A Study of Radiation Therapy and Cemiplimab With or Without Fianlimab In People With Bladder Cancer
Neoadjuvant STereotActic Body Radiotherapy and Cemiplimab With or Without Fianlimab for Cisplatin-Ineligible or Cisplatin-Declining Patients With Muscle-Invasive Bladder Cancer (NeoSTAR Bladder)
1 other identifier
interventional
44
1 country
7
Brief Summary
The researchers are doing this study to find out whether stereotactic body radiation therapy (SBRT) in combination with immunotherapy (cemiplimab with or without fianlimab) before cystectomy is an effective and safe treatment for people with muscle-invasive bladder cancer (MIBC).
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for phase_2
Started Jul 2026
7 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
February 11, 2026
CompletedFirst Posted
Study publicly available on registry
February 17, 2026
CompletedStudy Start
First participant enrolled
July 1, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
March 1, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
March 1, 2028
June 24, 2026
June 1, 2026
1.7 years
February 11, 2026
June 23, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Rate of pathologic downstaging
Pathologic downstaging will be defined as lack of muscle invasive carcinoma (\<ypT2) and the absence of lymph node metastasis (ypN0) in the final cystectomy specimen after radical cystectomy.
2 years
Secondary Outcomes (1)
Pathologic complete response
2 years
Study Arms (2)
Radiation Therapy and Cemiplimab
EXPERIMENTALStereotactic body radiotherapy (SBRT) and cemiplimab
Radiation Therapy and Cemiplimab With Fianlimab
EXPERIMENTALStereotactic body radiotherapy (SBRT) and cemiplimab with Fianlimab
Interventions
Stereotactic body radiotherapy (SBRT) Tumor-directed SBRT will be delivered in three once-daily 8 Gy fraction
Cemiplimab will be delivered on day 1 of each cycle for a total of 4 cycles,
Within 96 hours (i.e., 4 days) of completing the 3rd SBRT treatment, patients will receive their first cycle of cemiplimab and fianlimab in the morning or early afternoon. Patients will receive a total of 4 cycles of cemiplimab and fianlimab with each cycle lasting 3 weeks and treatment occurring during weeks 0, 3, 6, and 9. Cemiplimab and fianlimab infusions in the morning or early afternoon will be encouraged.
Within 60 days of completing the 4 cycles of cemiplimab and fianlimab, patients will undergo radical cystectomy which is standard of care.
Eligibility Criteria
You may qualify if:
- Age ≥ 18 years at the time of informed consent
- ECOG 0-1
- Histologically confirmed diagnosis of urothelial carcinoma.
- ° Variant histology is acceptable if there is a predominant urothelial component. Any neuroendocrine / small cell components are excluded (Investigators are encouraged to discuss with study team and PI)
- Cystoscopically and radiographically confirmed cT2-4a cN0 cM0 disease per American Joint Committee on Cancer Staging Manual, 8th edition.
- Patients with cT4a disease invading into the prostatic stroma with no cystoscopic confirmation of muscle invasion are eligible.
- Clinically node-negative pelvis (cN0) on CT or MRI within 56 days: no pelvic lymph node ≥15 mm short-axis. Pelvic nodes 10-14 mm are permitted if not suspicious by GU radiology morphology; if deemed suspicious, biopsy or repeat imaging in 4-6 weeks must confirm cN0 prior to enrollment. PET may inform adjudication but is not required.
- Patients declines cisplatin-based therapy or is ineligible for cisplatin-based therapy based on any of the following criteria:
- Estimated or calculated creatinine clearance ≥ 30ml/min but \< 60 ml/min
- Grade 2 or above audiometric hearing loss (per CTCAE v5.0)
- Grade 2 or above peripheral neuropathy (per CTCAE v5.0)
- Availability of tumor specimen block or 20 unstained slides from diagnosis of muscle-invasive disease. Patients with fewer than 20 slides available may be enrolled after discussion with the Principal Investigator.
- Medically appropriate candidate for radical cystectomy, as per MSK Attending Urologic Oncologist
- Life expectancy ≥ 12 weeks at randomization
- Required initial laboratory values:
- +11 more criteria
You may not qualify if:
- Evidence of metastatic disease on standard staging CT and/or MR imaging
- Evidence of nodal metastasis (cN+), defined as any pelvic node ≥15 mm short-axis on CT/MRI or biopsy-proven nodal disease of any size.
- Prior systemic chemotherapy or non-BCG immunotherapy (e.g., T cell co-stimulation or targeting of immune checkpoint pathways with anti-PD-1, anti-PD-L1, anti-LAG-3, anti-PD-L2, anti-CTLA-4, anti-CD137, IL-15 superagonist, or other medicines specifically targeting T cells other than prior IL-2 therapy) for the treatment of bladder cancer
- Prior therapy with intravesical BCG within 6 weeks of treatment.
- Prior pelvic RT
- Patients using immunosuppressive doses (≥ 10 mg per day of prednisone or equivalent) of systemic corticosteroids other than for corticosteroid replacement will not be eligible for the study. It is recommended that patients do not receive systemic corticosteroids such as hydrocortisone, prednisone, prednisolone (Solu-Medrol®) or dexamethasone (Decadron®) at any time throughout the study except in the case of a life-threatening emergency and/or to treat an immune-mediated adverse event.
- °Immunosuppressive doses (≥ 10 mg per day of prednisone or equivalent) of systemic corticosteroids other than for corticosteroid replacement must be discontinued within 14 days of initiating neoadjuvant SBRT.
- Received a live vaccine within 30 days of planned start of study medication.
- Live or live attenuated vaccination with replicating potential. If a patient intends to receive a COVID-19 vaccine before the start of study drug, participation in the study should be delayed at least 1 week after any COVID-19 vaccination. During treatment period, it is recommended to delay COVID-19 vaccination until patients are receiving and tolerating a steady dose of study drug. A vaccine dose should not be less than 48 hours before or after study drug dosing.
- Live vaccines are also prohibited during neoadjuvant therapy and for 90 days after completing neoadjuvant therapy.
- Has had an allogenic tissue/solid organ transplant
- Unstable angina.
- New York Heart Association (NYHA) Grade II or greater congestive heart failure.
- History of myocardial infarction within 6 months.
- History of stroke within 6 months.
- +36 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Memorial Sloan Kettering Cancer Centerlead
- Regeneron Pharmaceuticalscollaborator
Study Sites (7)
Memorial Sloan Kettering Basking Ridge (Limited Protocol Activities)
Basking Ridge, New Jersey, 07920, United States
Memorial Sloan Kettering Monmouth (Limited Protocol Activities)
Middletown, New Jersey, 07748, United States
Memorial Sloan Kettering Bergen (Limited Protocol Activities)
Montvale, New Jersey, 07645, United States
Memorial Sloan Kettering Suffolk - Commack (Limited Protocol Activities)
Commack, New York, 11725, United States
Memorial Sloan Kettering Westchester (Limited Protocol Activities)
Harrison, New York, 10604, United States
Memorial Sloan Kettering Cancer Center (All Protocol Activities)
New York, New York, 10065, United States
Memorial Sloan Kettering Nassau (Limited Protocol Activities)
Uniondale, New York, 11553, United States
Related Links
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Daniel Gorovets, MD
Memorial Sloan Kettering Cancer Center
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- NON RANDOMIZED
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
February 11, 2026
First Posted
February 17, 2026
Study Start
July 1, 2026
Primary Completion (Estimated)
March 1, 2028
Study Completion (Estimated)
March 1, 2028
Last Updated
June 24, 2026
Record last verified: 2026-06
Data Sharing
- IPD Sharing
- Will share
Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.