74 Real-world study characterizing patient characteristics, treatments, and unmet need in IO-ineligible patients with metastatic triple-negative breast cancer

This retrospective study, using electronic health record data from the ConcertAI Patient360™ Breast dataset (01/2021–01/2025), included US patients ≥18 years with mTNBC who initiated first-line treatment in the metastatic setting. Patients were classified as IO-eligible and IO-ineligible. IO-eligible patients were PD-L1 positive (combined positive score ≥10, or other positive reported result) and had a disease-free interval (DFI) more than 12 months if treated with neoadjuvant/adjuvant IO; while IO-ineligible patients were PD-L1 negative or had a DFI of 12 months or less. Kaplan-Meier analyses were used to estimate median real-world progression-free survival (rwPFS), real-world overall survival (rwOS), real-world time to discontinuation (rwTTD), and real-world time to next treatment (rwTTNT).

A total of 432 patients with mTNBC treated with first-line therapy were identified, of whom 129 (29.9%) were IO-eligible and 303 (70.1%) were IO-ineligible. Overall, among IO-eligible and IO-ineligible patients, respectively, median age was 61 years; 69.0% and 61.7% were White; 79.1% and 74.0% received care in community settings; 12.5% and 5.4% had brain metastases; and 70.6% and 73.6% had ECOG performance status 0–1. Treatments used in the first line in patients who were IO-eligible and IO-ineligible were: 85.3% and 12.5% received IO-based regimens, 10.9% and 57.4% received chemotherapy-based regimens (without IO), and 3.9% and 30.0% received other regimens (without IO or chemotherapy), respectively. Overall, 13.2% of patients who were IO-eligible and 28.1% of IO-ineligible patients received first-line sacituzumab govitecan, either as monotherapy or in combination with chemotherapy, IO, or other agents. Only 43.4% and 39.0% of patients who were IO-eligible and IO-ineligible received treatment beyond first line. Patients who were IO-eligible had longer median rwPFS, rwOS, rwTTD, and rwTTNT compared with those who were IO-ineligible (Table).

In this real-world cohort of patients with mTNBC treated in the first-line setting, 70% were classified as IO-ineligible. While most patients who were IO-ineligible relied on conventional chemotherapy as first-line treatment, some were treated with IO or sacituzumab govitecan despite not being recommended by NCCN guidelines in the first-line setting for this population. Clinical outcomes were significantly worse for IO-ineligible patients compared with IO-eligible patients. Overall, limited treatment options and poor clinical outcomes, particularly in IO-ineligible patients, highlight significant unmet need in this population.