Sickle Cell DiseasePhase 2NCT06635902
Intravenous L-Citrulline for Vaso-occlusive Pain Episode in Sickle Cell Disease
A Phase 2 study testing L-citrulline in people with Sickle Cell Disease and Vaso-occlusive Pain Episode, run by Suvankar Majumdar at 1 site in United States.
Trial summary
The goal of this clinical trial is to learn if intravenous citrulline works to treat acute pain in hospitalized patients with sickle cell disease. It will also learn about the safety of intravenous citrulline. Read more about this study
- Who is it for?
- Ages 4 to 21 years
- Conditions the study is for
- Sickle Cell Disease, Vaso-occlusive Pain Episode
- What is being tested?
- L-citrulline
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 99 participants
- Where
- 1 siteUnited States
- Study dates
- 22 Dec 2024to Mar 2029
- Phase
- Phase 2
- 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 4 to 21 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Sickle cell disease (all genotypes)
- Patients with sickle cell disease ages 4 to 21 years old
- Presence of sickle cell vaso-occlusive pain episode requiring hospitalization and parenteral opioid therapy
- Able to randomize to study drug/placebo within 12 hours of first dose of parenteral opioid in the Emergency Department
Who cannot join
- Current pain lasting >3 days.
- >9 hospitalizations in the prior year
- Presence of any other complication related to sickle cell disease requiring the hospitalization such as splenic sequestration, hepatic sequestration, stroke, transient ischemic attack, etc.
- History of opioid use disorder, chronic pain or medical regimen requiring daily opioid use.
- Severe anemia (hemoglobin <6g/dL)
- Pregnant (as confirmed by a positive urine pregnancy test) or lactating female.
Show all 14Show fewer
- Alanine/aspartate transferase >2x upper limit of normal laboratory range for age.
- Subject has the following serum creatinine:
- Age 4 to 13 years > 0.9 mg/dL
- Age 14 to 17 years 1.0 mg/dL
- Age ≥18 years >1.5mg/dL
- Presence of acute chest syndrome, sepsis, bacterial infection, hemodynamic instability
- Use of L-glutamine
- History of allergic reaction to L-citrulline products
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Children's National Hospital
Washington D.C., District of Columbia, 20010
Jillian Baker, RN, 202-476-1311, jbaker5@childrensnational.org
Suvankar Majumdar, MD
About this study
Official title: A Phase 2 Randomized Double-blind, Placebo-controlled Clinical Trial of Intravenous Citrulline for Vaso-occlusive Pain Episode in Hospitalized Patients With Sickle Cell Disease (CONQUER SCD Pain Trial)
The goal of this clinical trial is to learn if intravenous citrulline works to treat acute pain in hospitalized patients with sickle cell disease. It will also learn about the safety of intravenous citrulline. The main questions it aims to answer are:
- Does intravenous citrulline decrease the duration of sickle cell pain during hospitalization
- What medical problems do participants have when taking intravenous citrulline? Researchers will compare intravenous citrulline to a placebo (a look-alike substance that contains no drug) to see if intravenous citrulline works to treat acute pain.
Read more
Participants will:
- Receive baseline tests and intravenous citrulline for 16 hours during the hospital stay
- After hospital discharge, visit the clinic in about 30 days for checkup and tests
Read the detailed description
This is a single-center phase 2 randomized double-blind, placebo-controlled trial of intravenous L-citrulline for sickle cell patients ages 4 to 21 years experiencing a vaso-occlusive pain crisis episode (VOE). Eligible subjects will have a documented history of sickle cell disease and inpatient hospitalization for treatment of acute pain with parenteral opioid. Subjects will be randomized to receive high dose intravenous L-citrulline, low dose intravenous L-citrulline or placebo in addition to standard of care. Subjects will be followed closely to evaluate time-to-crisis resolution as the primary outcome defined by time from first dose of intravenous study drug/placebo to the last dose of parenteral opioid prior to hospital discharge. Participants will be monitored for any adverse events including 30-day re-hospitalization rates. Total opioid consumption during the time-to-crisis resolution will be compared between the three arms. In addition, exploratory outcomes will be evaluated for pain score, tissue blood flow, genetic and candidate biomarkers related to vaso-occlusion.
Objectives Primary Objective
- To demonstrate the efficacy of intravenous L-citrulline in reducing the time-to-crisis resolution in sickle cell subjects experiencing a vaso-occlusive pain crisis episode (VOE).
