Testing a radioactive antibody, LNTH-2403, for osteosarcoma that returned or did not respond

Trial details

Who runs it

Lantheus Medical Imaging

Trial code

NCT07357519

Record updated

1 May 2026

Original description

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.Read full original descriptionShow less

A Phase 1/2, Multi-Center, Open-Label Study to Evaluate the Safety, Tolerability, Pharmacokinetics, -Radiation Dosimetry, and Preliminary Anti-Neoplastic Activity of LNTH-2403, a LRRC15-targeted 177Lutetium-labeled Monoclonal Antibody, in Participants With Relapsed / Refractory Osteosarcoma

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: Histopathologic documented diagnosis of R/R osteosarcoma; 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); Measurable as defined in RECIST 1.1; Evaluable non-measurable disease as per RECIST 1.1; Bone only without a soft tissue component: must be 18F-FDG-PET avid and evaluable by serial 18F-FDG-PET imaging studies; Age: a. First Cohort in Phase 1: ≥ 18 years-of-age at the time of signature of the main study ICF. b. Second and subsequent cohorts, in Phase 1 and all participants in Phase 2: ≥12years-of-age at the time of signature of the main ICF; Performance Status:; Eastern Cooperative Oncology Group (ECOG) Performance Score (PS): 0 - 2; Lansky PS ≥ 50; Body weight: ≥ 30 kg; Tumor biopsies; Fresh or Archival; Progression following at least one course of chemotherapy, which includes neoadjuvant / perioperative systemic therapy; All adverse events (AEs) related to prior therapies (chemotherapy / systemic therapies, radiation, surgery) must have resolved to Grade 1 or baseline; Organ Function; Pregnancy Women of Child-Bearing Potential (WOCBP) must have a negative serum pregnancy test result at screening; Contraception- Male participants with a WOCBP partner must use 2 forms of acceptable contraception; Written informed consent and/or assent must be obtained according to local guidelines and signed and dated by the participant, parent, and/or legal guardian prior to the performance of any study-specific procedures, sampling, or analyses.

Exclusion: Concurrent treatment with any other anti-neoplastic agents, including localized radiation therapy; Participation in an interventional study of another investigational agent; Prior therapies or diagnostics; Active prior or concurrent malignancy: immunoglobulin),; Receipt of live vaccine within the 30 days prior to the first dose o; Major surgical procedure within 28 days of the first dose of LNTH-2403; Known allergies, hypersensitivity, or intolerance to LNTH-2403 and/or its excipients; Known active infection; Known active liver disease from any cause, Hepatitis A Virus; Known to be human immunodeficiency virus (HIV) positive; Clinically relevant cardiovascular disease; Prior or ongoing clinically significant illness, medical condition, surgical history, physical finding, or laboratory abnormality that, in the investigator's opinion, may affect the participant's safety, compliance with the study, or otherwise impair the assessment of study results; Participant is unwilling or unable to comply with the scheduled visits, drug administration plan, laboratory tests, or other study procedures and study restrictions; Participants meeting any of the following criteria will be excluded from the study; A female participant who is pregnant or breastfeeding.

ClinicalTrials.gov NCT07357519