Plus Therapeutics has secured $5.7 million in combined financing to advance its innovative radiotherapy program for leptomeningeal metastases (LM), a rare but devastating cancer complication. The funding comprises a $3.7 million private placement from existing investors and a $2.0 million advance payment from the Cancer Prevention & Research Institute of Texas (CPRIT).
Strategic Funding to Accelerate Clinical Development
The new capital will primarily support the company's ReSPECT-LM Phase 2a single-dose expansion trial, evaluating Rhenium (186Re) Obisbemeda for LM treatment. Additionally, the funds will advance the development of CNSide, a proprietary diagnostic test crucial for trial endpoints. The $2.0 million CPRIT advance is part of an existing $17.6 million grant award, with approximately $5.2 million still remaining.
Addressing an Urgent Unmet Medical Need
Leptomeningeal metastases represent a severe complication affecting approximately 5% of cancer patients, with particularly high incidence in breast cancer patients (3-5%). The condition occurs when cancer spreads to the cerebrospinal fluid and the protective layers surrounding the brain and spinal cord. Current survival rates are extremely poor, with only 7% of patients surviving one year and 3% reaching two years.
Innovative Therapeutic Approach
Rhenium (186Re) Obisbemeda represents a novel approach to treating CNS tumors, designed to deliver targeted high-dose radiation with improved safety and efficacy. The radiotherapy's unique properties include:
- Short half-life for optimal treatment duration
- Beta energy capabilities for precise tumor destruction
- Gamma energy emissions enabling real-time imaging
- Targeted delivery system to minimize off-target effects
Diagnostic Innovation: CNSide Platform
In parallel with the therapeutic development, Plus Therapeutics is advancing its CNSide diagnostic platform, scheduled for commercial launch in 2025. The platform includes:
- Quantitative analysis of tumor cells in cerebrospinal fluid
- Molecular characterization capabilities
- Multiple laboratory-developed tests for diagnosis and treatment monitoring
- Integration into the ReSPECT-LM trial as an exploratory endpoint
Financial Restructuring
As part of the financing package, Plus Therapeutics has also executed a strategic exchange agreement with existing investors, issuing secured convertible promissory notes worth $3,188,922 in exchange for the cancellation of previously issued warrants. This restructuring provides additional financial flexibility for the company's development programs.
