NEW ORLEANS--(BUSINESS WIRE)--Gilead Sciences, Inc. (Nasdaq: GILD) today announced results of a Phase 2 study (Study 101-09) evaluating idelalisib, an investigational oral inhibitor of PI3K delta, for the treatment of patients with indolent non-Hodgkin's lymphoma (iNHL) that is refractory (non-responsive) to rituximab and to alkylating-agent-containing chemotherapy. In this study, single-agent treatment with idelalisib achieved an overall response rate of 57 percent with a median duration of response of 12.5 months. The data were presented today during an oral session at the Annual Meeting of the American Society of Hematology (ASH) in New Orleans (Abstract #85).
"It has been more than ten years since a treatment with a novel mechanism of action has been approved for indolent NHL, underscoring the medical need for new treatments for patients who are no longer responsive to currently available therapies," said Ajay Gopal, MD, Associate Professor, University of Washington School of Medicine and Associate Member, Clinical Research Division, Fred Hutchinson Cancer Research Center in Seattle, Washington. "The overall response rate and durability of response observed in this study suggest that idelalisib may become a valuable new therapy for iNHL patients who have very limited treatment options."
Of the 71 patients who responded to therapy, seven (six percent) achieved a complete response, 63 (50 percent) had a partial response and one (one percent) had a minor response. Among patients who responded, the median duration of response was 12.5 months and the median time to response was 1.9 months. Median progression-free survival for all patients was 11.0 months and median overall survival was 20.3 months. Ninety percent of patients experienced shrinkage in lymph node size.
The most common Grade ≥3 adverse event was diarrhea, which was reported in 16 patients (13 percent). Grade ≥3 transaminase elevations (a measure of liver function) were reported in 16 patients (13 percent). Of the 16 patients who had Grade ≥3 transaminase elevations, 14 were retreated with idelalisib and of those, 10 (71 percent) had no recurrence. Grade ≥3 neutropenia occurred in 34 patients (27 percent). Twenty-five patients (20 percent) discontinued therapy because of adverse events.
These results in iNHL support Gilead's recent regulatory filings for idelalisib in the United States and European Union. On September 11, 2013, Gilead submitted a New Drug Application to the U.S. Food and Drug Administration for idelalisib for the treatment of refractory iNHL. Following Gilead's NDA submission for iNHL, FDA granted idelalisib a Breakthrough Therapy designation for chronic lymphocytic leukemia (CLL) in relapsed patients. Gilead is now engaging in a dialogue with the FDA regarding a regulatory filing in CLL.
Gilead's Marketing Authorization Application (MAA) for idelalisib for the treatment of iNHL and CLL was validated by the European Medicines Agency (EMA) on November 20. Review of the MAA will be conducted under the centralized licensing procedure, which, when finalized, provides one marketing authorization in all 28 member states of the European Union (EU). The Committee for Medicinal Products for Human Use (CHMP) has accepted Gilead's request for accelerated assessment for idelalisib, a designation that is granted to new medicines of major public health interest. Although accelerated assessment could shorten the review time of idelalisib by approximately two months, it does not guarantee a positive opinion from the CHMP or final approval by the European Commission. If approved, idelalisib could be available for marketing in the EU in the second half of 2014.
About Study 101-09
Study 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 90 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).
Idelalisib is an investigational, highly selective oral inhibitor of phosphoinositide 3-kinase (PI3K) delta. PI3K delta signaling is critical for the activation, proliferation, survival and trafficking of B lymphocytes and is hyperactive in many B-cell malignancies. Idelalisib is being developed both as a single agent and in combination with approved and investigational therapies.
Gilead's clinical development program for idelalisib in iNHL includes Study 101-09 in highly refractory patients and two Phase 3 studies of idelalisib in previously treated patients. In addition to Study 116, the development program in CLL includes two ongoing Phase 3 studies of idelalisib in previously treated patients. Combination therapy with idelalisib and GS-9973, Gilead's novel spleen tyrosine kinase (Syk) inhibitor, also is being evaluated in a Phase 2 trial of patients with relapsed or refractory CLL, iNHL and other lymphoid malignancies.
Additional information about clinical studies of idelalisib and Gilead's other investigational cancer agents can be found at www.clinicaltrials.gov. Idelalisib and GS-9973 are investigational products and their safety and efficacy have not been established.
About Indolent Non-Hodgkin's Lymphoma
Indolent non-Hodgkin's lymphoma refers to a group of largely incurable slow-growing lymphomas that run a relapsing course after therapy and can 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.
About Gilead Sciences
Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. The company's mission is to advance the care of patients suffering from life-threatening diseases worldwide. Headquartered in Foster City, California, Gilead has operations in North and South America, Europe and Asia Pacific.
This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other factors, including the possibility of unfavorable results from clinical trials involving idelalisib, including in combination with GS-9973 or other product candidates. Gilead also faces risks related to its ability to file for U.S. regulatory approval of idelalisib for CLL in the currently anticipated timelines. Gilead may also be unable to enroll patients in Phase 3 studies and may need to modify or delay these studies. In addition, FDA, EMA and other regulatory agencies may not approve idelalisib for the treatment of iNHL or CLL in the anticipated timelines or at all, and any marketing approval may have significant limitations on its use. As a result, idelalisib may never be successfully commercialized. Further, Gilead may make a strategic decision to discontinue development of idelalisib, as a single agent or in combination with other products if, for example, Gilead believes commercialization will be difficult relative to other opportunities in its pipeline. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. The reader is cautioned not to rely on these forward-looking statements. These and other risks are described in detail in Gilead's Quarterly Report on Form 10-Q for the quarter ended September 30, 2013, as filed with the U.S. Securities and Exchange Commission. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation to update any such forward-looking statements.
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