Patient Quality of Life (QOL) In Nonsplenectomized Immune Thrombocytopenia (ITP) Patients Receiving Romiplostim or Medical Standard of Care (SOC)

Romiplostim, a novel peptibody that increases platelet production, is approved for the treatment of adult chronic ITP. Positive results from a previous study suggest the potential that romiplostim could improve QOL (Kuter, ASH 2009, #679). Immunosuppressive therapies for ITP may adversely affect patient QOL. We compared QOL between SOC- and romiplostim-treated pts from this study, and examined changes among subgroups of pts.

This was an open-label study of nonsplenectomized ITP pts who were randomized to receive either once-weekly subcutaneous romiplostim or SOC. SOC treatments were prescribed according to standard institutional practices or therapeutic guidelines. QOL was assessed using the ITP patient assessment questionnaire (ITP-PAQ; consisting of 10 scales scored from 0–100); assessments were taken at baseline and every 12 weeks to week 52. Scores were also assessed for subgroups of pts with the following favorable outcomes: (1) did not receive blood transfusions or rescue medications, (2) did not experience bleeding ≥ grade 2, (3) did not experience a platelet count < 20 × 10⁹/L. Mean and change from baseline scores were computed, and differences between treatment groups and among subgroups were assessed. Clinical significance was determined from the minimal important difference (MID), which is the smallest difference in QOL considered clinically meaningful (Mathias et al., CMRO 375-83) and corresponds to an 8–15 point improvement depending on the scale. The time to MID was also computed for Symptoms, Bother, Activity and Fatigue.

In total, 157 pts were randomized to receive romiplostim and 77 to receive SOC. At baseline, no statistically significant differences were found between the romiplostim and the SOC group on any of the scales. At 52-weeks, change scores for both the romiplostim group and the SOC group showed improvements that exceeded the MID with the exception of Fatigue in both arms and Activity in the SOC arm (Table). In comparison to the SOC group, the romiplostim group showed statistically significantly greater improvements from baseline for all scales except Fatigue. The differences between treatment groups did not exceed the MID for any of the scales. The time to MID was significantly shorter for the romiplostim group vs the SOC group on the Symptoms and Bother (p<0.0001), and Fatigue (p=0.0068) scales. Among subgroups with favorable clinical outcomes, statistically significantly greater improvements were seen in the romiplostim group compared with the SOC group in many of the scales. The difference between treatment groups exceeded the MID only once: romiplostim-treated pts in the subgroup who did not experience platelet counts < 20 × 10⁹/L had a 12.6 point greater improvement in Activity score compared to SOC pts.

Nonsplenectomized ITP pts receiving romiplostim had greater improvements in QOL than pts receiving SOC. These improvements were maintained even among subgroups of pts with favorable clinical outcomes. However, the open-label study design limits our ability to make conclusions, and the clinical significance of the QOL improvements in romiplostim-treated pts relative to those receiving SOC remains uncertain.

Kuter:Amgen Inc.: Consultancy, Research Funding; GlaxoSmithKline: Consultancy, Research Funding; ONO: Consultancy; Pfizer: Consultancy, Research Funding; Shionogi: Consultancy, Research Funding. Mandanas:Celgene: Honoraria; Genentech/Roche: Honoraria; Amgen Inc.: Honoraria; GlaxoSmithKline: Speakers Bureau; Pfizer: Speakers Bureau; Genomic Health: Speakers Bureau. Giagounidis:Celgene: Consultancy, Honoraria. Wang:Amgen Inc.: Employment, Equity Ownership. Mathias:Amgen Inc.: Consultancy. Deuson:Amgen Inc.: Employment, Equity Ownership.