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Calithera Biosciences to Present New Preclinical Data for CB-839 at AACR Annual Meeting 2018


Synergy of CB-839 with CDK4/6 and PARP inhibitors

SOUTH SAN FRANCISCO, Calif., April 13, 2018 (GLOBE NEWSWIRE) -- Calithera Biosciences, Inc. (Nasdaq:CALA), a clinical stage biotechnology company focused on the development of novel cancer therapeutics, today announced that preclinical research for its glutaminase inhibitor CB-839 will be shared as poster presentations at the American Association for Cancer Research (AACR) Annual Meeting 2018 in Chicago.  CB-839 is a potent, selective, orally bioavailable glutaminase inhibitor in Phase 2 trials.  The company and its academic collaborators will highlight data of CB-839 in novel therapeutic combinations in preclinical models of selected cancers.

“Tumor metabolism is a novel therapeutic approach that exploits the way in which cancer cells utilize nutrients to grow and survive,” said Susan Molineaux, PhD, President and Chief Executive Officer of Calithera. “CB-839, a novel glutaminase inhibitor, has the potential to be developed in combination with standard of care cancer therapeutics such as CDK4/6 or PARP inhibitors to improve patient outcomes.”

Preclinical data will be presented by Ethan Emberley, PhD, in a poster titled, “The glutaminase inhibitor CB-839 synergizes with CDK4/6 and PARP inhibitors in preclinical models,” on April 17, 2018 (Abstract #3509/6). Data will be presented demonstrating that CB-839 synergizes with the CDK4/6 inhibitor palbociclib in colorectal carcinoma, triple negative breast cancer (TNBC), and ER+ breast cancer cell lines, and enhances anti-tumor activity in both an ER+ breast cancer and a colorectal cancer (CRC) xenograft tumor model.  CB-839 treatment in combination with the PARP inhibitors niraparib and talazoparib has synergistic anti-proliferative activity in TNBC, CRC, non-small cell lung carcinoma, ovarian and prostate cancer cells.  In vivo, the combination of CB-839 with PARP inhibitors enhances anti-tumor activity compared to single agent treatment in a CRC tumor xenograft model.

Two additional posters will be presented by academic collaborators:

  • Suppression of clear cell ovarian carcinoma growth by glutaminase-1 inhibitor as single agent and in combination with PARP-1 inhibitor

    Abstract # LB-253/20
    Presenter: T. Li, Laboratory of Othon Iliopoulos, Massachusetts General Hospital
    Tuesday April 17, 2018

  • Combination treatment with CB-839 and romidepsin induces apoptosis and suppresses cell viability in preclinical models of chondrosarcoma

    Abstract #1329/7
    Presenter: T.N. Sheikh, Laboratory of Gary Schwartz, Columbia University
    Monday, April 16, 2018

About CB-839

Calithera’s lead product candidate, CB-839, is a potent, selective, reversible and orally bioavailable inhibitor of glutaminase.  CB-839’s onco-metabolism activity takes advantage of the unique metabolic requirements of tumor cells and cancer-fighting immune cells such as cytotoxic T-cells.  It is currently being evaluated in Phase 2 clinical trials in multiple tumor types, in combination with standard of care agents.

About Calithera

Calithera is a clinical-stage biopharmaceutical company focused on fighting cancer by discovering, developing, and commercializing novel small molecule drugs that target tumor and immune cell metabolism. Calithera is headquartered in South San Francisco, California.  For more information about Calithera, please visit

Forward Looking Statements

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "may," "will," "expect," "anticipate," "estimate," "intend," "poised" and similar expressions (as well as other words or expressions referencing future events, conditions, or circumstances) are intended to identify forward-looking statements.  These statements include those related to the safety, tolerability and efficacy of CB-839, the overall advancement of CB-839 in clinical trials, the unmet need in the treatment of patients with advanced disease, and Calithera’s plans to continue development of CB-839 in combination with PARP inhibitors niraparib and talazoparib for the treatment of TNBC, CRC, non-small cell lung carcinoma, ovarian and prostate cancer cells.  Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements.  The product candidates that Calithera develops may not progress through clinical development or receive required regulatory approvals within expected timelines or at all. In addition, clinical trials may not confirm any safety, potency or other product characteristics described or assumed in this press release.  Such product candidates may not be beneficial to patients or successfully commercialized.  The failure to meet expectations with respect to any of the foregoing matters may have a negative effect on Calithera's stock price.  Additional information concerning these and other risk factors affecting Calithera's business can be found in Calithera's most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission, and other periodic filings with the Securities and Exchange Commission at These forward-looking statements are not guarantees of future performance and speak only as of the date hereof, and, except as required by law, Calithera disclaims any obligation to update these forward-looking statements to reflect future events or circumstances.

SOURCE: Calithera Biosciences, Incorporated

Jennifer McNealey

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Source: Calithera Biosciences, Inc.