Recombinant Interleukin-15 in Combination With Checkpoint Inhibitors Nivolumab and Ipilimumab in People With Refractory Cancers

December 3, 2025 updated by: Jibran Ahmed, National Cancer Institute (NCI)

Phase I Study of Recombinant Interleukin 15 in Combination With Checkpoint Inhibitors Nivolumab and Ipilimumab in Subjects With Refractory Cancers

Background:

The drug Interleukin-15 (IL-15) activates the immune system. The drugs nivolumab and ipilimumab unblock immune cells. The drugs together may allow immune cells to recognize and attack cancer cells, causing tumors to shrink.

Objective:

To test the effects and maximum dose of IL-15, nivolumab, and ipilimumab.

Eligibility:

People ages 18 and older who have cancer that does not respond to treatment

Design:

Participants will be screened with:

  • Medical history
  • Physical exam
  • Heart, blood, and urine tests
  • Scans

Tumor biopsy: A small needle removes a tumor sample.

Participants will be in 1 of 3 treatment groups:

  • IL-15 with nivolumab
  • IL-15 with ipilimumab
  • IL-15 with nivolumab and ipilimumab

Participants will take the drugs in four 6-week cycles. IL-15 is injected under the skin. The other two drugs are injected into an arm vein over 60-90 minutes. Participants may need to stay at the hospital 2-3 hours after the first dose of any drug to watch for side effects.

Each cycle will include:

  • Weekly blood and urine tests
  • 16 IL-15 injections
  • 1 ipilimumab injection if applicable
  • 3 nivolumab injections if applicable
  • Blood tests weekly during cycles 1 and 2
  • Urine tests weekly during cycles 1 and 2
  • Scans and a tumor biopsy on day 42

After cycle 4, participants will stop taking IL-15. They will continue the other drugs until they can no longer tolerate the side effects, or their cancer gets worse. Those cycles will include:

  • 1 ipilimumab injection if applicable
  • 3 nivolumab injections if applicable
  • Scans every other cycle

After participants stop treatment, their doctor will monitor their side effects for 4 months or until they go away.

Study Overview

Detailed Description

BACKGROUND:

  • Interleukin-15 (IL-15) is a stimulatory cytokine that activates the immune system, inducing proliferation of T lymphocytes and natural killer (NK) cells. Administration of recombinant human IL-15 (rhIL-15) has been shown to result in a dramatic increase of circulating cytotoxic T lymphocytes (CD8+T cells) and NK cells; these changes in immune cell populations suggest potential for anti-tumor activity.
  • Immune checkpoint inhibitors, including nivolumab (anti-programmed cell death protein 1 (PD-1) and ipilimumab (anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), block the engagement of specific T-cell signaling pathways by tumor cells. These regulatory pathways typically act to downregulate T cell activity and are co-opted by tumors to allow the malignant cells to evade the immune response.
  • The combination of rhIL-15 with two checkpoint inhibitor therapies has potential to lead to enhanced immune activation, resulting in anti-tumor T cell responses that are effective in refractory cancers.

PRIMARY OBJECTIVE:

- Determine the safety, toxicity profile, dose-limiting toxicity (DLT) and maximum tolerated doses (MTD) of subcutaneous administration of rhIL-15 given in combination with the anti- CTLA-4 antibody ipilimumab and the anti-PD-1 antibody nivolumab in patients with metastatic or treatment-refractory cancers.

EXPLORATORY OBJECTIVE:

  • Assess the clinical activity of rhIL-15, ipilimumab, and nivolumab combination therapy as characterized by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and immune RECIST (iRECIST) response rate of patients treated in this trial.
  • Investigate the biological effects of this combination on circulating T cell subsets and on PD-1/programmed death-ligand 1 (PD-L1) expression and immune cell activation in tumor tissue.

ELIGIBILITY:

- Patients greater than or equal to 18 years of age with histologically confirmed solid tumor malignancy that is metastatic or treatment-refractory cancers.

