NEW YORK – Cancer diagnostic and vaccine startup Calviri said on Thursday that it has been awarded a $300,000 Phase I grant through the National Cancer Institute's Small Business Innovation Research Program, which will support the development of a new proteomic test for assessing whether a cancer patient’s tumor has high microsatellite instability.
MSI-high status is associated with a higher likelihood of response to checkpoint inhibitor immunotherapies and was the first tumor-agnostic biomarker recognized by the US Food and Drug Administration to determine patients eligible for treatment with pembrolizumab (Merck's Keytruda) in 2017.
According to Calvari, despite that pan-cancer recognition, MSI testing is still mostly conducted in cancer types where MSI-high cases are the most prevalent. The company believes it can create a simpler, less expensive test technology that would help drive more widespread use.
The company's research is focused on the identification of protein molecules linked to tumor immunogenicity. The firm said that it has found that frameshifted peptides — the product of errors in RNA processing — are a rich source of highly immunogenic neoantigens.
The company intends to create assays by predicting these peptides, which can take a limited number of forms, and attaching them to microarrays. According to Calviri, evidence has shown that MSI-high patients will produce many more immune responses specific to the frameshifted peptides than microsatellite stable patients.
Under the SBIR grant, Calviri will test this further in colon and endometrial cancer patients — measuring whether these FS peptide arrays can accurately read out an individual's microsatellite instability status from a drop of blood. The firm expects to report study results in early 2020.