Real-World Experience with Anemia and Iron Overload Therapies in Myelodysplastic Syndromes (MDS): Treatment Sequence, Duration, and Patient Compliance
Authors: Huey Krystal , Zhao Ruizhi , Gu Tao , Le Trong Kim , Jones Shalon , Bueno Luciana , Tang Derek 
Published: February 2021

Introduction: MDS is a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis resulting in severe cytopenia, predominantly anemia. Therefore, some patients (pts) develop iron overload. Few published studies have reported evidence on the treatment patterns of existing anemia therapy and iron chelation therapy (ICT) in pts with MDS. This study analyzed treatment sequencing, compliance, and duration of anemia therapy and ICT in pts with MDS in a real-world setting.
Methods: Pts aged ≥ 18 years with MDS (identified by International Classification of Diseases 9th [ICD-9] or 10th [ICD-10] Revision diagnosis codes), and with ≥ 1 inpatient or ≥ 2 outpatient MDS claims from the IBM MarketScan (formerly Truven Health) Commercial and Medicare Supplemental Plan Claims databases, were included in this retrospective analysis. The index date was date of the first MDS diagnosis between January 2007 and October 2019. Pts had continuous pharmacy and medical benefit enrollment for ≥ 6 months pre- and post-index date. MDS-related anemia and iron overload treatment data were collected from the index date until progression to acute myeloid leukemia, end of continuous enrollment, or end of the study period, whichever occurred first. Outcomes included treatment duration and patient compliance (measured by proportion of days covered [PDC]), stratified by line of therapy (LOT). All treatments initiated within 30 days were considered the treatment regimen for a specific LOT; a new LOT was defined as initiation of a new treatment regimen. As red blood cell transfusions (RBCT) do not have a recommended treatment interval per United States Prescribing Information (USPI), RBCT was not considered in the calculation of PDC. PDC ≥ 0.8 was considered compliant to therapy. Descriptive statistics were used to summarize the data.
Results: The median age of 16,706 pts with MDS in the overall cohort was 73 years (range 18-106); 8,470 pts (50.7%) were female; 66.4% were on Medicare at enrollment. Median follow-up was 25.4 months (range 6-159.7). Post-index date, 3,272 pts (19.6%) received RBCT.
Of the 9,187 pts who had first-line (1L) MDS anemia treatments (Table 1), the most frequently used were erythropoiesis-stimulating agents (ESA) alone (49.9%), RBCT alone (11.0%), and chemotherapy alone (10.1%). Of 3,576 pts who received second-line (2L) treatment, ESA alone (22.6%), ESA + RBCT (14.4%), and RBCT alone (11.0%) were used most often. Of the 1,645 pts who received third-line (3L) therapy, ESA alone (20.1%), ESA + RBCT (10.2%), and RBCT alone (6.5%) were used most often. Across all 3 lines of MDS anemia treatments, ESA- and RBCT-based therapies were most used.
Of the 3,576 pts who had ≥ 2 lines of anemia therapy, 1,576 (44.1%) transitioned from 1L ESA-based therapy to 2L ESA-based therapy, 970 (27.1%) transitioned from 1L ESA-based therapy to 2L RBCT-based therapy, and 475 (13.3%) transitioned from 1L RBCT-based therapy to 2L RBCT-based therapy. Of the 1,931 pts who had only 2 lines of anemia therapy, 313 (16.2%) transitioned from 1L ESA alone to 2L ESA alone, 261 (13.5%) transitioned from 1L ESA alone to 2L ESA + RBCT, and 143 (7.4%) transitioned from 1L ESA alone to 2L RBCT alone.
In all treatment lines, deferasirox and deferoxamine were the most frequently used ICT. In 1L, 379/469 (80.8%) pts used deferasirox and 84 (17.9%) used deferoxamine. Thirty-nine pts had 2L ICT. Of the 29 pts who had only 2 lines of ICT, 13 (44.8%) switched from 1L deferasirox to 2L deferoxamine and 10 (34.5%) switched from 1L deferoxamine to 2L deferasirox. Ten pts had 3L ICT.
Overall, median duration of anemia therapy was 11.7 months (range 0-146.9). Median duration of 1L, 2L, and 3L anemia therapy was 6.4, 3.7, and 3.0 months, respectively (Table 2).
For anemia therapy, 1,209/8,575 (14.1%) pts were compliant with therapy and median PDC was 0.31 (Table 2). For ICT, 99/469 (21.1%) pts were compliant; median PDC was 0.37 (Table 2).
Conclusions: A large proportion of pts with MDS received ESAs and RBCT across the first 3 lines of anemia therapy. For pts who had 2 lines of anemia therapy, 48% had 1 of the 3 most common treatment sequences, indicating lack of a standard treatment approach. The short duration of therapy (median 3.0-6.4 months) and poor compliance across different lines of anemia treatments and ICT may reflect suboptimal real-world effectiveness and/or tolerability, showcasing an important unmet need for new treatments.

Disclosures
Huey: Bristol Myers Squibb: Current Employment. Zhao:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Gu:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Le:Bristol Myers Squibb: Current Employment. Jones:Bristol Myers Squibb: Current Employment. Bueno:Bristol Myers Squibb: Current Employment. Tang:BMS: Current Employment, Current equity holder in publicly-traded company.