STUDY DESIGN:

  • The first 4-6 patients enrolling in the study will be placed into lead-in doublets with a combination of rhIL-15 and either nivolumab OR ipilimumab; once toxicity is cleared in both doublets (i.e., 2 patients enrolled on each doublet remain free of DLTs for 6 weeks) and a safety analysis is reviewed and approved by the Institutional Review Board (IRB), new patients will be enrolled directly onto the triple agent combination.
  • For the first four 42-day cycles on the triplet, patients will receive subcutaneous (SC) rhIL-15 on days 1-8 and 22-29, intravenous (IV) nivolumab on days 8, 22, and 36, and IV ipilimumab on day 8. Cycles 5 and onwards will not include treatment with rhIL-15.
  • Patients will be encouraged to report any and all adverse events, given the high likelihood of toxicities with the triplet combination therapy.
  • Blood for pharmacodynamic (PD) endpoints will be collected throughout the study and tumor biopsies will be collected pretreatment and on cycle 1, day 42 (C1D42) (optional during the doublets and triplet escalation phase, mandatory during the triplet expansion phase)

Study Type

Interventional

Enrollment (Actual)

31

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

  • INCLUSION CRITERIA:

Subjects must have histologically confirmed solid tumor malignancy that is metastatic or treatment refractory cancers which are not curable or do not have known measures or treatments that are associated with a survival advantage (as defined by the subject or the physician investigator). Enrollment of subjects with tumors that can be safely biopsied is encouraged.

Subjects must have evaluable, or measurable disease defined as greater than or equal to 1 lesion that can be accurately measured in greater than or equal to 1 dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as greater than or equal to 20 mm with conventional techniques or as greater than or equal to 10 mm with a spiral computed tomography (CT) scan.

Subjects must have recovered to less than or equal to grade 1 National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) or stabilized from toxicity of prior chemotherapy or biologic therapy administered more than 4 weeks or 5 half-lives earlier, whichever is shorter.

Subjects on bisphosphonates/denosumab for any cancer or on hormone therapy for prostate cancer may continue this therapy. However, subjects with prostate cancer must have confirmed metastatic disease that has progressed despite hormonal therapy or refused or is intolerant of hormonal therapy.

Age greater than or equal to 18 years.

Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 2 (Karnofsky or Lansky greater than or equal to 70%.

Subjects must have normal organ and marrow function as defined below:

  • Leukocytes greater than or equal to 2,000/mm^3
  • Absolute neutrophil count (ANC) greater than or equal 1,500/mm^3
  • Platelets greater than or equal to 100,000/mm^3
  • Total bilirubin less than or equal to 1.5 times institutional upper limit of normal (ULN)
  • Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) less than or equal to 1.5 times institutional upper limit of normal (ULN) or if liver metastasis, less than or equal to 2.5 times ULN
  • Serum creatinine less than or equal to 1.5 times institutional ULN, OR Creatinine clearance greater than or equal to 50 mL/min/1.73 m^2 for subjects with serum creatinine levels greater than 1.5 times higher than institutional normal
  • For patients with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated.
  • Patients with a history of hepatitis C virus (HCV) infection must have been treated and cured. For patients with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load.

Subjects with inactive central nervous system (CNS) metastasis are eligible. Inactive CNS metastasis is defined as: no symptoms of brain metastases after successful definitive treatment of brain metastases (surgical resection, whole brain irradiation, stereotactic radiation therapy, or a combination of these) with stable or improved radiographic appearance on magnetic resonance imaging (MRI) scan at least 1 month after completion of treatment.

Subjects may have previously progressed on treatment with one of the 3 agents being used in this trial or treatment with other checkpoint inhibitors, as long as they have recovered from previous toxicity. Subjects that previously progressed on treatment with a combination of any 2 of the 3 agents being used in this trial are eligible for the triplet cohort only.

The effects of ipilimumab, nivolumab, and rhIL-15 on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, during the treatment portion of the study, and for a minimum for 5 months (women) and 7 months (men) after the last dose of study drug. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately.

Ability to understand and the willingness to sign a written informed consent document.

Willingness to provide blood and biopsy samples for research purposes if on the expansion phase of the study.

