An observational study in Sickle Cell Disease, sponsored by Ochuko Orherhe. Recruiting at 1 site in Nigeria. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-27.
Sponsored by Ochuko Orherhe · Observational
The wide interindividual variability in clinical response to hydroxyurea therapy in the management of sickle cell disease has limited its use. These variabilities have been linked to differences in pharmacodynamics, pharmacokinetics, and pharmacogenetics. This study, therefore, aims to enhance understanding of these factors as they relate to hydroxyurea therapy, with the overall goal of developing a precision medicine algorithm.
The study will be a prospective cohort pharmacokinetic study of 100 Nigerian patients with sickle cell disease, including current hydroxyurea users and naive patients. Pharmacodynamic markers will be collected to evaluate response. PopPK and PK-PD models will be developed in Monolix, exposure-response relationships will be analysed in R, and pregnancy, lactation, and paediatrics PBPK models will be developed in Simcyp or PK-SIM to inform dose optimisation.
This study aims to build a pharmacometric model by integrating differences in pharmacokinetics, pharmacodynamics, and pharmacogenetics of hydroxyurea, which could aid the optimisation of hydroxyurea for sickle cell patients in Nigeria.
The objectives of the study are i. To determine the prevalence of genetic polymorphisms in metabolic enzymes and transporters relevant to the disposition of hydroxyurea in the Nigerian sickle cell disease population, ii. To develop and validate an analytical method for the quantification of hydroxyurea using high-performance liquid chromatography.
iii. To evaluate the influence of genetic and other covariates on hydroxyurea disposition in the Nigerian sickle cell disease population using population pharmacokinetic modelling, iv. To investigate the relationship between hydroxyurea exposure and clinical outcomes (foetal haemoglobin, mean corpuscular volume, reduction in vaso-occlusive crises (VOC), and improved blood count) using pharmacokinetic-pharmacodynamic modelling, v. To develop physiologically-based pharmacokinetic (PBPK) models that could predict hydroxyurea concentrations in special populations of sickle cell disease patients in Nigeria i.e. pregnant women, lactating mothers, breastfed infants, and paediatrics.
vi. To develop a dosing guideline for hydroxyurea therapy in Nigerian sickle cell patients.
Overall, this study will provide scientific knowledge that can enhance clinical decision-making in sickle cell management within the Nigerian population, and the models could serve as a template to optimize hydroxyurea use in this population.
1,134 studies on the registry are indexed under Anemia, Sickle Cell; 238 are open to participants now.
This study's planned enrollment of 100 is close to the median of 100 across 296 observational studies indexed under Anemia, Sickle Cell.
Browse Anemia, Sickle Cell studies →This is the only study on the registry with Ochuko Orherhe as lead sponsor.
Counted across the registry records on this site, refreshed daily.
The study population for this research comprises patients diagnosed with sickle cell disease (SCD) of Nigerian descent, recruited from selected clinical centres within Nigeria ( Sickle Cell Foundation, Ibadan and the Obafemi Awolowo University Teaching Hospital Complex). They will be consented SCD adult patients who have been on hydroxyurea at least six months before study commencement or who are willing to commence hydroxyurea therapy. In both instances, they will be SCD patients whose genetic profile for the major metabolising enzymes are known.
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.
Exclusion Criteria:
All study participants are sickle cell disease patients who are currently on hydroxyurea therapy or who would be willing to commence hydroxyurea therapy.
Increase in foetal haemoglobin
Hydroxyurea exerts its therapeutic effects primarily through the induction of foetal haemoglobin production, thereby inhibiting the polymerization of sickled haemoglobin and ameliorating the pathophysiological sequelae of sickle cell disease. By inhibiting ribonucleotide reductase, hydroxyurea interferes with DNA synthesis, prompting the differentiation of erythroid progenitors into red cells containing elevated levels of foetal haemoglobin.
Time frame: 6 months
Reduction in frequency of vaso-occlusive crises
The phenotypic expression of the increase in foetal haemoglobin is the overall reduction of the incidences of painful crises due to vaso-occlusion, acute chest syndrome, hospitalizations, and blood transfusions, consequently reducing hospitalisations and morbidity
Time frame: 6 months
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No — Each study participant will be assigned a study ID. The hard copies of data collection materials will use the study ID only as identifiers and not the personal identifying information. The code linking the data to the patient's personal information will only be available to the me, the principal investigator. However, in the event that a discovery is made in a study particpant that requires medical attention, the attending physician (who are the facility contacts and patients' medical doctors) will be communicated and individual participant data shared with them.
Started May 2026 (actual). Primary completion is estimated for Apr 2027, 11 months after the start.
Of 130 non-industry observational studies under Anemia, Sickle Cell, half reached primary completion within 48 months of starting (the median), counting those still running; a quarter within 23 and three quarters within 109. This study's planned 11 months is below that.
Counting every sponsor, half of 139 studies reached it within 49 months; a quarter within 24 and three quarters within 109.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 27, 2026: primary completion Oct 2026 → Apr 2027 and completion Mar 2027 → Oct 2027.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.