– Phase 1a/1b dose escalation study to begin in the second half of 2020 –

LEXINGTON, MA, USA I June 10, 2020 I Curis, Inc. (NASDAQ: CRIS), a biotechnology company focused on the development of innovative therapeutics for the treatment of cancer, today announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for CI-8993, the first-in-class monoclonal anti-VISTA antibody. Curis plans to initiate a Phase 1a/1b study of CI-8993 in the second half of 2020.

“The clearance of our IND is an important step for the advancement of VISTA therapies, as CI-8993 becomes the first anti-VISTA antibody in development to enter clinical testing,” said James Dentzer, President and Chief Executive Officer of Curis. “When activated, VISTA plays a critical role in suppressing T cell activity. Conversely, it has been shown in preclinical studies that blocking VISTA reduces the suppression of T cells and reactivates anti-tumor immune function. We are eager to leverage our extensive experience with VISTA and pioneer this first-in-class anti-VISTA antibody program.”

Certain cancers, such as mesothelioma, triple negative breast cancer, non-small cell lung cancer, and gynecologic malignancies, are known to be highly driven by VISTA. These cancers may be amenable to monotherapy treatment with anti-VISTA therapy.

In other cancers, anti-VISTA therapy may be more effective as part of a combination approach. VISTA is independent of, and complementary to, other immune checkpoints, including PD1 and CTLA4. Published studies have shown that VISTA expression increases up to 5-fold as a compensatory mechanism following anti-CTLA4 or anti-PD1 treatment. Further preclinical studies have explored this relationship more deeply and support the potential of combining anti-VISTA therapy with anti-PD1 or anti-CTLA4 therapies.

The multi-center, open-label Phase 1a/1b dose escalation study of CI-8993 in patients with relapsed / refractory solid tumors will evaluate approximately 50 patients, with the goal of identifying a recommended dose and schedule. Curis expects to initiate this study in the second half of 2020.

About VISTA

VISTA is a novel negative checkpoint ligand that is homologous to PD-1/PD-L1 and suppresses T cell activation. VISTA relieves negative regulation by hematopoietic cells and enhances protective anti-tumor immunity, and is highly expressed on myeloid cells and T cells. Preclinically, VISTA monoclonal antibody treatment increased the number of tumor-specific T cells in the periphery, and enhanced the infiltration, proliferation and effector function of tumor-reactive T cells within the tumor microenvironment (TME). VISTA blockade alters the suppressive feature of the TME by decreasing the presence of monocytic myeloid-derived suppressor cells and increasing the presence of activated dendritic cells (DCs) within the TME leading to enhanced T cell mediated immunity. VISTA monoclonal antibody administration as a monotherapy has been shown to suppress the growth of both transplantable and inducible melanoma in preclinical models. Previous studies have demonstrated that VISTA blockade may be synergistic with peptide-based cancer vaccines to impair the growth of established tumors.

About Curis, Inc.

Curis is a biotechnology company focused on the development of innovative therapeutics for the treatment of cancer. In 2015, Curis entered into a collaboration with Aurigene in the areas of immuno-oncology and precision oncology. As part of this collaboration, Curis has exclusive licenses to oral small molecule antagonists of immune checkpoints including, the VISTA/PDL1 antagonist CA-170, and the TIM3/PDL1 antagonist CA-327, as well as the IRAK4 kinase inhibitor, CA-4948. CA-4948 is currently undergoing testing in a Phase 1 trial in patients with non-Hodgkin lymphoma. In addition, Curis is engaged in a collaboration with ImmuNext for development of CI-8993, a monoclonal anti-VISTA antibody. Curis is also party to a collaboration with Genentech, a member of the Roche Group, under which Genentech and Roche are commercializing Erivedge® for the treatment of advanced basal cell carcinoma. For more information, visit Curis’ website at www.curis.com.

SOURCE: Curis