PROSTOX™ Standard test predicts long-term urinary side effects from radiation therapy, identifying those at higher risk for late genitourinary toxicity

Growing PROSTOX™ portfolio now includes risk assessment tests for multiple radiation therapy types, including CFRT or MHFRT

MiraDx, a molecular diagnostics company focused on genetic testing to personalize cancer treatment, today announced the U.S. commercial launch of PROSTOX™ Standard, a new, clinically validated genetic test that expands access to personalized radiation therapy for patients with localized prostate cancer. The test identifies those at increased risk of developing long-term urinary side effects following conventionally fractionated or moderately hypofractionated radiation therapy (CFRT or MHFRT), and complements the company’s existing PROSTOX Ultra offering, for patients being considered for stereotactic body radiation therapy (SBRT). By offering both tests, MiraDx is expanding access to toxicity risk assessment testing to a broader group of prostate cancer patients at risk for genitourinary (GU) toxicity following external beam radiation therapy (EBRT).

While EBRT is an effective and widely used treatment for localized prostate cancer, more than 20% of patients treated with radiation therapy experience persistent urinary side effects, referred to as late GU toxicity.¹ PROSTOX tests help predict late-onset genitourinary (GU) toxicity—side effects such as urinary urgency, leakage, or discomfort—that can appear months or years after radiation treatment and significantly impact quality of life.

Localized prostate cancer has an excellent prognosis with a five-year survival rate of over 99%.² Although SBRT, CFRT, and MHFRT have similar efficacy in this population, individual responses to each treatment method can vary due to a patient’s genetics. Until now, clinicians have lacked a biology-driven tool to identify which patients are most at risk for GU toxicity from each EBRT method. PROSTOX tests address this gap by analyzing inherited genetic variants in microRNAs and their pathways that influence how individual patients tolerate radiation. Using a simple cheek swab, PROSTOX delivers actionable results in 5-7 days, enabling physicians and patients to make more personalized radiation treatment decisions based upon each patient’s individual side effect risk profile.

“PROSTOX tests bring precision medicine to radiation oncology by shifting the focus from the tumor alone to determining the most effective treatment approach for each patient based upon their unique biology and resulting treatment risks,” said Melissa C. Stoppler, MD, Executive Vice President of Medical Affairs at MiraDx. “Having information about which type of radiation each patient will tolerate best allows clinicians to better tailor radiation treatments to patients, helping them avoid future long-term side effects.”

Each PROSTOX test evaluates genetic risk across a different radiation therapy regimen. A result that a patient is at high risk with PROSTOX Standard does not imply a high-risk result for PROSTOX Ultra, and vice versa. In rare cases (less than 2% of patients), PROSTOX tests will identify that a patient has a high risk for late GU side effects with both SBRT and CFRT/MHFRT. For these patients, other interventions may be available.

“Being diagnosed with prostate cancer is life altering and comes with many decisions and so much uncertainty,” said Ron Stewart, a patient who received PROSTOX testing. “The PROSTOX test helped me feel more confident about my treatment plan and more optimistic that my cancer treatment would not hamper my quality of life down the road.”

PROSTOX Standard and PROSTOX Ultra are commercially available in the U.S. and performed at MiraDx’s CLIA-certified and CAP-accredited molecular diagnostics laboratory in Los Angeles, Calif. Coverage may vary by insurance plan. MiraDx offers a financial assistance program to help ensure patient access to PROSTOX tests.

Learn more at miradx.com/prostox.

About PROSTOX Tests

PROSTOX tests are clinically validated diagnostic tests used to predict genitourinary toxicity following external beam radiation therapy (EBRT). The tests analyze inherited genetic variants in microRNAs and their pathways that influence how individual patients tolerate radiation, delivering actionable insights to enable clinicians to make informed therapeutic choices with their families. The PROSTOX Standard test is designed to predict toxicity following CFRT (37-45 fractions over 7-9 weeks) or MHFRT (20-28 fractions over 4-5 weeks). The PROSTOX Ultra test is designed to predict toxicity following SBRT (5–7 fractions over approximately 10 days).

About MiraDx

MiraDx is a molecular diagnostics company that specializes in developing genetic tests that support individualized cancer treatment choices. By analyzing an individual’s unique microRNA-based germline genetic signatures, MiraDx enables clinicians and their patients to optimize therapeutic decision choices across radiation therapy 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.

¹Tree AC, Ostler P, Voet H van der, et al. Intensity-modulated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): 2-year toxicity results from an open-label, randomised, phase 3, non-inferiority trial. Lancet Oncol. 2022;23(10):1308-1320. doi:https://doi.org/10.1016/S1470-2045(22)00517-4

²Litwan, Mark S., Tan, Hung-Jui. The Diagnosis and Treatment of Prostate Cancer--A Review JAMA. 2017;317(24):2532-2542. doi:10.1001/jama.2017.7248

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New PROSTOX™ Standard test expands personalized radiation risk assessment to patients considering CFRT or MHFRT.