Idelalisib+Obinutuzumab in Patients With Relapsed/Refractory Follicular Lymphoma

Single arm, prospective, multi-centric, phase II study. Patients with histologically confirmed follicular lymphoma, in need of a systemic approach and failing (i.e. with refractory disease \[no response or response lasting less than 6 months at any previous line of treatment\] or with a proven disease relapse) at least 2 previous lines of treatment, including any antibody directed against the CD20 antigen-containing chemotherapy, will undergo a combined chemo-free treatment with obinutuzumab and idelalisib. Obinutuzumab will be administered intravenously at a flat dose of 1000 mg on day 1, 8, 15 of the first cycle, then repeated on day 1 of each subsequent cycle, for 6 cycles (each cycle is completed in 28 days). Idelalisib will be given concomitantly with obinutuzumab and on a daily 150 mg bid schedule. For patients achieving at least a partial response at the end of induction, a maintenance phase with obinutuzumab is scheduled (on day 1 every two months for two years or until progression or unacceptable toxicity, whichever comes first) If one of the two drugs has to be permanently discontinued due to any cause, patient may continue treatment with the other agent if it is judged to be a clinical benefit. Patients with at least a stable disease will enter the follow-up phase and will be followed with repeated CT scans every six months for two years or until death/progression occurs (whichever comes firsts). Patients with progressive disease, whenever progression is documented, will enter a survival follow up period of two years after PD was documented. These patients are however considered evaluable for OS.