Participate in a Leptomeningeal Metastases Clinical Trial

Now Recruiting Patients with LM

Trial Information

Leptomeningeal Metastases (LM) is sometimes referred to as leptomeningeal cancer, leptomeningeal disease, neoplastic meningitis, or meningeal carcinomatosis. This rare but serious condition happens when cancer cells spread to the membranes surrounding the brain and spinal cord.  Leptomeningeal Metastases is most commonly found in patients with melanoma, breast, lung, or gastrointestinal cancer. Unfortunately, there are no FDA approved treatments specifically for Leptomeningeal Metastases.

Plus Therapeutics is developing a new targeted radiation therapy, Rhenium (186Re) Obisbemeda, for central nervous system cancers such as Leptomeningeal Metastases.  In the U.S. ReSPECT-LM clinical trial, doctors will give Leptomeningeal Metastases patients a single dose of Rhenium (186Re) Obisbemeda through a small catheter placed under the patient’s scalp. This drug will be administered in less than 5 minutes in a hospital setting and the patient will go home the same day.

The ReSPECT-LM clinical trial is funded, in part, by a $17.6 million grant from the Cancer Prevention & Research Institute of Texas, the second largest public funding source for cancer research in the world.

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View the ReSPECT-LM Trial Guide for Patients



When speaking with your physician, please have the national trial reference number available.

Patients Treated to Date

Single Group

  • All patients who enroll in the trial will receive medication while on the study.
  • All patients will receive a single dose of Rhenium (186Re) Obisbemeda.

Phase 1

  • A Phase 1 study is the first step in testing a new treatment in humans. A phase I clinical trial tests the safety, side effects, best dose, and timing of a new treatment. It may also test how the treatment affects the body. The dose is usually increased a little at a time in order to find the highest dose that does not cause harmful side effects. Phase I clinical trials usually include only a small number of patients who have not been helped by other treatments.


  • Actual Study Start:  December 6, 2021
  • Estimated Primary Completion:  December 21, 2025 (the date that the last participant in a clinical study was examined or received an intervention and that data for the primary outcome measure were collected)
  • Estimated Study Completion:  June 30, 2026 (the date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events, that is, the last participant's last visit). 

Plus Therapeutics is evaluating rhenium (186Re) obisbemeda, a novel radiotherapy for patients with Leptomeningeal Metastases in a Phase 1 clinical trial.

Watch now to learn more.

Patient Eligibility

Only a qualified healthcare professional can determine whether or not you are eligible to participate in a clinical trial. However, this information may be beneficial in initiating a conversation with your physician.  Patient reimbursement of up to $599 for time and travel is available.

Age Range

Adults, 18 years and older


Leptomeningeal Metastases from any solid tumor cancers (i.e. breast, lung, melanoma, gastrointestinal)


Informed Consent

Able to understand the study purposes and risks


All; Women have negative pregnancy test at screening; Subjects must use effective contraception during study

Additional eligibility criteria may be found on

Principal Investigators

There is a physician who is responsible for the scientific and technical direction of the clinical trial at each location.

Andrew Brenner, M.D., Ph.D.

UT Health San Antonio, Mays Cancer Center


A specialist in both breast cancer and malignancies of the brain and spinal cord, Andrew Brenner, M.D., Ph.D., not only focuses on clinical management, but also on the development of novel therapies to treat breast cancers and central nervous system tumors.

A graduate of Texas A&M University, he earned his bachelor’s degree in biochemistry and went on to earn his doctorate in biological science and tumor biology at The University of Texas M.D. Anderson Cancer Center – Science Park. His doctoral thesis focused on the role of the cyclin dependent kinase inhibitor p16INK4a in mammary tumorigenesis and immortilization. Dr. Brenner’s current interests have transitioned from cell cycle to the effect of hypoxia on chemokines and escape from antiangiogenics and the role of obesity in promoting breast tumorigenesis.

Dr. Brenner received his medical degree from the Texas Tech University Health Science Center and completed a residency in internal medicine at Scott and White Hospital in Lubbock. He completed his fellowship in hematology and medical oncology at the UT Health San Antonio.

Michael Youssef, M.D.

UT Southwestern Medical Center


Michael Youssef, M.D., is an Assistant Professor in the Department of Neurology and the Department of Hematology and Oncology at UT Southwestern Medical Center. He specializes in neuro-oncology.

Dr. Youssef earned his medical degree at the Medical University of South Carolina. He completed a residency in neurology at Baylor College of Medicine and then received advanced training in neuro-oncology through a fellowship at the University of Texas MD Anderson Cancer Center.

Certified by the American Board of Psychiatry and Neurology, he joined the UT Southwestern faculty in 2020.

Dr. Youssef’s clinical and research interests include glioblastoma; primary brain tumors; rare brain tumors, including ependymoma and medulloblastoma; neurologic complications of systemic cancer therapy; brain metastasis; and leptomeningeal disease.

He is a member of the American Academy of Neurology, the American Brain Tumor Association, the Society for Neuro-Oncology, and the American Society for Clinical Oncology.

Priya Kumthekar, M.D.

Northwestern Memorial Hospital


Dr. Priya Kumthekar is an Associate Professor of Neurology and Hematology/Oncology, and the Director of the Cancer Trials Office at the Robert H Lurie Comprehensive Cancer Center at Northwestern University. Kumthekar is board certified in neurology and neuro-oncology and has an MD from Northeastern Ohio Universities College of Medicine.

