[Cost per responder associated with romiplostim and rituximab treatment for adult primary immune thrombocytopenia in France]

Cost-Effectiveness of Thrombopoietin Mimetics in Patients with Thrombocytopenia: A Systematic Review

OBJECTIVES

Thrombopoietin (TPO) mimetics are a potential alternative to platelet transfusion to minimize blood loss in patients with thrombocytopenia. This systematic review aimed to evaluate the cost-effectiveness of TPO mimetics, compared with not using TPO mimetics, in adult patients with thrombocytopenia.

METHODS

Eight databases and registries were searched for full economic evaluations (EEs) and randomized controlled trials (RCTs). Incremental cost-effectiveness ratios (ICERs) were synthesized as cost per quality-adjusted life year gained (QALY) or as cost per health outcome (e.g. bleeding event avoided). Included studies were critically appraised using the Philips reporting checklist.

RESULTS

Eighteen evaluations from nine different countries were included, evaluating the cost-effectiveness of TPO mimetics compared with no TPO, watch-and-rescue therapy, the standard of care, rituximab, splenectomy or platelet transfusion. ICERs varied from a dominant strategy (i.e. cost-saving and more effective), to an incremental cost per QALY/health outcome of EUR 25,000-50,000, EUR 75,000-750,000 and EUR > 1 million, to a dominated strategy (cost-increasing and less effective). Few evaluations (n = 2, 10%) addressed the four principal types of uncertainty (methodological, structural, heterogeneity and parameter). Parameter uncertainty was most frequently reported (80%), followed by heterogeneity (45%), structural uncertainty (43%) and methodological uncertainty (28%).

CONCLUSIONS

Cost-effectiveness of TPO mimetics in adult patients with thrombocytopenia ranged from a dominant strategy to a significant incremental cost per QALY/health outcome or a strategy that is clinically inferior and has increased costs. Future validation and tackling the uncertainty of these models with country-specific cost data and up-to-date efficacy and safety data are needed to increase the generalizability.

The Efficacy and Safety of Different Dosages of Rituximab for Adults with Immune Thrombocytopenia: A Systematic Review and Meta-Analysis

Background

Rituximab has been frequently used as a second-line treatment for patients with immune thrombocytopenia (ITP). The optimal dose and course of rituximab are uncertain.

Methods

A comprehensive search for randomized controlled trials reporting the use of low-dose (100 mg) or standard-dose (375 mg/m²) rituximab in ITP treatment was conducted. Meta-analyses were performed on CRR (complete response rate), ORR (overall response rate), PRR (partial response rate), SRR (sustained response rate), infection rate, SB (significant bleeding) rate, and SAE (serious adverse event) rate.

Results

A total of 12 studies were included, comprising 869 patients. Compared to the control group, rituximab treatment resulted in an obvious increase in CRR (P < 0.00001), ORR (P < 0.0001), and SRR at month 6 and 12 (P = 0.0007, P = 0.0003), without increasing the infection rate (P = 0.12) and SAE rate (P = 0.11). No significant differences in CRR (RR 1.61 vs. 1.42, P = 0.45), ORR (RR 1.26 vs. 1.49, P = 0.28), PRR (RR 1.25 vs. 1.00, P = 0.11), SRR at month 12 (RR 2.00 vs. RR 1.64, P = 0.54), infection rate (RR 0.85 vs. 1.46, P = 0.36), and SB rate (RR 0.14 vs. 1.19, P = 0.17) were found in subgroups of low dose and standard dose.

Conclusion

Rituximab was effective and safe for adult patients with ITP. A low-dose rituximab regimen might be an effective alternative to the standard-dose regimen in ITP, as it showed similar CRR, ORR, and SRR at month 12 and was relatively safer with a lower cost.

Cost-consequence model comparing eltrombopag and romiplostim in pediatric patients with chronic immune thrombocytopenia

Background

Immune thrombocytopenia (ITP) is an auto-immune disorder characterized by enhanced platelet destruction and, subsequently, the potential for increased bleeding. Thrombopoietin receptor (TPO-R) agonists have recently emerged as promising therapies for ITP patients who are refractory to other treatments. While eltrombopag (EPAG) is the only TPO-R agonist US Food and Drug Administration approved for use in pediatric patients, romiplostin (ROMI) has been used in Phase III clinical studies.

Methods

A cost-consequence model (CCM) was developed to evaluate the costs of EPAG, ROMI, and watch-and-rescue (W&R) in relation to their respective treatment outcomes in previously-treated pediatric chronic ITP (cITP) over a 26-week time horizon. The costs of drugs, administration, routine care, rescue medications, adverse events, and mortality were included. Data on platelet count response rate, bleeding events, and adverse events were derived from all relevant identified Phase III-registered clinical trials, health outcomes were compared via indirect treatment comparison.

Results

The overall estimated cost of EPAG per patient was US$66,550, compared to US$101,056 for ROMI and US$32,720 for W&R. EPAG's lower cost compared to ROMI was largely due to lower drug costs (US$62,202 vs US$84,396), administration costs (US$0 vs US$1,955), and significantly lower costs due to severe bleeding (US$354 vs US$10,191). When assessing cost per severe bleeding event avoided, EPAG was dominant over ROMI (less expensive and more effective). EPAG was again dominant over ROMI when assessing the cost per responder and per bleeding event (any grade). Sensitivity analysis was consistent with the base case findings.

Conclusion

EPAG was the preferred TPO-R agonist to treat cITP when indirectly compared to ROMI, largely driven by its favorable severe bleeding outcomes and lower drug and administration costs.

Cost-consequence model comparing eltrombopag versus romiplostim for adult patients with chronic immune thrombocytopenia

Background

Thrombopoietin-receptor agonists eltrombopag (EPAG) and romiplostim (ROMI) are treatment options for adults with chronic immune thrombocytopenia (cITP) who have had an insufficient response to corticosteroids or immunoglobulins.

Methods

A cost-consequence model was developed to evaluate the costs relative to treatment success of EPAG, ROMI, and watch and rescue (W&R) in previously treated patients. The primary endpoint assessed was severe bleeding, derived from all identified phase III registered clinical trials. Health outcomes were compared via indirect treatment comparison. Costs incorporated in the model included drug and administration, routine care, rescue medications, bleeding-related adverse events, other adverse events, and mortality costs. A trial (26-week) time horizon was used, as certain endpoints used in the model were bound to within-trial results.

Results

In the intent-to-treat (ITT) population, the overall estimated cost per patient for EPAG was US$66,560 compared to US$91,039 for ROMI and US$30,099 for W&R. Compared to the ITT population, the difference in cost between EPAG and ROMI was slightly greater in splenectomized patients (US$65,998 for EPAG compared to US$91,485 for ROMI) and slightly less in non-splenectomized patients (US$67,151 for EPAG compared to US$91,455 for ROMI), though the overall trend remained the same. When assessing cost per severe bleeding event avoided in the ITT population, EPAG dominated (less expensive, more effective) ROMI. Sensitivity analyses confirmed these results.

Conclusion

EPAG was preferred over ROMI in the treatment of cITP, largely driven by the reduction in severe bleeding events associated with its use.