EXCLUSION CRITERIA:

Subjects who have received any prior cytotoxic therapy, immunotherapy, major surgery, antitumor vaccines or monoclonal antibodies in the 4 weeks or 5 half-lives, whichever is shorter, prior to cycle 1, day 1 (C1D1) (6 weeks prior for checkpoint inhibitors such as anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or anti-programmed cell death protein 1 (PD1)/programmed death-ligand 1 (PD-L1) and for nitrosoureas or mitomycin C). Subjects must not have received radiotherapy in the 2 weeks prior to C1D1. Subjects who had grade greater than or equal to 3 immune-related adverse events (irAE) (excluding endocrinopathies) during previous treatment with one of the checkpoint inhibitors are excluded from the trial; subjects who had grade 1 or 2 irAE (including serious AEs) that have resolved to grade 1 are eligible at the discretion of the principal investigator (PI).

Subjects with primary brain cancers or active central nervous system (CNS) metastases should be excluded from this clinical trial because of their poor prognosis and because they often develop progressive neurologic dysfunction that would confound the evaluation of neurologic and other adverse events.

History of allergic reactions attributed to compounds of similar chemical or biologic composition to any of the agents on this trial.

Concurrent anticancer therapy (including other investigational agents) with the exception of hormone therapy for breast or prostate cancer. Patients that have received treatment for a different cancer previously and have been disease-free for less than one year are excluded.

Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, cognitive impairment, active substance abuse, or psychiatric illness/social situations that, in the view of the Investigator, would preclude safe treatment or the ability to give informed consent and limit compliance with study requirements.

Inability or refusal to practice effective contraception during therapy or the presence of pregnancy or active breastfeeding. Because there is no significant preclinical information regarding the risk to a fetus or newborn infant, pregnant or breastfeeding women will be excluded from participation in this trial.

Documented human immunodeficiency virus (HIV) infection or positive serology. Since rhIL-15 treatment stimulates the subject's immune system to attack their tumor, the defective immune systems of subjects with HIV makes responses to this treatment much less likely to provide benefit and these subjects are not eligible for this trial.

History of severe asthma (subjects with a history of mild asthma that are on or can be switched to non-corticosteroid bronchodilator regimens are eligible).

