Research validates MiraDx’s PROSTOX® test, highlighting value of predictive radiation toxicity testing in prostate and other cancers
LOS ANGELES–(BUSINESS WIRE)–#ASTRO26–MiraDx, a molecular diagnostics company focused on genetic testing to personalize cancer treatment, today announced that research supporting its PROSTOX technology and the role of germline biomarkers in predicting treatment-related adverse events and response will be featured in five presentations and educational sessions at the 2026 American Society for Radiation Oncology (ASTRO) Annual Meeting, taking place September 26-30, 2026, in Boston, Mass.
The presentations reflect a growing body of evidence about the genetic underpinnings of differences in radiation sensitivity and how they can help physicians identify patients at greater risk of late-onset adverse events as well as treatment responses. This knowledge could support more personalized treatment choices.
A key highlight will be new data presented by Amar Kishan, MD, Professor and Executive Vice Chair for the Department of Radiation Oncology at the David Geffen School of Medicine at UCLA and UCLA Jonsson Comprehensive Cancer Center, and Chair of the American Society for Radiation Oncology (ASTRO) Prostate/GU Resource Panel. These findings, drawn from a cohort of multiple prospective clinical trials including the landmark PACE-B trial, validate the germline biomarker used in MiraDx’s PROSTOX tests to predict late genitourinary (GU) adverse events in a fractionation-specific manner following radiotherapy for localized prostate cancer. A mediation analysis performed on a prospective clinical utility study showed that use of the PROSTOX tests resulted in an absolute 17.5% reduction in 2+ late GU adverse events.
Additional research presented by Joanne Weidhaas, MD, PhD, Professor of Radiation Oncology and Vice Chair of Molecular and Cellular Oncology at the David Geffen School of Medicine at UCLA and co-founder of MiraDx, demonstrates the ability of MiraDx’s PROSTOX test to predict late GU adverse events following stereotactic body radiation therapy (SBRT) to the prostate fossa after radical prostatectomy. Her research also describes the role of microRNA (miRNA) variations identified by PROSTOX testing in the regulation of global messenger RNA (mRNA) and miRNA expression patterns across key cellular pathways.
Beyond prostate cancer, Weidhaas will present research examining genetic signatures associated with adverse events and overall survival in patients with head and neck squamous cell carcinoma receiving radiation therapy and cisplatin chemotherapy. She is also participating in an educational session and presenting on germline miRNA signatures and their role in predicting radiation treatment toxicity.
“As cancer treatment becomes more targeted and complex, we need predictive tools based on an individual’s personal genetics to identify optimal treatment pathways, including those predicting who is at increased risk for treatment-related adverse events,” said Dr. Weidhaas. “Our genetics can help determine how susceptible we are to these side effects. Understanding not only which genetic biomarkers contribute to that risk, but also how those biomarkers impact gene expression and biological processes gives insights into why patients receiving the same treatment can experience very different outcomes.”
ASTRO 2026 Presentations
EDU 08 – Biomarkers to Predict Radiation Treatment Toxicity
Title: Germline microRNA-Based Signatures to Predict Radiation Treatment Toxicity
Presenter: Joanne Weidhaas, MD, PhD
Date/Time: September 27, 2026, 5:17-5:32 p.m. ET
Location: Room 156
PQA 03 – Digital Health Innovation and Informatics, Patient Safety & Quality, and Radiation and Cancer Biology
Title: mRNA and miRNA Expression Differences Between High- and Low-Risk PROSTOX Patients
Presenter: Joanne Weidhaas, MD, PhD
Date/Time: September 28, 2026, 10:45 a.m.-12:00 p.m. ET
Location: Poster Hall – Exhibit Hall A, Screen 4
SS 36 – Predicting Benefit and Toxicity: Biomarkers in Prostate Radiotherapy
Title: Germline Biomarker for Late Genitourinary Adverse Events after Radiotherapy for Prostate Cancer: Validation in Multiple Prospective Trials
Presenter: Amar Kishan, MD
Date/Time: September 29, 2026, 5:45 p.m. ET
Location: Room 210
QP 28 – Actionable Biomarkers: Guiding Therapy Selection and Deescalation
Title: Germline Biomarker Predicts Adverse Events Following SBRT to the Prostate Fossa After Radical Prostatectomy
Presenter: Joanne Weidhaas, MD, PhD
Date/Time: September 29, 2026, 5:40-5:45 p.m. ET
Location: Room 205
QP 40 – Personalized Therapy and Special Populations in Head and Neck Cancer
Title: Genetic Signatures Predicting Toxicity and Overall Survival in Head and Neck Squamous Cell Carcinoma
Presenter: Joanne Weidhaas, MD, PhD
Date/Time: September 30, 2026, 9:20-9:25 a.m. ET
Location: Room 156
Meet the Investigators
Amar Kishan, MD, Professor and Executive Vice Chair for the Department of Radiation Oncology at the David Geffen School of Medicine at UCLA and UCLA Jonsson Comprehensive Cancer Center, and Chair of the American Society for Radiation Oncology (ASTRO) Prostate/GU Resource Panel, will present research validating a germline biomarker for late GU adverse events following prostate cancer radiotherapy.
Joanne Weidhaas, MD, PhD, Professor of Radiation Oncology and Vice Chair of Molecular and Cellular Oncology at the David Geffen School of Medicine at UCLA and co-founder of MiraDx, will present four studies focused on miRNA-based genetic predictors of radiation outcomes.
About MiraDx
MiraDx is a molecular diagnostics company that specializes in developing tests that support individualized cancer treatment. By analyzing an individual’s unique miRNA-based germline signatures, MiraDx enables clinicians and their patients to optimize therapeutic decision choices across radiation therapy, chemotherapy, and immunotherapy. Its tests offer a first-of-their-kind ability to predict treatment-related outcomes based on the patient, facilitating more informative, personalized cancer care.
To learn more about MiraDx and PROSTOX, visit https://miradx.com.
Contacts
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Media Contact, [email protected]

