World News: 13:00 GMT Wednesday 14th August 2019. [Gritstone Oncology, Inc via Globe Newswire via SPi World News]
EMERYVILLE, Calif., Aug. 14, 2019 (GLOBE NEWSWIRE) -- Gritstone Oncology, Inc. (Nasdaq: GRTS), a clinical-stage biotechnology company developing the next generation of immunotherapies to fight multiple cancer types, today announced that the first SLATE patient has been dosed. SLATE is an investigational immunotherapy directed at shared tumor-specific neoantigens (TSNA) which are derived from driver mutations, functionally important gene alterations recurrently observed in cancer patients (such as ). Gritstone has used its proprietary EDGE artificial intelligence platform to identify the top twenty immunogenic shared TSNA to engineer into the cassette of its first SLATE immunotherapy. SLATE is designed to induce robust anti-tumor T-cell responses that result in selective tumor cell destruction through the recognition of TSNA on tumor cells. The ongoing Phase 1 study is evaluating SLATE in combination with the anti-PD-1 antibody nivolumab and the anti-CTLA-4 antibody ipilimumab for the treatment of patients with advanced solid tumors, including metastatic lung adenocarcinoma, pancreatic ductal carcinoma and microsatellite-stable colorectal cancer, as well as in patients with other solid tumor types who have relevant mutation/HLA (human leukocyte antigen) combinations. This study is being conducted by Gritstone, under a clinical collaboration agreement with Bristol-Myers Squibb.
“Our ability to predict common shared neoantigens using EDGE is one of the unique differentiators for SLATE,” said Andrew Allen, M.D., Ph.D., co-founder, president and chief executive officer of Gritstone Oncology. “The robustness of the prediction model is important as not all driver mutations create neoantigens in tumors. To act as a neoantigen, a mutated protein must be processed by the tumor cell into a short mutant peptide which is stably presented on the cell surface by an HLA molecule. It is this HLA-peptide complex that is recognized by cytotoxic T cells. Using EDGE, we predicted common shared neoantigens, and directly observed many of them on the surface of human tumor samples with immunopeptidomics. The existence of T-cell precursors against the neoantigens was demonstrated for the majority of cases examined. We have identified shared neoantigens in well-known driver mutations, such as (G12C, G12D, G12V, etc.) and , that are often found in common tumor types.”
Dr. Allen continued, “This has enabled us to develop an ‘off-the-shelf’ immunotherapy for patients who, following routine tumor mutation and blood HLA analysis, are expected to possess at least one shared neoantigen contained in the SLATE immunotherapy on their tumor. The appeal of SLATE lies in the potential for one pre-made therapy to target tumor-specific mutations across a number of patients and cancer types. We are pleased to have been able to advance this study well ahead of schedule and look forward to presenting preliminary data at year-end.”
SLATE immunotherapy consists of two components: first, a priming adenoviral vector, that has been shown to be highly immunogenic in humans in other disease settings, is used to deliver the cassette of 20 shared TSNA; and second, the same shared TSNA cassette is delivered using a self-amplifying RNA vector in a repeated boost sequence to drive and sustain high numbers of tumor-targeted T cells. To develop SLATE, Gritstone is utilizing its genomics, proteomics, and informatics labs in Cambridge, MA and its 43,000 square foot biomanufacturing facility in Pleasanton, CA. Additionally, the company partners with third-party contract manufacturing organizations such as AmpTec GmbH, a leading provider of RNA technology products and GMP manufacturing, to support the production of SLATE for clinical trial use.
Investors:Alexandra SantosWheelhouse Life Science Advisors(510) 871-6161
Globe Newswire: 13:00 GMT Wednesday 14th August 2019
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