CLEVELAND, Feb. 15, 2022 /PRNewswire/ -- ViewRay, Inc. (NASDAQ: VRAY) today announced that interim data from the single center Phase III randomized MIRAGE trial, led by UCLA, comparing MRIdian MRI-guided vs. CT-guided SBRT for localized prostate cancer, will be featured at the 2022 American Society of Clinical Oncology (ASCO) Genitourinary (GU) Cancers Symposium, held February 17-19 in San Francisco. Interim analysis of the primary endpoint signaled superiority of MRIdian MRI-guided SBRT with a significant reduction in acute grade ≥2 GU toxicity in men receiving MRI-guided SBRT over those receiving CT-guided SBRT.

The poster, titled "Magnetic resonance imaging-guided versus computed tomography-guided stereotactic body radiotherapy for prostate cancer (MIRAGE): Interim analysis of a phase III randomized trial" and authored by Amar Kishan, MD., Associate Professor and Chief of the Genitourinary Oncology Service at UCLA, will be showcased on Thursday, February 17 from 11:30 AM PT to 1:00 PM PT as part of the Prostate Cancer poster session. Following the poster session, Dr. Kishan (@AmarUKishan) will host a LIVE Twitter Q&A to answer questions about the interim findings. Those interested can join the conversation and post their questions using #MIRAGEQA.

The interim analysis of data from 100 patients eligible for evaluation (51 in the CT group and 49 in the MRI group) showed a statistically significant reduction in acute grade ≥2 GU toxicity in men receiving MRI-guided SBRT (47.1 percent in the CT group vs. 22.4 percent in the MRI group) and a significant reduction in acute grade ≥2 gastrointestinal (GI) toxicity in men receiving MRI-guided SBRT (13.7 percent in the CT group vs. 0 percent in the MRI group). Acute grade ≥2 GU toxicity can include adverse events range from frequent, urgent, or painful urination to pelvis pain, bladder spasms, or blood in the urine. Acute grade ≥2 GI toxicity can include adverse events ranging from diarrhea, discharge, or rectal/abdominal pain to abdominal distention or obstruction.
Patient-reported outcomes were measured using the International Prostate Symptom Score (I-PSS) and Expanded Prostate cancer Index Composite (EPIC-26). Patient reported urinary and bowel function metrics were better preserved at the 1-month time point with MRI-guidance, though this difference dissipates at the 3-month time point, potentially due to management of side effects.

"Beyond a reduction in the standardized metric of physician-scored toxicity, we also saw differences in one-month patient-reported urinary and bowel function metrics favoring the MRI-guidance arm. These data are highly indicative of less radiation dose being delivered to sensitive structures, such as the bladder, urethra, and rectum, with MRI-guidance," said Dr. Kishan. "Potential explanations for the magnitude of these results can be attributed to the real-time tissue tracking of actual anatomy and automatic gating of beam delivery, which thereby allows for tighter contours and treatment of smaller volumes. The high dose regions are significantly smaller for patients receiving MRI-guided SBRT."

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