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Sickle Cell DiseasePhase 2ASCENT1NCT05405114

Research Study Investigating How Well NDec Works in People With Sickle Cell Disease

A Phase 2 study testing NDec - oral decitabine-tetrahydrouridine and HU - Hydroxyurea in people with Sickle Cell Disease, run by Novo Nordisk A/S at 118 sites in 14 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

This study examines how well a new, potential medicine called NDec works and is tolerated in people with sickle cell disease. NDec is a combination of two medicines (decitabine-tetrahydrouridine). Both medicines are new for the treatment of sickle cell disease. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Sickle Cell Disease
What is being tested?
NDec - oral decitabine-tetrahydrouridine and HU - Hydroxyurea
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
96 participants
Where
118 sitesin 14 countries
Study dates
7 Jul 2022to 24 Jul 2025
Phase
Phase 2
Are there results?
None posted in the registry

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

  • Age above or equal to 18 years at the time of signing informed consent
  • Confirmed diagnosis of SCD (including HbSS, HbSC, HbSβ0 thalassaemia and HbSβ+ thalassaemia or other Sickle Cell disease variants)
  • 2-10 episodes of documented vaso-occlusive crisis (VOCs) within the last 12 months prior to the screening visit
  • Haemoglobin greater than or equal to 5.0 g/dL and below or equal to 10.5 g/dL at visit 1
  • Absolute reticulocyte count above upper limit of the normal (ULN) at visit 1
  • Body weight 40 to 125 kg (inclusive).

Who cannot join

  • Patient is on chronic transfusion therapy as defined by receiving scheduled (pre-planned) series of blood transfusion (simple or exchange) for prophylactic purposes, or the patient is likely to begin chronic transfusion therapy during the course of the trial, or has received RBC or whole blood transfusion for any reason within 28 days of visit 1
  • Receipt of erythropoietin or other haematopoietic growth factor treatment within 28 days of signing ICF, or planned treatment with these agents during the trial
  • Receipt of voxelotor, crizanlizumab or L-glutamine treatment within 12 weeks of signing the informed consent form, or planned treatment with such agents during the trial
  • Platelet count greater than 800 x 10^9/L at visit 1
  • Absolute neutrophil count below or equal to 1.5 x 10^9/L at visit 1
  • Any condition/concurrent chronic disease involving the stomach or small intestine which may affect drug absorption, as per investigator's judgement
Show all 13Show fewer
  • Female who is
  • pregnant, breast-feeding or intends to become pregnant within 6 months after the final trial product administration
  • child-bearing potential and not using highly effective methods of contraception and whose male partner is not using effective contraception, at screening and until 6 months after the last dose of trial product
  • Male with female partner of childbearing potential who does not agree to use condom and whose female partner of childbearing potential is not using a highly effective contraceptive measure from trial start to:
  • Six (6) months after the last dose of trial product for patients on NDec/Placebo
  • Six (6) months after the last dose of trial product for patients outside US and CA randomised to HU
  • Twelve (12) months after the last dose of trial product for patients randomised to HU in US and CA

Trial locations and contacts

118 sites in 14 countries.

