PHOENIX DDR/Anti-PD-L1 Trial: A Pre-surgical Window of Opportunity and Post-surgical Adjuvant Biomarker Study of DNA Damage Response Inhibition With or Without Anti-PD-L1 Immunotherapy in Patients With Neoadjuvant Treatment Resistant Residual Triple Negative Breast Cancer

PHOENIX is a window of opportunity (WOP), open-label, multi-centre, phase IIa trial comprising multiple non-comparative treatment cohorts with patient allocation via minimisation (cohorts A-D) or allocation according to HRD and germline BRCA1/2 mutation status (cohorts E-G). The trial consists of two parts: a post-neoadjuvant treatment preoperative WOP component (PART 1); and a post-operative component (PART 2). Cohorts A-D: To assess whether short exposure to a DDR inhibitor or anti-PD-L1 immunotherapy in a preoperative WOP in patients with post-NACT high risk residual disease, generates a signal of anti-tumour biological activity within residual disease tissue. Cohort E: To assess whether short exposure to a DDR inhibitor with or without anti-PD-1 immunotherapy in a preoperative WOP in patients with non-HRD associated TNBC and post-neoadjuvant treatment high risk residual disease, generates a signal of anti-tumour biological activity within residual disease tissue. Cohorts F \& G: To assess whether short exposure to the DDR inhibitor olaparib with or without anti-PD-1 immunotherapy in a preoperative WOP in patients with HRD associated TNBC and post-neoadjuvant treatment high risk residual disease, generates a signal of anti-tumour biological activity within residual disease tissue.

NCT Number	NCT03740893
Lead Sponsor	Institute of Cancer Research, United Kingdom Collaborators: AstraZeneca
Conditions	Breast Neoplasm, Triple Negative Breast Cancer (TNBC), HRD
Enrollment	119 participants
Start Date	2019-10-15
Primary Completion	2026-12 (estimated)
Study Completion	2029-06 (estimated)
Updated on ClinicalTrials.gov	2025-08-11