The purpose of this study is to evaluate the safety, tolerability, dosimetry and preliminary efficacy of \[225Ac\]Ac-ETN029 and the safety and imaging properties of \[111In\]In-ETN029 in patients aged ≥ 18 years with locally advanced or metastatic DLL3 positive cancers.
Age ≥ 18 years old
Locally advanced, unresectable, or metastatic SCLC with disease progression following, or intolerance to, at least 1 line of systemic therapy, including platinum-containing chemotherapy, unless patient was ineligible to receive such therapy. Prior DLL3-targeted therapy is allowed. For dose expansion, patients should have received no more than 2 prior lines of systemic therapy.
Dose escalation only: LCNEC of the lung with disease progression following, or intolerance to, at least 1 line of systemic therapy, including platinum-containing chemotherapy, unless patient was ineligible to receive such therapy.
Dose expansion only: Locally advanced, unresectable, or metastatic de novo or castration-resistant, treatment-emergent NEPC with neuroendocrine differentiation confirmed by local histology and NEPC marker expression (e.g., chromogranin, synaptophysin) confirmed by local IHC. Prior PSMA-targeted, Lu-177-based RLT is allowed. Patients must have at least one measurable lesion (per RECIST 1.1) that shows 111In-ETN029 uptake higher than surrounding tissues on SPECT/CT as assessed by the Investigator.
Absolute neutrophil count (ANC) < 1.0 x 109/L, hemoglobin < 9 g/dL, or platelet count < 75 x 109/L
QT interval corrected by Fridericia's formula (QTcF) ≥ 470 msec
eGFR < 60 mL/min (<0.835 mL/s), calculated using the CKD-EPI 2021 formula or measured
Unmanageable urinary tract obstruction or urinary incontinence