A Phase 1/2 interventional study of Cemiplimab and Cemiplimab+Fianlimab Fixed Dose Combination (FDC) in High-Grade Glioma (HGG) and Posterior Fossa-A Ependymoma, sponsored by Regeneron Pharmaceuticals. Not yet recruiting. Open to participants aged 0 Years to 39 Years. Per ClinicalTrials.gov, last updated 2026-05-05.
Sponsored by Regeneron Pharmaceuticals · Phase 1/2, Interventional, and Treatment
This study is researching an experimental drug called cemiplimab (called "study drug") and the combination of experimental drugs of fianlimab and cemiplimab (called "study drugs"). The study is focused on children and young adults with recurrent or progressive High-Grade Glioma (HGG) or ependymoma. "Recurrent" means that the cancer came back after treatment. "Progressive" means that the tumor has grown or spread.
The aim of the study is to see how safe, tolerable, and effective cemiplimab and the combination of fianlimab and cemiplimab are.
The study is looking at several other research questions, including:
224 studies on the registry are indexed under Ependymoma; 35 are open to participants now.
This study's planned enrollment of 120 is above the median of 28 across 174 interventional studies indexed under Ependymoma.
Browse Ependymoma studies →Regeneron Pharmaceuticals is the lead sponsor of 411 studies on the registry; 90 are open to participants now.
Of its 125 completed or terminated interventional studies of FDA-regulated products, 79 (63%) have results posted.
Compared within Ependymoma, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Glioma. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Key Inclusion Criteria:
Key Exclusion Criteria:
Note: Other protocol defined Inclusion/ Exclusion Criteria apply
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 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.
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
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.
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.
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.
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.
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.
Karnofsky performance status (KPS)
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
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.
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.
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.
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.
Neoadjuvant Period: cemiplimab Adjuvant Period: fianlimab+cemiplimab
Drug: Cemiplimab · Drug: Cemiplimab+Fianlimab Fixed Dose Combination (FDC)
Neoadjuvant Period: fianlimab+cemiplimab Adjuvant Period: fianlimab+cemiplimab
Drug: Cemiplimab+Fianlimab Fixed Dose Combination (FDC)
Neoadjuvant Period: fianlimab+cemiplimab Adjuvant Period: fianlimab+cemiplimab
Drug: Cemiplimab+Fianlimab Fixed Dose Combination (FDC)
Administered per the protocol
Also known as: REGN2810, Libtayo®
Drug pages: Cemiplimab · Fianlimab
Administered per the protocol
Also known as: REGN 2810, Libtayo®, REGN3767
Occurrence of Treatment Emergent Adverse Events (TEAEs)
Time frame: Up to 26 months
Severity of TEAEs
Time frame: Up to 26 months
Overall Survival (OS)
Time frame: 12 months
Progression Free Survival (PFS)
Time frame: 12 months
Concentrations of fianlimab in serum
Time frame: Up to 5 years
Concentrations of cemiplimab in serum
Time frame: Up to 5 years
Occurrence of Anti-Drug Antibody (ADA) to fianlimab
Time frame: Up to 5 years
Occurrence of ADA to cemiplimab
Time frame: Up to 5 years
Magnitude of ADA to fianlimab
Time frame: Up to 5 years
Magnitude of ADA to cemiplimab
Time frame: Up to 5 years
Progression Free Survival (PFS)
Time frame: Up to 5 years
Death due to any cause
Time frame: Up to 5 years
Overall Survival
Time frame: Up to 5 years
Occurrence of TEAEs
Time frame: Up to 5 years
Severity of TEAEs
Time frame: Up to 5 years
No study locations are listed for this record.
Plan to share: Yes — All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: When Regeneron has: received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry) the legal authority to share the data, and ensured the ability to protect participant privacy
Access criteria: Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf
Data sharing details ↗ · vivli.org
No publications or documents are linked to this record.
Start is estimated for Aug 2026; primary completion for Aug 2032, 71 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Cemiplimab · Fianlimab