Nicotinamide Chemoprevention for Keratinocyte Carcinoma in Solid Organ Transplant Recipients - Pivotal Trial

This study is testing whether a vitamin B3 supplement called nicotinamide can prevent skin cancer in people who have received an organ transplant. People on anti-rejection medications after transplants have a much higher risk of developing skin cancers, and this trial aims to reduce that risk. **You may be eligible if...** - You are 18 or older - You received a kidney, liver, heart, or lung transplant at least two years ago - You have had at least one confirmed skin cancer (squamous or basal cell type) in the past - You are currently taking anti-rejection medications that include cyclosporine or tacrolimus - You are able to attend follow-up visits **You may NOT be eligible if...** - You currently take high-dose nicotinamide or niacin supplements (250 mg or more daily) - You have untreated skin cancer right now (you may enroll after treatment) - You had a biopsy-confirmed organ rejection episode in the last 3 months - You have active liver or severe kidney disease - You have had a serious cancer (other than skin) in the past 5 years - You are pregnant or breastfeeding - You take carbamazepine or primidone (seizure medications) - You are allergic to nicotinamide Talk to your doctor to see if this trial is right for you.