Selenium in the Treatment of Arsenic Toxicity and Cancers (SETAC)
Context: Approximately 100 million people throughout the world consume water contaminated with arsenic at levels above carcinogenic thresholds, including 40 million in Bangladesh alone, with up to one-fourth of deaths attributed to arsenic exposure in the worst-affected regions. There are no proven therapies for treating chronic arsenic toxicity or for preventing arsenical cancers. Selenium has been known to counter arsenic toxicity in a variety of animal models. The investigators have recently shown in animals and humans that this effect is mediated by the formation of [(GS)2AsSe]- , the seleno-bis(S-glutathionyl) arsinium ion, which is then rapidly excreted via the hepatobiliary system. Concurrently, two Phase II studies in China and Bangladesh have suggested clinical benefit to selenium supplementation in arsenicosis patients.
Objective: To assess whether daily selenium supplementation counters arsenic toxicity in patients exposed to drinking water arsenic. If proven effective, selenium supplementation might be safely and cost-effectively implemented in the worst-affected localities.
Drug: sodium selenite
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
|Official Title:||Selenite in the Detoxification of Arsenic and the Prevention of Arsenical Melanosis and Cancers Amongst Bangladeshi Arsenicosis Patients: A 48-week, Randomized, Double-blinded, Placebo-controlled Phase III Trial|
- changes in arsenical melanosis [ Time Frame: 0 weeks (baseline), 24 weeks, and 48 weeks (end) ] [ Designated as safety issue: No ]Arsenical melanosis was recorded in 4 quadrants of each patients' torsos using the Dermlite epiluminescence microscopy system. The images were then scored in a blinded, randomized fashion by a dermatologist.
- changes in blood arsenic levels [ Time Frame: week 0, week 24 and week 48 ] [ Designated as safety issue: No ]The levels of arsenic in patients' blood was measured to determine whether intervention had a differential effect.
- changes in urinary arsenic levels [ Time Frame: week 0, week 24 and week 48 ] [ Designated as safety issue: No ]The levels of arsenic in patients' urine was measured to determine whether intervention had a differential effect.
|Study Start Date:||December 2006|
|Study Completion Date:||April 2009|
|Primary Completion Date:||April 2009 (Final data collection date for primary outcome measure)|
Placebo Comparator: Placebo
Patients who receive control (placebo)
dicalcium phosphate capsule matching the selenium capsule in appearance; consumed once daily with breakfast
Active Comparator: Selenium
Patients who receive treatment (selenium)
Drug: sodium selenite
200 micrograms (µg) of selenium in the form of sodium selenite; capsule form consumed once daily with breakfast.
|SETAC Trial Field Office|
|Kalibari town, Chandpur District, Bangladesh|
|Principal Investigator:||Julian E Spallholz, PhD||Texas Tech University|
|Principal Investigator:||Paul F La Porte, PhD||Pritzker School of Medicine, The University of Chicago|
|Principal Investigator:||Selim Ahmed, MBBS, FCPS||Institute of Child & Mother Health, Dhaka, Bangladesh|