About Study 101-09Study 101-09 is a Phase 2, open-label, single-arm efficacy and safety study of idelalisib in patients with previously treated iNHL that is refractory both to rituximab and to alkylating-agent-containing chemotherapy (refractory defined as no response while on therapy or progression within six months of completion of therapy). The study enrolled 125 patients from approximately 50 study sites in the United States and Europe. Patients were a median age of 64 and had confirmed diagnoses of follicular lymphoma (n=72), small lymphocytic lymphoma (n=28), lymphoplasmacytic lymphoma / Waldenström macroglobulinemia (n=10) or marginal zone lymphoma (n=15). Patients had received a median of four prior treatment regimens before study entry, with 79 percent of patients refractory to two or more prior regimens and 74 percent refractory to their most recent regimen. All patients received idelalisib 150 mg twice daily and are allowed to continue daily dosing as long as they benefit from therapy. The primary endpoint of the study is overall response rate, defined as the proportion of patients achieving a confirmed complete or partial response with idelalisib treatment (response definitions based on standard criteria; responses assessed by study investigators and an independent review committee). About Idelalisib Idelalisib is an investigational, targeted, highly selective oral inhibitor of phosphoinositide 3-kinase (PI3K) delta, a molecular target that is critical for the activation, proliferation and survival of B lymphocytes. PI3K delta signaling is hyperactive in many B-cell leukemias and lymphomas and drives proliferation, survival and trafficking to lymphoid tissue. Idelalisib is being developed both as a single agent and in combination with approved and investigational therapies. Gilead’s clinical development program for idelalisib includes three Phase 3 studies evaluating the drug in combination with approved therapies for patients with previously treated chronic lymphocytic leukemia (CLL) and two Phase 3 studies of idelalisib in combination with approved therapies for patients with previously treated indolent non-Hodgkin’s lymphoma (iNHL). In addition, combination therapy with idelalisib and GS-9973, Gilead’s novel spleen tyrosine kinase (Syk) inhibitor, is being studied in a Phase 2 trial of patients with relapsed or refractory CLL, iNHL and other lymphoid and hematological malignancies.