Phase I testing of 225Ac-ETN029 for advanced DLL3-positive tumors

A Phase I, Open-label, Multi-center Study to Evaluate the Safety, Tolerability, Dosimetry, and Preliminary Activity of [225Ac]Ac-ETN029 in Patients With Advanced DLL3-expressing Solid Tumors

Phase 1 Interventional Novartis · NCT07006727

This trial will test 225Ac-ETN029, with 111In-ETN029 used for imaging, to see if the treatment is safe, tolerable, and shows early anti-tumor activity in adults with advanced DLL3-positive neuroendocrine cancers.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment116 (estimated)
Ages18 Years to 100 Years
SexAll
SponsorNovartis Industry-sponsored
Drugs / interventionschemotherapy
Locations6 sites (Iowa City, Iowa and 5 other locations)
Trial IDNCT07006727 on ClinicalTrials.gov

What this trial studies

This is an open-label, multi-center Phase I trial using a dose-escalation then dose-expansion design to determine the recommended radioactive dose(s) of 225Ac-ETN029. The study will collect safety, tolerability, dosimetry, pharmacokinetics, pharmacodynamics, and preliminary efficacy data, with 111In-ETN029 used to characterize imaging and biodistribution. Adults with locally advanced or metastatic DLL3-expressing tumors (including SCLC, LCNEC, NEPC, and GEP-NEC) are eligible under specified prior-therapy criteria. Results will guide further development of this DLL3-targeted alpha-emitter approach.

Who should consider this trial

Good fit: Adults (≥18) with locally advanced or metastatic DLL3-positive SCLC, LCNEC (dose escalation), NEPC, or GEP-NEC who have progressed on or are intolerant to prior systemic therapies and meet baseline organ function and safety criteria are the intended participants.

Not a fit: Patients whose tumors lack DLL3 expression, who have poor organ function or uncontrolled comorbidities, who are pregnant, or who have very early-stage disease are unlikely to benefit from this trial.

Why it matters

Potential benefit: If successful, this targeted alpha-emitter therapy could shrink tumors or control disease in DLL3-positive cancers while limiting radiation exposure to surrounding tissues.

How similar studies have performed: Previous DLL3-targeted antibody-drug conjugates showed limited success in larger trials, whereas targeted radioligand therapies for other neuroendocrine targets (e.g., 177Lu-DOTATATE) have been effective, making DLL3-targeted alpha therapy a novel and early approach with unproven but plausible potential.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥ 18 years old
* Patients with one of the following indications:
* 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.
* Dose expansion only: Locally advanced, unresectable, or metastatic GEP-NEC 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. 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.

Exclusion Criteria:

* 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
* Presence of leptomeningeal disease, of symptomatic CNS metastases or of CNS metastases that require local CNS-directed therapy
* History of or current interstitial lung disease or pneumonitis ≥ Grade 2
* Any prior DLL3-targeted therapy (except for SCLC) and any prior RLT (except for NEPC)

Other protocol-defined inclusion/exclusion criteria may apply.

Where this trial is running

Iowa City, Iowa and 5 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Small Cell Lung CarcinomaLarge Cell Neuroendocrine Carcinoma of the LungNeuroendocrine Prostate CancerGastroenteropancreatic Neuroendocrine CarcinomaDLL3Neuroendocrine neoplasmsRadioligand therapy[225Ac]Ac-ETN029
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.