Abstract OT2-04-01: An open label, phase II trial of continuous low-irradiance photodynamic therapy (CLIPT) using verteporfin for the treatment of cutaneous breast cancer metastases

Abstract

Abstract Background Cutaneous metastases occur in approximately 20% of patients (pts) with metastatic breast cancer (mBC) and can be highly symptomatic and distressing. Radiation therapy is frequently used, but progression often occurs quickly. Systemic therapies are also typically used, but also often result in limited benefit. Photodynamic therapy is a promising approach with encouraging results in small studies. Here we will evaluate a novel Continuous Low-Irradiance Photodynamic Therapy (CLIPT) system that emits 690nm LED via a handheld Power Pack attached to a single-use sterile Light Patch to deliver a total energy level of 20J/cm2. Verteporfin (Visudyne®) is a photosensitizer approved for ophthalmological use that, when combined with CLIPT, generates activated oxygen species which can destroy tumor cells with limited normal tissue reaction. Methods This open label, Phase 2 study will evaluate the efficacy and safety of CLIPT with verteporfin in 15 patients with cutaneous lesions from mBC. Patients will receive a single IV injection of Verteporfin on day 1. The 9x9cm Light Patch with an adhesive border is placed over the treatment site and attached to the CLIPT portable Power Pack. The patient turns the device on at home 6 hours after the Verteprofin injection and it automatically turns off after 24 hours. The patient then removes the Light Patch and returns to clinic on day 3. The primary endpoint is objective response rate (RR) at 3 weeks following CLIPT using a modified RECIST which accounts for nodular or diffuse plaque-like lesions. Response will be confirmed by independent dermatologist review. Secondary endpoints include RR at 2, 8 and 12 weeks, toxicity, and quality of life (using FACT-B and Brief Pain Inventory). A novel Participant Symptom Scale (PSS) will also be used in which the first 8 patients will list their most distressing symptoms from cutaneous metastases and score the severity of the symptoms from 1 to 10. The six most common symptoms among the first 8 patients will then be used in the PSS for the remaining 7 patients. The PSS will be assessed at baseline and at subsequent visits to explore any improvement in severity of symptoms after treatment with CLIPT. Patients who derive clinical benefit may be retreated up to 3 times to the same or different region. Eligible patients will have: cutaneous metastases from mBC with measurable disease by protocol defined modified RECIST 1.1, ≥ 1 line of prior systemic or local therapy for mBC, ≥ 14 days from prior systemic therapy or 60 days from radiation to target lesion, and no expectation for systemic therapy for ≥ 14 days after CLIPT. RR will be reported with 95% CI. With 15 patients, if ≥ 3 responses (RR ≥ 20%) are observed, the null hypothesis of RR ≤ 5% will be rejected. At the time of abstract submission, 4 patients have been accrued. Clinical Trials Reg: NCT02939274 Citation Format: Isakoff SJ, Rogers GS, Hill S, McMullen P, Habin KR, Chen ST, Bartenstein DW, Barry W, Overmoyer BA. An open label, phase II trial of continuous low-irradiance photodynamic therapy (CLIPT) using verteporfin for the treatment of cutaneous breast cancer metastases [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-04-01.