Plus Therapeutics Successfully Treats First Patient in Cohort 8 of ReSPECT-GBM Phase 1/2a Trial

Company also enrolling ReSPECT-GBM Phase 2 trial

Presentation of data from Phase 1/2a and Phase 2 trials planned in 2023

AUSTIN, Texas, March 28, 2023 (GLOBE NEWSWIRE) -- Plus Therapeutics, Inc. (Nasdaq: PSTV) (the “Company”), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system cancers, today announced the first patient in Cohort eight of the ReSPECT-GBM Phase 1/2a dose escalation clinical trial evaluating the Company’s lead investigational targeted radiotherapeutic, rhenium (¹⁸⁶Re) obisbemeda, in recurrent glioblastoma (GBM) has been successfully treated.

The dose escalation phase of the trial has now treated 25 patients with no dose-limiting toxicities observed through 7 completed dosing cohorts. Cohort 8 is now enrolling using 41.5 millicuries (mCi) administered dose rhenium (¹⁸⁶Re) obisbemeda with an infused volume of 16.34 milliliters (mL) which allows the treatment of large and morphologically complex tumors.

In parallel, the Company has treated five patients to date with rhenium (¹⁸⁶Re) obisbemeda in the Phase 2 trial in recurrent GBM administering a dose of 22.3 mCi and 8.8 mL in small- to medium-sized tumors.

“Taken together, the safety and efficacy signals observed thus far in 30 treated recurrent GBM patients are very promising,” said Norman La France, M.D., President and Chief Medical Officer of Plus Therapeutics. “We remain on track in 2023 to continue to dose escalate to the yet unreached maximal tolerated dose, expand the number of clinical trial sites and present data from the Phase 1/2a and 2 trials in the second half of 2023.”

Thus far, no treatment emergent dose-limiting toxicities have been observed in either trial. The absorbed radiation doses from the 30 patients treated to date have resulted in an absorbed dose of up to 740 gray to the tumor.

The U.S. Food and Drug Administration granted both Orphan Drug designation and Fast Track designation to rhenium (¹⁸⁶Re) obisbemeda for the treatment of GBM. More information about the ReSPECT-GBM trial may be found at ReSPECT-Trials.com and ClinicalTrials.gov (NCT01906385).

About Rhenium (¹⁸⁶Re) obisbemeda
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.