Inflammation in Primary and Secondary Malignancies of the Central Nervous System Using [C-11]-CS1P1

Investigation of Inflammation in Primary and Secondary Malignancies of the Central Nervous System Using [C-11]-CS1P1

Adult patients with primary or secondary central nervous system malignancies will be invited to undergo a baseline [C-11]-CS1P1 PET scan and a follow-up scan within 24 months of the baseline scan (preferably within 6-months post-treatment).The study will describe patterns of tracer uptake in tumors and normal brain and explore how these patterns relate to MRI findings, treatments received, and clinical outcomes.

Study Overview

• Status: Recruiting
• Conditions: Brain Metastases; Central Nervous System Cancer
• Intervention / Treatment: Drug: [C-11]-CS1P1; Device: Brain MRI

Detailed Description

This is a prospective, single-arm interventional imaging study designed to evaluate the investigational PET radiotracer [C-11]-CS1P1 in adults with primary or secondary central nervous system malignancies. [C-11]-CS1P1 PET may provide complementary information about disease activity, treatment response, and the tumor microenvironment in central nervous system cancers.

Eligible participants will be adults with confirmed primary central nervous system tumors (for example, gliomas) or secondary central nervous system involvement (brain metastases or other CNS metastases). After providing informed consent, participants will undergo a baseline [C-11]-CS1P1 PET scan in addition to their routine clinical imaging. The PET scan will be performed on a PET/CT or PET/MR scanner following intravenous administration of [C-11]-CS1P1, using a standardized acquisition protocol for brain imaging. Participants will be monitored for adverse events related to tracer administration and radiation exposure, which are expected to remain within accepted research limits.

Participants will be invited to return for one follow-up [C 11]-CS1P1 PET scan within 24 months of the baseline scan, preferably within approximately 6 months after treatment. Follow up imaging will allow assessment of longitudinal changes in [C 11]-CS1P1 uptake in relation to treatment and disease course. Clinical management will not be altered by participation in this study.

Quantitative PET parameters (for example, standardized uptake values, tumor to background ratios, and volumetric measures) will be derived from tumor and normal appearing brain. Qualitative assessments of tracer uptake patterns will also be performed. These PET measures will be compared with MRI characteristics, treatment history, and available clinical outcomes (including radiographic progression and survival) to explore the potential of [C 11]-CS1P1 PET as a diagnostic biomarker of tumor activity and treatment response in central nervous system malignancies. This exploratory study is intended to generate preliminary data that may inform the design of future trials using [C 11]-CS1P1 PET in this patient population.

• Study Type: Interventional
• Enrollment (Estimated): 104
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Jayashree Rajamanickam; Phone Number: 314-273-6140; Email: jayashree.r@wustl.edu
• Study Contact Backup: Name: Tammie L.S. Benzinger, M.D., Ph.D.; Phone Number: 314-362-6110; Email: benzingert@wustl.edu

Study Locations

• United States
  • Missouri
    • St Louis, Missouri, United States, 63110
      • Recruiting
      • Washington University School of Medicine
      • Sub-Investigator: Hongyu An, Ph.D.
      • Contact: Jayashree Rajamanickam; Phone Number: 314-273-6140; Email: jayashree.r@wustl.edu
      • Sub-Investigator: Esther Lu, Ph.D.
      • Sub-Investigator: Jiayi Huang, M.D.
      • Sub-Investigator: Richard Laforest, Ph.D.
      • Contact: Tammie L.S. Benzinger, M.D., Ph.D.; Phone Number: 314-362-1558; Email: benzingert@wustl.edu
      • Principal Investigator: Tammie L.S. Benzinger, M.D., Ph.D.
      • Sub-Investigator: G. Richard Benzinger, M.D., Ph.D.
      • Sub-Investigator: Matthew R Brier, M.D., Ph.D.
      • Sub-Investigator: Yong Wang, Ph.D.
      • Sub-Investigator: Qing Wang, Ph.D.
      • Sub-Investigator: Zhude Tu, Ph.D.
      • Sub-Investigator: C. Ryan King, M.D., Ph.D.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Male or female, any race
• Age ≥ 18 years
• Capable of providing written informed consent OR having a legally authorized representative (LAR) to provide informed consent for volunteering to undergo research procedure
• Has a clinical, radiographic, or pathological diagnosis of primary or secondary CNS malignancy that has not been treated with radiotherapy

Exclusion Criteria:

• Hypersensitivity to [C-11]-CS1P1 or any of its excipients
• Contraindications to PET, CT or MRI (e.g. certain incompatible electronic medical devices, inability to lie still for extended periods) that make it potentially unsafe for the individual to participate
• Prior cranial radiotherapy
• Severe claustrophobia that would require general anesthesia
• Women who are currently pregnant or breastfeeding
• Any condition that, in the opinion of the Sponsor-Investigator or designee could increase risk to the participant, limit the participant's ability to tolerate the research procedures or interfere with the collection of the data (e.g., advanced renal or liver failure)
• Current or recent (within 12 months prior to screening) participation in research studies involving radioactive agents such that the total research-related radiation dose to the participant in any given year would exceed the limits set forth in the U.S. Code of Federal Regulations (CFR) Title 21 Section 361.1. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?FR=361.1.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: [C-11]-CS1P1 PET; C-11]-CS1P1 PET image acquisition up to 90 minutes will be acquired at baseline and at follow-up visit within 24 months (preferably within 6 months post treatment), along with an optional brain MRI.	Drug: [C-11]-CS1P1; The investigational radiotracer [C-11]-CS1P1 is an S1P1 PET imaging agent.; The PET imaging will be acquired either in a PET/MR scanner or the PET/CT scanner; Device: Brain MRI; Optional

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
[C-11]CS1P1 Standardized uptake value (SUV) ratio of tumor to non-tumor regions of interest (ROIs)	[C-11]CS1P1-SUV ratio at the baseline and associated 95% confidence interval (CI) will be calculated.	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Follow-up changes from the baseline in [C-11]CS1P1 SUV ratio	[C-11]CS1P1-SUV ratio at the follow up scan and change from the baseline as well as their associated 95% confidence interval (CI) will be calculated.	Baseline and 24 months
Number of participants with adverse events	Measured and graded per CTCAE v 6.0.	From time of scan through 2-3 days

Collaborators and Investigators

• Sponsor: Washington University School of Medicine
• Investigators: Principal Investigator: Tammie L.S. Benzinger, M.D., Ph.D., Washington University School of Medicine

Publications and helpful links

Helpful Links

• Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): April 16, 2026
• Primary Completion (Estimated): June 30, 2031
• Study Completion (Estimated): June 30, 2033

Study Registration Dates

• First Submitted: March 4, 2026
• First Submitted That Met QC Criteria: March 4, 2026
• First Posted (Actual): March 10, 2026

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: April 17, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Glioma; Glioblastoma; Primary brain tumor; Astrocytoma; Oligodendroglioma; Brain metastasis
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neoplasms by Site; Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Neoplasms, Neuroepithelial; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms, Nerve Tissue; Nervous System Neoplasms; Glioblastoma; Glioma; Brain Neoplasms; Astrocytoma; Central Nervous System Neoplasms; Oligodendroglioma
• Other Study ID Numbers: 202603116

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes