Plus Therapeutics Announces Topline Results from Recurrent Glioblastoma External Control Analysis at ASCO 2023

Plus Therapeutics’ partnership with Medidata resulted in a valid historical control arm for the Company’s Phase 1/2 clinical and potential Phase 3 trials evaluating rhenium (¹⁸⁶Re) obisbemeda in recurrent glioblastoma (rGBM)

799 control rGBM patients treated by either bevacizumab or convection enhanced delivery show median overall survival of 7.9 and 8.4 months, respectively

AUSTIN, Texas, May 30, 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 that a new analysis from its partner Medidata, a Dassault Systèmes company, was accepted for online publication at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting, taking place June 2-6, in Chicago, Illinois.

The abstract titled, “Clinical characterization of patients with recurrent glioblastoma in trials involving CED and non-CED treatment [#417610],” included data sourced from Medidata’s more than 30,000 clinical trials involving more than nine million de-identified participants. Aggregate summary statistics comparing bevacizumab and convection-enhanced delivery (CED) patients were based on combined study-level and patient-level data using sample size weighted means, incidence and overall survival.

A total of 799 patients were evaluated from MEDS and studies referenced in D’Amico [J Neurooncol 2021]. Both cohorts (bevacizumab and CED, respectively) were comparable in terms of median age (56 years vs. 55 years), Caucasian race (91% vs. 93%), male sex (68% vs. 65%) and median overall survival (7.9 months vs. 8.4 months).

“The purpose of this analysis was to determine whether bevacizumab patients could form an appropriate external control for evaluating overall survival in current and upcoming CED trials,” said Norman LaFrance, M.D., Chief Medical Officer of Plus Therapeutics. “The results of this analysis provide confidence in the use of an external control arm formed from aggregated clinical trial data of patients previously treated with bevacizumab to interpret the results of the ReSPECT-GBM Phase 1/2 trials. Thus far, our clinical outcomes are promising compared to those using an external control. In a potential future pivotal trial, the use of a historical control arm will enable Plus Therapeutics to more rapidly enroll the trial while simultaneously reducing trial costs.”