Patients with active autoimmune disease or history of autoimmune disease that might recur, which may affect vital organ function or require immune suppressive treatment including systemic corticosteroids, should be excluded. The use of inhaled corticosteroids is allowed.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Lead-in Doublet A
Lead-in doublet for initial safety evaluation: Recombinant interleukin-15 (rhIL-15) given subcutaneous (SC) days 1-8 and 22- 29 + nivolumab (anti-programmed cell death protein 1 (PD1) given intravenous (IV) on days 8, (IL-15 doses are limited to first 4 cycles only).
Recombinant human interleukin 15 (IL-15) is a stimulatory cytokine that activates the immune system, inducing proliferation of T lymphocytes and naturel killer (NK) cells. Administration of recombinant human IL-15 (rhIL-15) has been shown to result in a dramatic increase of circulating cytotoxic T lymphocyte (CD8+T) cells and NK cells; these changes in immune cell populations suggest potential for anti-tumor activity.
Other Names:
  • recombinant human interleukin 15
Nivolumab is a humanized monoclonal antibody against programmed death 1 (PD-1), a receptor present on the surface of activated T cells that functions as an immune checkpoint. One of the ligands for PD-1, programmed death-ligand 1 (PD-L1), is commonly expressed by tumor cells. Similar to inhibition of the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) pathway by ipilimumab, blocking of PD-1/PD-L1 signaling by nivolumab allows infiltrating T cells to mount an immune response against the tumor. Nivolumab is approved as a single agent for several cancer types, as well as for the treatment of advanced melanoma in combination with ipilimumab.
Other Names:
  • Opdivo
Pre-study
Other Names:
  • Electrocardiogram
Pre-study
Other Names:
  • Echocardiogram
Restaging every cycle (every 6 weeks) ± 1 week during cycles 1-4 and every 2 cycles (every 12 weeks) ± 1 week thereafter.
Other Names:
  • Computed tomography scan
Experimental: Lead-in Doublet B
Lead-in doublet for initial safety evaluation: Recombinant interleukin-15 (rhIL-15) given subcutaneous (SC) days 1-8 and 22- 29 + ipilimumab (anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) given intravenous (IV) on day 8, (IL-15 doses are limited to first 4 cycles only).
Recombinant human interleukin 15 (IL-15) is a stimulatory cytokine that activates the immune system, inducing proliferation of T lymphocytes and naturel killer (NK) cells. Administration of recombinant human IL-15 (rhIL-15) has been shown to result in a dramatic increase of circulating cytotoxic T lymphocyte (CD8+T) cells and NK cells; these changes in immune cell populations suggest potential for anti-tumor activity.
Other Names:
  • recombinant human interleukin 15
Pre-study
Other Names:
  • Electrocardiogram
Pre-study
Other Names:
  • Echocardiogram
Restaging every cycle (every 6 weeks) ± 1 week during cycles 1-4 and every 2 cycles (every 12 weeks) ± 1 week thereafter.
Other Names:
  • Computed tomography scan
Ipilimumab is a fully human monoclonal antibody against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), a receptor present on the surface of activated T cells that functions as an immune checkpoint. Immune checkpoints pathways typically act to downregulate T cell activity and are co-opted by tumors to allow the malignant cells to evade the immune response. Blocking the engagement of CTLA-4 with ipilimumab allows infiltrating T cells to mount an anti-tumor response. Ipilimumab is approved by the Food and Drug Administration (FDA) for the treatment of certain patients with melanoma and has shown clinical activity in other tumor types as well.
Other Names:
  • Yervoy
Experimental: Triplet C
Dose escalation of the triplet combination: Recombinant human interleukin-15 (rhIL-15) given subcutaneous (SC) days 1-8 and 22- 29 + nivolumab (anti-programmed cell death protein 1 (PD1) given intravenous (IV) on days 8 + ipilimumab (anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) given intravenous (IV) on day 8, IL-15 will initially be given at 0.5 µg/kg/day (dose level 1, DL1). If the safety profile is acceptable at DL1, the dose of IL-15 will be increased to 1.0 µg/kg/day (DL2) in subsequent patients, then to 2.0 µg/kg/day (DL3) if the safety profile of DL2 is acceptable. (IL-15 doses are limited to first 4 cycles only).
Recombinant human interleukin 15 (IL-15) is a stimulatory cytokine that activates the immune system, inducing proliferation of T lymphocytes and naturel killer (NK) cells. Administration of recombinant human IL-15 (rhIL-15) has been shown to result in a dramatic increase of circulating cytotoxic T lymphocyte (CD8+T) cells and NK cells; these changes in immune cell populations suggest potential for anti-tumor activity.
Other Names:
  • recombinant human interleukin 15
Nivolumab is a humanized monoclonal antibody against programmed death 1 (PD-1), a receptor present on the surface of activated T cells that functions as an immune checkpoint. One of the ligands for PD-1, programmed death-ligand 1 (PD-L1), is commonly expressed by tumor cells. Similar to inhibition of the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) pathway by ipilimumab, blocking of PD-1/PD-L1 signaling by nivolumab allows infiltrating T cells to mount an immune response against the tumor. Nivolumab is approved as a single agent for several cancer types, as well as for the treatment of advanced melanoma in combination with ipilimumab.
Other Names:
  • Opdivo
Pre-study
Other Names:
  • Electrocardiogram
Pre-study
Other Names:
  • Echocardiogram
Restaging every cycle (every 6 weeks) ± 1 week during cycles 1-4 and every 2 cycles (every 12 weeks) ± 1 week thereafter.
Other Names:
  • Computed tomography scan
Ipilimumab is a fully human monoclonal antibody against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), a receptor present on the surface of activated T cells that functions as an immune checkpoint. Immune checkpoints pathways typically act to downregulate T cell activity and are co-opted by tumors to allow the malignant cells to evade the immune response. Blocking the engagement of CTLA-4 with ipilimumab allows infiltrating T cells to mount an anti-tumor response. Ipilimumab is approved by the Food and Drug Administration (FDA) for the treatment of certain patients with melanoma and has shown clinical activity in other tumor types as well.
Other Names:
  • Yervoy
Triplet C Pre-study and Cycle 1, Week 6.
Other Names:
  • Tumor bx

