Plus Therapeutics Inc (NASDAQ:PSTV) has expanded its supply agreement with Biocept Inc (NASDAQ:BIOC) by acquiring an option to exclusively license Biocept's CNSide, a cerebrospinal fluid (CSF)-based tumor cell capture and enumeration platform, for patients receiving CNS radiotherapy.

Under the terms of the agreement, CNSide developer Biocept has granted Plus Therapeutics a non-exclusive license to its CNSide cell enumeration assay for Plus' investigational therapy for leptomeningeal metastases (LM), rhenium (186Re) obisbemeda and an option for an exclusive license to the assay.

In exchange, Plus Therapeutics will provide $150,000 in stock to Biocept.

Before January 1, 2024, Plus Therapeutics will have the option for exclusivity for the field of radiotherapy in exchange for a $1.0 million payment, to be exercised at Plus Therapeutics' discretion.

"Thus far, in our ReSPECT-LM trial, we have had a very positive experience with the CNSide assay and think it has significant potential," said Marc Hedrick, President & CEO of Plus Therapeutics.

CNSide is an assay based on a proprietary quantitative tumor cell capture method paired with digital imaging and molecular markers used to detect, characterize, and quantify tumor cells in CSF of patients with a variety of solid organ carcinomas and suspected LM, particularly breast and lung cancer and melanoma which are leading causes of LM.

In March 2023, Biocept initiated enrollment in the FORESEE trial with CNSide to evaluate the performance of CNSide in monitoring LM's response to treatment and to assess the impact of CNSide on treatment decisions.

The feasibility phase of the study is expected to be completed in 1H of 2024, followed by a validation phase estimated to include between 40 and 100 subjects.

Price Action: PSTV shares closed at $2.97 on Thursday.