The PROLONG Trial - Rituximab Maintenance Therapy in ITP

This study is a two phase study that aims to evaluate if low-dose Rituximab maintenance therapy may prolong the the effect of Rituximab in immune thrombocytopenia.

This is a multi-center, international, randomized, two-phase study: First phase (induction phase) is open-label, hypothesis-generating, involving 1:1 randomization into: rituximab (group 1) or rituximab plus dexamethasone (group 2) to determine if the response to rituximab can be improved by the addition of dexamethasone. Second Phase (maintenance phase) is the main part of the study, involving 1:1 double-blind randomization into low dose rituximab or placebo to determine if the response achieved in the first phase can be prolonged by administrating maintenance treatment with low dose rituximab. Primary objective: To determine if maintenance therapy with low-dose rituximab is superior to placebo in prolonging responses among ITP patients who achieved an initial response with rituximab. Secondary objectives: 1. To explore if the initial overall response rate, at week 24, can be improved by at least 10% by adding dexamethasone to rituximab (induction phase). 2. To assess the safety of study treatment, especially infectious episodes (induction \& maintenance phases). 3. To assess bleeding complications during the study (induction \& maintenance phases). 4. To assess the use of rescue medications and other platelet-elevating therapies during the study (induction \& maintenance phases). 5. To determine rate of Complete Response (CR) during induction phase and sustained CR during maintenance phase (induction \& maintenance phases). 6. To determine the duration of overall response and CR (induction \& maintenance phases). 7. To assess health-related quality of life and fatigue (induction \& maintenance phases).