A Phase 1/2 interventional study of LNTH2403 Phase 1 dose and Phase 2; LNTH2403 a single agent recommended phase 2 dose (RP2D). in Relapsed / Refractory Osteosarcoma, sponsored by Lantheus Medical Imaging. Recruiting at 2 sites in United States. Open to participants aged 12 Years and older. Per ClinicalTrials.gov, last updated 2026-05-01.
Sponsored by Lantheus Medical Imaging (part of Lantheus Holdings, Inc.) · Phase 1/2, Interventional, and Treatment
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Among 278 studies in Osteosarcoma with a site in United States — 55 open to participants now, 83 under way, 1 of them phase 3. Osteosarcoma · United States.
Among the 278 studies in Osteosarcoma with a site in United States, this one is the 74th largest by planned enrollment of the 229 interventional ones that give a count, is one of 17 that started in 2026, is one of 33 in phase 1/2, reaches primary completion later than 44 of the 82 other live ones, and was the 269th registered.
488 studies on the registry are indexed under Osteosarcoma; 123 are open to participants now.
Browse Osteosarcoma studies →55 of the 278 studies in Osteosarcoma with a site in United States are open now. Recruiting first, the newest first:
Wake Forest University Health Sciences · Sites in United States
Ages 7–22
Emory University · Sites in United States
Ages up to 50
St. Jude Children's Research Hospital · Sites in United States
Ages up to 21
St. Jude Children's Research Hospital · Sites in United States
Baylor College of Medicine · Sites in United States
Ages 1–24
A study can be open while its sites in United States have not opened yet or have stopped. Only those recruiting at a site in United States →
Of the 100 Osteosarcoma studies recruiting now, 41 (41%) set no upper age limit and 55 (55%) stop at 75 or younger; 75 take children under 18; 3 take healthy volunteers.
This study: 12 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
278 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 124 · Phase 2 131 · Phase 3 8
First in 1986; this study’s year is marked. 17 started in 2026.
By drug class, each counting the studies that test any of its medicines:
This study's planned enrollment of 55 is above the median of 40 across 354 interventional studies indexed under Osteosarcoma.
Median enrollment 30 across the 229 interventional studies, 155 across the 32 observational. Of the 179 that completed or were terminated, 66 (37%) have results posted.
This tab as a report to print or save as PDF → With an account.
36 of 278 have an industry lead sponsor. The 10 most frequent:
This study is registered under Lantheus Medical Imaging, one of the names counted as Lantheus Holdings, Inc.. Under that name alone:
Lantheus Medical Imaging is the lead sponsor of 30 studies on the registry; 3 are open to participants now.
Lantheus Holdings, Inc. has 1 study filed under Osteosarcoma — fewer than ten, so there is no comparison to draw.
28 of the studies in Osteosarcoma with a site in United States that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07129226Case Comprehensive Cancer CenterMusculoskeletal Cancers Remote Monitoring and Care | 2026-11 |
| NCT02508038University of Wisconsin, MadisonAlpha/Beta CD19+ Depleted Haploidentical Transplantation + Zometa for Pediatric Hematologic Malignancies and Solid Tumors | 2026-12 |
| NCT02013336South Plains Oncology ConsortiumPhase 1 Dose-escalating Study of MM-398 (Irinotecan Sucrosofate Liposome Injection) Plus Intravenous Cyclophosphamide in Recurrent or Refractory Pediatric Solid Tumors | 2026-12 |
| NCT05400603Emory UniversityAllogeneic Expanded Gamma Delta T Cells With GD2 Chemoimmunotherapy in Relapsed /Refractory Neuroblastoma or Refractory/ Relapsed Osteosarcoma | 2026-12 |
| NCT04901702St. Jude Children's Research HospitalStudy of Onivyde With Talazoparib or Temozolomide in Children With Recurrent Solid Tumors and Ewing Sarcoma | 2026-12-31 |
Add all 28 to your calendar (.ics) → With an account.
Among the 278 studies in Osteosarcoma with a site in United States, from their registry updates:
This tab as a report to print or save as PDF → With an account.
This is a multi-center, non-randomized, open-label, dosimetry and dose-escalation, cohort-expansion study of LNTH-2403 administered to subjects with relapsed / refractory (R/R) osteosarcoma. This study consists of 2 phases: (1) a dosimetry and dose escalation phase; and (2) a cohort expansion phase.
Inclusion Criteria: Participants must meet all the following criteria to be enrolled in the study
Must have disease characterized by at least one of the following (Participants meeting only (b.), only (c.), or only (b. and c.) must be discussed with and receive written approval from the Sponsor to qualify).
Performance Status:
Exclusion Criteria:
Participants meeting any of the following criteria will be excluded from the study
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 standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
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.
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.
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.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
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.
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.
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.
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.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
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 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.
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.
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.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
RECIST
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
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.
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.
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.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
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.
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.
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.
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.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
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.
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.
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.
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.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Phase 1 will evaluate escalating doses of LNTH-2403 administered once every 8 weeks, with the potential to explore other dosing schedules based on observed radiation dosimetry and PK parameters and safety and tolerability data.
Drug: LNTH2403 Phase 1 dose
Phase 2 will evaluate LNTH-2403 as a single agent in participants with R/R osteosarcoma at the recommended phase 2 dose (RP2D).
Drug: Phase 2; LNTH2403 a single agent recommended phase 2 dose (RP2D).
LNTH-2403 administered once every 8 weeks, with the potential to explore other dosing schedules based on observed radiation dosimetry and PK parameters and safety and tolerability data.
Once the RP2D is selected, phase 2 will commence
To identify the maximum tolerated dose (MTD) of LNTH-2403 in participants with R/R osteosarcoma (Ph1)
Incidence of DLTs during the first 8 weeks (DLT evaluation window) after the first dose of LNTH-2403
Time frame: From enrollment to the end of treatment at 8 weeks
To evaluate the safety and tolerability profile of LNTH-2403 in participants with R/R osteosarcoma (Ph1)
Type, frequency, severity, timing, and relationship to LNTH-2403 of all Treatment-emergent adverse event, (TEAEs) and Serious adverse events, (SAEs)
Time frame: From enrollment to the end of treatment at 8 weeks
To assess the preliminary anti-neoplastic activity of LNTH-2403 in participants with R/R osteosarcoma (Ph2)
Event-Free Survival (EFS) at 4 months
Time frame: From enrollment to Event-Free Survival (EFS) at 4 months
To assess the preliminary anti-neoplastic activity of LNTH-2403 in participants with R/R osteosarcoma (Ph1)
Event-Free Survival (EFS) at 8 weeks
Time frame: 8 weeks
To describe the safety and tolerability profile of LNTH-2403 in participants with R/R osteosarcoma (Ph2)
Type, frequency, severity, timing, and relationship to LNTH-2403 of any TEAEs and SAEs
Time frame: 4 months
Started Feb 2026 (actual). Primary completion is estimated for Aug 2027, 18 months after the start.
Of 33 phase 1/2 interventional studies under Osteosarcoma, half reached primary completion within 77 months of starting (the median), counting those still running; a quarter within 40 and three quarters within 92. This study's planned 18 months is below that.
How these figures are worked out, and which studies are left out of them.
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