Plus Therapeutics, Inc. announced that the first patient has been dosed in the ReSPECT-GBM Phase 2b dose expansion clinical trial evaluating rhenium (186Re) obisbemeda for the treatment of recurrent glioblastoma (GBM). This Phase 2b multi-center trial is designed to evaluate the safety, tolerability, distribution and efficacy of rhenium (186Re) obisbemeda infused directly into the tumor via convection-enhanced delivery catheters in patients with recurrent GBM progressing after conventional treatment. The Phase 2b trial is expected to enroll up to 31 additional patients with small- to medium-sized tumors (20 mL or less) in approximately 24 months.

The trial is supported by an award from the National Cancer Institute (NCI), part of the U.S. National Institutes of Health (NIH). GBM affects approximately 14,490 patients annually in the U.S. and is the most common and lethal form of brain cancer. The average life expectancy with GBM is less than 24 months, with a one-year survival rate of 40.8% and a five-year survival rate of only 6.9%.

There is no clear standard of care for recurrent GBM and even the few currently approved treatments provide only marginal survival benefit and are associated with significant side effects, which limit dosing and prolonged use. Approximately 90% of patients experience GBM tumor recurrence at or near the original tumor location, yet there are no FDA-approved treatments in the recurrent or progressive setting that can significantly extend a patient's life. Rhenium (186Re) obisbemeda is a novel injectable radiotherapy specifically formulated to deliver highly targeted high dose radiation in CNS tumors in a safe, effective and convenient manner to optimize patient outcomes.

Rhenium (186Re) obisbemeda has the potential to reduce risks and improve outcomes for CNS cancer patients, versus currently approved therapies, with a more targeted and potent radiation dose. Rhenium is an ideal radioisotope for CNS therapeutic applications due to its short half-life, beta energy for destroying cancerous tissue and gamma energy for live imaging.