PREVENTION OF TOXICITIES INDUCED BY RADIATION
Radiation, or radiotherapy, is a common treatment for various cancers that uses high doses of radiation to kill cancer cells. This high dose of radiation indiscriminately destroys healthy tissue in the process resulting in devastating and life-threatening conditions. Further, the amount of radiation is dose limited and patients are often prevented from receiving subsequent radiotherapy based on lifetime dose limitations.
Toxicities associated with radiotherapy include dermatitis (inflammation of the skin), depression, fatigue, erectile dysfunction, cardiovascular disease, mucositis (oral ulceration/inability to swallow), infertility, enteritis (inflammation of the intestine), pneumonitis (inflammation of the lung), secondary malignancy (cancer), and many more.
Preclinical Evidence Supporting TEMPOL’s Protection Against Radiation-Induced Toxicities
TEMPOL reacts with potentially toxic oxygen species, produced during therapeutic radiation treatment – including superoxide (O2.-), hydroxyl radical (.OH), and secondary radicals produced by the oxidation of biological macromolecules, including lipid radicals that propagate lipid peroxidation reactions (Jones, 2015) Cancer cells are not protected because TEMPOL is reduced to an inactive hydroxyl amine therein.
TEMPOL protects normal cells against radiation-induced chromosomal abberation induction (DeGraff, et al 1992) and double-stranded DNA breaks (DeGraff et al, 1992, Augosto, et al, 2008)
Due to TEMPOL’s overwhelming success as a radioprotector, the FDA has granted Matrix Biomed, Inc. Phase III approval for the prevention of radiation induced dermatitis with the TEMPOL gel.
- Objective: Prevention of Radiation Induced Skin Toxicity
- Stage: Phase III
- Study Population: Women with Breast Cancer Receiving Radiation Treatment
- Number of Patients: 500 (1:1 Randomization TEMPOL Topical Gel v Placebo)
- Primary Endpoint: Reduction is the incidence of Severe Radiation-Induced Skin Toxicity based on the RTOG Scoring System
Noteworthy: During the Phase II study, no TEMPOL treated patient developed severe radiation dermatitis. Based on literature and previous clinical studies, approximately 25% of participants would be expected to experience severe dermatitis characterized by severe swelling, confluent, moist desquamation greater than 1.5 cm diameter, and/or skin necrosis or ulceration. By completely removing the incidence of severe dermatitis, the FDA considered the results very favorably and approved TEMPOL for phase III studies.