Dr. Kumthekar completed her residency training in neurology at Northwestern University/McGaw and her Neuro-Oncology UCNS Accredited Clinical Fellowship at the same institution.

Dr. Kumthekar is involved in many committees and councils at the university and hospital, including the Neuro-Oncology Fellowship Director and the Internal Advisory Committee for the Quantitative Data Sciences Core. Additionally, she is an Executive Officer of the Alliance for Clinical Trials in Neuro-Oncology, which oversees all Neuro-oncology clinical trials for the Alliance for Clinical Trials, a member of the National Clinical Trial Network. Dr. Kumthekar is the recipient of several teaching awards and is a member of numerous professional societies and organizations.

Trial Locations

Please visit this website regularly for updates as new locations are added.

UT Health Science Center

San Antonio

UT Southwestern Medical Center


Northwestern Memorial Hospital


What Can You Do Next?

Participating in a clinical trial is an important decision. If you believe this clinical trial might be a good fit and are interested in participating, please take the next step to see if you are eligible.

Discuss With Your Physician

Anyone participating in a clinical trial should know as much as possible about what is being studied, what risks are involved and what potential benefits may be gained before deciding to enroll.  If you are interested in participating in a clinical trial, please talk to your physician first.

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Print, save, or email this page to your physician to discuss at your next visit.

Be sure to have National Trial Reference Number NCT05034497 available.

View the ReSPECT-LM Trial Guide for Patients

Contact A Trial Coordinator

A trial coordinator is a specialized researcher who supports the management and coordination of clinical research studies.  If you are interested in participating in a clinical trial, you may call a trial coordinator directly at one of the trial locations below.

UT Health Science Center
San Antonio

Epp Goodwin

UT Southwestern Medical Center

Omar Raglan

Northwestern Memorial Hospital

Laura Sharp

Contact Us


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Plus Therapeutics Granted U.S. FDA Orphan Drug Designation to Rhenium (186Re) Obisbemeda for the Treatment of Breast Cancer with Leptomeningeal Metastases

October 10, 2023

Plus Therapeutics Completes Dosing in Cohort 4 of ReSPECT-LM Phase 1 Clinical Trial of Rhenium (¹⁸⁶Re) Obisbemeda in Leptomeningeal Metastases

  • Cohort 4 of the ReSPECT-LM Phase 1 dose escalation trial is the first of 4 planned cohorts in Part B; the Company anticipates moving into Cohort 5 following standard safety review

September 11, 2023

Plus Therapeutics Receives $1.9 Million Advance Payment from CPRIT and Plans to Present at the CPRIT Innovations in Cancer Prevention and Research Conference

September 5, 2023

Plus Therapeutics Initiates Part B of ReSPECT-LM Phase 1/2a Trial for Leptomeningeal Metastases

  • Plus Therapeutics announced treatment of the first patient in Part B (Cohort 4) of the ReSPECT-LM Phase 1/2a dose escalation clinical trial of rhenium (186Re) obisbemeda for the treatment of leptomeningeal metastases (LM) from solid tumors.

August 11, 2023

Plus Therapeutics Reports ReSPECT-LM Phase 1 Trial Data at the 2023 SNO/ASCO CNS Cancer Conference

  • Dose escalation trial demonstrates preliminary safety and efficacy results including median overall survival of 10 months for patients with leptomeningeal metastases. FDA approves continuation to Phase 1 Part B of the ReSPECT-LM clinical trial.

June 29, 2023

Plus Therapeutics Reports Positive Interim Updates from Two ReSPECT™ Clinical Trials at SNMMI Annual Meeting

  • ReSPECT-LM Phase 1/Part A leptomeningeal metastases trial demonstrates safety and high absorbed radiation doses to the cerebrospinal fluid and leptomeninges

April 18, 2023

Plus Therapeutics Completes Phase 1/Part A of the ReSPECT-LM Clinical Trial for Leptomeningeal Metastases

  • The Company plans to meet with U.S. FDA to discuss next steps for the Phase 1/Part B trial in the third quarter of 2023. Plus Therapeutics also expanded the number of active clinical trial sites by adding Northwestern Memorial Hospital, a world-class medical center and leader in clinical research, and the Company’s first site outside of Texas

March 22, 2023

Plus Therapeutics Initiates Cohort 3 in Phase 1/Part A of the ReSPECT-LM Trial for Leptomeningeal Metastases

  • Plus Therapeutics announced treatment of the first patient in Cohort 3 of the ReSPECT-LM Phase 1/2a dose escalation clinical trial of rhenium (186Re) obisbemeda for the treatment of leptomeningeal metastases (LM) from solid tumors.

February 1, 2023

Plus Therapeutics Completes Enrollment in Second ReSPECT-LM Phase 1 Trial Cohort of Rhenium (¹⁸⁶Re) Obisbemeda for the Treatment of Leptomeningeal Metastases

  • Plus Therapeutics, Inc. (Nasdaq: PSTV) (the “Company”), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system cancers, today announced completion of enrollment in Cohort 2 of the ReSPECT-LM Phase 1/2a dose escalation clinical trial of rhenium (186Re) obisbemeda for the treatment of leptomeningeal metastases (LM).




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