e15684 Background: Light Infusion Therapy™ (Litx™) consists of the light-activated drug, talaporfin sodium (LS11®; mono-L-aspartyl chlorin e6), activated by a single-use, disposable device with an array of light-emitting diodes (LEDs). We evaluated talaporfin in combination with the light source in a phase 1/2 safety and efficacy trial in patients with hepatocellular carcinoma (HCC). To the best of our knowledge, this is the first clinical study of light-activated drug therapy in patients with HCC. Methods: Patients had confirmed primary HCC, 1–3 liver lesions, an ECOG score of 0–2, and a life expectancy of at least 16 weeks. Prior treatment failure with locally ablative techniques was allowed. The light-activated drug used in the study was talaporfin, a semi-synthesized, water-soluble chlorin e6 derivative. The LED device used in this study was a 1.5 mm diameter linear array of LEDs with a 25 mm emitting length at a wavelength of 664 nm. Patients underwent image-guided percutaneous placement of 1–4 LED device(s) using either local anesthesia or conscious sedation. The LED devices were used in single lesions or in multiple lesions. Following intratumoral placement of the LED devices, patients received talaporfin at 1 mg/kg IV bolus. Delivery of light energy commenced 15 min to 1 hr following drug administration with a total illumination time of 2.8 hrs. Results: The enrolled study group consisted of 8 patients. All 8 patients completed the week 4 assessment and were evaluated for tumor response. One (12.5%) out of 8 patients in this study was reported to have a complete response at week 4. Five patients (62.5%) were reported to have stable disease, and another 2 patients (25%) showed progressive disease. During the study, 7 patients reported a total of 16 treatment-related adverse events. There were no treatment-related adverse events that were greater than grade 2. At 1 year post treatment, all patients were alive. Conclusions: The results from this phase 2 study demonstrated that the therapy was safe for the treatment of HCC. A subsequent randomized controlled phase 3 pivotal trial is nearing completion and is designed to prove efficacy in patients with inoperable HCC. [Table: see text]