Evaluation of Fenofibrate on Radiation-induced Skin Injury

Fenofibrate is a specific ligand for PPARα, which has been used for the treatment of hypercholesterolemia, hypertriglyceridemia, diabetes and cardiovascular diseases for long time. Fenofibrate reduces low-density lipoprotein (LDL), very low density lipoprotein (VLDL) and triglyceride levels, while increases high-density lipoprotein (HDL) levels. PPARα has also shown antioxidant and anti-inflammatory properties. Fenofibrate confers cytoprotective effect against myocardial ischemia-reperfusion (I/R) injury in rats by suppressing cell apoptosis and ameliorates age-related renal injury through the activation of AMPK and SIRT1 signaling. However, the safety and effectiveness of fenofibrate on the progression of radiation-induced skin injury remain unknown. The purpose of this study is to determine whether topical application of fenofibrate is safe and effective for radiation-induced skin injury.

Radiation-induced skin injury is a significant side effect of ionizing radiation delivered to the skin during cancer treatment as well as a result of other exposure to radiation. The skin is one of radiosensitive organ systems in human body because it is a continuously renewing organ containing rapidly proliferating and maturing cells. Ionizing radiation promotes reactive nitrogen and oxygen species (RNS/ROS) production due to radiolysis of water and direct ionization of target molecules, which result in oxidative damage and skin injuries. It is considered that ~95 % of cancer patients receiving radiation therapy will develop some form of radiodermatitis, including erythema, dry desquamation, and moist desquamation. Radiation-induced skin injury negatively affects the process of radiotherapy and the quality of patients' life. Despite substantial improvements in radiation technology, radiation-induced skin toxicity is still a concerning problem. The purpose of this study is to determine whether topical application of fenofibrate is safe and effective for radiation-induced skin injury.

Fenofibrate should be topically spread three times per day at the irradiated areas, with a concentration of 400 μg/mL for week.

Fenofibrate is dissolved in Saline and topically spread three times per day at the irradiated areas, with a concentration of 400 μg/mL for week.

Toxicity of Fenofibrate was graded using the NCI Common Terminology Criteria for Adverse Events v. 3.0. Any adverse event. Grade 1 attributed to fenofibrate was considered dose-limiting toxicity (DLT).

Skin toxicity of radiotherapy was evaluated every day, once radiation began. Fenofibrate administration was given immediately when Grade 1 dermatitis occurred, and then dermatitis was recorded weekly. The score at the end of radiotherapy was the one of the last week of radiotherapy. The evaluation continued until 2 weeks after the end of radiotherapy with two approaches. The standard was the RTOG score defined by the observers.

Skin toxicity of radiotherapy was evaluated every day, once radiation began. Fenofibrate administration was given immediately when Grade 1 dermatitis occurred, and then dermatitis was recorded weekly. The score at the end of radiotherapy was the one of the last week of radiotherapy. The evaluation continued until 2 weeks after the end of radiotherapy with two approaches. Patient-reported symptom scores was adapted from the Skin Toxicity Assessment Tool as pain, burning, itching, pulling and tenderness in the treatment area.

Inclusion Criteria: Eligible patients had to have a pathologically proven cancer with a planned course of radiotherapy. Normal haematological function (granulocyte count > 1.5 X 109 cells per litre, platelet count > 100 X 109 cells per litre and haemoglobin > 100 g/L) and organ function (creatinine clearance > 50 mL/min) and aspartate aminotransferase/alanine aminotransferase < 2.5 of upper normal limit). Exclusion Criteria: The presence of rash or unhealed wound in the radiation field, known allergy or hypersensitivity to fenofibrate, pregnancy or lactation, history of/current connective tissue disorder and prior radiation to the thorax.

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