According to researchers from Harvard Medical School, a recent case report suggests that the side effects of Rituxan, a leukemia drug, may impact the autoimmune systems for unborn children.
The findings were published in the August edition of the medical journal Pediatrics, detailing two cases of severe septic episodes that sickened a premature newborn.
Rituxan (rituximab) is a chimeric monoclonal antibody drug that helps the immune system fight specific types of cells, like lymphoma cancer cells. The drug is manufactured jointly by Genentech, Inc. and Biogen Idec, Inc., and was approved by the FDA in 1997 for treatment of non-Hodgkin’s lymphoma and rheumatoid arthritis, resulting in annual sales of about $2.3 billion. It is also approved for the treatment of chronic lymphocytic leukemia (CLL).
The case study indicates that the infants the mother was treated with Rituxan while pregnant, which appears to have affected the baby after birth, resulting in two cases of Enterococcus faecalis infections. The doctors noted that the newborn had critically depressed B-lymphocytes, and undetectable immunoglobulin levels.
In both cases, the episodes occurred when the infant was switched from donor human milk to formula.
“Current evidence of the impact of this medication on the developing fetus is limited, but there is little to suggest that fetal exposure to this medication places an infant at increased risk of immunosuppression and subsequent infection,” the researchers noted. “We postulate that placental transfer of rituximab, prematurity, and the low levels of protective maternal antibodies increased the susceptibility of this patient to sepsis by E faecalis, a resident of the normal gut flora, whereas the secretory (immunoglobulin) in donor human milk may have played a protective role.”
There are concerns about Rituxan’s connection to the deadly brain virus, progressive multifocal leukoencephalopathy (PML), and whether the long-term use of Rituxan, without interrupting the treatment, may be a potential factor increasing the risk of PML.
Some experts have suggested that having patients take time away from the drug’s use, referred to as “drug holidays,” may give their body the opportunity to fight off the virus that causes the infection and reduce the risk of progressive multifocal leukoencephalopathy from Rituxan. There is a black box warning on the label about the possible link between Rituxan and PML.
Progressive multifocal leukoencephalopathy is a viral infection that causes inflammation at multiple locations in the brain, leading to potentially life-threatening brain damage. Symptoms could include loss of vision, impaired speech, paralysis, cognitive decline and weakness. There is no known cure for PML, but the disease can sometimes be slowed or stopped by reducing immunosuppression.