Eltrombopag for the treatment of chronic idiopathic (immune) thrombocytopenic purpura (ITP)

Eltrombopag can promote platelet implantation after allogeneic hematopoietic stem cell transplantation as safely and similarly to thrombopoietin

Background

Eltrombopag has demonstrated efficacy in treating low platelet (PLT) levels, but it remains unclear whether eltrombopag can promote PLT engraftment after hematopoietic stem cell transplantation (HSCT).

Methods

Forty-one HSCT patients received eltrombopag 50 mg/d from +1 day until PLT >50 × 109/L or 1 month after HSCT. Fifty-one patients in the same period received thrombopoietin (TPO) to promote PLT graft after HSCT and served as a control group.

Results

A total of 51 patients who applied TPO during the same period were treated as a control. In the eltrombopag group, the median time to white blood cells (WBC) graft was 12 days (range, 10-17 days) and the PLT graft was 15 days (range, 10-30 days), whereas for the patients in the TPO group, the median time to WBC and PLT graft was 12 days (range, 9-23 days) and 15.5 days (range, 9-41 days), respectively. In the first month after HSCT, the median WBC count in the eltrombopag group was 4.41 × 109/L (range, 0.87-40.01 × 109/L) and the median PLT was 89x109/L (range, 30-401 × 109/L); the median WBC and PLT \counts in the TPO group were 4.65 × 109/L (range, 0.99-23.63 × 109/L) and 86 × 109/L (range, 5-512 × 109/L), respectively. Patients in the TPO or eltrombopag group did not experience serious side effects after drug administration, and the difference in side effects on liver and kidney function between the two groups was not statistically significant.

Conclusion

Eltrombopag is safe and similarly promotes platelet engraftment to thrombopoietin after allogeneic HSCT.

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.