OBJECTIVES:
I. Determine the long-term efficacy and safety of L-cysteine in the prevention photosensitivity in patients with erythropoietic protoporphyria.
PROTOCOL OUTLINE: This is a phase III study, lasting 3 years; 1996-1999. Patients are administered L-cysteine orally twice daily, 2 capsules with breakfast and 2 with lunch.
Patients fill in questionnaires and diary sheets about their reaction to sunlight exposure, and have blood tested 3 times a year.
Completion date provided represents the completion date of the grant per OOPD records
PROTOCOL ENTRY CRITERIA:
--Disease Characteristics--
Erythropoietic protoporphyria RBC protoporphyrin greater than 50 micrograms/100 dL
--Prior/Concurrent Therapy--
At least 3 months since prior betacarotene or L-cysteine
No concurrent betacarotene
--Patient Characteristics--