OncXerna Therapeutics Announces Final Results and New Xerna™ TME Panel Biomarker Data from a Phase 2 Trial of Bavituximab Plus Pembrolizumab in Patients with Previously Untreated Advanced Hepatocellular Carcinoma

Bavituximab plus pembrolizumab combination achieved a 62.5% response rate in biomarker positive subgroup of hepatocellular cancer patients

Data reinforce the potential of Xerna TME Panel to substantially improve outcomes for patients

WALTHAM, Mass., Jan. 23, 2023 (GLOBE NEWSWIRE) — OncXerna Therapeutics, Inc. (“OncXerna”), a precision medicine company using an innovative RNA expression-based biomarker platform to predict patient responses to its targeted oncology therapeutic candidates, announced final results from a Phase 2 trial of bavituximab plus pembrolizumab in patients with previously untreated advanced hepatocellular carcinoma and new biomarker data demonstrating that the Xerna™ TME Panel clearly identified trial participants more likely to benefit from treatment. The data were featured in a poster that was presented on January 20, 2023 at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI).

The biomarker results presented at ASCO GI are from a planned analysis of tumor biopsies using the Xerna TME Panel, a novel RNA expression-based diagnostic panel that uses a machine learning-based algorithm to classify patients based on the interplay between angiogenic and immunogenic dominant biologies of the tumor microenvironment (TME). In the study featured in the ASCO GI poster, pre-treatment tumor biopsies were analyzed using the Xerna TME Panel and findings were correlated with objective tumor response to test the hypothesis that tumors with high immune scores (immune active or immune-suppressed TME subtypes [biomarker-positive]) are more likely to respond to bavituximab plus pembrolizumab than those with low immune scores (angiogenic or immune-desert TME subtypes [biomarker-negative]).

David Hsieh, M.D., Assistant Professor at University of Texas Southwestern Medical Center and lead investigator of the Phase 2 trial, commented, “Our newly reported clinical data in front-line liver cancer show a near doubling of response rate in the subset of patients classified as biomarker-positive by the Xerna TME Panel. The high response rate seen in these patients is rarely achieved in this challenging disease. Moreover, our patients are potentially more reflective of typical U.S.-based patients compared to those included in recent large, pivotal trials that enrolled the majority of their patients at sites outside of the U.S. We are therefore excited by the prospect of using this panel to optimize the care of patients with liver cancer.”

Key data featured in the ASCO GI poster are summarized below.

¹Analysis based on evaluable patients per protocol. ²All patients with available biomarker results; 9 patients did not have tissue available for testing and biomarker status could not be determined. ³Responses were confirmed by radiographic assessment no sooner than 4 weeks from the time of initial response.

Hagop Youssoufian, M.D., Chief Medical Officer of OncXerna Therapeutics and Adjunct Professor of Medicine at Brown University, commented, “The Xerna TME Panel has demonstrated remarkable consistency in identifying patients who are more likely to benefit from targeted and immune therapies across several malignancies. Although this was a proof-of-concept study, the responses noted in the biomarker-positive subgroup of patients in this lethal disease indicate substantial activity by comparison to the most active and contemporary combination therapies. This is the latest example of OncXerna’s longstanding commitment to utilize the Xerna TME Panel to bring the right medicines to the right patients.”   

A copy of the ASCO GI poster, entitled: “A phase II clinical trial of the phosphatidylserine targeting antibody, bavituximab in combination with pembrolizumab in patients with advanced hepatocellular carcinoma,” will be available on the OncXerna website following the conclusion of the ASCO GI Symposium.

About the Phase 2 Trial

The trial featured in the ASCO GI poster was an investigator-sponsored, Phase 2, single arm study conducted at the University of Texas Southwestern Harold C. Simmons Comprehensive Cancer Center. The trial evaluated the combination of bavituximab and pembrolizumab in previously untreated patients with advanced hepatocellular carcinoma (HCC). The primary objective of the study was to determine the overall response rate (ORR) of the studied combination in patients with advanced HCC. Results showed bavituximab plus pembrolizumab was well tolerated, with no new safety signals, and that the studied combination induced objective tumor response in a meaningful subset of trial participants. Analysis of tumor biopsies showed that the response rate was enhanced in Xerna TME biomarker positive patients, while higher progressive disease rates were observed in biomarker negative patients. For more information on the trial, see Clinicaltrials.gov Identifier: NCT03519997.

About Bavituximab

Bavituximab is an antibody designed to reverse immune suppression by inhibiting phosphatidylserine (PS) signaling and is currently in Phase 2 clinical trials. The mechanism of action of bavituximab is to block tumor immune suppression signaling from PS to multiple immune cell receptor families (e.g., TIMs and TAMs). This biology is relevant across multiple types of solid tumors. Bavituximab is an investigational agent that has not been approved, and it has not been demonstrated to be safe or effective for any use, including for the treatment of advanced gastric cancer.

About the Xerna TME Panel        

The Xerna TME Panel uses proprietary RNA-based gene expression data and a machine learning-based algorithm to classify patients based on the interplay between angiogenic and immunogenic dominant biologies of the tumor microenvironment (TME). The Xerna TME Panel is an investigational assay that has not been approved and has not been demonstrated to be safe or effective for any use.

About OncXerna Therapeutics

OncXerna Therapeutics is a clinical stage precision medicine oncology company developing novel therapies to treat solid tumors. Utilizing its innovative precision medicine platform (Xerna™), OncXerna leverages artificial intelligence technologies and RNA expression-based biomarkers to match a specific patient’s tumor with the drugs best suited to treat that tumor. By integrating the Xerna Platform with our deep expertise in clinical development, we believe we can accelerate the development, approval and commercialization of drug product candidates and bring meaningful new treatments to patients as soon as possible.  OncXerna’s lead product candidate, navicixizumab, is a bispecific antibody that inhibits both DLL4 and VEGF and is currently being studied in ovarian cancer, triple negative breast cancer, and colorectal cancer. Another product candidate, bavituximab, is an antibody designed to reverse immune suppression by inhibiting phosphatidylserine (PS) signaling and is currently in Phase 2 clinical trials. Navicixizumab and bavituximab are investigational agents that have not been approved and have not been demonstrated to be safe or effective for any use.  For more information, please visit oncxerna.com, or follow us on LinkedIn and Twitter.

Investor and Media Contact:

Ashley R. Robinson
LifeSci Partners, LLC
arr@lifesciadvisors.com