118 sites in 14 countries

United States53 sites

  • Emory University School Of Med

    Atlanta, Georgia, 30333

  • Aflac Cancer/Blood Dis CCH

    Atlanta, Georgia, 30342

  • Emory University School Of Med

    Atlanta, Georgia, 30342

  • Augusta University

    Augusta, Georgia, 30912

  • Clinical and Transl Res Center

    Aurora, Colorado, 80045

  • Mass General Cancer Center

    Boston, Massachusetts, 02114

  • Interfaith Medical Center

    Brooklyn, New York, 11238

  • University of North Carlolina-Chapel Hill

    Chapel Hill, North Carolina, 27599

  • Medical Univ of SC Charleston

    Charleston, South Carolina, 29425

  • Atrium Levine Children's/Atrium Health

    Charlotte, North Carolina, 28204

  • University Of Virginia Hospital

    Charlottesville, Virginia, 22908

  • Rush University Med. Cntr

    Chicago, Illinois, 60612

  • Univer Of Illinois at Chicago

    Chicago, Illinois, 60612

  • Dayton Children's Hosptial

    Dayton, Ohio, 45404

  • Wayne State University/University Health Center

    Detroit, Michigan, 48201

  • Duke Comprehen Sickle Cell

    Durham, North Carolina, 27710

  • Carole&Ray Neag Comp S.C. Ctr

    Farmington, Connecticut, 06030

  • East Carolina Univ-Greenville

    Greenville, North Carolina, 27834-4300

  • East Carolina Univ-Greenville

    Greenville, North Carolina, 27834

  • Hackensack University Medical Center

    Hackensack, New Jersey, 07601

  • Foundation for Sickle Cell Disease Research

    Hollywood, Florida, 33023

  • Baylor College of Medicine Texas Childen's Hospital

    Houston, Texas, 77030

  • Baylor College of Medicine_Houston

    Houston, Texas, 77030

  • Dan L. Duncan Comprehensive Cancer Center

    Houston, Texas, 77030

  • Univ Texas HSC-Houston

    Houston, Texas, 77030

  • University of Florida, College of Medicine Jacksonville

    Jacksonville, Florida, 32209

  • Queens Hospital Center

    Jamaica, New York, 11432-1121

  • Cure 4 the Kids Foundation

    Las Vegas, Nevada, 89135

  • Keck Medical Center of USC - Outpatient Clinic

    Los Angeles, California, 90033

  • Mississippi Center Advanced Medicine

    Madison, Mississippi, 39110

  • University Of Tennessee

    Memphis, Tennessee, 38163

  • Tulane Sickle Cell Ctr- So LA

    Metairie, Louisiana, 70002

  • University of Miami Hospital & Clinics

    Miami, Florida, 33136

  • Medical College of Wisconsin & Zablocki VAMC

    Milwaukee, Wisconsin, 53226

  • Children's Hospitals And Clinics Of Minnesota

    Minneapolis, Minnesota, 55404

  • University of Minnesota_Minneapolis_0

    Minneapolis, Minnesota, 55455

  • University Of South Alabama

    Mobile, Alabama, 36617

  • Mount Sinai School of Medicine

    New York, New York, 10029

  • UCSF Oakland Benioff ChildHosp

    Oakland, California, 94609

  • Univ Oklahoma HSC_Okla City

    Oklahoma City, Oklahoma, 73104

  • University of Oklahoma Health Sciences Center_Oklahoma City

    Oklahoma City, Oklahoma, 73104

  • Univ of NE Med Center_Omaha

    Omaha, Nebraska, 68198

  • Center for Inherited Blood Dis

    Orange, California, 92868

  • Penn Comprehensive Hemophilia & Thrombosis Program

    Philadelphia, Pennsylvania, 19104

  • Thomas Jefferson University Hospital

    Philadelphia, Pennsylvania, 19107

  • St Christopher Hosp for Child

    Philadelphia, Pennsylvania, 19134

  • Hemophilia Center of Western PA

    Pittsburgh, Pennsylvania, 15213

  • Jacobi Medical Center

    The Bronx, New York, 10461

  • Montefiore Medical Center

    The Bronx, New York, 10467

  • Harbor-UCLA Medical Center

    Torrance, California, 90502-2004

  • Howard University Hospital Department Med

    Washington D.C., District of Columbia, 20060

  • Howard University

    Washington D.C., District of Columbia, 20060

  • Tova Community Health Inc

    Wilmington, Delaware, 19805

Other trials in United States

India23 sites

  • Victoria Hospital (Bangalore Medical College and Research Institute)