Secondary Objectives
- To evaluate the safety of intravenous L-citrulline in the treatment of VOE
- To determine if intravenous L-citrulline improves cumulative opioid consumption during the treatment of VOE Exploratory Objectives
- To determine if intravenous L-citrulline improves pain scores during the hospitalization
- To determine if intravenous L-citrulline improves 30-day re-hospitalization rates
- To determine the pharmacokinetic (PK) profile of intravenous L-citrulline
- To evaluate whether intravenous L-citrulline improves tissue blood flow and candidate biomarkers related to vaso-occlusion.
- To assess whether genetic single nucleotide polymorphisms related to the nitric oxide pathway influence study outcomes
- Conditions
- Sickle Cell Disease, Vaso-occlusive Pain Episode
- Being tested
- L-citrulline, Placebo
- Keywords
- sickle cell disease, sickle cell pain crisis, citrulline
- Medical subject headings
- Anemia, Sickle Cell
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
L-citrullineDrug
Intravenous L-citrulline (50 mg/kg + 9mg/kg/hr.) for 16 hours
PlaceboOther
Isotonic normal saline
L-citrullineDrug
Intravenous L-citrulline (25 mg/kg + 9mg/kg/hr.) for 16 hours
| Study group | Role | What they receive |
|---|---|---|
| Low dose intravenous L-citrulline | Experimental | Not described Receives: Drug: L-citrulline |
| High dose intravenous L-citrulline | Experimental | Not described Receives: Drug: L-citrulline |
| Placebo | Placebo comparator | Not described Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time-to-crisis resolution
Change in time-to-crisis resolution as defined by the time (in hours) from first dose of intravenous study drug or placebo to the time of last dose of intravenous opioid during hospitalization
Measured: Baseline to 30 days
Secondary outcomes (3)
Safety
Number of Participants With Treatment-Related Adverse Events as Assessed by CTCAE v4.0
Measured: Baseline to 30 days
Opioid consumption
Change in cumulative opioid consumption (calculated in morphine equivalents) from time of study drug administration to last dose of IV/oral opioid during hospitalization
Measured: Baseline to 30 days
Pain scores
Change in baseline pain scores will be recorded from a 0-10 scale, 10 is worst pain
Measured: Baseline to 30 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Oct 2024
- Study start22 Dec 2024
- Primary completionJun 2028 (estimated)
- Study completionMar 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sickle Cell DiseaseStudies 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 99 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Suvankar Majumdar
- Sponsor type
- University, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Responsible party
- Sponsor-investigator, Suvankar Majumdar, Children's National Research Institute
- Investigators
- Suvankar Majumdar, MD, Principal investigator, Children's National Research Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06635902
- Sponsor's protocol ID
- 00000880
- Other IDs
- 1R61HL167806
- Status last verified
- Apr 2026
- First submitted
- 7 Oct 2024
- Last updated
- 13 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: All IPD that underlie results in a publication will be shared
Study at a glance
From the registry record, last updated by the sponsor on 13 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2 Randomized Double-blind, Placebo-controlled Clinical Trial of Intravenous Citrulline for Vaso-occlusive Pain Episode in Hospitalized Patients With Sickle Cell Disease (CONQUER SCD Pain Trial)
- ClinicalTrials.gov ID
- NCT06635902
- Acronym / sponsor ID
- 00000880
- Conditions
- Sickle Cell Disease, Vaso-occlusive Pain Episode
- Keywords
- sickle cell disease, sickle cell pain crisis, citrulline
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 99 participants (estimated)
- Lead sponsor
- Suvankar MajumdarUniversity, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Study start
- 22 Dec 2024 (actual)
- Primary completion
- Jun 2028 (estimated)
- Study completion
- Mar 2029 (estimated)
- First posted
- 10 Oct 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.
The goal of this clinical trial is to learn if intravenous citrulline works to treat acute pain in hospitalized patients with sickle cell disease. It will also learn about the safety of intravenous citrulline. The main questions it aims to answer are:
- Does intravenous citrulline decrease the duration of sickle cell pain during hospitalization
- What medical problems do participants have when taking intravenous citrulline? Researchers will compare intravenous citrulline to a placebo (a look-alike substance that contains no drug) to see if intravenous citrulline works to treat acute pain.
