Low initial trough concentration of rituximab is associated with unsatisfactory response of first-line R-CHOP treatment in patients with follicular lymphoma with grade 1/2

Rituximab Concentration Varies in Patients With Different Lymphoma Subtypes and Correlates With Clinical Outcome

“…In Mangel's study (Mangel et al, 2003), no correlation was observed between serum rituximab levels and clinical benefit in 6 MCL patients in an autologous stem cell transplant setting. However, in the induction treatment setting, a statistically significant correlation was found between the serum rituximab concentration and clinical response in a number of studies for patients with DLBCL (Tout et al, 2017;Liu et al, 2021) and FL (Liu et al, 2020), which were consistent with the results in this study. The different treatment setting could be the main reason for this contradicts.…”

“…A similar phenomenon was observed in the current study in that the MCL patient group had much lower rituximab concentrations (median, 10.28 μg/ml) than the patients in the other lymphoma subtype groups, and this level was also lower than that of FL patients (median, 18.49 μg/ml) in our previous study (Liu et al, 2020), who were subjected to the same dosing interval. Mangel et al (2003) postulated that perhaps more active non-specific clearance accounts for the lower levels of rituximab observed in patients with MCL.…”

“…On the day of treatment with rituximab, samples were obtained immediately before and 0-3 h after each infusion. Plasma levels of rituximab and human antibodies against rituximab were determined through a solid phase enzyme-linked immunosorbent assay (ELISA), as previously described (Liu et al, 2020).…”

“…For individuals with chronic lymphocytic leukaemia, the recommended rituximab dose is 500 mg/m 2 , because in that disorder, cells express lower levels of CD20, and the disease is associated with higher levels of free circulating CD20 antigen than other B-cell non-Hodgkin's lymphoma (O'Brien et al, 2001). Moreover, high variability in patient outcomes after rituximabbased treatment could be partially explained by the individual variation in rituximab concentration that was observed in individuals with FL and DLBCL (Berinstein et al, 1998;Golay et al, 2013;Tout et al, 2017); higher rituximab concentrations were associated with better clinical response, and some patients did not achieve an effective concentration at a dosage of 375 mg/ m 2 (Liu et al, 2020). Furthermore, in Pfreundschuh's study (Pfreundschuh et al, 2017), elderly males who received an initial dosage of 500 mg/m 2 rituximab displayed improved progression-free survival (PFS) and overall survival (OS), and other trials (Murawski et al, 2014;Strussmann et al, 2017) in DLBCL confirmed that initial dense-dose rituximab provided a promising response for patients with a poor prognosis.…”

Rituximab exposure‐response in triweekly R‐CHOP treatment in DLBCL: A loading dose is recommended to improve clinical outcomes

“…Plasma levels of rituximab were determined by the commercial Matriks Biotek kit (SHIKARI Q-RITUX) through solid phase enzyme-linked immunosorbent assay. 16…”