A Phase 2 interventional study of Enfortumab vedotin and Pembrolizumab in Bladder Cancer, Urothelial Carcinoma and Muscle-Invasive Bladder Carcinoma, sponsored by Fox Chase Cancer Center. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by Fox Chase Cancer Center · Phase 2, Interventional, and Treatment
RETAIN-3 is a phase II study in patients with cT2-T3N0M0 muscle-invasive urothelial carcinoma of the bladder. Participants will receive neoadjuvant enfortumab vedotin and pembrolizumab followed by clinical and biomarker-based assessment to inform subsequent treatment management.
RETAIN-3 is a multicenter, open-label, phase II study evaluating a biomarker- and response-adapted bladder preservation strategy in patients with cT2-T3N0M0 muscle-invasive bladder cancer treated with neoadjuvant enfortumab vedotin and pembrolizumab. Following treatment, participants undergo clinical restaging and biomarker assessment to guide subsequent management, which may include active surveillance, maintenance therapy, cystectomy, or chemoradiation. The study aims to determine whether a biomarker-guided approach can preserve the bladder in selected patients while maintaining favorable oncologic outcomes.
1,798 studies on the registry are indexed under Urinary Bladder Neoplasms; 445 are open to participants now.
This study's planned enrollment of 70 is above the median of 60 across 1,296 interventional studies indexed under Urinary Bladder Neoplasms.
Browse Urinary Bladder Neoplasms studies →Fox Chase Cancer Center is the lead sponsor of 216 studies on the registry; 29 are open to participants now.
Of its 16 completed or terminated interventional studies of FDA-regulated products, 9 (56%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
RECIST
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
PD-1, PD-L1 and checkpoint inhibitors
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive neoadjuvant enfortumab vedotin plus pembrolizumab for 3 cycles followed by protocol-specified clinical restaging and biomarker assessment. All enrolled participants begin study treatment in this arm.
Drug: Enfortumab vedotin · Drug: Pembrolizumab
Participants with positive post-treatment circulating tumor DNA (ctDNA) and favorable clinical restaging findings may receive an additional 3 cycles of enfortumab vedotin plus pembrolizumab followed by repeat assessment.
Drug: Enfortumab vedotin · Drug: Pembrolizumab
Participants meeting protocol-defined criteria may undergo active surveillance while receiving maintenance pembrolizumab and scheduled disease evaluations.
Drug: Pembrolizumab
Participants requiring definitive bladder-directed treatment may receive chemoradiation with radiation therapy and investigator-selected radiosensitizing chemotherapy according to protocol specifications.
Drug: Cisplatin · Drug: Gemcitabine · Drug: Fluorouracil · Drug: Mitomycin c · Procedure: Radiation therapy
Participants requiring definitive surgical management may undergo radical cystectomy.
Procedure: Radical cystectomy
1.25 mg/kg (maximum 125 mg) intravenously on Days 1 and 8 of each 21-day cycle for 3 cycles.
200 mg intravenously on Day 1 of each 21-day cycle or subcutaneous pembrolizumab/berahyaluronidase formulation administered per protocol.
Cisplatin administered as a radiosensitizing chemotherapy regimen in participants receiving chemoradiation.
Gemcitabine administered as a radiosensitizing chemotherapy regimen in participants receiving chemoradiation.
Fluorouracil administered as a radiosensitizing chemotherapy regimen in participants receiving chemoradiation.
Mitomycin C administered in combination with fluorouracil as a radiosensitizing chemotherapy regimen in participants receiving chemoradiation.
Surgical removal of the bladder performed according to institutional standards.
Definitive bladder-preserving treatment consisting of external beam radiation therapy administered with concurrent radiosensitizing chemotherapy according to institutional standards and protocol specifications.
2-Year Metastasis-Free Survival (MFS)
Metastasis-free survival is defined as the time from initiation of neoadjuvant therapy to metastatic urothelial carcinoma or death from any cause, whichever occurs first.
Time frame: 2 years
Bladder-intact metastasis-free survival in active surveillance patients
Time frame: 2 years
Pathologic complete response (pT0) rate among participants undergoing cystectomy
Time frame: At cystectomy
Clinical complete response rate
Time frame: Up to 5 years
Rate of urothelial carcinoma recurrence in active surveillance participants
Time frame: Up to 5 years
Overall survival (OS)
Time frame: Up to 5 years
Rate of distant recurrence among post-treatment ctDNA-positive participants undergoing definitive local therapy
Time frame: Up to 5 years
Proportion of participants undergoing cystectomy
Time frame: Up to 5 years
Bladder-intact metastasis-free survival in all evaluable participants
Time frame: 2 years
Plan to share: No
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drugs tested here: Enfortumab vedotin · Pembrolizumab · Cisplatin · Gemcitabine · Fluorouracil · Mitomycin