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

Abstract

TPS1121 Background: Cutaneous metastases occur in approximately 20% of patients (pts) with metastatic breast cancer (mBC) and can be highly symptomatic and distressing. Radiation is frequently offered, but progression often occurs quickly. 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 powerpack attached to a single-use sterile light patch to deliver a total energy level of 10J/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 pts with cutaneous lesions from mBC. Pts will receive a single IV injection of verteporfin on day 1. The 9x9cm patch with an adhesive border is placed over the treatment site and attached to the CLIPT portable power pack. The pt turns the device on at home 6 hours after the verteprofin injection and it automatically turns off after 24 hours. The pt will remove the patch and return 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. Secondary endpoints include RR at 2, 8 and 12 weeks, toxicity, and quality of life (using FACT-B, a Participant Symptom Scale, and Brief Pain Inventory). Pts who derive clinical benefit may be retreated up to 3 times to the same or different region. Eligible pts 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. If ≥ 3 responses (RR ≥ 20%) are observed, the null hypothesis of RR ≤ 5% will be rejected. At the time of abstract submission, 1 patient has been accrued. Clinical trial information: NCT02939274.