    Bangalore, Karnataka, 560002

  • IMS and SUM Hospital

    Bhubaneswar, Odisha, 751003

  • S.C.B. Medical College

    Cuttack, Odisha, 753007

  • Zydus Medical College & Hospital

    Dohad, Gujarat, 389151

  • Gauhati Medical College and Hospital

    Guwahati, Assam, 781032

  • Yashoda hospital

    Hyderabad, Telangana, 500082

  • NRS Medical College & Hospital

    Kolkata, West Bengal, 700014

  • NRS Medical College & Hospital

    Kolkata, West Bengal, 70014

  • Government Medical College, Kozhikode

    Kozhikode, Kerala, 673008

  • Sanjay Gandhi Postgraduate Institute of Medical Sciences

    Lucknow, Uttar Pradesh, 226014

  • K.J Somaiya Hospital and Research Centre

    Mumbai, Maharashtra, 400022

  • J.S.S.Hospital

    Mysore, Karnataka, 570004

  • Government Medical College and Hospital

    Nagpur, Maharashtra, 440003

  • Government Medical College and Super Speciality Hospital, Nagpur

    Nagpur, Maharashtra, 440003

  • Government Medical College and Super Speciality Hospital, Nagpur

    Nagpur, Maharashtra, 440009

  • KIMS - Kingsway Hospital

    Nagpur, 440001

  • All India Institute of Medical Sciences (AIIMS), Raipur

    Raipur, Chhattisgarh, 492099

  • Christian Medical College Hospital, Vellore

    Ranipet, Tamil Nadu, 632517

  • Nirmal Hospital Pvt. Ltd.

    Surat, Gujarat, 395002

  • BAPS Pramukh Swami Hospital

    Surat, Gujarat, 395009

  • SSG Hospital, Baroda

    Vadodara, Gujarat, 390001

  • SSG Hospital, Baroda

    Vadodara, Gujarat, 390006

  • Christian Medical College Hospital, Vellore

    Vellore, Tamil Nadu, 632004

Other trials in India

Canada8 sites

  • Univ of Alberta Hosp Edmonton

    Edmonton, Alberta, T6G 2B7

  • LHSC - Victoria Hospital

    London, Ontario, N6A 5W9

  • LHSC - Victoria Hospital

    London, Ontario, ON N6A 5W9

  • Hospitalier de l'Universite de Montreal (CHUM)-Hôpital Notre

    Montreal, Quebec, H2L 4M1

  • McGill University Health Centre

    Montreal, Quebec, H4A 3J1

  • The Hospital for Sick Children

    Toronto, Ontario, M5G 1X8

  • Toronto General Hospital, Liver Clinic

    Toronto, Ontario, M5G 2C4

  • Toronto General Hospital, Liver Clinic

    Toronto, Ontario, M5G2C4

Other trials in Canada

United Kingdom7 sites

  • University Hospital of Wales

    Cardiff, CF14 4XW

  • Royal London Hospital_London

    London, E1 1BB

  • University College Hospital - Paediatric Services

    London, NW1 2PG

  • Central Middlesex Hospital

    London, NW10 7NS

  • Guy's Hospital

    London, SE1 9RT

  • King's College Hospital

    London, SE5 9RS

  • Manchester Royal Infirmary

    Manchester, M13 9WL

Other trials in United Kingdom

Italy5 sites

  • Ospedali Galliera

    Genova, 16128

  • Fondazione IRCSS Ca' Granda Ospedale Maggiore Policlinico

    Milan, 20122

  • Azienda Ospedale Universita Padova

    Padova, 35128

  • Azienda Ospedaliera Universitaria Integrata Verona Policlinico GB Rossi - Borgo Roma

