Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the company has submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for approval of idelalisib, an investigational, targeted, oral inhibitor of PI3K delta, for the treatment of indolent non-Hodgkin’s lymphoma (iNHL). The data submitted in this NDA support the use of idelalisib for patients with iNHL that is refractory (non-responsive) to rituximab and to alkylating-agent-containing chemotherapy. Indolent non-Hodgkin’s lymphoma refers to a group of largely incurable slow-growing lymphomas that run a relapsing course after therapy and lead ultimately to life-threatening complications such as serious infections and marrow failure. Most iNHL patients are diagnosed at an advanced stage of disease, and median survival from time of initial diagnosis for patients with the most common form of iNHL, follicular lymphoma, is 8 to 10 years. The outlook for refractory iNHL patients is significantly poorer. “Gilead is committed to advancing a pipeline of novel cancer therapies that have the potential to improve the lives of patients,” said John C. Martin, PhD, Chairman and Chief Executive Officer of Gilead Sciences. “Based on the rate and duration of response observed to date in this highly refractory iNHL patient population, we believe idelalisib could become an important new therapy for patients who have limited treatment options.” Gilead’s NDA for idelalisib is supported by data from a single-arm, open-label Phase 2 study (Study 101-09) of 125 patients with iNHL refractory to rituximab and to alkylating-agent-containing chemotherapy. In an interim data analysis presented in June at the International Conference on Malignant Lymphoma in Lugano, Switzerland, single-agent idelalisib achieved an overall response rate of 53.6 percent, with a median duration of response of 11.9 months. Median progression-free survival for all patients was 11.4 months. 89 percent of patients experienced lymph node shrinkage. The most common Grade ≥3 adverse events or laboratory abnormalities were diarrhea (10 percent), transaminase elevations (measure of liver function, 13 percent) and neutropenia (26 percent).