Plus Therapeutics announces validation, implementation of CSF-01 diagnostic

Plus Therapeutics completed key validation testing and implementation of its tumor cell enumeration assay, known as CSF-01, to be used initially as an exploratory endpoint in its ReSPECT-LM clinical trials. Plus’ CSF-01 cancer cell enumeration test is an exploratory endpoint in the ReSPECT-LM Phase 1 trial that has shown promise in the trial’s early cohorts. In Phase 1/Part A of the ReSPECT-LM trial presented at the 2023 SNO/ASCO Meeting in San Francisco, Plus showed an average 53% reduction in CSF tumor cells 28 days after a single intrathecal administration of rhenium obisbemeda in patients with LM. On December 12, 2023, Plus announced its partnership with K2bio to implement Plus’ CSF-01 diagnostic for LM cancers in the ReSPECT-LM trials. While validated for use in Plus’ clinical development programs, full Clinical Laboratory Improvement Amendments certification is not anticipated until 2025. The ReSPECT-LM trial, including support for CSF-01 testing, is currently receiving grant funding from the Cancer Prevention and Research Institute of Texas. The FORSEE trial was performed by the original developer and licensor of CSF-01 and is a multi-center, prospective clinical trial enrolling patients with breast or non-small cell lung cancer who have suspicious or confirmed LM. If the FORSEE data is positive, we intend to work toward increasing commercial reimbursement for the CLIA-certified test and explore partnerships to maximize diagnostic utilization for the broader CNS cancer space.