A Phase 1 interventional study of Biospecimen Collection and Computed Tomography in Recurrent Mycosis Fungoides, Recurrent Sezary Syndrome and Recurrent Transformed Mycosis Fungoides, sponsored by City of Hope Medical Center. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by City of Hope Medical Center · Phase 1, Interventional, and Treatment
This phase I trial tests the safety, side effects and best dose of lenalidomide in combination with cosibelimab for the treatment of patients with mycosis fungoides or Sézary syndrome that has come back after a period of improvement (relapsed) or that does not respond to treatment (refractory).Lenalidomide is in a class of medications called immunomodulatory agents. It works by helping the immune system kill cancer cells and by helping the bone marrow to produce normal blood cells. Immunotherapy with monoclonal antibodies, such as cosibelimab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving lenalidomide in combination with cosibelimab may be safe and tolerable in treating patients with relapsed or refractory mycosis fungoides or Sézary syndrome.
PRIMARY OBJECTIVE:
I. Obtain a preliminary estimate of the safety and tolerability of the combination of cosibelimab with lenalidomide in patients with relapsed/refractory (R/R) mycosis fungoides (MF) or Sézary Syndrome (SS).
SECONDARY OBJECTIVE:
I. Obtain a preliminary estimate of the efficacy of the combination of cosibelimab with lenalidomide in patients with relapsed/refractory (R/R) mycosis fungoides (MF) or Sézary Syndrome (SS), as assessed by overall response rate (ORR), complete response (CR) rate, time to response, duration of response, sustained response (ORR4), progression-free survival, and overall survival.
EXPLORATORY OBJECTIVES:
I. To obtain a preliminary assessment of quality of life (QoL) parameters before, during and after the regimen.
II. To evaluate the anti-tumor and immunomodulatory effects in the tumor microenvironment in skin and blood samples of patients with R/R MF or SS treated with combination cosibelimab and lenalidomide.
OUTLINE: This is a dose-escalation study of lenalidomide in combination with fixed dose cosibelimab followed by a dose-expansion study.
Patients receive cosibelimab intravenously (IV) over 1 hour on day 1 and lenalidomide orally (PO) once daily (QD) on days 1-14 of each cycle. Cycles repeat every 21 days for up to 18 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo computed tomography (CT) scan with or without positron emission tomography (PET) at baseline and may undergo CT scan with or without PET scan throughout the trial. Patients undergo skin biopsy and blood sample collection throughout the study.
After completion of study treatment, patients are followed up at 30, 60, and 90 days then every 2 months until progression or initiation of a new therapy (for patients without progression) or every 6 months for patients in survival follow up.
447 studies on the registry are indexed under Mycosis Fungoides; 42 are open to participants now.
This study's planned enrollment of 14 is below the median of 34 across 321 interventional studies indexed under Mycosis Fungoides.
Browse Mycosis Fungoides studies →City of Hope Medical Center is the lead sponsor of 677 studies on the registry; 181 are open to participants now.
Of its 31 completed or terminated interventional studies of FDA-regulated products, 12 (39%) have results posted.
Counted across the registry records on this site, refreshed daily.
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.
Documented of the participant and/or legally authorized representative.
Agreement to allow the use of from diagnostic tumor biopsies
confirmed mycosis fungoides (MF)/ Sezary syndrome (SS) including transformed MF, stage IB or higher
≥ 9g/dL
Agreement by females of childbearing potential to use an effective method of (i.e., failure rate of \< 1% per year described below) or abstain from heterosexual activity, and agree to refrain from donating eggs for the course of the study treatment period through at least 30 days after the last dose of lenalidomide, or 4 months after the last dose of cosibelimab whichever is longer
Highly effective methods include:
Hormonal contraceptive methods must be supplemented by a barrier method
Barrier methods:
Agreement by males to either practice complete abstinence or agree to use a latex or synthetic condom, even with a successful vasectomy (medically confirmed azoospermia), during sexual contact with a female of childbearing potential, and to agree to refrain from donating sperm for the course of the study treatment period through at least 90 days after the last dose lenalidomide, or 4 months after the last dose of tocilizumab (if applicable) whichever is longer
Exclusion Criteria:
Unstable cardiac disease, as defined by one of the following:
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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
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.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
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 New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
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.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
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.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
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.
