A Phase 1/2 interventional study of Ifinatamab Deruxtecan in Malignant Neoplasm, sponsored by Merck Sharp & Dohme LLC. Recruiting at 35 sites in 13 countries. Open to participants aged 1 Month to 17 Years. Per ClinicalTrials.gov, last updated 2026-10-30.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 1/2, Interventional, and Treatment
Researchers are looking for new ways to treat children with relapsed or refractory solid tumors:
The study treatment I-DXd (also known as MK-2400 or ifinatamab deruxtecan) is an antibody-drug conjugate (ADC). An ADC attaches to a protein on cancer cells and delivers treatment to destroy those cells. The goals of this study are to learn:
This study will have 2 parts: Part 1 will evaluate the safety and tolerability and determine the recommended dose for expansion (RDE) of I-DXd, followed by Part 2 an efficacy expansion.
10,818 studies on the registry are indexed under Neoplasms; 2,324 are open to participants now.
This study's planned enrollment of 134 is above the median of 60 across 7,703 interventional studies indexed under Neoplasms.
Browse Neoplasms studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,166 studies on the registry; 132 are open to participants now.
Of its 501 completed or terminated interventional studies of FDA-regulated products, 370 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
The main inclusion criteria include but are not limited to the following:
The main exclusion criteria include but are not limited to 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.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on 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.
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.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
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.
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.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
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 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.
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).
Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.
Cancer that has spread to the leptomeninges, the thin layers covering the brain and spinal cord, and the fluid between them. It is not the same as brain metastases.
Criteria often treat it separately, and many studies leave it out even where treated brain metastases are allowed.
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.
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
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.
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.
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.
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.
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.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
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.
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.
Allogeneic and autologous transplant
Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Brain metastases
Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).
Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Leptomeningeal disease
Cancer that has spread to the leptomeninges, the thin layers covering the brain and spinal cord, and the fluid between them. It is not the same as brain metastases.
Criteria often treat it separately, and many studies leave it out even where treated brain metastases are allowed.
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.
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.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive ifinatamab deruxtecan via intravenous (IV) infusion on day 1 of each 3-week cycle until discontinuation or progression
Biological: Ifinatamab Deruxtecan
IV infusion
Also known as: MK-2400, I-DXd, DS-7300a
Part 1: Number of Participants From ≥1 Month to <12 Years Who Experience a Dose-limiting Toxicity (DLT)
A DLT is any of a prespecified list of adverse events (AEs) that occur during Cycle 1 (up to 21 days) if attributed to the study treatment and not attributed to any other clearly identifiable cause. The percentage of participants who experience DLTs will be reported. Each cycle is 21 days.
Time frame: Cycle 1 (up to approximately 21 days); each cycle is 21 days
Part 1: Number of Participants From ≥1 Month to <12 Years Who Experience One or More Adverse Events (AEs)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who experience AEs will be reported.
Time frame: Up to approximately 5 years
Part 1: Number of Participants From ≥1 Month to <12 Years Who Discontinue Study Intervention Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who discontinue study treatment due to an AE will be reported.
Time frame: Up to approximately 5 years
Part 1: Number of Participants From ≥1 Month to <12 Years Who Receive Dose Modifications Due to AEs
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who receive dose modification due to an AE will be reported.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Objective Response Rate (ORR) for Participants with neuroblastoma (NBL), rhabdomyosarcoma (RMS), and Wilms tumor (WT)
ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions). The percentage of participants who experience CR or PR as assessed by the investigator will be presented.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Disease Control Success at 4 Months (DCS-4) for Participants with osteosarcoma (OST)
DCS-4 is defined as no occurrence of disease progression per disease specific criteria as assessed by investigator or death due to any cause by Month 4 following the first administration of study intervention for participants with OST. Participants who discontinue from study for any reason prior to completing the third post baseline (or at least 16 weeks) response assessments will be considered disease control failures.
