Gritstone Announces Updated Overall Survival Results from GRANITE Phase 1/2 Study and Poster at SITC 2022
-- Median overall survival (OS) for patients with metastatic, microsatellite stable colorectal cancer (MSS-CRC) who had two prior lines of therapy and had molecular response will now exceed 22 months – median not yet reached --
-- Patients who achieve a molecular response include those with liver metastasis and are not enriched for baseline PD-L1 expression, high tumor mutation burden or IFNg-related genes --
“The follow-up data from our Phase 1/2 study in patients with MSS-CRC who have received at least two prior lines of therapy continue to demonstrate an association between molecular response and overall survival,” said
The Phase 1/2 study is evaluating the safety, immunogenicity, and clinical activity of GRANITE in combination with PD-1 checkpoint inhibitor, nivolumab and subcutaneous anti-CTLA-4 antibody ipilimumab in advanced solid tumors. This study enrolled and treated 29 patients with previously treated, metastatic solid tumors including patients with colorectal cancer, gastroesophageal adenocarcinoma, and non-small cell lung cancer. Of 13 patients with MSS-CRC, 6 experienced a molecular response defined as ≥30% reduction in circulating tumor DNA (ctDNA) and continue to have an overall survival advantage compared to those patients without a molecular response.
Updated OS data from GRANITE Phase 1/2:
- 6 of 13 treated patients with MSS-CRC had a molecular response and the observed median overall survival in this group will now exceed 22 months (median OS not yet reached versus 7.8 months in those without a molecular response). This compares to a median overall survival not yet reached and exceeding 18 months as reported in
Clinicopathologic characteristics from GRANITE Phase 1/2:
- 4 of 6 patients with molecular response had liver metastasis.
- All patients had PD-L1 expression <1% and low levels of IFNg-related gene expression.
- Median tumor mutational burden was 2.9 and 3.6 mutations/MB in those with and without molecular response, respectively.
SITC presentation details are as follows:
Abstract 660: Clinicopathologic Characteristics of Patients with Metastatic Colorectal Cancer with Molecular Responses Following Treatment with an Individualized Neoantigen Vaccine Regimen
Session: Clinical Trials In Progress
Gritstone’s neoantigen-based immunotherapies are engineered to elicit a significant T cell response (particularly CD8+ cytotoxic T cells) against mutation-derived tumor-specific neoantigens (TSNA). Gritstone identifies these TSNA using its proprietary artificial intelligence platform, EDGE™. GRANITE is an individualized neoantigen-based immunotherapy program that uses adenoviral ("prime”) and self-amplifying mRNA ("boost”) vectors to deliver personalized immunotherapy containing the relevant neoantigens. GRANITE was granted Fast Track designation by the
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Gritstone is working to create the world’s most potent vaccines. We leverage our innovative vectors and payloads to train multiple arms of the immune system to attack critical disease targets and have programs in viral diseases and solid tumors. Independently and with our partners, we are advancing a portfolio of product candidates with the aim of improving patient outcomes and eliminating disease. www.gritstonebio.com
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