Healthcare Resource Utilization and Real-World Burden of Illness in Patients With PD-L1-Negative Metastatic Triple-Negative Breast Cancer in the First-Line Setting

Objectives
To describe healthcare resource utilization (HCRU) and real-world disease burden in patients with PD-L1-negative (PD-L1-) metastatic triple-negative breast cancer (mTNBC) in the first-line (1L) setting.

Methods
This retrospective cohort study analyzed de-identified mTNBC patient records linked to claims using the Tempus Lens Platform (Tempus AI, Inc., Chicago, IL). Adults with PD-L1- mTNBC who initiated 1L treatment between January 2018 and June 2024 (index date) were included. Patients were followed from index to death, last record, or study end (June 2025), requiring ≥3 months follow-up if alive. Treatment patterns were described. Real-world overall survival (rwOS), progression-free survival (rwPFS), time to next treatment or death (rwTTNTD), and time on treatment (rwToT) were estimated using Kaplan-Meier methods with risk-set adjustment to correct for left truncation. All-cause HCRU was reported per-patient-per-month (PPPM) among a subset of patients with continuous claims enrollment.

Results
316 patients with PD-L1- mTNBC were included (mean age, 59.7 years; 182 [58%] had recurrent disease, and 16 [9%] received pembrolizumab in the early setting; median follow-up, 16.2 months). In 316 patients who received 1L treatment, 128 (41%) received chemotherapy monotherapy and 105 (33%) received chemotherapy combinations. Among 189 patients who received subsequent lines of therapy, sacituzumab govitecan was used in 2L for 52 (28%) patients and in 3L for 32 (17%) patients. Among patients who received 1L treatment, median rwOS was 17.1 months, rwPFS 5.1 months, rwTTNTD 6.5 months, and rwToT 4.8 months. Among 135 patients eligible for all-cause HCRU analyses, there were 0.88 hospitalizations, 0.21 emergency room visits, 1.98 outpatient medical visits, and 2.55 office visits PPPM.

Conclusions
Patients with PD-L1- mTNBC experienced suboptimal outcomes and substantial HCRU with heavy reliance on acute medical services, highlighting a significant unmet need in this population.