Plus Therapeutics, Inc. announced positive data from the ongoing ReSPECT-GBM Phase 2 trial evaluating the Company?s lead radiotherapeutic, rhenium (186Re) obisbemeda, for the treatment of recurrent glioblastoma (rGBM) at the Society for NeuroOncology (SNO) 28th Annual Meeting held November 15-19, 2023 in Vancouver, Canada. Key Highlights from the ReSPECT-GBM Phase 2 Trial: ReSPECT-GBM is an ongoing, first-in-human, open-label, Phase 1/2 study investigating dose escalation and other delivery parameters (i.e., number of catheters (1-5), infusion rates, drug volumes, and drug concentrations) to determine the maximum tolerated dose (MTD), maximum feasible dose (MFD), safety, and efficacy of rhenium (186Re) obisbemeda in recurrent adult glioma (IND 116117). The primary objective of the Phase 2 study is to assess overall survival (OS) following rhenium (186Re) obisbemeda administration.

As of November 14, 2023, 15 patients with rGBM have been treated with rhenium (186Re) obisbemeda at a dose of 22.3 mCi delivered directly to the tumor by Convection Enhanced Delivery (CED). In 15 treated patients, mOS is 13 months (95% CI 5 months). Currently, 9 out of the 15 treated patients remain alive.

Median PFS is 11 months (95% CI 6-11 months). The average percent of treated tumor across all 15 patients was 87.2% at 120 hours, with 13/15 patients receiving greater than or equal 70% tumor volume coverage by the drug and =100 Gy absorbed dose to the tumor. Advanced longitudinal imaging analysis supports the observed efficacy signal of rhenium (186Re) obisbemeda.

Rhenium (186Re) obisbemeda continues to be generally safe and well tolerated, consistent with data accumulated in the Phase 1 trial.