The purpose of this study is to develop initial efficacy, feasibility, and safety data regarding the use of Tamoxifen in combination with amphotericin B and fluconazole in the treatment of cryptococcal meningitis. The results of the study will inform the design and feasibility of a larger study powered to a survival endpoint. The study hypothesis is that adding tamoxifen to standard antifungal therapy increases the rate of clearance of yeast from cerebrospinal fluid. Increased rates of clearance of yeast from cerebrospinal fluid have previously been associated with improved clinical outcomes, including survival and disability.
A randomized, open-label trial with 2 parallel arms: standard antifungal therapy versus tamoxifen augmented antifungal therapy during the first 2 weeks (induction phase) of treatment. The study will recruit in two sites in Ho Chi Minh City: the Hospital for Tropical Diseases (HTD), and Cho Ray Hospital (CRH). 25 patients will be enrolled into the two study arms (intervention versus control). All anti-fungal administration will be directly observed by ward staff. Intervention arm: Induction phase treatment (days 1-14): Tamoxifen will be given orally in a dose of 300mg/day for the first 14 days following randomization. It will be administered by nasogastric tube where patients are unconscious. In addition patients will receive amphotericin 1mg/kg once daily iv and fluconazole 800mg once daily orally. The tamoxifen will be administered in the morning combined with amphotericin and fluconazole dose. Control arm: Induction phase treatment (days 1-14): Patients will receive amphotericin 1mg/kg/day combined with fluconazole 800mg once daily for the first 2 weeks. Amphotericin and fluconazole will be administered simultaneously. The primary efficacy endpoint will be the rate of clearance of yeast cells from cerebrospinal fluid (CSF) over the first 2 weeks following randomisation. Patients will be followed for 10 weeks, which is conventional in clinical trials in cryptococcal meningitis. After the first 2 weeks of study treatment, all patients will receive fluconazole 800mg/day for 8 further weeks, until the study end. At this point, HIV infected patients will be switched to long term secondary prophylaxis with fluconazole 200mg/day as per standard practice. For HIV uninfected patients, the decision to continue antifungal treatment, and at which dose, will be made on a case by case basis by the attending physician in consultation with the patient.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
50
Tamoxifen will be given orally in a dose of 300mg/day for the first 14 days following randomization. It will be administered by nasogastric tube where patients are unconscious. The Tamoxifen will be administered in the morning combined with amphotericin and fluconazole dose.
Patients will receive amphotericin 1mg/kg/day i.v. once daily orally for the first 2 weeks.
Patients will receive fluconazole 800mg once daily orally for the first 2 weeks. Amphotericin and fluconazole will be administered simultaneously. After the first 2 weeks of study treatment, all patients will receive fluconazole 800mg/day for 8 further weeks, until the study end.
Cho Ray Hospital
Ho Chi Minh City, Vietnam
Hospital for Tropical Diseases
Ho Chi Minh City, Vietnam
Oxford University Clinical Research Unit
Ho Chi Minh City, Vietnam
Early Fungicidal Activity (EFA), i.e. the rate of clearance of yeast from cerebrospinal fluid
In the trial, lumbar punctures are scheduled on days 1, 3, 7, 14, and additionally as clinically indicated. Whenever a lumbar puncture is performed, the study team will determine the amount of viable yeast in CSF through culture. Based on the patients' longitudinal quantitative yeast count measurements, EFA will be determined as previously described e.g. see N Engl J Med 2016; 374:542-54
Time frame: over the first 2 weeks following randomisation
Survival until 10 weeks after randomization
International treatment guidelines recommend 10 weeks of high dose antifungal therapy for cryptococcal meningitis - an initial phase of amphotericin based induction therapy for 2 weeks followed by 8 weeks of moderate to high dose fluconazole. The rate of survival until this 10 week period of therapy is completed is a frequent endpoint in trials of treatment for cryptococcal meningitis.
Time frame: 10 weeks after randomisation
Disability at 10 weeks
Disability is an expected consequence of cryptococcal meningitis, including blindness, deafness and other focal neurological deficits. Neurological disability will be assessed using the modified Rankin score and the Two Simple Questions, and the results of each test combined and classified as good, intermediate, severe disability, or death, as we have previously published.
Time frame: at 10 weeks
Adverse events
The proportion of patients with any grade 3 or 4 adverse event, serious adverse event, or unexpected serious adverse event will be compared between treatment groups.
Time frame: During hospital stay, an average of 10 weeks
Rate of IRIS until 10 weeks (in HIV infected patients only)
The investigators will model the rate of IRIS over time with a cause-specific hazards model taking into account the competing risk of prior death.
Time frame: until 10 weeks
Rate of Cryptococcal meningitis relapse
A pragmatic definition of relapse will be used. This is defined as either intensification of antifungal therapy above that according to the study antifungal schedule, or readmission for treatment of cryptococcal disease.
Time frame: until 10 weeks
QT prolongation
Prolongation of the QT interval is a potential side-effect of both Tamoxifen and fluconazole, although it is not clear that either drug increases the risk of Torsade de Pointes, a potentially life-threatening arrhythmia. The QT interval will be estimated manually from 3 chest and 3 limb leads from a high resolution (50mm/sec) 12-lead ECG. The median value will be determined and used to calculate the corrected QT interval (QTc) using using Framingham's formula
Time frame: During hospital stay, an average of 10 weeks
Visual deficit at 10 weeks
Visual deficit occurs in 5-40% of patients with cryptococcal meningitis depending upon underlying immune status. The pathogenesis is unclear. The study team will compare the incidence of blindness and other visual deficit between treatment groups. Visual deficit will be assessed using a simple 6 point scale.
Time frame: at 10 weeks
Time to new neurological event or death until 10 weeks
A neurological event is defined as a fall in Glasgow coma score by ≥2 points for ≥2 days from the highest previously recorded Glasgow coma score (including baseline) or the occurrence of any of the following adverse events: cerebellar symptoms, coma, hemiplegia, paraplegia, seizures, cerebral herniation, new onset blindness or deafness, or cranial nerve palsy.
Time frame: until 10 weeks
Longitudinal measurements of intracranial pressure during the first 2 weeks
Intracranial pressure (ICP) will be measured at study entry, day 3, 7, and 14, and at other times as clinically indicated. The decline in raised intracranial pressure over the first 2 weeks will be modelled and compared between treatment arms.
Time frame: during the first 2 weeks
CD4 count at 10 weeks
CD4 count measurement is indicated in HIV infected patients, and CD4 lymphopenia has been described in HIV uninfected patients with cryptococcal meningitis. Moreover, Tamoxifen may reduce CD4 cell apoptosis which may be beneficial.
Time frame: at 10 weeks
Blood and CSF concentrations of amphotericin, Tamoxifen and fluconazole
All patients will undergo pharmacokinetic sampling to enable the description of the concentrations of Tamoxifen and fluconazole in plasma and CSF, and of amphotericin in blood, and relate these to the rate of clearance of yeast from CSF.
Time frame: During hospital stay, an average of 10 weeks
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