I don't mean to disparage the drug, but I find some of the information from the pharmacology review to be very interesting.
For example, the pharmacology reviewer for the FDA did not recommend approval based on unresolved safety issues with regards to potential cancer risk and renal fibrosis:
It's quite a long read, but check out this quote from page 2:
"The pharm/tox reviewer did not recommend approval of this NDA based on the
nonclinical data. Renal toxicity in nonclinical species was the specific reason for
this conclusion. The pharm/tox supervisor agreed that the nonclinical studies
demonstrate the potential for renal toxicity."http://www.accessdata.fda.gov/drugsatfd ... PharmR.pdf
There are several instances of cell dysplasia in multiple animal models
This actually did make it onto the package insert as well:
"Carcinogenicity studies of dimethyl fumarate (DMF) were conducted in mice and rats. In mice, oral administration of DMF (25, 75, 200, and 400 mg/kg/day) for up to two years resulted in an increase in nonglandular stomach (forestomach) and kidney tumors: squamous cell carcinomas and papillomas of the forestomach in males and females at 200 and 400 mg/kg/day; leiomyosarcomas of the forestomach at 400 mg/kg/day in males and females; renal tubular adenomas and carcinomas at 200 and 400 mg/kg/day in males; and renal tubule adenomas at 400 mg/kg/day in females. Plasma MMF exposure (AUC) at the highest dose not associated with tumors in mice (75 mg/kg/day) was similar to that in humans at the recommended human dose (RHD) of 480 mg/day."http://www.accessdata.fda.gov/drugsatfd ... 063lbl.pdf
However, to my knowledge, these issues have not been soon in humans during the clinical trials CONFIRM and DEFINE and have not been seen so far post-market...yet.
There are no specific guidelines for screening for potential renal complications