EFFICACY, SAFETY AND COST ANALYSIS OF SUBCUTANEOUS VS INTRAVENOUS RITUXIMAB IN PATIENTS WITH DIFFUSE LARGE B-CELL LYMPHOMA TREATED WITH RCHOP

Introduction: Rituximab (R) in combination with cyclophosphamide, doxorubicin and prednisone (R-CHOP) is the standard of care for patients (pts) with diffuse large B-cell lymphoma (DLBCL). A subcutaneous (sc) formulation that provides a fixed dose of R is being tested in a number of studies. Results indicate that the pharmacokinetics is not inferior and the response rates comparable to those obtained with the intravenous (iv) formulation. In August 2014, the Italian Medicine Agency (AIFA) approved the sc formulation for follicular lymphoma and DLBCL. We performed a retrospective analysis at our Centre in pts with DLBCL treated with RCHOP. The aim was to evaluate the costs of the 2 different formulations of R (sc vs iv) combined with CHOP and the efficacy in terms of complete response (CR) rates and toxicity. Meth- ods: We collected data from 71 consecutive pts with untreated DLBCL who received 6 cycles of RCHOP plus 2 doses of R between January 2014 and January 2016; 35 pts received iv R (375mg/mq) and 36 sc R (1400 mg) from May 2015. We compared the direct costs of the 2 for- mulations of R, the rate of CR and of adverse events (AEs) of the two subgroups of patients. Univariate analysis was used to evaluate efficacy and toxicity. Results: The clinical characteristics were well balanced be- tween the iv and sc RCHOP groups: mean age 61 years in both groups, with a mean BSA of 1.8 (1.4-2.2); IPI score ≥3, 20% vs 30%; Ann Arbor stage III-IV, 62% vs 69%. There was no significant difference in terms of efficacy: the CR rates were 30/35 (85%) and 29/36 (83%), p=0.177, respectively. Grade ≥3 AEs (45% vs 47%) were almost all hematologic (90% in both groups) and the most common AE was grade 3/4 neu- tropenia in both groups. The cost of the treatment was 472.227€ for the iv R group and 449.870€ for sc R group; with a decrease of 4.73% only of the direct costs of R. In addition, the calculated infusion time for the sc RCHOP was 135 min compared to 240 min for the iv RCHOP; this translated into a 44% chair time reduction. Conclusions: In our analysis, the use of a sc formulation of R allowed a gain of 22.357€ in terms of only direct costs compared to the schedule with iv R, with comparable response rates and similar safety profile. Given the shorter delivery time, the sc formulation could also improve pts’ comfort and reduce the burden on health care resources. Finally, the reduction in required chair time allows for a greater number of pts to be treated daily.