Rituxan and Infections

Good news on a potential side effect of Rituxan: according to a small German study of patients in a single treatment center, Rituxan doesn't seem to increase the likelihood of a patient developing infections.

Rituxan works by targeting the protein CD20 on B cells, the type of white blood cell that (when being normal) works to keep out invaders, or (when being pains the rear) get all cancery and give you Follicular Lymphoma. Rituxan just goes for the CD20 -- it doesn't care if it's on a normal cell or a lymphoma cell.

The problem, of course, is that if Rituxan is wiping out normal cells, then those cells can't do their job of fighting off invaders. Thus, Rituxan can do a good job (warding off cancer) while doing a bad job (keeping the immune system from doing one of its jobs, and thus inviting infections).

This study looked at 125 patients with various types of lymphoma (80 of them had Follicular Lymphoma), who were given Rituxan as a first treatment -- either Rituxan by itself, or as part of a chemotherapy combination (lots of R-CHOP, some R-Bendamustine, and a few others, incluidng some funky German chemotherapies).

The article breaks down the number of patients with the different types of lymphomas, the numbers of patients who received which treatments, and the number and types of infections they developed. All very interesting.

The bottom line, though is this: there was no statistical significance to the number and type of infections. In other words, there is no evidence that receiving Rituxan increases the likelihood of developing an infection.

This is good news. While this has always been a concern, the authors note that very few actual studies have looked to see if the concern should really be a concern.

A couple of important things to consider, though: first, the study looked back at patients who received Rituxan between 2000 and 2005, before Rituxan Maintenance was used widely. It's possible that receiving Rituxan for a prolonged amount of time (after that initial 4 or 6 or 8 weeks) could have a stronger impact on the immune system. Makes sense -- while those first few doses last for a few months, a common course of R-Maintenance could see the effects go for more than 2 years. That might have a greater impact on the immune system, and encourage more infections.

The other important issue: it seems like infections are more likely for people who take Prednisone as part of their chemo (that's the P in CHOP). So that's something to keep an eye on, too.

Overall, though, it seems like good news. From my personal experience, I didn't really have any significant infection issues after my Rituxan. But I was a study of 1, not 125. Good to see it all played out in a broader, more serious study.