Plus Therapeutics Expands Management Team and Reports $3.3M Advance Payment from CPRIT

On June 7, 2024 Plus Therapeutics, Inc. (Nasdaq: PSTV) ("Plus" or the "Company"), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system (CNS) cancers, reported the appointment of Dr. Greg Fuller as the Company’s Vice President of Medical Affairs and Medical Director (Press release, Plus Therapeutics, JUN 7, 2024, View Source [SID1234644198]). Additionally, the Company received notice of an advance payment of $3.3 million from CPRIT, part of the $17.6 million award granted in September 2022.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

Dr. Fuller will help lead the implementation of the recently acquired CNSide cerebrospinal fluid cancer diagnostic portfolio, ensuring its successful transition to commercial use under the current Laboratory Developed Test (LDT) requirements. Currently utilized in the CPRIT-funded ReSPECT-LM clinical trial, CNSide is on track for commercial launch as soon as Q4 2024. Next-generation diagnostic testing, such as CNSide, is vital for improving patient care for leptomeningeal metastases (LM) and advancing the Company’s broader LM program for several reasons:

Recently published data indicated that CNSide is over 90% sensitive for detecting LM, significantly outperforming MRI and cytology
Autopsy studies suggested LM incidence is underdiagnosed by 2-4 times and the increased diagnostic sensitivity of CNSide could expand the total addressable market for the Company’s lead radiotherapeutic candidate rhenium (Re186) obisbemeda
CNSide potentially addresses a total commercial market of over 500,000 tests annually
The CNSide test demonstrated clinical utility in 40 patients with LM from breast or non-small cell lung cancer in the FORESEE trial; a presentation of the full analysis is planned for the SNO/ASCO Meeting in Denver, Colorado, on August 8-10
"I am excited to join the Plus team and to dedicate my expertise to accelerating the adoption of CNSide in a clinical and commercial setting," said Greg Fuller, M.D., Ph.D. "Driving the availability of this testing to our patients is imperative, especially given the complexities of treating LM."

Furthermore, the Company also received notice of a $3.3 million advance grant payment from CPRIT in June 2024. This funding supports the clinical development of rhenium (Re186) obisbemeda for LM as well as CNSide testing in the RePSECT-LM trial. In addition to determining the safety and potential efficacy of rhenium (Re186) obisbemeda for LM, data gathered from the RePSECT-LM trial will further validate CNSide’s clinical utility and support commercialization. An update on enrollment and safety data from the ReSPECT-LM trial is planned for the August SNO/ASCO Meeting in Denver.

New Employment Inducement Grants
In connection with Dr. Fuller’s hire, on June 6, 2024, the Company granted option awards to Dr. Fuller to purchase up to 13,116 shares of the common stock of the Company. The Company agreed to grant these option awards as an inducement of Dr. Fuller commencing employment with the Company. The options are scheduled to vest over four years, with one-fourth of the options vesting on the first anniversary of the grant date with the remaining options vesting thereafter in equal monthly installments. The vesting of the options is also subject to certain requirements, including Dr. Fuller’s continued service as an employee of the Company through the applicable vesting dates. The exercise price of the options is equal to the closing price of the Company’s common stock on June 6, 2024, the grant date.

The Company believes that these equity grants create a strong alignment of interests between Dr. Fuller and Company shareholders. The equity awards were granted with terms and conditions consistent with the Company’s 2015 New Employee Incentive Plan.

About Leptomeningeal Metastases (LM)
LM is a rare complication of cancer in which the primary cancer spreads to the cerebrospinal fluid (CSF) and leptomeninges surrounding the brain and spinal cord. All malignancies originating from solid tumors, primary brain tumors, or hematological malignancies have this LM complication potential. Although breast cancer is the most common cancer linked to LM, with ~10-15% of all breast cancer patients developing LM (and ~25% for inflammatory breast cancer), lung cancer, GI cancers, and melanoma can also spread to the CSF and have high LM risk. LM occurs in approximately 5% of all people with cancer and is usually terminal with 1-year and 2-year survival of just 7% and 3%, respectively. The incidence of LM is on the rise, partly because cancer patients are living longer and partly because many standard chemotherapies cannot reach sufficient concentrations in the spinal fluid to kill the tumor cells, yet there are no FDA-approved therapies specifically for LM patients, who often succumb to this complication within weeks to several months, if untreated.

About Rhenium (186Re) obisbemeda
Rhenium (186Re) obisbemeda is a novel injectable radiotherapy specifically formulated to deliver direct targeted high dose radiation in CNS tumors in a safe, effective, and convenient manner to optimize patient outcomes. Rhenium (186Re) obisbemeda has the potential to reduce off target risks and improve outcomes for CNS cancer patients, versus currently approved therapies, with a more targeted and potent radiation dose. Rhenium-186 is an ideal radioisotope for CNS therapeutic applications due to its short half-life, beta energy for destroying cancerous tissue, and gamma energy for real-time imaging. Rhenium (186Re) obisbemeda is being evaluated for the treatment of recurrent glioblastoma and leptomeningeal metastases in the ReSPECT-GBM and ReSPECT-LM clinical trials. ReSPECT-GBM is supported by an award from the National Cancer Institute (NCI), part of the U.S. National Institutes of Health (NIH), and ReSPECT-LM is funded by a three-year $17.6M grant by the Cancer Prevention & Research Institute of Texas (CPRIT).

About CNSide Test
CNSide is a laboratory developed test (LDT) based on proprietary quantitative tumor cell capture and detection method, paired with assays to identify actionable molecular treatment targets. Given the genetic changes that can occur as metastatic cancer spreads to the CNS, the evaluation of cerebrospinal fluid with CNSide provides a unique opportunity to identify biomarkers in patients with metastatic carcinoma or melanoma to help guide physicians in therapy selection. In addition, the quantitative tumor cell count assay is designed to be used in a serial fashion to monitor the response to therapy more effectively than other current methods.