Clinical Trial Details
— Status: Not yet recruiting
Administrative data
| NCT number |
NCT05605366 |
| Other study ID # |
2022-0375 |
| Secondary ID |
|
| Status |
Not yet recruiting |
| Phase |
Phase 1
|
| First received |
|
| Last updated |
|
| Start date |
June 1, 2024 |
| Est. completion date |
June 2026 |
Study information
| Verified date |
December 2023 |
| Source |
University of Cincinnati |
| Contact |
Christian Mpulumba, MD |
| Phone |
513-558-2115 |
| Email |
mpulumcm[@]ucmail.uc.edu |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Sickle cell disease (SCD) is a common, inherited blood disorder that primarily affects people
of African Ancestry. It has a lot of complications including neurological complications. The
neurological complications of SCD are particularly devastating and lead to cognitive decline
even in the absence of overt brain injury. In such cases, it is thought that inflammation in
the brain maybe partly responsible for the cognitive decline.
The main reasons for this research study are to see 1) how safe and 2) how well minocycline
works to try to stop/reverse cognitive decline in people with SCD. People with SCD are at
risk for changes in their brain over time that can cause problems with learning, memory, and
attention. Part of the reason for this is inflammation within the brain. Minocycline may be
able to stop these brain changes by stopping this brain inflammation.
Minocycline is a second-generation tetracycline antibiotic that has been shown to both
inhibit neuroinflammation and improve cognitive function in a variety of neurodegenerative
and psychiatric disorders but has not yet been studied in SCD. We are proposing here, a pilot
double-blinded, randomized controlled trial to examine the tolerability and early efficacy of
minocycline in adults with SCD at two dosing regimens (200 mg and 300 mg daily) versus
placebo over one year. Participants will undergo a neuropsychological exam using the NIH
Toolbox Cognition Battery at both study enrollment and exit (after one year) to assess for
changes/stability of cognition. Participants will receive monthly phone calls/text messages
to assess for adverse events and will be seen every three months for pill counts and routine
laboratory monitoring. The primary outcome will be a comparison of adverse events across the
two dosing strategies versus placebo. Early evidence for cognitive benefit will also be
assessed from the results of the NIH Toolbox.
Description:
Study Overview: This is a pilot study examining tolerability of low (200 mg daily) and high
(300 mg daily) oral minocycline in adults with SCD compared to placebo. We will aim to enroll
and randomize 30 adults with SCD and monitor for 12 months. Preliminary data regarding
cognition will be obtained at baseline and 12 months, safety/laboratory monitoring will be
incorporated into clinical care at 3 month intervals, with monthly phone calls and/or text
messaging to inquire about any adverse event that may have occurred since the last clinic
visit.
Inclusion/Exclusion: Adults (age ≥ 18 years old) with SCD (HbSS and HbS-β0thalassemia
genotypes only) who are followed at the University of Cincinnati Medical Center's SCD clinic
are eligible to participate. As hydroxyurea is the standard-of-care in SCD, individuals on
hydroxyurea will be included. The exclusion criteria are as follows: 1) adults with other SCD
genotypes (HbSC or HbS- β+thalassemia), 2) individuals with a history of overt stroke or
other known neurological disorder, 3) premature birth before 30 weeks gestation, 4) monthly
therapy with chronic blood transfusions, 5) coexisting autoimmune condition due to an
elevated risk for autoimmune-related complications with tetracyclines, and 6) tetracycline
allergy. Study members will approach eligible individuals at their regularly scheduled
hematology visits to assess for interest and complete consent. All study-related procedures
will be performed by the University of Cincinnati's specifications.
Dose Justification: The proposed dosing is based on previous double-blind placebo-controlled
studies of minocycline use in neuropsychiatric disorders. In the Minocycline in Alzheimer
Disease Efficacy (MADE) trial 200 mg daily resulted in no difference in adverse event or drug
discontinuation rates compared to placebo, in contrast to 400 mg daily, which had
significantly higher rates of dermatologic and gastrointestinal side effects.22 In patients
with schizophrenia, minocycline 200 mg daily was associated with improvement in cognition at
3 months compared to placebo with no difference in adverse events.19, 38 A larger study of
204 patients with schizophrenia receiving minocycline 300 mg daily found no difference in
adverse events between the minocycline and placebo groups.21 Finally, patients with clinical
isolated syndrome (a precursor to multiple sclerosis) who received minocycline 200 mg daily
saw a decrease in conversion to multiple sclerosis at six months; however, the rates of trial
withdrawal and adverse events, including rash, dizziness, and dental discoloration, were
higher in the minocycline versus placebo arm.39 Thus, it is unclear whether 200 mg daily or
300 mg daily is the optimal dose in adult SCD.
