Real-World Feasibility, Toxicity, and Early Outcomes of Neoadjuvant Pembrolizumab-Based Systemic Therapy in Early Triple-Negative Breast Cancer: A Single-Centre Chinese Cohort from Hong Kong
- 1Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong SAR, China
Abstract
Background: Neoadjuvant treatment for early-stage triple-negative breast cancer has been widely used, and the KEYNOTE-522 (KN522) regimen has become a standard of care for early-stage TNBC, with alternative treatment options including a dose-dense anthracycline/taxane-based regimen for patients without access to neoadjuvant immunotherapy. Nevertheless, real-world evidence in Chinese populations, especially high-risk cohorts such as older populations and those with substantial nodal burden, is limited regarding both efficacy and tolerability. This study describes the outcomes associated with neoadjuvant systemic therapy in a Hong Kong Chinese cohort. Objectives: This study aimed to describe the feasibility, treatment delivery, tolerability and safety of the KN522 regimen in stage I-III TNBC in a Chinese cohort in Hong Kong. Another cohort treated with dose-dense neoadjuvant chemotherapy, which is also a standard-of-care treatment alternative, is presented to provide context of local treatment practice. Methods: We conducted a retrospective observational cohort study of 59 patients with stage I-III TNBC who received neoadjuvant systemic treatment prior to breast surgery at a tertiary centre in Hong Kong between February 2022 and June 2025. The primary cohort received the KN522 regimen (n = 30). A contextual reference cohort received dose-dense epirubicin/cyclophosphamide followed by paclitaxel (n = 29) to describe local treatment patterns. Descriptive outcomes included pathological complete response (pCR), treatment delivery, adverse events, surgery completion, and exploratory event-free survival (EFS). Analyses were primarily descriptive; between-cohort comparisons were exploratory in nature. Results: Fifty-nine patients were included overall: 30 treated with the KN522 regimen and 29 treated with dose-dense neoadjuvant chemotherapy. In the KN522 cohort, the median age was 56 years, 80.0% of patients were postmenopausal, and 33.3% had N3 disease. Pathological complete response occurred in 13 of 30 patients (43.3%; exact 95% CI 25.5–62.6%). Grade ≥3 chemotherapy-related adverse events occurred in 15 patients (50.0%), immune-related adverse events occurred in 11 patients (36.6%), and Grade 3 or higher immune-related adverse events occurred in four patients (13.3%). Pembrolizumab was suspended in six patients (20.0%), while all 30 patients proceeded to definitive surgery. In the dose-dense chemotherapy cohort, the pCR rate was 31.0%, with a grade ≥3 chemotherapy-related adverse event rate of 20.7%, and all patients proceeded to definitive surgery. Conclusions: In this descriptive real-world single-centre Hong Kong study, the neoadjuvant KN522 regimen was feasible in Chinese patients with early TNBC, although treatment-related toxicity and treatment modification were common. The observed pCR rate was lower than that reported in the original KN522 trial, possibly reflecting differences in patient selection and real-world treatment delivery patterns. Larger multi-centre studies are needed to evaluate outcomes in Chinese and other Asian populations.
Related
- 523 Lymphaticsparing neoadjuvant SABR and pembrolizumab (neo-ImmunoSABR) in HPVnegative HNSCC: results from a phase II multi-center trial with immune correlates
- Residual Invasive Disease After Neoadjuvant Therapy in Triple-Negative Breast Cancer: Risk Stratification and Postoperative Radiotherapy-Pembrolizumab Integration.
- Neoadjuvant pembrolizumab plus nimotuzumab as a bridge to surgery in a frail elderly patient with maxillary gingival and palatal squamous cell carcinoma: a case report
- Skin toxicity and effectiveness of first-line enfortumab vedotin plus pembrolizumab for urothelial carcinoma: a prospective multicenter real-world study in Japan.
