Photodynamic Therapy for the Prevention of Lung Cancer
Description
Design:
PEARL is a phase III multicentre 2:1 randomised controlled trial, with an incorporated phase II (pilot) component. All patients consented/registered onto the trial will have an autofluorescence bronchoscopy (AFB) to check for the presence of high grade lesions (HGLs) in the lung, as verified by tissue biopsy. Only patients with one or more histologically confirmed lung HGL will be randomised to receive either photodynamic therapy (PDT) treatment and surveillance, or surveillance alone.
Treatment:
Treatment-arm patients will receive two courses of PDT treatment using the photosensitiser drug Fotolon®. Fotolon®, which preferentially accumulates in HGLs, is first administered via IV infusion. Patients then undergo bronchoscopy during which their HGLs are irradiated with red light (via non-heat emitting laser). Red-light activation of the photosensitiser causes chemical transformation of the cells and cell death. Follow up in both arms consists of AFB surveillance at 6 and 12 months post-randomisation, then every 6-12 months, with CT scanning of the thorax and spirometry at 12, 24 and 36 months post randomisation.
Key inclusion/exclusion criteria:
Histopathological confirmation of ≥1 lung HGL. Patients with HGLs which have remained stable on AFB surveillance for ≥5 years are excluded. Previous radiotherapy to the central airways, porphyria or hypersensitivity against porphyrins, chlorine-e6-trisodium salt or photosensitivity is also not permitted.
Duration of recruitment:
Anticipated recruitment for phase II is 1 year (12 months), and an additional 2 years (24 months) for the phase III.
Aim
The overall aim of the phase II pilot is to demonstrate a response to PDT in at least 20% of patients treated with PDT. This will be used as an efficacy signal to determine whether the trial will continue into phase III. Response will be measured by regression of high grade lesions (HGLs) to either low grade lesions (LGLs), or to normal epithelium at 6 months post treatment (blind assessment). The overall aim of the phase III is to show that the time period over which HGLs progress to invasive lung cancer is significantly longer when treated with PDT compared to surveillance alone.