Clinical Report: A Phase II Study Assessing Neoadjuvant Chemotherapy with Immunotherapy

Overview

This phase II study evaluates the feasibility, safety, and preliminary efficacy of combining Toripalimab with chemotherapy and varied radiotherapy fractionation in treatment-naïve patients with early-stage HR+/HER2- breast cancer. The study consists of three cohorts differentiated by radiotherapy fractionation schedules. The primary endpoint is pathological complete response (pCR), with secondary endpoints including survival outcomes and safety.

Background

Breast cancer is the most commonly diagnosed malignancy among women, with HR+/HER2- subtype being the most prevalent. This subtype has limited sensitivity to neoadjuvant systemic therapy, resulting in low pCR rates. Enhancing neoadjuvant efficacy in HR+/HER2- disease is crucial for improving long-term outcomes.

Data Highlights

No numerical data available in the provided source.

Key Findings

• The study investigates three distinct radiotherapy fractionation schedules combined with Toripalimab and chemotherapy.
• A total of 45 patients will be enrolled, with 15 patients in each of the three cohorts.
• The primary endpoint is pathological complete response (pCR), with secondary endpoints including objective response rate and survival outcomes.
• Radiotherapy is hypothesized to enhance the efficacy of immunotherapy through immune modulation.

Clinical Implications

The study aims to provide preliminary data on the safety and efficacy of a novel multimodal neoadjuvant strategy. The results may inform future randomized trials aimed at improving outcomes in HR+/HER2- breast cancer.

Conclusion

This exploratory study will contribute to understanding the integration of immunotherapy and varied radiotherapy fractionation in HR+/HER2- breast cancer treatment. The findings will guide future research directions.

Related Resources & Content

1. The ASCO Post, Chemotherapy-Free Neoadjuvant Therapy for HER2-Enriched Early Breast Cancer, 2025
2. The ASCO Post, MRI-Based Neoadjuvant Chemotherapy Duration in HER2-Positive Breast Cancer, 2026
3. Early breast cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up, ScienceDirect, 2023
4. The ASCO Post — MRI-Based Neoadjuvant Chemotherapy Duration in HER2-Positive Breast Cancer
5. The ASCO Post — MRI-Based Neoadjuvant Chemotherapy Duration in HER2-Positive Breast Cancer
6. Early breast cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up - ScienceDirect
7. https://www.nature.com/articles/s41591-024-03415-7.pdf
8. PEARL: A Phase Ib/II Biomarker Study of Adding Radiation Therapy to Pembrolizumab Before Neoadjuvant Chemotherapy in Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer - PMC