Participants will:
- Receive baseline tests and intravenous citrulline for 16 hours during the hospital stay
- After hospital discharge, visit the clinic in about 30 days for checkup and tests
Detailed description
This is a single-center phase 2 randomized double-blind, placebo-controlled trial of intravenous L-citrulline for sickle cell patients ages 4 to 21 years experiencing a vaso-occlusive pain crisis episode (VOE). Eligible subjects will have a documented history of sickle cell disease and inpatient hospitalization for treatment of acute pain with parenteral opioid. Subjects will be randomized to receive high dose intravenous L-citrulline, low dose intravenous L-citrulline or placebo in addition to standard of care. Subjects will be followed closely to evaluate time-to-crisis resolution as the primary outcome defined by time from first dose of intravenous study drug/placebo to the last dose of parenteral opioid prior to hospital discharge. Participants will be monitored for any adverse events including 30-day re-hospitalization rates. Total opioid consumption during the time-to-crisis resolution will be compared between the three arms. In addition, exploratory outcomes will be evaluated for pain score, tissue blood flow, genetic and candidate biomarkers related to vaso-occlusion.
Objectives Primary Objective
- To demonstrate the efficacy of intravenous L-citrulline in reducing the time-to-crisis resolution in sickle cell subjects experiencing a vaso-occlusive pain crisis episode (VOE).
Secondary Objectives
- To evaluate the safety of intravenous L-citrulline in the treatment of VOE
- To determine if intravenous L-citrulline improves cumulative opioid consumption during the treatment of VOE Exploratory Objectives
- To determine if intravenous L-citrulline improves pain scores during the hospitalization
- To determine if intravenous L-citrulline improves 30-day re-hospitalization rates
- To determine the pharmacokinetic (PK) profile of intravenous L-citrulline
- To evaluate whether intravenous L-citrulline improves tissue blood flow and candidate biomarkers related to vaso-occlusion.
- To assess whether genetic single nucleotide polymorphisms related to the nitric oxide pathway influence study outcomes
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Low dose intravenous L-citrulline | Experimental | Drug: L-citrulline |
| High dose intravenous L-citrulline | Experimental | Drug: L-citrulline |
| Placebo | Placebo comparator | Other: Placebo |
Who may qualify
- Ages
- 4 to 21 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (4 listed)
- Sickle cell disease (all genotypes)
- Patients with sickle cell disease ages 4 to 21 years old
- Presence of sickle cell vaso-occlusive pain episode requiring hospitalization and parenteral opioid therapy
- Able to randomize to study drug/placebo within 12 hours of first dose of parenteral opioid in the Emergency Department
Key exclusion criteria (14 listed)
- Current pain lasting >3 days.
- >9 hospitalizations in the prior year
- Presence of any other complication related to sickle cell disease requiring the hospitalization such as splenic sequestration, hepatic sequestration, stroke, transient ischemic attack, etc.
- History of opioid use disorder, chronic pain or medical regimen requiring daily opioid use.
- Severe anemia (hemoglobin <6g/dL)
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 |
|---|---|---|
| L-citrullineIntravenous L-citrulline (50 mg/kg + 9mg/kg/hr.) for 16 hours | Drug | High dose intravenous L-citrulline |
| PlaceboIsotonic normal saline | Other | Placebo |
| L-citrullineIntravenous L-citrulline (25 mg/kg + 9mg/kg/hr.) for 16 hours | Drug | Low dose intravenous L-citrulline |
Primary outcome
Time-to-crisis resolution
Time frame: Baseline to 30 days
Change in time-to-crisis resolution as defined by the time (in hours) from first dose of intravenous study drug or placebo to the time of last dose of intravenous opioid during hospitalization
3 secondary outcomes
Safety
Time frame: Baseline to 30 days
Opioid consumption
Time frame: Baseline to 30 days
Pain scores
Time frame: Baseline to 30 days
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 13 Apr 2026.
- Individual participant dataSharing planned: Yes. All IPD that underlie results in a publication will be shared
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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.
Suvankar Majumdar, MD principal investigator
Children's National Research Institute
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing L-citrulline in people with Sickle Cell Disease and Vaso-occlusive Pain Episode, run by Suvankar Majumdar at 1 site 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 4 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 13 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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. Some participants in this study may receive a placebo. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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 Jillian Baker, RN (202-476-1311, jbaker5@childrensnational.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time-to-crisis resolution (time frame: Baseline to 30 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 13 Apr 2026; AzTrials last refreshed its copy on 8 Nov 2026.