SKIN REACTIONS WITH SUNITINIB

A warning about serious skin reactions, some of which have been fatal, has been issued in Canada for sunitinib (Sutent, Pfizer).

These serious skin reactions have been "very rarely reported," but some cases have been fatal, notes a letter issued to health professionals by Pfizer Canada, which is endorsed by the government agency Health Canada. The product labeling has been updated to include a note that cases of toxic epidermal necrolysis (TEN) and Stevens–Johnson syndrome (SJS) have been reported in patients taking sunitinib, mostly in the postmarketing setting.

Sunitinib is approved for use in the treatment of metastatic renal cell carcinoma, gastrointestinal stromal tumor, and pancreatic neuroendocrine tumors.

If a patient on sunitinib is showing signs or symptoms of either TEN or SJS, the drug should be discontinued. If TEN or SJS is confirmed, treatment must not be restarted, the letter notes.

This appears to be the first report of TEN and SJS being associated with sunitinib.

The current product monograph mentions skin adverse reactions, including rash, dry skin, hand–foot syndrome, skin discoloration, erythema, pruritus, and pyoderma gangrenosum. However, it does not list either TEN or SJS.

Nine Cases in Total, 2 Were Fatal

The letter notes that the association of TEN and SJS with sunitinib was noted in a review of currently available safety data from published literature, the Pfizer global safety database containing clinical trial serious adverse events and postmarketing reports, the US Food and Drug Adminitration Adverse Event Reporting System database, and the Canada Vigilance database. Reporting rates determined on the basis of spontaneously reported postmarketing adverse effects are generally presumed to underestimate the risks associated with health product treatments, it adds.

Of an estimated 214,848 patients exposed to sunitinib between January 26, 2006 and April 30, 2013, there were 4 reported cases of TEN (2 of which were fatal) and 5 reported cases of SJS internationally, although diagnosis was not confirmed in all cases.

The letter also notes that there have been no Canadian cases reported as of April 30, 2013.