Long-Term Safety of Rituximab Save

Rituximab has been used for years with good efficacy, but with several safety concerns. Van Vollenhoven and colleagues have published the cumulative clinical trial safety experience of RTX wherein 3595 patients 1–20 (average - 4) courses over 11 years [14,816 patient-years (PY)]. Nearly one-third of patients had more than 5 years of followup.

Overall, no new safety risks were identified over 11 years of observation. There were no cases of tuberculosis and opportunistic infections were rare. The serious infectious event (SIE) rate was 3.76/100 PY was similar to that seen in the previous 9.5 years (3.94/100 PY and 3.26/100 PY, respectively). Low IgM seen in 24% and low IgG (>4 mos) was seen in 4% of RTX patients.  While IgA and IgM levels falling below the lower limits of normal did not predict SIE, low IgG levels (either before or after RTX) were at increased risk for SIE.  Nonethless, SIE rates were similar before and after falls in serum immunoglobulin levels.