Patient Reported Outcomes Comparison of Chronic Immune Thrombocytopenia (ITP) Patients Switched to Promacta and Nplate

Thrombopoietin receptor agonists (TPO-RA) increase platelets in patients with chronic ITP regardless of splenectomy status. Recommendations for their use are included in several recent guidelines, however there is little published data on their impact on patients' (Quality of Life) QOL in the ‘real-world’ clinical setting. The purpose of this study is to understand how TPO-RAs impact the daily lives of chronic ITP patients and the treatment decisions surrounding the choices of respective agents.

A representative sample of 42 oncology/hematology practices was recruited from a national database encompassing 4 US census regions. The study sponsor was blinded to participating physicians and patients. Physician investigators selected patients who were: ≥18 years with a history of chronic ITP for at least 12 months; currently treated with a TPO-RA for ≥ 4 weeks; with at least 12 months of medical history; and capable of completing the self-administered general health and satisfaction questionnaires (SF-36, Treatment Satisfaction Questionnaire with Medication [TSQM]). Patients were stratified 1:1 on current TPO-RA therapy and further stratified 1:1:1 on immediate prior therapy (corticosteroids, rituximab, or TPO-RA). Part 1 of the study, reported here, includes retrospective chart review and collection of patient reported outcomes whilst on current therapy; Part 2 will consist of a 12-month follow-up.

280 patients were enrolled in Part 1: 130 treated with eltrombopag (prior treatments included 44 previously on corticosteroids, 44 on rituximab and 42 on romiplostim), 150 treated with romiplostim (58 previously on corticosteroids, 48 on rituximab and 44 on eltrombopag). Baseline characteristics of the two treatment cohorts were similar. Statistically significant differences were reported only in the prevalence of comorbid hyperlipidemia (8% eltrombopag, 16% romiplostim) and incidence of ER visits prior to switching (16% eltrombopag, 9% romiplostim). At the time of analysis [June 30, 2011], the median time on treatment with eltrombopag and romiplostim was 11.6 wks (4–93 wks) and 10.6 wks (4–125 wks), respectively. Upon enrollment, patients currently treated with eltrombopag reported statistically higher scores on 3 of 8 domains (energy/fatigue, emotional well-being and social functioning). For these three domains, the mean score difference between treatment cohorts was ±5 points on a 100-point scale, described by the survey developer as ‘patient perceptible differences’ but unlikely to be clinically meaningful. No statistically significant differences were found between treatment cohorts on effectiveness or on side effect domains of the TSQM. Patients currently treated with eltrombopag reported significantly greater global treatment satisfaction and convenience. Convenience domain scores differed between treatment cohorts by 9 points, which may be a minimal important difference (MID). MID has not however been validated as an effective QOL measurement for patients with chronic ITP. Compared to the romiplostim treatment cohort, patients in the eltrombopag treatment cohort were more likely to report greater convenience (OR 3.74, p<0.0001), greater overall satisfaction with treatment (OR 1.63, p=0.034), and less fatigue (OR 0.65, p=0.04) subsequent to the switch in their ITP medication.

In this study of patients switching among therapies for chronic ITP and currently treated with a TPO-RA, there was no evidence of significant differences in the odds of achieving greater patient satisfaction, efficacy, nor reductions in reported side effects between the eltrombopag and romiplostim treatment cohorts. Patients in the eltrombopag treatment cohort reported greater convenience and overall treatment satisfaction.

Wang:GSK: Employment. Dawson:GSK: Employment. Grotzinger:GSK: Employment.