Health Resource Utilization and Costs Associated with the Use of Obinutuzumab-Based Regimens Are Similar to Rituximab-Based Regimens for the First-Line Treatment of Follicular Lymphoma
Authors: To Tu My , Dawson Keith L. , Masaquel Anthony S , Seetasith Arpamas 
Published: November 2019

Introduction: Obinutuzumab (GA101; G), a fully humanized, glycoengineered, type II anti-CD20 monoclonal antibody, is approved in the US for the first-line (1L) treatment of follicular lymphoma (FL). Despite the superior efficacy of G plus chemotherapy (G-chemo) versus rituximab (R) plus chemotherapy (R-chemo) in patients with previously untreated FL demonstrated in the Phase III, randomized GALLIUM study (NCT01332968; Marcus et al. N Engl J Med 2017), information on healthcare resource use (HRU) and real-world costs with G in previously untreated FL patients is limited. The aim of this retrospective cohort study was to examine HRU and costs for G-based and R-based therapies for the 1L treatment of FL using a US claims database.
Methods: The data source for this study was the PharMetrics Plus Commercial Claims database. Adult patients (≥18 years) diagnosed with FL between February 1, 2015 and September 30, 2018 and who began any treatment for FL between February 1, 2016 and September 30, 2018 were included. The first FL treatment date within this selection window was denoted the index date. Patients were required to have ≥12 months of pre-index and ≥3 months of post-index continuous study enrolment, and to have at least one FL diagnosis on or during the 12-month pre-index period. Patients with FL treatment during the 12-month pre-index period were excluded in order to select only previously untreated patients. HRU and cost data during the 1L treatment period were descriptive and categorized by HRU category. Costs are in 2018 US dollars ($) and standardized as per patient per month (PPPM) costs. FL treatment determination was based on National Comprehensive Cancer Network guidelines.
Results: A total of 1584 FL patients with ≥3 months follow up were analyzed. Overall, 26 patients received G-chemo (any combination) as their 1L treatment, 208 patients received R-CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone), 391 patients received R-Benda (bendamustine) and 17 patients received R-CVP (cyclophosphamide, vincristine, prednisone); the remaining 942 patients received other regimens (predominantly other R combinations). Data are reported for those patients who received G-chemo, R-CHOP, R-Benda or R-CVP as 1L therapy (n=642; 281 females, 361 males). Baseline patient characteristics were similar for most variables across treatment groups. Mean (standard deviation [SD]) age was 56.9 (9.7) years and all patients had a Charlson Comorbidity Index (CCI) of ≥2 (mean [SD]: 2.9 [1.9]). Mean (SD) patient follow-up was 14.1 (8.0) months and mean (SD) duration of 1L treatment was 7.0 (5.1) months. A summary of all-cause HRU in patients receiving 1L treatment is provided by treatment category (Figure 1A). The proportion of patients with at least one hospitalization was highest with R-CHOP (23.6%). The proportion of patients with at least one emergency room (ER) visit was highest with R-Benda (29.4%). Mean (SD) total all-cause healthcare costs PPPM during 1L treatment were comparable among G-chemo, R-CHOP and R-Benda (Figure 1B) and lowest with R-CVP ($17,874 [$13,465]). Medical costs (mean [SD]) were highest for R-Benda ($27,716 [$19,610] PPPM) and lowest for R-CVP ($17,373 [$12,908] PPPM). G-chemo was associated with the lowest pharmacy costs ($76 [$107] PPPM) (Figure 1B). Mean (SD) total cost of FL drug treatment PPPM was $16,028 ($9,942) for G-chemo, $11,684 ($6,122) for R-CHOP and $12,108 ($8,794) for R-CVP. Mean (SD) total cost of FL drug treatment PPPM was highest with R-Benda ($21,263 [$15,328]). G-specific drug costs PPPM ($9,643 [$6,071]) were similar to R-specific drug costs ($9,992 [$5,234] R-CHOP; $9,083 [$5,859] R-Benda; and $10,702 [$7,717] R-CVP).
Conclusions: Our results depict real-world HRU and costs associated with G and commonly used 1L regimens for FL. In this setting, HRU and costs associated with G-chemo were comparable with R-chemo, supporting the use of G-chemo as a treatment option for patients with previously untreated FL. The study findings are limited by the small sample size of the G-chemo patient cohort (n=26) and short follow-up; to address this, an updated analysis incorporating a larger number of patients is planned.

Disclosures
To: Genentech, Inc.: Employment, Equity Ownership. Dawson:Roche/Genentech: Equity Ownership; Genentech: Employment. Masaquel:Genentech: Employment; Roche: Equity Ownership. Seetasith:Genentech: Employment, Equity Ownership.