Clinical Research Directory

Transbroncheal Novel PDT Peripheral Lung Tumor Ablation With 5-ALA

Sponsor: Taoyuan General Hospital

Summary

Photodynamic therapy (PDT) involves the use of special light-sensitive drugs that are selectively absorbed by cancer cells. When exposed to a specific wavelength of light, these drugs are activated within the tumor cells, triggering a free radical reaction that destroys the cancer cells. Currently, PDT is used in the treatment of early-stage lung cancer in the central airways or for advanced tumors causing airway obstruction. With advancements in medical technology, electromagnetic navigation bronchoscopy (EMB) can now be employed in a hybrid operating room (Hybrid OR) under radiological guidance to direct photodynamic therapy fibers to the tumor site for light therapy. Our research team previously proposed a novel light transmission method, using Sodium Porfimer as the photosensitizer. In the Hybrid OR, electromagnetic navigation bronchoscopy was utilized to infuse Lipiodol into the bronchial tree, enhancing the illumination range through the optical fiber effect. Energy of 630 nm at 200 J/cm (400 mW/500 seconds) delivered through a 3 cm cylindrical laser fiber was deemed safe, with no significant acute complications observed. However, due to the low light dosage, the therapeutic outcome was suboptimal, although one case demonstrated tumor necrosis with no apparent damage to the surrounding lung tissue. A second-phase pilot clinical trial aimed at improving light energy and treatment coverage through a multi-session, multi-angle light exposure model is also proved this method is feasible and safe. In addition to Sodium Porfimer, other photosensitizers are approved for clinical use in photodynamic diagnosis and therapy. For example, 5-Aminolevulinic Acid (5-ALA) has been approved for the treatment of brain cancer surgery. Similar to Sodium Porfimer, 5-ALA is a precursor of heme, and in certain cells (such as cancer cells and reticuloendothelial tissues) where there is a deficiency of the enzyme ferrochelatase, administering large amounts of 5-ALA or Sodium Porfimer leads to the accumulation of Protoporphyrin IX (PpIX). PpIX is a photosensitizer, and when exposed to a specific wavelength of light, it generates oxygen free radicals that destroy cancer cells, thereby producing the therapeutic effect of PDT. We propose this clinical trial to explore the use of 5-ALA as a substitute for Sodium Porfimer in the novel PDT treatment of peripheral lung tumors. Compared to Sodium Porfimer, 5-ALA has the same therapeutic mechanism but a shorter half-life. It can be taken orally 2-4 hours before treatment, requires only one day of light protection post-procedure, and is more cost-effective. 5-ALA (Gliolan) has also been approved by the FDA for photodynamic diagnosis and treatment of brain cancer, and clinical trials in other cancers have demonstrated its safety and feasibility. This phase 0 pilot clinical study plans to recruit six patients with peripheral malignant lung tumors (tumor diameter ≤ 30 mm). 5-ALA (Gliolan) will be used as the photosensitizer, and in the hybrid operating room, electromagnetic navigation bronchoscopy will guide a catheter to the tumor site. Lipiodol (iodized poppy seed oil) will be infused to coat the tumor, enhancing the light exposure range. The first three subjects will undergo a single-session light exposure to assess the feasibility and safety of the procedure. The remaining three subjects will receive multi-session, multi-angle light exposure to further verify the safety and effectiveness of the treatment. The findings from these subjects will serve as a reference for light energy parameters for future phase I clinical trials.

Official title: Development of 5-Aminolevulinic Acid (5-ALA) Based Novel Tranbroncheal Photodynamic Ablation for Peripheral Lung Malignant Tumors

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