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MelanomaPhase 1/2NCT06521567

A Study of Cobolimab Plus Dostarlimab in Pediatric and Young Adult Participants With Cancer

A Phase 1/2 study testing Cobolimab and Dostarlimab in people with Melanoma and Hodgkin Lymphoma, run by GlaxoSmithKline at 20 sites in 6 countries.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
Search all trials

Trial summary

The goal of this interventional study is to determine the strength of cobolimab and dostarlimab that is most tolerated in children and young adults who have advanced solid tumors. Read more about this study

Who is it for?
Ages 0 to 21 years
What is being tested?
Cobolimab and Dostarlimab
Could I receive a placebo?
No, everyone receives an active treatment
How many people
83 participants
Where
20 sitesin 6 countries
Study dates
6 Mar 2025to 13 Oct 2026
Phase
Phase 1/2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 0 to 21 years
  • All sexes
  • No healthy volunteers
  • Child, Adult

Who may be able to join

  • Participants are eligible to be included in the study only if all of the following criteria apply:
  • Participants between the age of 0 to not more than 21 years at the time of signing informed consent form (ICF).
  • Disease characteristics:
  • Part 1: Participants with advanced or metastatic solid tumors who have had disease progression after treatment with available therapies that are known to confer clinical benefit and who have limited available treatment options as determined by the investigator. Additionally, exposure to prior immunotherapy or experimental therapies is acceptable:
  • Melanoma
  • Hodgkin Lymphoma
Show all 18Show fewer
  • High and Low Grade Glioma: including Glioblastoma multiforme (GBM), Diffuse intrinsic pontine glioma (DIPG), and ependymoma.
  • Osteosarcoma
  • Hepatic tumors [including Hepatoblastoma, Hepatocellular carcinoma (HCC), and Fibrolamellar carcinoma]
  • Rhabdomyosarcoma
  • Part 2:
  • Participants with Melanoma who have not received prior systemic therapy:
  • Participants with BRAF gene, found on chromosome 7 (BRAF) mutations who are eligible for a BRAF-targeted therapy are eligible if they qualify for immunotherapy.
  • Participants with locally treated and controlled metastatic central nervous system (CNS) lesions without leptomeningeal spread are eligible
  • Relapsed/refractory Hodgkin lymphoma (HL) that has failed at least 2 prior lines of systemic therapy)
  • Participants must have performance status >=60 percent (%) on the Karnofsky scale for participants >16 years of age and >=60% on the Lansky scale for participants <=16 years of age.
  • Adequate organ function as demonstrated by a complete blood count at screening obtained without transfusion [platelets or red blood cells (RBC)] or receipt of Colony stimulating factor (CSF), Granulocyte colony stimulating factor (G-CSF), Granulocyte macrophage colony stimulating factor (GMCSF) or rErythropoeitin (rEPO) within 2 weeks prior to screening.
  • Adolescent participants who have entered puberty must consent (be willing) to use of contraceptive measures, or refrain from sexual intercourse, if in line with their usual practice, as well as sperm/egg donation for the duration of treatment

