The FDA said in a release that it is aware of reports of infants born with serious congenital anomalies, including microtia and cleft lip and palate, following exposure to mycophenolate mofetil (MMF) during pregnancy.
MMF, the active drug substance in CellCept, is an ester of the active metabolite mycophenolic acid (MPA), the active drug substance in Myfortic. CellCept is produced by Roche, while Myfortic is a drug created by Novartis.

CellCept is approved to prevent heart, liver and kidney transplant rejection, while Myfortic is approved to prevent kidney transplant. In most cases, the mothers were taking MMF following an organ transplant to prevent organ rejection. However, some mothers taking MMF were being treated for immune-mediated conditions such as systemic lupus erythematosus (SLE) and erythema multiforme. Treatment began before their pregnancies and continued into the first trimester or until the pregnancy was detected.

The labeling for both MMF and MPA was revised in November 2007 to change the Pregnancy Category to "D" (positive evidence of human fetal risk, but potential benefits may warrant use of the drug in pregnant women despite the potential risk) and to add these findings about the risk of early pregnancy loss and congenital malformations to the boxed warning.

The Food and Drug Administration spokesman Christopher Kelly explained that the agency decided to issue a new alert about these two drugs because some physicians who prescribe the drugs for unapproved uses may not have noticed the labeling change.

Last month the FDS announced it was reviewing data concerning a link between these two drugs used to prevent organ rejection and the developmental of progressive multifocal leukoencephalopathy (PML).

PML is a rare but life-threatening disorder that affects the central nervous system. The disease usually occurs when a patient’s immune system is suppressed to disease or medicines. PML is caused by activation resulting from unknown factors of a polyomavirus, also known as the JC virus, which is latent in 80 percent of healthy adults.