Abstract OT2-02-01: Photodynamic therapy for the treatment of primary breast cancer: Preliminary results of a phase I/IIa clinical trial

Abstract

Abstract Background: Photodynamic therapy (PDT) has been used to treat skin metastases from breast cancer. We investigated the use of PDT for the treatment of primary breast cancer. Trial design: Phase I/IIA, open label, non-randomised, single site, light dose escalation trial in patients with primary breast cancer using verteporfin as the photosensitiser. Verteporfin 0.4mg/kg bodyweight is injected intravenously 60-90 minutes before laser activation through a thin optical fibre inserted percutaneously through a needle positioned under ultrasound guidance under local anaesthesia. The light dose is escalated from 20J to a maximum of 50J in intervals of 10J. Eligibility criteria: Patients aged 30 or over and have opted for mastectomy or wide local excision as primary treatment are included. The tumour should be uni-focal invasive ductal breast carcinoma, or discrete uni-focal site, within a multifocal invasive ductal carcinoma, in a single breast. Participants should not have confirmed distant metastases. The exclusion criteria include: patients who are not undergoing surgery as their primary treatment; patients undergoing surgery for DCIS without invasive breast cancer; lobular cancers and necrotic tumours; patients who have porphyria or are sensitive to verteporfin; patients who have severe cardiovascular disease or severe uncontrolled systemic disease (e.g. hepatic impairment); male breast cancer patients; pregnant or lactating patients; patients taking primary endocrine therapy or taking an experimental medicine as a part of a trial. Aims: We aim to establish the minimum light dose required to induce an area of necrosis with a diameter of at least 12mm perpendicular to the optical fibre; or to achieve a plateau with no increase in diameter of necrosis with increasing light dose. Secondary objectives are to examine the effect of Photodynamic Therapy on the abnormal breast tissue and study if necrosis extends to normal breast tissue. We will be assessing the role of MRI in predicting the response to treatment by measuring the diameter of tumour and the zone of necrosis before and after PDT and confirming it with histological findings. We will be monitoring the number of adverse events arising from the PDT. Statistical Methods: The sample size of the study is based on a standard 3+3 dose-escalation algorithm.Statistical analysis will be descriptive in nature with no formal statistical inference. Summary statistics and analysis will be provided for all patients who receive the study treatment, by dose level for each dosing regimen. Accrual Results: 11 patients have been enroled and completed the trial up to June 2016 with primary end point achieved and no adverse side- effects to treatment seen. Target Accrual: 21 patients. Acknowledgement: Royal Free Charity. Citation Format: Banerjee SM, Malhotra A, El-Sheikh S, Tsukagoshi D, Tran-Dang M-a, Mosse A, Parker S, Davidson TI, Williams NR, Bown S, Keshtgar MR. Photodynamic therapy for the treatment of primary breast cancer: Preliminary results of a phase I/IIa clinical trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-02-01.