Oncocyte's DetermaIO Assay Predicts Atezolizumab Response in Phase 2 Trial

Oncocyte Corp., a diagnostics technology company, has announced the publication of favorable data concerning its proprietary gene expression test, DetermaIO™, in the peer-reviewed journal Clinical Cancer Research. The data originates from the NeoTRIP Phase 2 clinical trial, which evaluated the effectiveness of combining neoadjuvant carboplatin and nab-paclitaxel (chemotherapies) with or without the immunotherapy atezolizumab in patients with triple-negative breast cancer (TNBC).

The trial assessed several established biomarkers and gene signatures to determine which patients with early-stage TNBC would benefit most from immunotherapy. Oncocyte's DetermaIO test emerged as the only biomarker that was both statistically significant and predictive of a pathologic complete response (pCR). Specifically, patients who tested positive with the DetermaIO assay (IO+) showed a significantly higher pCR rate when treated with atezolizumab plus chemotherapy (69.8%) compared to chemotherapy alone (46.9%). Conversely, patients who tested negative (IO-) did not exhibit significant improvements in pCR rates when atezolizumab was added to their chemotherapy regimen (44.6% versus 49.2% with chemotherapy alone).

The study, conducted in collaboration with the Michelangelo Foundation for Cancer Research in Milan, underscores the potential of DetermaIO to meet the unmet need for predictive biomarkers in TNBC. The results demonstrate that DetermaIO can effectively identify patients who are more likely to benefit from immune checkpoint inhibitors (ICIs).

Josh Riggs, CEO of Oncocyte, expressed his gratitude towards Dr. Matteo Dugo and his team for their support in the trial. He highlighted the impressive 69.8% response rate in the treatment arm for IO+ patients and noted its consistency with previous studies. Riggs also mentioned that the company would include this study's findings in their submission to the Centers for Medicare and Medicaid Services (CMS) to seek reimbursement coverage, aiming to broaden access to the test. Additionally, Oncocyte plans to use these results to support ongoing partnerships and explore further indications in TNBC.

Apart from its applications in TNBC, Oncocyte is committed to democratizing access to molecular diagnostic testing to improve patient outcomes. The company is actively investing in developing products across two main verticals: organ transplant testing and oncology. Currently, Oncocyte is commercializing its transplant product line, which includes the VitaGraft™ and GraftAssure™ tests. GraftAssure is set to be launched globally with assistance from Bio-Rad Laboratories, a leading diagnostics equipment company. The company also plans to commercialize its oncology product line, including DetermaIO, within the next 18 months.

The publication further validates DetermaIO's effectiveness in predicting the selective benefit of ICIs for patients. TNBC, an aggressive form of breast cancer, does not respond to typical hormonal or targeted therapies and is often treated with systemic therapies like chemotherapy and immunotherapy. DetermaIO, a novel gene expression assay, assesses the expression levels of 27 genes to evaluate various components of the tumor immune microenvironment.

In the NeoTRIP study, DetermaIO was the only biomarker among several analyzed that could predict which patients were most likely to achieve pCR by adding atezolizumab to their chemotherapy regimen. The findings were further validated using gene expression data from the I-SPY2 Trial, reinforcing DetermaIO's predictive value.

Oncocyte continues to develop and commercialize its diagnostic tests, aiming to provide clarity and confidence to physicians and patients. The company's product portfolio includes VitaGraft™, a clinical blood-based solid organ transplantation monitoring test; GraftAssure™, a research use only blood-based solid organ transplantation monitoring test; DetermaIO™, a gene expression test for predicting response to immunotherapies; and DetermaCNI™, a blood-based tool for monitoring therapeutic efficacy in cancer patients.