Infinity Reports New Translational Research and Updated Phase 1 Data of Investigational Oncology Compound Duvelisib at American Society of Hematology Annual Meeting

SAN FRANCISCO--(BUSINESS WIRE)--

Infinity Pharmaceuticals, Inc. INFI today presented new preclinical translational data showing the complementary effects of inhibiting both PI3K-delta and PI3K-gamma, two enzymes known to play a role in regulating the growth and survival of certain types of potentially fatal blood cancers, including indolent non-Hodgkin lymphoma (iNHL) and chronic lymphocytic leukemia (CLL). This translational research also highlights the important role that PI3K-gamma plays in forming and maintaining the protective tumor microenvironment. These data were presented today at the 56^th Annual Meeting of the American Society of Hematology (ASH).

“Our ability to develop PI3K-delta selective and PI3K-gamma selective inhibitors enabled us to identify the roles of these enzymes in the malignant B-cell tumor microenvironment, furthering our understanding of PI3K-delta,gamma biology,” stated Vito Palombella, Ph.D., chief scientific officer at Infinity. “These preclinical data demonstrate that inhibiting PI3K-delta and PI3K-gamma may have complementary effects on B-cell growth and survival.”

In an oral presentation, “Duvelisib (IPI-145) inhibits malignant B-cell proliferation and disrupts signaling from the tumor microenvironment through mechanisms that are dependent on PI3K-delta and PI3K-gamma” (Abstract #328), researchers reported that, in preclinical studies, PI3K-delta is important in the proliferation of CLL cells while PI3K-gamma plays a critical role in the migration and activation of T-cells and polarization of myeloid cells – both key support cells – that help form and maintain the protective tumor microenvironment. These data, taken together, suggest that PI3K-delta and PI3K-gamma may have complementary effects on malignant B-cell growth and survival.

During the meeting, Infinity also reported updated Phase 1 data from a monotherapy study of duvelisib in 30 evaluable patients with relapsed/refractory CLL dosed at 25 mg twice daily (BID), showing that duvelisib treatment led to an overall response rate of 57 percent, including one complete response, and was generally well tolerated. Additionally, new data were presented showing early activity of duvelisib in CLL and aggressive non-Hodgkin lymphoma (aNHL) patients who had been previously treated with ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor.

“The single-agent activity of duvelisib observed in patients with relapsed/refractory CLL is encouraging,” stated Susan O'Brien, M.D., Ashbel Smith Professor of Medicine in the Department of Leukemia at the University of Texas MD Anderson Cancer Center in Houston and an investigator for the study. “In addition, the early responses observed in patients whose disease progressed following ibrutinib treatment are particularly interesting. Given the aggressive nature of the disease in patients who relapse following ibrutinib treatment, therapies with non-overlapping mechanisms of action, such as duvelisib, could represent an important potential treatment option for these patients.”

Duvelisib Shows Activity in Patients with Relapsed/Refractory CLL (Abstract #3334)

Updated Phase 1 data in patients with relapsed/refractory CLL were reported in a poster presentation, “Duvelisib (IPI-145), a PI3K-delta,gamma inhibitor, is clinically active in patients with relapsed/refractory chronic lymphocytic leukemia.”

Data showed that duvelisib administered at a dose of 25 mg BID was clinically active, with a 57 percent overall response rate (17 of 30 evaluable patients), including one complete response. The median progression free survival and median overall survival in the 31 patients who received the 25 mg BID dose have not yet been reached with a median time on treatment of 7.6 months (range: 0.9 months – 34.1 months).

In the study, duvelisib was generally well tolerated, and the majority of side effects were Grade 1-2, reversible and/or clinically manageable. Across all doses evaluated in the study (N = 55), the most common Grade 3 side effects were pneumonia (24 percent), neutropenia (18 percent) and anemia (16 percent). Grade 4 pneumonia was 2 percent (1 patient), Grade 4 neutropenia was 24 percent (13 patients) and Grade 4 anemia was 2 percent (1 patient).

Based on encouraging data from the Phase 1 study, Infinity and AbbVie Inc., its global strategic partner for the development and potential commercialization of duvelisib in oncology, are conducting DUO^TM, a Phase 3 monotherapy study of duvelisib designed to evaluate the safety and efficacy of duvelisib compared to ofatumumab in patients with relapsed/refractory CLL.