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Maximum Tolerated Dose (MTD) at Which Dose-Limiting Toxicities (DLT) Occurred With rhIL-15 Administered in Combination With Fixed Doses of Nivolumab and Ipilimumab
Time Frame: Cycle 1 (42 days)
Here is the maximum tolerated dose (MTD) (i.e., highest dose) of rhIL-15 administered in combination with fixed doses of nivolumab and ipilimumab at which dose-limiting toxicities occurred in ≤1 of 6 participants during cycle 1, dose escalation in participants receiving the triplet combination. A DLT is defined as an adverse event that is felt to be related (possibly, probably, or definitely) to administration of study drugs, and meets prespecified criteria, including any condition requiring long-term treatment with corticosteroids or permanent discontinuation of one of the agents.
Cycle 1 (42 days)
Number of Dose-limiting Toxicities (DLT) Possibly, Probably, or Definitely Related to Study Drugs
Time Frame: Cycle 1 (42 days)
A DLT is defined as an adverse event (AE) that is felt to be related (possibly, probably, or definitely) to administration of study drugs, and meets prespecified criteria, including any condition requiring long-term treatment with corticosteroids or permanent discontinuation of one of the agents.
Cycle 1 (42 days)
Number of Participants Experiencing Dose-Limiting Toxicities (DLT)
Time Frame: Cycle 1 (42 days)
Here is the number of participants experiencing dose-limiting toxicities (DLT). A DLT is defined as an adverse event that is felt to be related (possibly, probably, or definitely) to administration of study drugs, and meets prespecified criteria, including any condition requiring long-term treatment with corticosteroids or permanent discontinuation of one of the agents.
Cycle 1 (42 days)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With Serious and/or Non-serious Adverse Events Assessed by the Common Terminology Criteria for Adverse Events (CTCAE v5.0)
Time Frame: Adverse Events were monitored/assessed from the first study intervention through 30 days after the study agent (s) was/were administered up to approximately 23 months.
Here is the number of participants with serious and/or non-serious adverse events assessed by the Common Terminology Criteria for Adverse Events (CTCAE v5.0). A non-serious adverse event is any untoward medical occurrence. A serious adverse event is an adverse event or suspected adverse reaction that results in death, a life-threatening adverse drug experience, hospitalization, disruption of the ability to conduct normal life functions, congenital anomaly/birth defect or important medical events that jeopardize the patient or subject and may require medical or surgical intervention to prevent one of the previous outcomes mentioned.
Adverse Events were monitored/assessed from the first study intervention through 30 days after the study agent (s) was/were administered up to approximately 23 months.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Jibran Ahmed, M.D., National Cancer Institute (NCI)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 5, 2018

Primary Completion (Actual)

November 27, 2024

Study Completion (Actual)

May 8, 2025

Study Registration Dates

First Submitted

December 30, 2017

First Submitted That Met QC Criteria

January 2, 2018

First Posted (Actual)

January 3, 2018

Study Record Updates

Last Update Posted (Estimated)

December 18, 2025

Last Update Submitted That Met QC Criteria

December 3, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

We will share de-identified data in a National Institutes of Health (NIH) - funded or approved public repository, identified data in the Biomedical Translational Research Information System (BTRIS) (automatic for activities in the NIH Clinical Center), and de-identified or identified data with approved outside collaborators under appropriate agreements.

IPD Sharing Time Frame

At the time of publication or shortly thereafter.

IPD Sharing Access Criteria

Data will be shared through a National Institutes of Health (NIH) - funded or approved public repository: clinicaltrials.gov, Biomedical Translational Research Information System (BTRIS) (automatic for activities in the NIH Clinical Center), approved outside collaborators under appropriate individual agreements, and publication and/or public presentations.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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