A Phase 1/2 interventional study of Hydroxycarbamid in R/R AML, sponsored by Christer C Nilsson. Not yet recruiting at 1 site in Sweden. Open to participants aged 18 Years to 74 Years. Per ClinicalTrials.gov, last updated 2026-08-17.
Sponsored by Christer C Nilsson · Phase 1/2, Interventional, and Treatment
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This study is evaluating a new treatment approach for adults with acute myeloid leukemia (AML) that has either returned after previous treatment or has not responded to treatment. Outcomes for these patients are often poor, and there is a need for more effective therapies.
The study is investigating whether adding hydroxyurea to a combination of established AML medicines (fludarabine, cytarabine, idarubicin, and venetoclax) is safe and tolerable and can improve treatment results. Laboratory studies suggest that hydroxyurea may help leukemia cells become more sensitive to treatment and may increase the effectiveness of chemotherapy.
The study is being conducted in two parts. In the first part, researchers will determine the safest and most appropriate dose of hydroxyurea when given together with the study treatment. In the second part, researchers will evaluate whether adding hydroxyurea improves treatment outcomes, including the length of time patients remain free from disease progression, relapse, or death.
The overall goal of the study is to determine whether adding hydroxyurea to standard treatment for relapsed or refractory AML is safe and may improve patient outcomes.
This is the only study on the registry with Christer C Nilsson as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
A diagnosis of either:
Adequate renal and hepatic functions as indicated by the following laboratory values:
Exclusion Criteria:
Cardiac dysfunction as defined by:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hydroxyurea added to fludarabine, ara-C, idarubicin and venetoclax
Drug: Hydroxycarbamid
Hydroxyurea 500-1000 mg administered 1 hour before each infusion of cytarabine.
Also known as: Hydroxyurea
1-year EFS
Defined as event-free-survial from the time from initiation of study treatment to the first occurrence of treatment failure, hematologic relapse from CR/CRi, or death from any cause.
Time frame: From initiation of study treatment to the first occurrence of treatment failure, hematologic relapse after CR/CRi, or death from any cause, whichever occurs first, assessed up to 365 days.
Safety and tolerability: incidence and severity of treatment-emergent adverse events
Frequency, nature and severity of non-hematological toxicities, including potential ara-C or fludarabine related neurological or dermatological adverse events.
Time frame: From registration in the study until 60 days after the last dose of treatment.
Overall survival (OS)
Overall survival (OS), defined as the time from initiation of study treatment to death from any cause, with survival estimates reported at 1 and 2 years after initiation of study treatment.
Time frame: From initiation of study treatment through 2 years of follow-up.
2-year event-free survival (EFS)
Time from initiation of study treatment to the first occurrence of treatment failure, hematologic relapse after CR/CRi, or death from any cause, whichever occurs first.
Time frame: From initiation of study treatment through 2 years of follow-up.
Relapse-free survival (RFS)
Overall survival (OS), defined as the time from initiation of study treatment to the date of death from any cause or hematologic relapse from CR/CRi, with survival estimates reported at 1 and 2 years after initiation of study treatment.
Time frame: From initiation of study treatment through 2 years of follow-up.
Cumulative incidence of hematologic relapse
Cumulative incidence of hematologic relapse after achievement of CR/CRi, reported at 1 and 2 years. Death without prior relapse will be treated as a competing risk.
Time frame: From initiation of study treatment through 2 years of follow-up.
Response rate
Proportion of patients achieving complete remission (CR), complete remission with incomplete hematologic recovery (CRi), morphologic leukemia-free state (MLFS), partial remission (PR) and minimal residual disease (MRD) negativity.
Time frame: At response assessment after Cycle 1 (between Day 25 and Day 35 from the start of Cycle 1).
Time to hematopoietic recovery
Time to hematopoietic recovery (ANC 0.5 and 1.0 x 109/L; platelets 50 and 100 x 109/L) after each chemotherapy treatment cycle, defined as the time from the start of the cycle until recovery.
Time frame: From the start of each treatment cycle until hematopoietic recovery. Treatment cycles are of variable duration, with no predefined cycle length; the subsequent cycle is initiated only after hematopoietic recovery.
Rate of patients bridged to allo-HCT
Proportion of patients undergoing allogeneic hematopoietic cell transplantation.
Time frame: From treatment initiation until allogeneic hematopoietic cell transplantation, relapse/progression, death, or 2 years of follow-up, whichever occurs first.
Early mortality (30-day and 60-day mortality)
Proportion of patients who die from any cause within 30 and 60 days after initiation of study treatment.
Time frame: 30 and 60 days after initiation of study treatment.
Intracellular accumulation of ara-CTP and F-ara-ATP
Assessment of intracellular accumulation of ara-CTP and F-ara-ATP in circulating blasts as a biomarker for efficacy of added hydroxyurea.
Time frame: During the first 2 days of treatment (run-in phase), at 4 predefined time points.
SAMHD1 protein expression
Assessment of SAMHD1 protein expression in blasts before treatment as a biomarker for efficacy of added hydroxyurea
Time frame: At baseline, prior to initiation of study treatment.
Plan to share: No — IPD Sharing Statement: Individual participant data (IPD) will not be shared. Justification: The study is an early-phase investigator-initiated clinical trial in a rare and high-risk patient population. Due to the small sample size, detailed molecular data, and potential risk of re-identification despite de-identification, individual participant data will not be made publicly available.
No publications or documents are linked to this record.
Start is estimated for Oct 2026; primary completion for Jun 2029, 32 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Hydroxyurea