Novantrone Warnings Update

FDA has just posted a "Dear Healthcare Professional" letter advising of updates to the boxed [safety] warning for Novantrone. As Serano and FDA acknowledged in March, the risk of "diminished cardiac function" [heart damage] may occur much earlier in treatment than previously thought, and physicians are now advised to asses patient's cardiac function before EVERY dose of Novantrone. On the flip side, there's also new evidence that shows potentially fatal congestive heart failure may occur months to years after Novantrone therapy ends.

The letter goes on to point out that cases of secondary acute myleogenous leukemia (AML) have also been reported in Novantrone users. "Because the number of MS patients exposed to NOVANTRONE® in post-marketing is unknown and because spontaneous reporting of adverse events can be subject to under-reporting, it is not possible to determine incidence—or relative risk to an MS patient—of developing secondary AML." (And why should there be any wide-spread post-marketing surveillance, one might ask, if it would turn up potentially disturbing information?) However, the letter does go on to note that the Registry to Evaluate NOVANTRONE® Effects in Worsening MS (RENEW), which has been tracking 505 Novantrone patients since 2001, has reported one case of secondary AML, involving a 52-year-old female with secondary progressive multiple sclerosis. This patient had no other known risk factors for leukemia and no concomitant potentially cytotoxic drugs were listed. For the moment, at least, her leukemia is in remission. Still, from my standpoint, one case in 500 over a four year period is way too many cases for comfort.