while participating in the study, during dose interruptions, and for at least 24 weeks following treatment discontinuation, even if he had undergone a successful vasectomy.
Who cannot join
- Any patient meeting one of the following criteria cannot be included in the study:
- Severe infection or any uncontrolled severe condition
- Uncontrolled hypertension
- Significant cardiac disease - NYHA (New York Heart Association) Class III or IV or having suffered a myocardial infarction in the last 6 months
- QTcF (Fridericia's corrected QT interval) > 460ms
- Use of investigational agents within 30 days or any anticancer therapy (including IMiD (Immunomodulatory treatments)) within 2 weeks before the study entry with the exception of hydroxyurea. The patient must have recovered at least a grade 1 from all acute toxicity from any previous therapy. However, patients may have received Lenalidomide, hypomethylating agent, or anti-lymphocytic serum (ALS) (but not within 4 weeks before the study entry and, for ALS, within 16 weeks before the study entry).
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- Use of EPO within 4 weeks before the study entry
- Active cancer or cancer during the year prior to trial entry other than basal cell carcinoma, or carcinoma in situ of the cervix or breast
- Patient already enrolled in another therapeutic trial of an investigational drug
- Known Human Immunodeficiency Virus infection or active hepatitis B or C
- Women who are or could become pregnant or who are currently breastfeeding
- Any medical or psychiatric contraindication that would prevent the patient from understanding and signing the informed consent form
- Patient eligible for allogeneic stem cell transplantation
- No affiliation to a health insurance system
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Jean Baptiste MICOL, MD contact
France3 sites, 3 recruiting
- Recruiting
CHU de Nice - Hôpital l'Archet - Service d'hématologie clinique
Nice, 06200
Thomas CLUZEAU, MD/PHD, +33 4 92 03 58 44, cluzeau.t@chu-nice.fr
Thomas CLUZEAU, MD/PHD
- Recruiting
Hôpital Saint Louis - Service Hématologie séniors
Paris, 75010
Pierre FENAUX, MD/PHD, +33 1 71 20 70 18, pierre.fenaux@aphp.fr
Pierre FENAUX, MD/PHD
- Recruiting
Institut Gustave Roussy - Service d'hématologie
Villejuif, 94805
Jean-Baptiste MICOL, MD, + 33 1 42 11 57 90, Jeanbaptiste.MICOL@gustaveroussy.fr
Jean Baptiste MICOL, MD
About this study
Official title: Phase I Study With Dose-escalation and Expansion Evaluating the Safety and Efficacy of Oral Arsenic (ATO) in Low-risk Myelodysplastic Syndromes Failing Erythropoiesis Stimulating Agents and Luspatercept (or Ineligible for the Latter)
Phase I study with dose-escalation and expansion evaluating the safety and efficacy of oral Arsenic (ATO) in low-risk Myelodysplastic Syndromes having failed to Erythropoiesis Stimulating Agents and Luspatercept (or ineligible for the latter).
Read the detailed description
Dose escalation cohort to determine the dose limiting toxicity according to a BOIN (Bayesian optimal interval) scheme.
Patients will receive one dose of study treatment (oral Arsenic (ATO)) 5d/7 for 21 days over a 28-day cycle.
Three doses of ATO will be tested (0.10 mg/kg, 0.15 mg/kg and 0.20 mg/kg), and 9 patients will be treated at each dose.
An expansion cohort at the selected dose based on DSMB recommendations will be conducted with 6 patients, for a maximum of 15 patients included at this dose level.
Tolerability will be assessed after one treatment cycle. Response will be assessed after 3 cycles of treatment. Responders may continue study treatment until progression or limiting toxicity. Limiting toxicity is defined as any grade III/IV extra-hematological toxicity or grade IV hematological toxicity lasting more than 25 days.
If there is no response, patients will stop treatment and enter the follow-up phase of the study.
- Conditions
- Low-risk Myelodysplastic Syndromes
- Being tested
- Arsenic Trioxide (ATO)
- Keywords
- Oral Arsenic, Low-risk myelodysplastic syndromes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Arsenic Trioxide (ATO)Drug
Study treatment: oral Arsenic 5d/7 for 21 days over a 28-day cycle, three doses tested (0.10 mg/kg, 0.15 mg/kg and 0.20 mg/kg).
Dose escalation cohort to determine the dose limiting toxicity according to a BOIN (Bayesian optimal interval) scheme, 9 patients will be treated at each dose.
An expansion cohort at the selected dose will be conducted with 6 patients.
Tolerability will be assessed after one treatment cycle. Response will be assessed after 3 cycles of treatment. Responders may continue study treatment until progression or limiting toxicity. Limiting toxicity is defined as any grade III/IV extra-hematological toxicity or grade IV hematological toxicity lasting more than 25 days.
| Study group | Role | What they receive |
|---|---|---|
| ATO | Experimental | Oral Arsenic treatment Receives: Drug: Arsenic Trioxide (ATO) |
What is being measured
The primary outcome is the main question the study is designed to answer.
