Regranex, a gel used to treat foot and leg ulcers in diabetics, has been linked to an increased risk of cancer death, prompting the drug’s maker to add a new black box warning to the Regranex label. According to the Food & Drug Administration (FDA) patients who use three or more tubes of Regranex are five times more likely to die from cancer as those not exposed to the Johnson & Johnson drug.
Regranex was approved in 1997, and since then, has been used in more than 750,000 patients. Regranex is a recombinant form of human platelet-derived growth factor that has a biologic activity that is much like that produced naturally by the body. Growth factors have been associated with increased tumor growth, and Johnson & Johnson has been monitoring Regranex for any evidence of increased cancers or cancer deaths.
The FDA announced it was beginning a safety review of Regranex in March. According to the FDA notice announcing the black box warning, a retrospective study which compared 1,622 patients who used Regranex to 2,809 otherwise similar patients who did not found a five-fold increase in cancer deaths in the group exposed to three or more tubes of Regranex. No single type of cancer was identified, but rather deaths from all types of cancer combined were observed. While the study found no evidence that Regranex was linked to a higher rate of new cancers, the FDA said that the study has not gone on long enough to rule out this possibility.
The information on the retrospective study is included in the new black box, which has been placed in the “Warnings” section of the Regranex label. The new black box warning advises doctors to use caution when prescribing the drug to patients who have cancer.
“An increased rate of mortality secondary to malignancy was observed in patients treated with three or more tubes of Regranex Gel in a post-marketing retrospective cohort study. Regranex Gel should only be used when the benefits can be expected to outweigh the risks. Regranex Gel should be used with caution in patients with known malignancy,” the boxed warning states.