Who cannot join

  • Participants are excluded from the study if any of the following criteria apply:
  • Medical conditions:
  • Participant has uncontrolled CNS involvement by any tumor pathology
  • Participant has a heart rate-corrected QT interval according to QT interval (corrected) (Friderecia's formula) (QTcF) prolongation at screening >470 millisecond (msec) or >480 msec for participants with bundle branch block.
  • Participant has clinically significant cardiovascular disease
  • Participant has chronic respiratory disease
Show all 28Show fewer
  • Participant has known sensitivity to study intervention components or excipients or other allergy that, in the opinion of the investigator or medical monitor, contraindicates participation in the study.
  • Participants who have a history of immunodeficiency disease, including other acquired or congenital immunodeficiency diseases, or organ transplantation
  • Participants who have received plasma exchange within 7 days before the first dose of study intervention.
  • Participant has current active pneumonitis or any history of pneumonitis requiring steroids or immunomodulatory treatment within 90 days of planned enrollment or any history of drug-induced pneumonitis.
  • Participant has a history of autoimmune disease that has required systemic treatments in the 2 years prior to screening. Participants with prior history of autoimmune disease must be discussed with the medical monitor. Replacement therapy is not considered a form of systemic therapy (e.g., thyroid hormone for autoimmune thyroiditis or insulin is not exclusionary)
  • Participant has ongoing adverse reaction(s) from prior therapy that has (have) not recovered to ≤Grade 1 or to the Baseline status preceding prior therapy, excluding [e.g., alopecia, hearing loss, vitiligo, endocrinopathy managed with replacement therapy, and Grade 2 neuropathy], or that the investigator, with the agreement of the sponsor, considers to be not clinically relevant for the tolerability of study intervention in the current clinical study.
  • Participant has any active renal condition (e.g., infection, requirement for dialysis, or any other significant renal condition (that could affect the participant's safety).
  • Participant has any serious and/or unstable medical or psychiatric disorder or other condition(s) (including laboratory assessment abnormalities) that could interfere with the participant's safety, obtainment of informed consent, or compliance to the study procedures.
  • Prior/ Concomitant therapy:
  • Has received treatment with an investigational agent or any other anti-cancer therapy within 30 days, or <5 times the half-life of the most recent therapy prior to signing ICF, whichever is shorter.
  • Has received systemic steroid therapy within 3 days prior to the first dose of the study treatment or is receiving any other form of immunosuppressive medication. Replacement therapy is not considered a form of systemic therapy. Use of inhaled corticosteroids, local steroid injection, or steroid eye drops is allowed.
  • Has not met the following waiting/washout periods for X-ray therapy (XRT) including external beam radiation therapy/external beam irradiation including protons:
  • Participant has had major surgery within 28 days prior to the first dose of study treatment or has not adequately recovered from any AEs (Grade ≤1) and/or complications from any major surgery. Surgical implantation of a port catheter is not exclusionary.
  • Prior Bone Marrow Transplant <60 days of screening.
  • Participant has experienced Grade 3 or higher hypersensitivity to prior monoclonal antibody therapy.
  • Prior/Concurrent clinical study experience
  • Is currently enrolled or has participated in any other clinical study involving an investigational study or interventional medical research within 21 days or 5 half-lives, whichever is shorter, of an investigational medicinal product before signing ICF Diagnostic assessments
  • Has documented presence of Hepatitis B surface antigen (HbsAg) at Screening or within 3 months prior to first dose of study intervention.
  • Has a positive Hepatitis C virus (HCV) antibody test result at Screening or within 3 months prior to first dose of study intervention.
  • Has a positive HCV Ribonucleic Acid (RNA) test result at Screening or within 3 months prior to first dose of study intervention.
  • Has a known history of Human immunodeficiency virus (HIV) or has a HIV-positive test result at Screening.
  • Is pregnant or breastfeeding.

Trial locations and contacts

20 sites in 6 countries.

20 sites in 6 countries

United States6 sites

  • GSK Investigational Site

    Cincinnati, Ohio, 45229

  • GSK Investigational Site

    Hackensack, New Jersey, 07601

  • GSK Investigational Site

    Iowa City, Iowa, 52242

  • GSK Investigational Site

    Los Angeles, California, 90048

  • GSK Investigational Site

    Madison, Wisconsin, 53792

  • GSK Investigational Site

    Providence, Rhode Island, 02903

Other trials in United States

France5 sites

  • GSK Investigational Site

    Bordeaux, 33076

  • GSK Investigational Site

    Lyon, 69373

  • GSK Investigational Site

    Paris, 75248

  • GSK Investigational Site

    Strasbourg, 67098

  • GSK Investigational Site

    Villejuif, 94805

Other trials in France

Spain4 sites

  • GSK Investigational Site

    Barcelona, 08035

  • GSK Investigational Site

    Madrid, 28009

  • GSK Investigational Site

    Madrid, 28046

  • GSK Investigational Site

    Valencia, 46026

Other trials in Spain

Czechia2 sites

  • GSK Investigational Site

    Brno, 61300

  • GSK Investigational Site

    Phaha 5, 15006

Other trials in Czechia

Italy2 sites

  • GSK Investigational Site

    Bologna, 40138

  • GSK Investigational Site

    Naples, 80123

Other trials in Italy

Denmark1 site

  • GSK Investigational Site

    Copenhagen, 2100

Other trials in Denmark

About this study

Official title: Phase 1/2 Dose Determination and Dose Expansion Study of Cobolimab in Combination With Dostarlimab in Pediatric and Young Adult Participants With Newly Diagnosed and Relapsed/Refractory Tumors (POPSTAR)