Line of therapy
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Measurable disease
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
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.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
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.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients receive cosibelimab IV over 1 hour on day 1 and lenalidomide PO QD on days 1-14 of each cycle. Cycles repeat every 21 days for up to 18 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo CT scan with or without PET scan at baseline and may undergo CT scan with or without PET scan throughout the trial. Patients undergo skin biopsy and blood sample collection throughout the study.
Procedure: Biospecimen Collection · Procedure: Computed Tomography · Drug: Cosibelimab · Drug: Lenalidomide · Procedure: Positron Emission Tomography · Other: Questionnaire Administration · Procedure: Skin Biopsy
Undergo blood sample collection
Also known as: Biological Sample Collection, Biospecimen Collected, Sample Collection, Specimen Collection
Undergo CT scan
Also known as: CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography, Computerized axial tomography (procedure), Computerized Tomography, Computerized Tomography (CT) scan, CT, CT Scan, Diagnostic CAT Scan, Diagnostic CAT Scan Service Type, tomography
Given IV
Also known as: Anti-PD-L1 Monoclonal Antibody TG-1501, Anti-PDL1 Monoclonal Antibody TG-1501, CK 301, CK-301, CK301, Cosibelimab-ipdl, TG 1501, TG-1501, TG1501, Unloxcyt
Given PO
Also known as: CC 5013, CC-5013, CC5013, CDC 501, Revlimid
Undergo PET scan
Also known as: Medical Imaging, Positron Emission Tomography, PET, PET Scan, Positron emission tomography (procedure), Positron Emission Tomography Scan, Positron-Emission Tomography, PT
Ancillary studies
Undergo skin biopsy
Also known as: Biopsy of Skin
Incidence of dose limiting toxicities (DLT)
Defined as any of the following toxicity that occur during the first 3 cycles of treatment, and that are attributed as possibly, probably, or definitely related to protocol therapy. Toxicities include immune related toxicities, hematologic toxicities, specific non hematologic toxicities, any toxicity that would, in the opinion of the principal investigator, prevent continued administration of the combination treatment, or any toxicity that prevents the planned dose escalation of lenalidomide in cycles 1-3. DLT (if any) will be individually described.
Time frame: From baseline, up to completion of cycle 3 (cycle length = 21 days)
Incidence of adverse events
Toxicities will be graded by National Cancer Institute Common Terminology Criteria for Adverse Events version 6.0. Observed toxicities will be summarized by type, severity, time of onset, and attribution.
Time frame: Up to 1 year
Overall response
Defined as a response-evaluable patient achieving a documented complete response (CR) or partial response (PR) after start of protocol therapy and prior to progression/relapse/start of non-protocol anti-lymphoma treatment. Exact 95% confidence intervals will be calculated.
Time frame: Up to 1 year
Complete response
Defined as a response-evaluable patient achieving a documented CR after start of protocol therapy and prior to progression/relapse/start of non-protocol anti-lymphoma treatment. Exact 95% confidence intervals will be calculated.
Time frame: Up to 1 year
Time to response
Will be summarized descriptively.
Time frame: From initiation of study therapy to the first achievement of CR or PR prior to progression/relapse/start of non-protocol anti-lymphoma treatment, up to 1 year
Sustained response
Defined as a response-evaluable patient achieving an objective response (CR/PR) that lasts at least 4 months prior to progression/relapse/start of non-protocol anti-lymphoma treatment. Exact 95% confidence intervals will be calculated.
Time frame: Up to 1 year
Duration of response
Will be estimated using the product-limit method of Kaplan and Meier.
Time frame: From the first achievement of PR or CR to time of progression/relapse or death, up to 1 year
Progression free survival
Will be estimated using the product-limit method of Kaplan and Meier.
Time frame: From initiation of study therapy to disease relapse/progression or death from any cause, up to 1 year
Overall survival
Will be estimated using the product-limit method of Kaplan and Meier.
Time frame: From initiation of study therapy to death from any cause, up to 1 year
Start is estimated for May 2027; primary completion for May 2028, 12 months later.
Of 29 phase 1 interventional studies under Mycosis Fungoides, half reached primary completion within 56 months of starting (the median), counting those still running; a quarter within 28 and three quarters within 80. This study's planned 12 months is below that.
How these figures are worked out, and which studies are left out of them.
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 ↗
This study is not yet recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Cosibelimab · Lenalidomide