Time frame: Up to 4 Months
Part 1 and Part 2: Duration of Response (DOR) For Participants With NBL, RMS, WT, or OST
For participants who demonstrate a confirmed CR (disappearance of all target lesions) or PR (at least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1, DOR is defined as the time from first documented evidence of CR or PR until PD or death. PD is defined as at least a 20% increase in the sum of diameters of target lesions and an absolute increase of at least 5 mm. Note: The appearance of one or more new lesions is also considered PD. DOR as assessed by the investigator will be presented.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Disease Control Rate (DCR) For Participants With NBL, RMS, WT, or OST
DCR is defined, per RECIST 1.1, as the percentage of participants who have a CR (disappearance of all target lesions) or PR (at least a 30% decrease in the sum of diameters of target lesions) or Stable Disease (SD). SD is defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD: at least a 20% increase in the sum of diameters of target lesions and an absolute increase of at least 5 mm). Note: The appearance of one or more new lesions is also considered PD. The time from the first dose until the date of SD must be greater than or equal to 6 weeks. The DCR as assessed by the investigator will be presented.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Time to Response (TTR) For Participants With NBL, RMS, WT, or OST
For participants who demonstrate a confirmed CR (disappearance of all target lesions) or PR (at least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1, TTR is defined as the time from the first dose to the first documented evidence of a CR or PR. The TTR as assessed by the investigator will be presented.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Progression-free Survival (PFS) For Participants With NBL, RMS, WT, or OST
PFS is defined as the time from randomization to the first documented PD or death due to any cause, whichever occurs first as assessed by RECIST 1.1. PD is defined as at least a 20% increase in the sum of diameters of target lesions and an absolute increase of at least 5 mm. Note: The appearance of one or more new lesions is also considered PD. PFS as assessed by the investigator will be presented.
Time frame: Up to approximately 5 years
Part 1 and Part 2: ORR For participants with OST
ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions). The percentage of participants with OST who experience CR or PR as assessed by the investigator will be presented.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Overall Survival (OS)
OS is defined as time from first dose of study treatment to death due to any cause.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Number of Participants With NBL, RMS, WT, or OST Who Experience an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who experience AEs will be reported.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Number of Participants With NBL, RMS, WT, or OST Who Discontinue Study Treatment Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who discontinue study treatment due to an AE will be reported.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Number of Participants With NBL, RMS, WT, or OST Who Receive Dose Modification Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The percentage of participants who receive dose modification due to an AE will be reported.
Time frame: Up to approximately 5 years
Part 1 and Part 2: Maximum Plasma Concentration (Cmax) of I-Dxd
Blood samples will be collected at specified intervals to determine the Cmax of I-Dxd.
Time frame: At designated timepoints (up to approximately 5 years)
Part 1 and Part 2: Area under the concentration time curve from Time 0 to the End of the Dosing Period (AUCtau) of I-Dxd
Blood samples will be collected at specified intervals to determine the AUCtau of I-Dxd.
Time frame: At designated timepoints (up to approximately 5 years)
Part 1 and Part 2: Plasma Trough Concentration (Ctrough) of I-Dxd
Blood samples will be collected at specified intervals to determine the Ctrough of I-Dxd.
Time frame: At designated timepoints (up to approximately 5 years)
Part 1 and Part 2: Maximum Plasma Concentration (Cmax) of released drug payload (Dxd)
Blood samples will be collected at specified intervals to determine the Cmax of Dxd.
Time frame: At designated timepoints (up to approximately 5 years)
Part 1 and Part 2: Area under the concentration time curve from Time 0 to the End of the Dosing Period (AUCtau) of Dxd
Blood samples will be collected at specified intervals to determine the AUCtau of Dxd.
Time frame: At designated timepoints (up to approximately 5 years)
Part 1 and Part 2: Plasma Trough Concentration (Ctrough) of Dxd
Blood samples will be collected at specified intervals to determine the Ctrough of Dxd.
Time frame: At designated timepoints (up to approximately 5 years)
Part 1 and Part 2: Number of Participants with antidrug antibodies (ADA) against I-Dxd
Blood samples will be collected at specified intervals to assess I-Dxd immunogenicity by determining the incidence of ADA of I-Dxd.
Time frame: At designated timepoints (up to approximately 5 years)
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
Started Jul 2026 (actual). Primary completion is estimated for Aug 2031, 61 months after the start.
Of 194 industry-sponsored phase 1/2 interventional studies under Neoplasms, half reached primary completion within 61 months of starting (the median), counting those still running; a quarter within 41 and three quarters within 88. This study's planned 61 months is close to that.
Counting every sponsor, half of 296 studies reached it within 60 months; a quarter within 39 and three quarters within 89.
Neoplasms covers many different conditions, not one, so the studies compared here vary widely. Read these figures as a rough guide.
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 ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
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Studies of the drug tested here: Ifinatamab deruxtecan