Apparent Complete Response of a Treatment Refractory and Recurrent Squamous Cell Carcinoma Lesion to Photochemical Internalization: A Clinical Case Study

Photochemical internalization (PCI) depends on the delivery of sublethal photodynamic reaction to facilitate the work of a chemotherapeutic agent. We discuss our experience in managing a patient with extensive squamous cell carcinoma of the right face and scalp under the TPCS2a‐based bleomycin PCI treatment protocol. In this case, an 84‐year‐old Caucasian received 0.25 mg kg−1 of TPCS2a (Amphinex®, PCI Biotech AS, Oslo, Norway). Surface illumination photochemical internalization was carried out after 4 days, which was preceded by the chemotherapeutic agent infusion (Bleomycin). After one week from the illumination time, tissue necrosis was evident and tumor shrinkage was most noticeable at day 14 postillumination. Follow‐up at 6 weeks continued to show tissue healing and regeneration with no clinical evidence of recurrence. Multiple surgical biopsies were taken at 1 and 3 months postillumination and found to be tumor free. PCI’s depth of effect has been very significant with negligible damage to the collateral tissues. This technology has a role in interventional oncology especially when managing challenging cases. The photochemical internalisation (PCI) intervention was safe and tolerable by all patients when applied in a phase I first‐in‐human trial. The study dealt with a very difficult‐to‐treat group of patients who exhausted all the available treatment options of surgery, radiotherapy and chemotherapy. PCI showed excellent anti‐tumour effect in patients with life expectancy not exceeding few months, yet some of them still lived 4 years after the end of the trial. The PCI‐related adverse events were negligible. The current evidence highlighted the uniform PCI effect causing tumour death on a number of patients with very advanced and recurrent malignancies.