The goal of this interventional study is to determine the strength of cobolimab and dostarlimab that is most tolerated in children and young adults who have advanced solid tumors. This study also aims: (a) to check if it is safe to use cobolimab and dostarlimab combination in children and young adults, (b) to see how to manage the side effects that may occur, and (c) the effect of this treatment in participants

Being tested
Cobolimab, Dostarlimab
Keywords
Solid Tumours, Cobolimab, Dostarlimab
Medical subject headings
Melanoma, Hodgkin Disease, Glioblastoma, Diffuse Intrinsic Pontine Glioma, Ependymoma, Osteosarcoma, Carcinoma, Hepatocellular, Hepatoblastoma

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • CobolimabDrug

    Cobolimab will be administered

  • DostarlimabDrug

    Dostarlimab will be administered

Study groups in NCT06521567
Study groupRoleWhat they receive
Part 1- Dose determinationExperimentalNot described
Receives: Drug: Cobolimab; Drug: Dostarlimab
Part 2- Dose expansionExperimentalNot described
Receives: Drug: Cobolimab; Drug: Dostarlimab

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Part 1- Number of participants with Dose Limiting Toxicities (DLTs)

    Measured: Up to 42 days

  2. Part 1- Number of participants with treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), immune-mediated adverse events (imAEs) and adverse events (AEs) leading to discontinuation occurring during the study

    Measured: Up to approximately 46 months

  3. Part 1- Serum concentration of Cobolimab

    Measured: 1±0.5 hours (h) post-dose on Cycle 1 Day 1; 168±12 h post-dose Cycle 1Day 8; Pre-dose and 1±0.5 h post-dose on Cycle 2 Day 1; Cycle 4 Day 1 and Cycle 6 Day 1(Each cycle is of 21 days)

  4. Part 1- Serum concentration of Dostarlimab

    Measured: 1±0.5 h post start of cobolimab infusion on Cycle 1 Day 1; Pre-dose on Cycle 2 Day 1; Cycle 4 Day 1 and Cycle 6 Day 1(Each cycle is of 21 days)

  5. Part 1- Recommended Phase 2 Dose (RP2D) of Cobolimab and Dostarlimab combination

    Measured: Up to approximately 12 months

  6. Part 2- Confirmed Objective Response Rate (ORR)

    Confirmed ORR is defined as the proportion of participants who have achieved confirmed complete response (CR) or confirmed partial response (PR), evaluated using disease-specific tumor assessment criteria based on Investigator assessment

    Measured: Up to approximately 46 months

  7. Part 2- Number of participants with TEAEs, SAEs, imAEs, TEAEs leading to death and AEs leading to discontinuation

    Measured: Up to approximately 46 months

  8. Part 2-Number of participants with changes in laboratory parameters, vital signs and cardiac parameters

    Measured: Up to approximately 46 months

Secondary outcomes (11)

  1. Part 1 and 2: Receptor occupancy (RO)

    RO will be measured in whole blood and presented as normalized ratio [Fluorescence Minus One (FMO) subtracted values of free T cell immunoglobulin and mucin domain containing protein 3 (TIM-3) to total TIM-3]

    Measured: Pre-dose Cycle 1 Day 1, 5 h post-start of cobolimab administration Cycle 1 Day 1, anytime Cycle 1 Day 8, pre-dose Cycle 2 Day 1, and pre-dose Cycle 4 Day 1 (Each cycle is of 21 days)

  2. Part 1- Confirmed ORR

    Confirmed ORR is defined as the proportion of participants who have achieved confirmed CR or confirmed PR, evaluated using disease specific tumor assessment criteria based on Investigator assessment