Cognitive Assessments: Participants will complete the NIH Toolbox: Cognition Battery, the
Consortium to Establish a Registry for Alzheimer's disease Verbal Learning Test (CERAD-VLT),
and the Complex Taylor Figure at baseline visit and 12-month follow up. The NIH Toolbox, a
cognitive outcome measure designed for epidemiologic research and clinical trials, is
administered via tablet application with automated scoring and was validated in a diverse
cohort of 476 participants ages 3-85 years.40 The NIH Toolbox has previously been utilized in
pediatric SCD participants, detecting the decreased inhibitory control, processing speed, and
cognitive flexibility which have been observed in previous studies.41 To compliment the NIH
Toolbox we will utilize the CERAD-VLT to assess verbal learning, including episodic memory.42
Lastly, children with SCD can have significant visual spatial dysfunction as the result of
cerebral infarcts, we anticipate the same might be the case with the adults and as such, we
will assess visual spatial ability using the Complex Taylor Figure tool.8, 43 Intervention,
Measurements, & Data Collection: Upon enrollment, all participants will undergo
neuropsychological assessment at baseline using the tools described above. All participants
will also undergo a baseline symptom assessment, physical examination, peripheral oxygen
saturation, and laboratory analysis, including complete blood count (CBC) with differential,
reticulocyte count, complete metabolic panel (CMP), fetal hemoglobin (HbF), thyroid function
tests, and spot urine microalbumin. If any laboratory analysis had been completed within two
weeks prior to enrollment, this will not be repeated. Individuals will then be randomized to
receive minocycline 200 mg daily, minocycline 300 mg daily, or placebo via a random number
generator. Both the patient and investigator will be blinded to the enrollment status.
Participants will return for pill counts, laboratory examination, and physical exam every
three months. Participants will also fill out a standardized assessment regarding their
health and any side effects monthly; this will be administered via RedCAP survey either
through phone call/text message or via tablet application and can be completed at home during
the months between study visits. The study visits will be timed ideally with routine clinical
follow ups in the Hoxworth Clinic, but with all study-related procedures taking place in the
Schubert Research Clinic at Cincinnati Children's Hospital Medical Center. Participants will
also undergo the following labs every three months during study visits: CBC, CMP,
reticulocyte count, and HbF; these will not be repeated if obtained clinically within two
weeks of the study visit date. Thyroid function tests and urine microalbumin will be
collected every six months. Study enrollees will be followed for a period of 12 months from
their day of starting either the drug or placebo. Participants will then repeat the
components of the baseline studies, including the neuropsychological assessment. Participants
and study investigators will have the option to be unblinded to each participant's study arm.
Study Duration: The total study duration will be two years; we expect 6 months for patient
recruitment/randomization followed by 12 months of therapy and another 6 months for data
analysis/publication.
Statistical Analysis and Power Calculations: If the outcome distributions of the data are
close to normal distributions, Student's t test (paired or unpaired) or chi-square test will
be performed for descriptive statistics. If the outcome fails the normality tests,
Mann-Whitney rank sum test will be used. Additionally, when comparing all 3 groups, ANOVA
and/or non-parametric Kruskal-Wallis tests will be used when necessary. Post hoc testing on
ANOVA will be done by multiple pairwise comparison procedures using the Holm-Sidak method.
When repeated measurements of the outcomes are observed, mixed effect linear or generalized
linear models will be used. Our sample size calculations indicate that with the proposed
sample size (n=7 patients/group), we will be able to reach 80% power to detect an effect size
of 1.6 between groups for continuous outcomes (Aim 2 - rate of decline in neurocognition);
and an effect size of around 0.95 (using arcsine scale) for binary outcomes (Aim 1 - adverse
events). If the true effect sizes are smaller, our study will not be powered to detect
statistical significance between groups; however, the insights generated (especially for our
primary outcome of tolerability) from this study will be useful for planning a larger phase
II/III efficacy trial. All estimated differences in the outcomes, p-values and the
corresponding 95% confidence intervals will be provided. P values below 0.05 will be reported
as significant. All data will be analyzed using R, Version 3.3.3 (R Core Team 2012).
Rigor and Reproducibility: The NIH Toolbox: Cognition Battery is easily administered via
tablet application and has been validated in a diverse racial, ethnic, and socioeconomic
population; the scores are normalized to those of a standard neuropsychological battery
(including full scale intelligence quotient) with a mean = 100 and standard deviation = 15.
Thus, Toolbox results can be compared to those of participants of future studies.
Strengths, Limitations, & Alternative Approaches: This study is unique in that it is the
first assessment of safety and early efficacy for the use or potential long-term use of
minocycline in individuals with sickle cell disease to slow the expected rate of cognitive
decline. This study is strengthened using two dosing strategies, both of which have proven
efficacious and safe in other neurologic and psychiatric disorders. In addition, as this will
be a pilot for a large phase II/III study, only those individuals with the HbSS and HbS-
β0thalassemia genotypes will be included, which will be the expected population for the
proposed larger trial and will limit confounding from differences in SCD genotypes. The
primary limitation for this study is its small sample size; the study may not be powered to
evaluate efficacy of minocycline to slow the expected rate of neurocognitive decline in SCD;
however, the findings could be informative especially with regards to short and possibly
long-term tolerability of minocycline. Another limitation is the potential for drop out and
noncompliance with the study drug; however, we will attempt to minimize these risks with
pairing study visits with routine clinical visits and with a monetary honorarium of $20 for
the completion of study enrollment procedures, every three-month study visits, and the final
12 month study procedures. We will aim to recruit ten patients in each arm for a total of 30
patients to account for a 30% drop out rate. Finally, if recruitment becomes difficult, we
will limit the minocycline arm to the 300 mg dosing strategy only.
