Isoray - Innovative Brachytherapy

Isoray’s Cesium-131 Spotlighted in Multiple Presentations at ASTRO

Nov 24, 2020

Studies Demonstrate Impact of Proprietary Isotope on Prostate and Brain Cancers At World’s Premier Radiation Oncology Society

RICHLAND, WASHINGTON – November 24, 2020 – The importance of Isoray, Inc.’s (NYSE American: ISR) Cesium-131 in treating prostate and brain cancers was underscored in multiple presentations at the ASTRO 2020 annual meeting in Miami, Florida. During the virtual meeting, attendees were able to learn about the increasing body of clinical evidence showing that Cesium-131 has been found to be a valuable option in the treatment of prostate and brain cancer for clinicians and their patients.

Commenting on the presentations, Isoray CEO Lori Woods said, “It is very gratifying that so many Cesium-131 studies made it through review to the meeting proceedings of the world’s leading organization in radiation oncology. A tremendous amount of work goes into each study at these respective institutions, and each illustrates a continued interest in research related to Cesium-131 cancer treatment. We are proud that our leading brachytherapy treatment is at the forefront in bringing important benefits to cancer patients and the medical professionals who care for them.”

Two studies, The Effect of Positive Biopsy Cores on the Prognosis of Patients with Intermediate Risk Prostate Cancer Treated with Cs-131 Prostate Brachytherapy, Smith, Benoit, Beriwal, et al. UPMC, Pittsburgh PA and Report of a Large Cohort of Intermediate-Risk Prostate Cancer Patients Treated with Cs-131 Brachytherapy, Rodriguez-Lopez, Beriwal, Benoit, et al., UPMC Pittsburgh PA, looked at the use of Cesium-131, commercially known as Cesium Blu, in the treatment of intermediate risk prostate cancer. These studies make the case that many intermediate risk prostate cancer patients can be treated successfully with a Cesium-131 implant alone. Importantly, these studies show the excellent outcomes for Cesium-131 patients in this intermediate risk patient group.

Among the presentations that looked at Cesium-131 in the treatment of brain cancer was the study, A Matched Pair Analysis Of Clinical Outcomes After Intracavitary Cesium-131 Brachytherapy Versus Stereotactic Radiosurgery For Resected Brain Metastases, Vanderbilt, Schwartz, et al., Weill Cornell Medical College, NY. In this study, 30 patients with brain metastases underwent surgery and Cesium-131 brachytherapy. These patients were “matched” to 60 patients who underwent treatment of brain metastases with surgery and stereotactic radiosurgery (SRS). The patients who underwent Cesium-131 implantation at surgery as opposed to those who underwent SRS following surgery had lower rates of local recurrence and complications such as radiation necrosis.

Another study, Cs-131 Intracavitary Brachytherapy as an Adjunct to Maximal Safe Resection for Locally Recurrent High-Grade Glioma, Patel, Chen, Dusenbery, et al., Univ Minnesota, Minneapolis, involved the use of GammaTile, powered by Cesium-131 in the treatment of ten patients with brain cancers including some patients with glioblastoma multiforme (GBM). These patients had all been treated with surgery, chemotherapy, and radiation and their cancers had progressed. Nine of the ten patients had failed second line (salvage) therapy as well. The study demonstrated that treatment with Cs-131/GammaTile offers a way to provide therapeutic levels of re-irradiation that begin at the time of surgical placement of the GammaTiles. The successful delivery of high dose radiation with a low rate of complications and no radiation necrosis is very promising in the treatment of these brain malignancies.

Isoray is a medical technology company and innovator in seed brachytherapy. The Company is the world’s only producer of Cesium-131 brachytherapy, commercially known as Cesium Blu, which is powering expanding internal radiation treatment options throughout the body for difficult to treat lung, brain, gynecological, head and neck, pelvic, and colorectal cancers as well as prostate cancer.

Contact

Media and Public Relations: Sharon Schultz (302) 539-3747

Investor Relations: Mark Levin (501) 255-1910

About Isoray

Isoray, Inc., through its subsidiary, Isoray Medical, Inc. is the sole producer of Cesium-131 brachytherapy seeds, which are expanding brachytherapy options throughout the body. Learn more about this innovative Richland, Washington company and explore the many benefits and uses of Cesium-131 by visiting www.isoray.flywheelstaging.com. Join us on Facebook/Isoray. Follow us on Twitter @Isoray.

Safe Harbor Statement

Statements in this news release about Isoray’s future expectations, including whether the studies discussed in this news release will have favorable outcomes in commercial settings, the advantages of Cesium-131 and its delivery systems coupled with surgery, the perception by patients of quality of life outcomes compared to other treatment options, whether demand for and use of Cesium-131 will increase or continue as anticipated and all other statements in this release, other than historical facts, are “forward-looking statements” within the meaning of the Private Securities Litigation Reform

Act of 1995 (“PSLRA”). This statement is included for the express purpose of availing Isoray, Inc. of the protections of the safe harbor provisions of the PSLRA. It is important to note that actual results and ultimate corporate actions could differ materially from those in such forward-looking statements based on such factors as whether additional studies are released that support the conclusions of the studies discussed in this news release, whether ongoing patient results are favorable and in line with the conclusions of clinical studies and initial patient results, physician acceptance, training and use of our products, whether we, our distributors and our customers will successfully obtain and maintain all required regulatory approvals and licenses to market, sell and use our products in its various forms, changes in laws and regulations applicable to our products, and other risks detailed from time to time in Isoray’s reports filed with the U.S. Securities Exchange Commission. Unless required to do so by law, we undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.