To determine the dose-limiting toxicity (DLT) of oral Arsenic (ATO)
Dose-limiting toxicity will be defined by the occurrence during the first treatment cycle of any of the following toxicities related to the trial drug (oral ATO):
- Non-hematological toxicity of grade ≥ 3
- Hematological toxicity of grade ≥ 4 corresponding to a decrease of 50% or more of absolute neutrophil count (ANC) or platelet count from baseline or lower limit (if baseline was above normal), without recovery at D42 of the first cycle.
Measured: At the end of cycle 1 (each cycle is 28 days)
Secondary outcomes (8)
To determine safety profile
Toxicities measured according to CTCAE (Common Terminology Criteria for Adverse Events)
Measured: Through study completion, an average of 2 years
Pharmacokinetics
Measurement of the peak plasma concentration (Cmax) of oral ATO
Measured: At the end of cycle 1 (each cycle is 28 days)
Pharmacokinetics
Measurement of area under the plasma concentration versus time curve (AUC) for oral ATO
Measured: At the end of cycle 1 (each cycle is 28 days)
Pharmacokinetics
Measurement of the residual concentration (Cmin) of oral ATO
Measured: At the end of cycle 1 (each cycle is 28 days)
Efficacy
Response rate (Complete Response + Partial Response + stable disease with hematological improvement according to IWG (International Working Group) 2018 criteria)
Measured: At the end of cycle 3 (each cycle is 28 days)
Response duration
Response duration measured from date of objective response to date of relapse or progression (or date of last news in absence of event)
Measured: Through study completion, an average of 2 years
Progression-free survival
Rate and time to transformation to high-risk myelodysplastic syndrome (MDS) or Acute Myeloid Leukemia (AML)
Measured: Through study completion, an average of 2 years
Overall survival
Overall survival from date of inclusion to death or date of last news
Measured: Through study completion, an average of 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Nov 2024
- Study start22 Jul 2025
- Primary completion24 Oct 2026 (estimated)
- Study completionJul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Low-risk Myelodysplastic SyndromesStudies 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
- Single group
- Model description
- Dose escalation cohort to determine the dose limiting toxicity according to a BOIN (Bayesian optimal interval) scheme. Three doses of oral Arsenic will be tested, and 9 patients will be treated at each dose. An expansion cohort at the selected dose will be conducted with 6 patients, for a maximum of 15 patients included at this dose level.
- Masking
- None (open label)
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Groupe Francophone des Myelodysplasies
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06670222
- Sponsor's protocol ID
- ATOMYELO
- Other IDs
- 2024-515311-22-00
- Status last verified
- Sep 2026
- First submitted
- 15 Oct 2024
- Last updated
- 10 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase I Study With Dose-escalation and Expansion Evaluating the Safety and Efficacy of Oral Arsenic (ATO) in Low-risk Myelodysplastic Syndromes Failing Erythropoiesis Stimulating Agents and Luspatercept (or Ineligible for the Latter)
- ClinicalTrials.gov ID
- NCT06670222
- Acronym / sponsor ID
- ATOMYELO
- Conditions
- Low-risk Myelodysplastic Syndromes
- Keywords
- Oral Arsenic, Low-risk myelodysplastic syndromes
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- Groupe Francophone des MyelodysplasiesUniversity, hospital or other
- Study start
- 22 Jul 2025 (actual)
- Primary completion
- 24 Oct 2026 (estimated)
- Study completion
- Jul 2027 (estimated)
- First posted
- 1 Nov 2024 (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.
Phase I study with dose-escalation and expansion evaluating the safety and efficacy of oral Arsenic (ATO) in low-risk Myelodysplastic Syndromes having failed to Erythropoiesis Stimulating Agents and Luspatercept (or ineligible for the latter).
Detailed description
Dose escalation cohort to determine the dose limiting toxicity according to a BOIN (Bayesian optimal interval) scheme.
Patients will receive one dose of study treatment (oral Arsenic (ATO)) 5d/7 for 21 days over a 28-day cycle.
Three doses of ATO will be tested (0.10 mg/kg, 0.15 mg/kg and 0.20 mg/kg), and 9 patients will be treated at each dose.
An expansion cohort at the selected dose based on DSMB recommendations will be conducted with 6 patients, for a maximum of 15 patients included at this dose level.
Tolerability will be assessed after one treatment cycle. Response will be assessed after 3 cycles of treatment. Responders may continue study treatment until progression or limiting toxicity. Limiting toxicity is defined as any grade III/IV extra-hematological toxicity or grade IV hematological toxicity lasting more than 25 days.
