Real-World Outcomes With Inetetamab-Based Regimens for HER2-Positive Metastatic Breast Cancer: A Multicenter...

Area of Science:

• Oncology
• Medical Research
• Pharmacology

Background:

• HER2-positive metastatic breast cancer (MBC) remains a significant clinical challenge.
• Inetetamab is an anti-HER2 therapy with demonstrated potential in MBC treatment.
• Understanding the real-world efficacy and safety of inetetamab-based regimens is crucial.

Purpose of the Study:

• To evaluate the efficacy and safety of inetetamab-based regimens in patients with HER2-positive MBC.
• To assess the impact of treatment line on progression-free survival (PFS).
• To identify factors influencing treatment outcomes in this patient population.

Main Methods:

• Multicenter retrospective study including 140 patients with HER2-positive MBC.
• Patients received inetetamab-based regimens between November 2020 and April 2023.
• Primary endpoint: progression-free survival (PFS); Secondary endpoints: objective response rate (ORR), disease control rate (DCR), and safety.

Main Results:

• Median PFS was 6.1 months overall, with an ORR of 35.0% and DCR of 77.1%.
• Significantly longer median PFS observed with first- or second-line inetetamab (14.5 months) versus third-line or later (4.8 months; P < 0.0001).
• Common grade 3/4 adverse events included leukopenia (16.4%) and neutropenia (12.9%); no treatment-related deaths.

Conclusions:

• Inetetamab-based regimens demonstrate promising efficacy and favorable safety in HER2-positive MBC.
• Early-line treatment (first or second) is associated with significantly improved PFS.
• These regimens represent a viable alternative treatment option for HER2-positive MBC.