Plus Therapeutics Gains $5.7M Funding for Leptomeningeal Metastases Program

Plus Therapeutics, Inc., a clinical-stage pharmaceutical entity, recently garnered financial backing through a private placement with existing investors amounting to approximately $3.7 million. This strategic move, along with a $2 million advance from the Cancer Prevention and Research Institute of Texas (CPRIT), contributes significantly to the company's ongoing endeavors to develop targeted radiotherapeutics, especially for central nervous system (CNS) cancers.

These financial injections will primarily fuel the clinical advancement of Rhenium (186Re) Obisbemeda, a promising treatment for leptomeningeal metastases (LM), a rare but severe complication where cancer spreads to the cerebrospinal fluid (CSF) and the protective membranes surrounding the brain and spinal cord. The prevalence of LM is rising, partly due to extended patient survival rates and the limitation of conventional chemotherapies in penetrating the spinal fluid. Currently, there are no FDA-approved therapies for LM, which makes the ongoing research and clinical trials by Plus Therapeutics critical for patient outcomes.

Rhenium (186Re) Obisbemeda is a novel injectable radiotherapy designed to deliver high-dose targeted radiation safely to CNS tumors. It offers a potential breakthrough due to its ability to deliver potent radiation doses while minimizing exposure to non-targeted areas. Plus Therapeutics is conducting two pivotal clinical trials: ReSPECT-GBM, focusing on recurrent glioblastoma, and ReSPECT-LM, concentrating on leptomeningeal metastases. The ReSPECT-LM trial is prominently supported by CPRIT’s $17.6 million grant, facilitating extensive research and development. The funds from CPRIT have been used to further the trial's progress, with approximately $5.2 million still available from the initial grant.

The private placement deal involved the issuance of secured convertible promissory notes and common stock purchase warrants. The notes, convertible under certain conditions to company common stock, mature one year from the financing's closure and bear a 10% annual interest, payable quarterly. These financial arrangements with AIGH Capital Management LLC and other healthcare-oriented institutional investors bolster Plus Therapeutics’ financial standing, facilitating their ongoing clinical objectives.

The company is also advancing its CNSide LM diagnostic test, a crucial tool in the detection and management of leptomeningeal metastases. This diagnostic advancement will serve as a pivotal trial endpoint in ongoing studies. CNSide Diagnostics, a subsidiary of Plus Therapeutics, is responsible for developing these proprietary clinical diagnostic laboratory assays. The CNSide Assay Platform is designed to analyze and characterize tumor cells and circulating DNA in the cerebrospinal fluid, aiding in comprehensively managing patients with metastatic CNS involvement. This platform incorporates advanced technologies like immunocytochemistry, fluorescence in situ hybridization, and next-generation sequencing for accurate diagnosis and treatment monitoring.

Plus Therapeutics is strategically positioned in significant cancer research hubs such as Austin and San Antonio, Texas. The company’s efforts in advancing its pipeline of radiotherapeutic candidates aim to offer innovative treatment solutions for challenging CNS cancers. With a robust supply chain and a dedicated leadership team, Plus Therapeutics is poised to enhance clinical outcomes significantly and progress towards potential commercialization of its products. As they continue to push boundaries in CNS cancer treatment, these recent financial milestones mark a critical step in realizing their mission to provide effective therapeutic solutions for complex medical challenges.