    Measured: Up to approximately 70 months

  3. Part 1 and 2: Progression Free Survival (PFS)

    PFS is defined as the length of time until disease progression, from the date of first dose to the earliest date of assessment of disease progression based on disease-specific tumor assessment criteria by Investigator assessment, or death by any cause, whichever occurs first

    Measured: Up to approximately 70 months

  4. Part 1 and 2: Duration of response (DOR)

    DOR is defined as the time from first documented response (CR/PR) until the time of first documentation of disease progression based on disease-specific tumor assessment criteria by Investigator assessment, or death, whichever occurs first

    Measured: Up to approximately 70 months

  5. Part 1 and 2: Overall Survival (OS)

    OS is defined as the time from the date of first dose to the date of death by any cause

    Measured: Up to approximately 70 months

  6. Part 1 and 2: Number of participants with positive results in Anti-drug antibody (ADA) test against Cobolimab

    Measured: Pre-dose on Cycle 1 Day 1; Cycle 2 Day 1; Cycle 4 Day 1 and Cycle 6 Day 1[Each cycle is of 21 days]; 30-Day and 90-Day safety follow up (FUP) Visit

  7. Part 1 and 2: Number of participants with positive results in Anti-drug antibody (ADA) test against Dostarlimab

    Measured: Pre-dose on Cycle 1 Day 1; Cycle 2 Day 1; Cycle 4 Day 1 and Cycle 6 Day 1[Each cycle is of 21 days]; 30-Day and 90-Day safety follow up (FUP) Visit

  8. Part 1 and 2: Titers of ADA to Cobolimab

    Measured: Pre-dose on Cycle 1 Day 1; Cycle 2 Day 1; Cycle 4 Day 1 and Cycle 6 Day 1[Each cycle is of 21 days]; 30-Day and 90-Day safety follow up (FUP) Visit

  9. Part 1 and 2: Titers of ADA to Dostarlimab

    Measured: Pre-dose on Cycle 1 Day 1; Cycle 2 Day 1; Cycle 4 Day 1 and Cycle 6 Day 1[Each cycle is of 21 days]; 30-Day and 90-Day safety follow up (FUP) Visit

  10. Part 2- Serum concentration of Cobolimab

    Measured: 1±0.5 hours(h) post-dose on Cycle1Day 1;168±12h post-dose Cycle1Day8; Pre-dose & 1±0.5h post-dose on Cycle2Day1; Cycle4Day1 & Cycle6Day1[Each cycle is of 21 days];End of Treatment(EOT; EOT is within 7days of last dose), 30Day safety follow up(FUP) Visit

  11. Part 2- Serum concentration of Dostarlimab

    Measured: 1±0.5 h post start of cobolimab infusion on Cycle 1 Day 1; Pre-dose on Cycle 2 Day 1; Cycle 4 Day 1 and Cycle 6 Day 1 [Each cycle is of 21 days]; End of Treatment (EOT; EOT is within 7 days of last dose), 30-Day safety follow up (FUP) Visit

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 Jul 2024
  2. Study start6 Mar 2025
  3. Primary completion13 Oct 2026 (estimated)
  4. Study completion13 Oct 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1/2
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Sequential
Masking
None (open label)
Enrolment
83 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06521567
Sponsor's protocol ID
219451
Other IDs
2024-511350-41-00
Status last verified
Nov 2025
First submitted
22 Jul 2024
Last updated
12 Nov 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Qualified researchers may request access to anonymized individual patient-level data (IPD) and related study documents of the eligible studies via the Data Sharing Portal. Details on GSK's data sharing criteria can be found at: https://www.gsk.com/en-gb/innovation/trials/data-transparency/

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing Cobolimab and Dostarlimab in people with Melanoma and Hodgkin Lymphoma, run by GlaxoSmithKline at 20 sites in 6 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 18 inclusion and 28 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 12 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 20 sites in United States, France, Spain, Czechia, Italy and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part 1- Number of participants with Dose Limiting Toxicities (DLTs) (time frame: Up to 42 days). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06521567.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Nov 2025.

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