COBRAH is a randomized double-blind 2-steps controlled superiority trial, with 2 parallel groups. Patients will be randomly assigned in a 2:1 ratio to receive Cobimetinib orally or placebo during the first 12-weeks step, allowing the determination of the primary criteria.
Histiocytoses are rare multisystemic disorders characterized by accumulation of histiocytes in various organs. Virtually all the patients have a somatic mutation in the RAS-RAF-MEK-ERK pathway. BRAF inhibitors are efficacious to treat BRAF-mutated patients but one third of the patients are BRAF-wild type. For these patients, preliminary data have shown an efficacy of the MEK inhibitor cobimetinib. This trial aims to evaluate the efficacy of cobimetinib for treating BRAF-wild type or mutated patients with L or R group histiocytoses. The primary objective of the COBRAH trial is to demonstrate that the rate of objective metabolic response (complete or partial) according to PERCIST criteria is higher under Cobimetinib versus placebo. The objective metabolic response according to PERCIST criteria (Haroche, et al. 2015) is defined by the Positron Emission Tomography (PET) response and will be used to evaluate the overall therapeutic response at month 3 (Week 12). For PERCIST criteria, a quantitative analysis of uptake will be performed using the standard uptake value (SUV). Fitting regions of interest covering pathologic uptake will be used to define target lesions. PERCIST will be used to classify the patients as complete metabolic response, partial metabolic response (reduction of a minimum of 30% in target lesions), stable metabolic disease or progressive metabolic disease.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
54
Cobimetinib will be given at the dose of 40 milligrams once a day (21 days/28). Cobimetinib is available as 20 milligrams film-coated tablets
Placebo will be given at the dose of 40 milligrams once a day (21 days/28). Placebo is available as 20 milligrams film-coated tablets
Service de Médecine interne - La Pitié Salpêtrière
Paris, Paris, France
The objective metabolic responses
The objective metabolic responses is the percentage of patients with a complete metabolic response, partial metabolic response (reduction of a minimum of 30% in target lesions), stable metabolic disease or progressive metabolic disease according to PERCIST criteria (Haroche, et al. 2015) at Month 3. PERCIST criteria is defined by the PET response and will be used to evaluate the overall therapeutic response at month 3. For PERCIST criteria, a quantitative analysis of uptake will be performed using the standard uptake value (SUV). Fitting regions of interest covering pathologic uptake will be used to define target lesions. PERCIST will be used to classify patients metabolic response.
Time frame: at month 3
Overall survival
Overall survival is defined as the time between the date of randomisation and the death.
Time frame: every 12 weeks up to 36 weeks for Cobimetinib group and 48 weeks for Placebo group
Progression-free survival
Progression-free survival is defined as the time between the date of randomisation and the first documented event of disease progression according to PERCIST criteria (Haroche, et al. 2015).
Time frame: every 12 weeks up to 36 weeks for Cobimetinib group and 48 weeks for Placebo group
Number of participants with adverse events as assessed by CTCAE v4.0
All adverse events from clinical evaluations and laboratory measurements assessed by CTCAE v4.0
Time frame: From the randomisation up to 36 weeks for Cobimetinib group and 48 weeks for Placebo group.
Overall response of Cobimetinib (metabolic and tumor assessment)
Overall response of Cobimetinib (metabolic and tumor assessment) assessed after 36 weeks of Cobimetinib treatment or until Cobimetinib stop.
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Time frame: From the evaluation performed just before the treatment (Day 0 for Cobimetinib group, Week 12 for Placebo group)
CRP levels
CRP levels assessed from blood samples
Time frame: At Baseline, Week 12, Week 24, Week 36 and Week 48 (for Placebo group)