- Quantitative Molecular Breast Imaging for Early Prediction of Neoadjuvant Systemic Therapy Response in Locally Advanced Breast Cancer Patients
BibTeX
@article{lo2026realworld,
title = {{Real-World Feasibility, Toxicity, and Early Outcomes of Neoadjuvant Pembrolizumab-Based Systemic Therapy in Early Triple-Negative Breast Cancer: A Single-Centre Chinese Cohort from Hong Kong}},
author = {Yuk-Fong Grace Lo and Kuen Chan and Sung Inda Soong},
journal = {Cancers},
year = {2026},
month = oct,
doi = {10.3390/cancers18203339},
url = {https://www.mdpi.com/2072-6694/18/20/3339},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Real-World Feasibility, Toxicity, and Early Outcomes of Neoadjuvant Pembrolizumab-Based Systemic Therapy in Early Triple-Negative Breast Cancer: A Single-Centre Chinese Cohort from Hong Kong
AU - Yuk-Fong Grace Lo
AU - Kuen Chan
AU - Sung Inda Soong
PY - 2026
DA - 2026/10/16
JO - Cancers
DO - 10.3390/cancers18203339
UR - https://www.mdpi.com/2072-6694/18/20/3339
AB - Background: Neoadjuvant treatment for early-stage triple-negative breast cancer has been widely used, and the KEYNOTE-522 (KN522) regimen has become a standard of care for early-stage TNBC, with alternative treatment options including a dose-dense anthracycline/taxane-based regimen for patients without access to neoadjuvant immunotherapy. Nevertheless, real-world evidence in Chinese populations, especially high-risk cohorts such as older populations and those with substantial nodal burden, is limited regarding both efficacy and tolerability. This study describes the outcomes associated with neoadjuvant systemic therapy in a Hong Kong Chinese cohort. Objectives: This study aimed to describe the feasibility, treatment delivery, tolerability and safety of the KN522 regimen in stage I-III TNBC in a Chinese cohort in Hong Kong. Another cohort treated with dose-dense neoadjuvant chemotherapy, which is also a standard-of-care treatment alternative, is presented to provide context of local treatment practice. Methods: We conducted a retrospective observational cohort study of 59 patients with stage I-III TNBC who received neoadjuvant systemic treatment prior to breast surgery at a tertiary centre in Hong Kong between February 2022 and June 2025. The primary cohort received the KN522 regimen (n = 30). A contextual reference cohort received dose-dense epirubicin/cyclophosphamide followed by paclitaxel (n = 29) to describe local treatment patterns. Descriptive outcomes included pathological complete response (pCR), treatment delivery, adverse events, surgery completion, and exploratory event-free survival (EFS). Analyses were primarily descriptive; between-cohort comparisons were exploratory in nature. Results: Fifty-nine patients were included overall: 30 treated with the KN522 regimen and 29 treated with dose-dense neoadjuvant chemotherapy. In the KN522 cohort, the median age was 56 years, 80.0% of patients were postmenopausal, and 33.3% had N3 disease. Pathological complete response occurred in 13 of 30 patients (43.3%; exact 95% CI 25.5–62.6%). Grade ≥3 chemotherapy-related adverse events occurred in 15 patients (50.0%), immune-related adverse events occurred in 11 patients (36.6%), and Grade 3 or higher immune-related adverse events occurred in four patients (13.3%). Pembrolizumab was suspended in six patients (20.0%), while all 30 patients proceeded to definitive surgery. In the dose-dense chemotherapy cohort, the pCR rate was 31.0%, with a grade ≥3 chemotherapy-related adverse event rate of 20.7%, and all patients proceeded to definitive surgery. Conclusions: In this descriptive real-world single-centre Hong Kong study, the neoadjuvant KN522 regimen was feasible in Chinese patients with early TNBC, although treatment-related toxicity and treatment modification were common. The observed pCR rate was lower than that reported in the original KN522 trial, possibly reflecting differences in patient selection and real-world treatment delivery patterns. Larger multi-centre studies are needed to evaluate outcomes in Chinese and other Asian populations.
SN - 2072-6694
ER -