If there is no response, patients will stop treatment and enter the follow-up phase of the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Dose escalation cohort to determine the dose limiting toxicity according to a BOIN (Bayesian optimal interval) scheme. Three doses of oral Arsenic will be tested, and 9 patients will be treated at each dose. An expansion cohort at the selected dose will be conducted with 6 patients, for a maximum of 15 patients included at this dose level.
| Arm | Type | Receives |
|---|---|---|
| ATO | Experimental | Drug: Arsenic Trioxide (ATO)Oral Arsenic treatment |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (22 listed)
- Myelodysplastic syndrome according to WHO (World Health Organization) 2022 classification
- Age ≥ 18 years
- Patient with low-risk Myelodysplastic Syndromes according to Revised International Prognostic Scoring System (IPSS-R) classification (very low, low, intermediate):
- Transfusion dependence (at least 3 RBC (Red Blood Cell) within a 16-week period and at least 2 transfusion episodes during this period)
- Patient not eligible for another clinical trial
Key exclusion criteria (14 listed)
- Severe infection or any uncontrolled severe condition
- Uncontrolled hypertension
- Significant cardiac disease - NYHA (New York Heart Association) Class III or IV or having suffered a myocardial infarction in the last 6 months
- QTcF (Fridericia's corrected QT interval) > 460ms
- Use of investigational agents within 30 days or any anticancer therapy (including IMiD (Immunomodulatory treatments)) within 2 weeks before the study entry with the exception of hydroxyurea. The patient must have recovered at least a grade 1 from all acute toxicity from any previous therapy. However, patients may have received Lenalidomide, hypomethylating agent, or anti-lymphocytic serum (ALS) (but not within 4 weeks before the study entry and, for ALS, within 16 weeks before the study entry).
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 |
|---|---|---|
| Arsenic Trioxide (ATO)Study treatment: oral Arsenic 5d/7 for 21 days over a 28-day cycle, three doses tested (0.10 mg/kg, 0.15 mg/kg and 0.20 mg/kg). Dose escalation cohort to determine the dose limiting toxicity according to a BOIN (Bayesian optimal interval) scheme, 9 patients will be treated at each dose. An expansion cohort at the selected dose will be conducted with 6 patients. Tolerability will be assessed after one treatment cycle. Response will be assessed after 3 cycles of treatment. Responders may continue study treatment until progression or limiting toxicity. Limiting toxicity is defined as any grade III/IV extra-hematological toxicity or grade IV hematological toxicity lasting more than 25 days. | Drug | ATO |
Primary outcome
To determine the dose-limiting toxicity (DLT) of oral Arsenic (ATO)
Time frame: At the end of cycle 1 (each cycle is 28 days)
Dose-limiting toxicity will be defined by the occurrence during the first treatment cycle of any of the following toxicities related to the trial drug (oral ATO): * Non-hematological toxicity of grade ≥ 3 * Hematological toxicity of grade ≥ 4 corresponding to a decrease of 50% or more of absolute neutrophil count (ANC) or platelet count from baseline or lower limit (if baseline was above normal), without recovery at D42 of the first cycle.
8 secondary outcomes
To determine safety profile
Time frame: Through study completion, an average of 2 years
Pharmacokinetics
Time frame: At the end of cycle 1 (each cycle is 28 days)
Pharmacokinetics
Time frame: At the end of cycle 1 (each cycle is 28 days)
Pharmacokinetics
Time frame: At the end of cycle 1 (each cycle is 28 days)
Efficacy
Time frame: At the end of cycle 3 (each cycle is 28 days)
Response duration
Time frame: Through study completion, an average of 2 years
Progression-free survival
Time frame: Through study completion, an average of 2 years
Overall survival
Time frame: Through study completion, an average of 2 years
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 10 Sep 2026.
- Individual participant dataSharing planned: No
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A Study to Compare Elritercept With Epoetin Alfa to Treat Anemia in Adults With Lower Risk Myelodysplastic Syndromes (LR-MDS) Who Need Regular Blood Transfusions
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RecruitingPhase 2
A Study of TAK-226 for Anemia in Japanese Patients With Lower-Risk Myelodysplastic Syndromes
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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.
Jean Baptiste MICOL, MD contact
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 Arsenic Trioxide (ATO) in people with Low-risk Myelodysplastic Syndromes, run by Groupe Francophone des Myelodysplasies at 3 sites in France.
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 22 inclusion and 14 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 10 Sep 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 France. 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 Thomas CLUZEAU, MD/PhD (+33 492035839, cluzeau.t@chu-nice.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To determine the dose-limiting toxicity (DLT) of oral Arsenic (ATO) (time frame: At the end of cycle 1 (each cycle is 28 days)). 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 10 Sep 2026.