Among cases with follow-up data (n=35), all 17 tumors with disease progression were DLL3 positive (13 RET-mutated tumors, 1 RAS-mutated tumor, and 3 RET/RAS wild-type tumors), including 5 with moderate expression and 12 with high expression. Most MTCs express DLL3; moreover, DLL3 expression is associated with lymph node metastases at diagnosis and disease progression, indicating that DLL3 may be an effective therapeutic target in MTC.
11 days ago
Journal
|
RET (Ret Proto-Oncogene) • RAS (Rat Sarcoma Virus) • DLL3 (Delta Like Canonical Notch Ligand 3)
In cynomolgus monkeys, IAR025 was well-tolerated at a dose up to 10 mg/kg and exhibited linear pharmacokinetics with a half-life of 90 h. Collectively, these preclinical results demonstrate that IAR025 is a highly potent therapeutic strategy for treating SCLC.
DLL3 expression level is retained or increased in the majority of recurrent gliomas. Inclusion in trials with DLL3-targeting agents in recurrent glioma based on primary tumor material is justified, depending on the required level of DLL3 positivity for inclusion.
Histopathologic assessment of background organs demonstrated mild to moderate kidney and ovary toxicity in the SC16 group compared with the highest-dose TDI-Y-010 cohort (37.0 kBq). [225Ac]Ac-mcp-TDI-Y-010 exhibited excellent antitumor efficacy with mild and transient hematologic toxicity, supporting its potential as a radioimmunotherapeutic agent for patients with DLL3-expressing neuroendocrine cancers.
Acquired resistance to tarlatamab is associated in some cases with loss of DLL3 expression, but persistence of other targetable neuro-endocrine epitopes; in other patients, DLL3 is retained on CTCs, but accompanied by systemic markers of T cell dysfunction. Quantitation of DLL3-positive CTCs identifies patients likely to benefit from tarlatamab, and longitudinal monitoring may guide therapeutic decision-making at the time of acquired resistance.
DLL3 is expressed on a majority of GEP NECs and on a subset of high-grade PanNETs marked by poor outcomes. Functional imaging suggests DLL3 as a promising therapeutic target in both GEP NECs and high-grade PanNETs.
The demonstrated tolerability and efficacy of obrixtamig regimens, administered as step-up followed by target doses of 90-1,080 μg/kg (once weekly or once every 3 weeks), in patients with heavily pretreated DLL3-positive tumors support further exploration in SCLC, epNEC, and LCNEC-L.