Duvelisib Shows Preliminary Activity in Patients Previously Treated with Ibrutinib (Abstract #3335)

Early Phase 1 data in 6 patients with relapsed/refractory CLL and 7 patients with aNHL (5 Richter's Transformation and 2 diffuse large B-cell lymphoma) previously treated with ibrutinib were reported in a poster presentation, “Clinical activity of duvelisib (IPI-145), a phosphoinositide-3-kinase-delta,gamma inhibitor, in patients previously treated with ibrutinib.”

In this study, patients were treated with duvelisib administered at either 25 mg BID (2 CLL patients) or 75 mg BID (4 CLL and 7 aNHL patients). Early clinical activity was observed, with partial responses in 1 patient with CLL and 2 patients with aNHL. Stable disease was observed in 5 patients with CLL and 1 patient with aNHL. The safety profile of duvelisib in these patients appeared consistent with the safety profile observed in other patients with advanced hematologic malignancies treated with duvelisib in the Phase 1 study (O'Brien et al. ASH 2014; Campbell et al. ASH 2013).

A Phase 1b clinical study of duvelisib in combination with obinutuzumab in patients with CLL whose disease has progressed following treatment with a BTK inhibitor is expected to start by the end of the year.

About Duvelisib

Duvelisib is an investigational inhibitor of Class I phosophoinositide-3-kinase (PI3K)-delta and PI3K-gamma that is being jointly developed by Infinity Pharmaceuticals, Inc. and AbbVie Inc. The PI3K pathway is known to play a critical role in regulating the growth and survival of certain types of blood cancers. Duvelisib is designed to block the growth and survival of tumor cells by inhibiting PI3K-delta and PI3K-gamma signaling. The investigational agent is being evaluated in registration-focused studies, including DYNAMO^TM, a Phase 2 study in patients with refractory indolent non-Hodgkin lymphoma, DYNAMO+R, a Phase 3 study in patients with previously treated follicular lymphoma, and DUO^TM, a Phase 3 study in patients with relapsed/refractory chronic lymphocytic leukemia. Duvelisib is an investigational compound and its safety and efficacy have not been evaluated by the U.S. Food and Drug Administration or any other health authority.

About Infinity Pharmaceuticals, Inc.

Infinity is an innovative biopharmaceutical company dedicated to discovering, developing and delivering best-in-class medicines to people with difficult-to-treat diseases. Infinity combines proven scientific expertise with a passion for developing novel small molecule drugs that target emerging disease pathways. For more information on Infinity, please refer to the company's website at www.infi.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Such forward-looking statements include those regarding the Company's expectations about: its ability to execute on its strategic plans; the potential complementary effects of PI3K-delta and PI3K-gamma; the therapeutic potential of PI3K inhibition and duvelisib; and commencement of additional clinical studies. Such statements are subject to numerous important factors, risks and uncertainties that may cause actual events or results to differ materially from the company's current expectations. For example, there can be no guarantee that Infinity will report data in the time frames it has estimated, that any product candidate Infinity is developing will successfully complete necessary preclinical and clinical development phases, or that development of any of Infinity's product candidates will continue. Further, there can be no guarantee that Infinity;s strategic collaboration with AbbVie will continue or that any positive developments in Infinity's product portfolio will result in stock price appreciation. Management's expectations and, therefore, any forward-looking statements in this press release could also be affected by risks and uncertainties relating to a number of other factors, including the following: Infinity's results of clinical trials and preclinical studies, including subsequent analysis of existing data and new data received from ongoing and future studies; a failure of Infinity and/or AbbVie to fully perform under the strategic collaboration and/or an early termination of the collaboration and license agreement; the content and timing of decisions made by the U.S. FDA and other regulatory authorities, investigational review boards at clinical trial sites and publication review bodies; Infinity's ability to obtain and maintain requisite regulatory approvals and to enroll patients in its clinical trials; unplanned cash requirements and expenditures; development of agents by Infinity's competitors for diseases in which Infinity is currently developing or intends to develop its product candidates; and Infinity's ability to obtain, maintain and enforce patent and other intellectual property protection for any product candidates it is developing. These and other risks which may impact management's expectations are described in greater detail under the caption “Risk Factors” included in Infinity's quarterly report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on November 10, 2014, and other filings filed by Infinity with the SEC. Any forward-looking statements contained in this press release speak only as of the date hereof, and Infinity expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise.