TEMPE, Ariz.–(BUSINESS WIRE)– Calviri, Inc., a start-up focused on ending deaths from cancer through unconventional approaches to diagnostics and vaccines, was recently awarded a $300,000 Phase I grant through the Small Business Innovation Research Program (SBIR) at the National Cancer Institute (NCI). This one-year grant will support the development of a new test for establishing whether a cancer patient’s tumor has high microsatellite instability (MSI-H). This is important because MSI-H status is associated with very favorable responses to checkpoint inhibitor immunotherapies.
Today, only patients with cancers that have generally shown higher frequencies of MSI-H tumors (colon, endometrial and stomach) are routinely tested. “Our intention is to provide a simple, inexpensive test to effectively determine MSI-H status of a patient with any cancer,” said Stephen Albert Johnston, CEO of Calviri. “This would enable many more patients to be identified as optimal candidates for immunotherapy.”
Calviri’s research is centered on the discovery of a new source of neoantigens produced by tumor cells. Instead of point mutations in DNA, Calviri focuses on frameshift (FS) variants produced through errors in RNA processing, such as mis-splicing. Calviri has demonstrated that these frameshifted peptides are a rich source of highly immunogenic neoantigens. Since there are a limited number of possible FS peptides, they can be predicted and produced in-situ on arrays manufactured by the company’s proprietary process. Studies indicate that MSI-H patients produce many more immune responses specific to the FS peptides than microsatellite stable (MSS) patients. The product in development will identify and quantify those FS neopeptides that are made by a patient’s tumor and recognized by their blood-antibodies.
Currently MSI status is determined by sequencing defined genes of tumor cells. This depends on obtaining sufficient tumor tissue for DNA sequencing protocols. Under this SBIR grant, Calviri will determine whether the FS peptide arrays can readout microsatellite instability status from a drop of blood. The study will be conducted with blood samples from colon and endometrial cancer patients to assess if the same FS array can determine MSI status for more than one cancer. Calviri expects to report study results in early 2020.