    Verona, 37134

  • Policlinico GB Rossi

    Verona, 37134

Other trials in Italy

Jordan5 sites

  • Abdali Hospital

    Amman

  • Istiklal Hospital

    Amman

  • The Specialty Hospital, Advanced Clinical Center

    Amman

  • Irbid Specialty Hospital Clinical Research Center

    Irbid

  • King Abdullah University Hospital

    Irbid

Other trials in Jordan

France4 sites

  • Ap-Hp-Hopital Henri Mondor

    Créteil, 94000

  • Centre Hospitalier Universitaire Grenoble Alpes-Site Nord Michallon-3

    Grenoble, 38043

  • Hospices Civils de Lyon-Hopital Edouard Herriot

    Lyon, 69437

  • Ap-Hp-Hopital Europeen Georges Pompidou

    Paris, 75015

Other trials in France

Turkey (Türkiye)4 sites

  • Acıbadem Adana Hastanesi-Hematoloji

    Adana, 01130

  • Çukurova Üniversitesi Tıp Fakültesi Balcalı Hastanesi- Hematoloji

    Adana, 01130

  • Hacettepe Üniversitesi Hastanesi- Hematoloji

    Ankara, 06230

  • Mersin Üniversitesi Tip Fakültesi Hastanesi- Çiftlikköy Yerleşkesi- Hematoloji

    Mersin, 33110

Other trials in Turkey (Türkiye)

Greece3 sites

  • Aghia Sophia Childrens' Hospital

    Goudi, 11527

  • General Hospital Of Larissa Koutlibaneio And Triantafylleio - Thalassemia and SCD Unit

    Larissa, 41221

  • Gen Univ Hospital of Patras, Thalassemia/Hemoglobinopathies

    Pátrai, 26504

Other trials in Greece

Spain2 sites

  • Hospital Universitario La Paz

    Madrid, 28046

  • Hospital Regional Universitario de Málaga

    Málaga, 29010

Other trials in Spain

Lebanon1 site

  • Hospital Nini

    Tripoli, 1434

Other trials in Lebanon

Oman1 site

  • Sultan Qaboos University Hospital

    Muscat, Sultanet of Oman/Muscat/Al Khoud, 123

Other trials in Oman

South Africa1 site

  • Charlotte Maxeke Johannesburg Academic Hospital

    Parktown, Johannesburg, Gauteng, 2193

Other trials in South Africa

Switzerland1 site

  • Universitätsspital Zürich - Klinik für Medizinische Onkologie und Hämatologie

    Zurich, 8091

Other trials in Switzerland

About this study

Official title: A Multicentre Trial Evaluating the Efficacy and Safety of Oral Decitabine Tetrahydrouridine (NDec) in Patients With Sickle Cell Disease

This study examines how well a new, potential medicine called NDec works and is tolerated in people with sickle cell disease. NDec is a combination of two medicines (decitabine-tetrahydrouridine). Both medicines are new for the treatment of sickle cell disease. Participants who are not taking Hydroxyurea (HU) will get NDec, NDec and placebo, or placebo. Participants who are on HU treatment before joining the study will get NDec, NDec and placebo, or continue on HU. Which treatment participants get is decided by chance. Participants getting NDec and/or Placebo will get capsules to take twice weekly. The study will last for about a year.

Being tested
NDec - oral decitabine-tetrahydrouridine, HU - Hydroxyurea, Placebo
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.

  • NDec - oral decitabine-tetrahydrouridineDrug

    Participants will get capsules (oral administration) to take once or twice weekly. The number of capsules will be based on their body weight

  • HU - HydroxyureaDrug

    Participants will get capsules daily (oral administration) according to local labelling

  • PlaceboDrug

    Participants will get capsules (oral administration) to take once or twice weekly. The number of capsules will be based on their body weight

Study groups in NCT05405114
Study groupRoleWhat they receive
HU-non-eligible - NDec plus placeboExperimentalHU-non eligible patients randomised to treatment with NDec on one day and placebo on the other day
Receives: Drug: NDec - oral decitabine-tetrahydrouridine; Drug: Placebo
HU-non-eligible - NDec plus NDecExperimentalHU-non eligible patients randomised to treatment with NDec on both days
Receives: Drug: NDec - oral decitabine-tetrahydrouridine
HU-non-eligible - Placebo plus placeboPlacebo comparatorHU-non eligible patients randomised to treatment with placebo on both days
Receives: Drug: Placebo
HU-active - NDec plus placeboExperimentalHU-active patients randomised to treatment with NDec on one day and placebo on the other day
Receives: Drug: NDec - oral decitabine-tetrahydrouridine; Drug: Placebo
HU-active - NDec plus NDecExperimentalHU-active patients randomised to treatment with NDec on both days
Receives: Drug: NDec - oral decitabine-tetrahydrouridine
HU-active - HUActive comparatorHU-active patients randomised to continue on open-label HU treatment
Receives: Drug: HU - Hydroxyurea

