Health Economic Burden and Treatment-Based Survival for Current Follicular Lymphoma Treatment Practice in Japan Using a Nationwide Retrospective Claims Database
Authors: Tsutsue Saaya , Tobinai Kensei , Yi Jingbo , Crawford Bruce 
Published: November 2019

ABSTRACT
Introduction: Follicular lymphoma (FL) is an indolent form of non-Hodgkin lymphoma (NHL), which accounts for 20-30% of all NHL cases. In most patients, FL is diagnosed in advance stages, mild disease progression and long treatment period that may incur a great burden to patients and healthcare system. However, to our knowledge there is no comprehensive analysis which have been done in the real world setting in Japan. Therefore, we conducted a retrospective claim database study to elucidate the lines of treatment patterns as well as the associated healthcare resource utilization (HCRU), and 3- and 5-year overall survival (OS) among 3,593 Japanese patients with a median age of 65.0 years.
Methods: This retrospective study analyzed data from the Medical Data Vision (MDV) database for patients diagnosed with FL (ICD-10: C82). The MDV database is an electronic health records-based database comprised of anonymized inpatient and outpatient data covering over 25 million patients and over 374 Japanese hospitals, approximately 22% of acute phase hospitals, including 187 cancer therapeutic facilities. Patients who received treatment during the identification period from 1 October 2008 to 31 December 2017 were selected. Patients were required to have data for at least 6 months before the first treatment date (ie, patient index date) and at least 12 months after the index date (unless they died). Costs were converted from Japanese yen to US dollars using the exchange rate based on January of each year of service. For 3- and 5-year OS, patients who had a record of death in their hospital discharge were counted as an event, otherwise they were censored at the latest of: end of patient record, end of data availability, or end of the 3- or 5- year period.
Results: A total of 3,593 patients with FL met the inclusion criteria of which 51.2% was female patients. Of these 3,593 patients who met the inclusion criteria, 3,004 patients (83.6%) received rituximab-based (R) therapy as index treatment, of which 1309 (36.4%) of patients received R-CHOP. During the subsequent lines of therapies, patients received heterogeneous treatment regimens (fig 1). Overall, the average healthcare cost during follow-up period was $67,557.40 for all FL patients, ranging from $39,340 (immunotherapy, targeted therapy, or hormone therapy without R) to $ 95,095 (other R-based chemotherapy). The average number of outpatient visits during follow-up for all FL patients was 51, ranging from 44.6 to 55.1 for each treatment group. There were 3,394 (94.5%) patients who had at least one hospitalization during follow up period. Among those who had at least one hospitalization, the average number of hospitalizations was 3.8 for all FL patients, ranging from 2.5 to 4.6 for each treatment group. The average number of days of hospitalization during follow-up was 74.5 for all FL patients, ranging from 31 to 110.4 for each treatment group. 85 (2.4%) FL patients received a stem cell transplant (SCT) during follow-up at the age under 79 years, with other R-based therapies having the highest percentage (7.6%). There were 346 (9.7%) FL patients receiving radiation therapy, ranging from 8.1% (other treatment groups) to 24.1% (immunotherapy, targeted therapy, or hormone therapy without R).
There were 337 deaths (9.4%) recorded within 3 years and 400 (11.1%) within 5 years of index treatment. The median Kaplan-Meier OS was not reached for most analysis groups due to the overall high survival rates. When comparing overall survival by index regimen group, chemotherapy without R consistently had worse survival, especially compared to R-based regimens (fig. 2).
Conclusions: Patients with FL in Japan received diverse treatment regimens and multiple lines of therapy with relatively high survival rates. Majority of patients have received R-based therapies and have shown longer survival rates compared to those who have received chemotherapy without R. This is the first study to clarify lines of treatment patterns using retrospective claims database and treatment group-based OS in FL patients in Japan, which will give clinical insights of the landscape of daily practices and the associated real world health economic burden for patients, clinicians and healthcare providers to support their better decision makings.

Disclosures
Tsutsue: Celgene: Employment. Tobinai:Solasia: Honoraria; Mundi Pharma: Consultancy, Honoraria, Research Funding; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding; Yakult: Honoraria; AbbVie: Research Funding; Meiji Seika: Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; HUYA Bioscience: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Eisai: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Verastem: Honoraria; Kyowa Kirin: Honoraria, Research Funding. Yi:Celgene: Consultancy. Crawford:Celgene: Consultancy.