Benzinga | Oct 27, 2021 02:00PM EDT

Plus Therapeutics Announces Presentation Of ReSPECT-GBM Trial Dosimetery Data At American Society For Radiation Oncology (ASTRO) 2021 Annual Meeting

Plus Therapeutics, Inc. (Nasdaq: PSTV) (the "Company"), a clinical-stage pharmaceutical company developing innovative, targeted radiotherapeutics for rare and difficult-to-treat cancers, today presented data at the American Society for Radiation Oncology (ASTRO) 2021 Annual Meeting indicating Rhenium-186 NanoLiposome (186RNL) delivered to patients with recurrent glioblastoma (GBM) through convection enhanced delivery results in predictable distribution and stable retention to the targeted tissues, providing days of sustained, localized radiation treatment to the tumor.

Data from the ePoster titled "Image-guided Rhenium-186 NanoLiposome (186RNL) brachytherapy in the treatment of recurrent glioblastoma: technique, image analysis, dosimetry, and monitoring" demonstrated the following:

* Mean locoregional retention in the brain volume at the end of infusion (85.9% ? 17.1% ID, n=18) and at eight days post-infusion (46.6% ? 16.7% ID, n=17).

* Following dose escalation, the mean radiation absorbed dose in the two most recent cohorts to the tumor volume was 354.7 ? 144.0 Gy, to the whole brain was 1.32 ? 1.06 Gy, and to the whole body was 0.16 ? 0.04 Gy (n=6), establishing evidence of a high radiation absorbed dose to the tumor with minimal brain and whole body radiation exposure.

"We're very encouraged by this latest data supporting investigational 186RNL for the treatment of recurrent glioblastoma, specifically underscoring its potential to effectively treat difficult to reach brain tumors, without harming surrounding tissue," said John Floyd, M.D., University of Texas Health Science Center San Antonio, study investigator, and presenter of the ePoster. "Coupled with state-of-the-art imaging technology tools, treatment with 186RNL has shown to be highly precise, which may give reassurance to patients living with recurrent glioblastoma and advance understanding of convection therapy and targeted radiation for healthcare providers treating this unforgiving disease."

In addition, the analysis shows image monitoring can provide a predictive tool to evaluate therapy delivery and treatment effectiveness. In this study, up to four catheters showed to have effectively enhanced locoregional drug distribution and tumor volume coverage, supporting that the 3D dose distribution calculation leads to convenient dose and therapy evaluation, and application of additional therapy for better tumor control.

"This presentation documents the potential safety and utility of locoregional radiotherapeutic delivery to the brain or any organ or tissue in the body," said Marc Hedrick, M.D., President and Chief Executive Officer of Plus Therapeutics. "We are committed to further investigating the potential of 186RNL in hopes of offering a novel treatment to patients in need of minimally invasive and convenient therapeutic options for recurrent GBM and other difficult to treat cancers. This new data builds on existing evidence and reinforces the clinical promise of providing precise, targeted radiotherapeutics for cancer."

186RNL is under investigation as a potentially safe, effective and convenient way to deliver a very high dose of radiation, possibly over 20 times greater than traditional external beam radiation therapy. This trial is supported by the U.S. National Institutes of Health/National Cancer Institute at three trial sites in the U.S., including UT Health Science Center San Antonio, UT Southwestern Medical Center Dallas and UT MD Anderson Cancer Center Houston.

The U.S. Food and Drug Administration has granted both Orphan Drug designation and Fast Track designation to 186RNL for the treatment of patients with GBM. Additional details about the ReSPECT(tm) trial are available at clinicaltrials.gov (NCT01906385).

A copy of the poster will be available under the Presentations tab of the Investors section of the Company's website at ir.plustherapeutics.com/.