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in total haemoglobin

    measured in g/dL

    Measured: From baseline (week 0) to week 24

Secondary outcomes (14)

  1. Cmax for decitabine from pharmacokinetic assessment

    measured in ng/mL

    Measured: At week 24

  2. Cmax for tetrahydrouridine from pharmacokinetic assessment

    measured in ng/mL

    Measured: At week 24

  3. Change in DNA methyltransferase 1 (DNMT1) activity

    measured in MFI units

    Measured: From baseline (week 0) to week 24

  4. Change in cytidine deaminase (CDA) activity

    µmol/L/min

    Measured: From baseline (week 0) to week 24

  5. Change in foetal haemoglobin (g/dL)

    measured in g/dL

    Measured: From baseline (week 0) to week 24

  6. Change in foetal haemoglobin as a proportion of total haemoglobin (%HbF)

    measured in %

    Measured: From baseline (week 0) to week 24

  7. Change in F-cell level as a proportion of total red blood cell (RBC) (%F-cells)

    measured in %

    Measured: From baseline (week 0) to week 24

  8. Change in haemolysis measure: absolute reticulocyte count

    measured in cells × 10^9/L

    Measured: From baseline (week 0) to week 24

  9. Change in haemolysis measure: indirect bilirubin

    measured in mg/dL

    Measured: From baseline (week 0) to week 24

  10. Change in haemolysis measure: lactate dehydrogenase

    measured in U/L

    Measured: From baseline (week 0) to week 24

  11. Number of vaso-occlusive crises

    number of events

    Measured: From baseline (week 0) to week 48

  12. Number of acute chest syndrome

    number of events

    Measured: From baseline (week 0) to week 48

  13. Number of RBC units transfused

    measured in Units

    Measured: From baseline (week 0) to week 48

  14. Number of adverse events of grade 3 or higher

    number of events

    Measured: From baseline (week 0) to week 52

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 Jun 2022
  2. Study start7 Jul 2022
  3. Primary completion24 Jul 2025
  4. Study completion24 Jul 2025

Resources

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
96 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05405114
Sponsor's protocol ID
NN7533-4470
Other IDs
U1111-1255-1324, 2020-003485-39
Acronym
ASCENT1
Status last verified
Jul 2026
First submitted
31 May 2022
Last updated
22 Jul 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: "According to the Novo Nordisk disclosure commitment on novonordisk-trials.com"

Publications

  • Helleberg H, Bjornsdottir I, Offenberg HK. Effects of Tetrahydrouridine Pre-dosing on Absorption, Metabolism, and Excretion of Decitabine in the Mouse. Eur J Pharm Sci. 2026 Jan 1;216:107353. doi: 10.1016/j.ejps.2025.107353. Epub 2025 Oct 27.

    PubMed 41161613

  • Abbasi M, Srivastava A, Saraf SL. Management of Kidney Disease with Sickle Cell Disease. J Am Soc Nephrol. 2025 Oct 1;36(10):2041-2054. doi: 10.1681/ASN.0000000804. Epub 2025 Jun 26.

    PubMed 40569673

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing NDec - oral decitabine-tetrahydrouridine and HU - Hydroxyurea in people with Sickle Cell Disease, run by Novo Nordisk A/S at 118 sites in 14 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 6 inclusion and 13 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: finished, as of the sponsor's last update on 22 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 118 sites in United States, India, Canada, United Kingdom, Italy and 9 more countries. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Change in total haemoglobin (time frame: From baseline (week 0) to week 24). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05405114, which also lists 2 linked publications.

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 22 Jul 2026.

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