Investigational Drug
[177Lu]Lu-NeoB
TrialFetch AI Analysis
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Overview
[¹⁷⁷Lu]Lu-NeoB (formerly lutetium-177 NeoBOMB1) is an investigational radioligand therapy studied in people with advanced solid tumors whose lesions take up the companion imaging agent [⁶⁸Ga]Ga-NeoB. Clinical results are limited to small, early-phase studies. (pmc.ncbi.nlm.nih.gov)
Mechanism of action
NeoB is an antagonist that binds the gastrin-releasing peptide receptor (GRPR), which is expressed by some tumors. Coupling NeoB to radioactive lutetium-177 is intended to deliver radiation to GRPR-expressing lesions; gallium-68–labeled NeoB is used to identify lesions with tracer uptake before treatment. (pmc.ncbi.nlm.nih.gov)
Efficacy
In the phase IIa portion of the single-arm NeoRay study, 18 patients received treatment. Among the 10 with centrally assessed post-baseline scans, one patient with prostate cancer had a partial response (1/10), five had stable disease, and four had progressive disease. Two patients with gastrointestinal stromal tumors had stable disease lasting at least 20 weeks. The small evaluable group and lack of a comparator mean clinical benefit remains uncertain. (ascopubs.org)
Safety
In phase IIa, 7/18 patients (39%) had treatment-related adverse events and 2/18 (11%) had grade 3 or higher treatment-related events. Fatigue was the most common treatment-related event. In the earlier phase I dose-escalation study, 4/17 patients (24%) had grade 3 or higher treatment-related events; dose-limiting toxicities occurred at the highest tested dose, and 9.25 GBq was selected as the recommended phase II dose. (ascopubs.org)
Further reading
- NeoRay phase IIa results (2026 conference abstract)
- NeoRay phase I safety and dosimetry results (peer-reviewed article)
- NeoRay clinical-trial record
Last updated: Sep 2026
Active trials using [177Lu]Lu-NeoB
Found 2 active trials using this drug:
TrialFetch AI summary: Adults with measurable, GRPR-positive, ER-positive/HER2-negative metastatic breast cancer that progressed after endocrine therapy plus a CDK4/6 inhibitor receive capecitabine with [177Lu]Lu-NeoB, an investigational GRPR-binding radioligand that delivers radiation to receptor-expressing tumors. The trial evaluates different [177Lu]Lu-NeoB doses and schedules; prior capecitabine or therapeutic radiopharmaceutical treatment is excluded.
ClinicalTrials.gov ID: NCT06247995
TrialFetch AI summary: Adults with ER-positive, HER2-negative unresectable or metastatic breast cancer and GRPR-positive disease on [68Ga]Ga-NeoB PET may be eligible after early relapse on (neo)adjuvant endocrine therapy or progression after one endocrine-therapy line for advanced disease. Treatment combines dose-escalated [177Lu]Lu-NeoB, a GRPR-targeted radioligand that delivers lutetium-177 radiation, with ribociclib and fulvestrant.
ClinicalTrials.gov ID: NCT05870579
