Cost-effectiveness of pazopanib in advanced soft tissue sarcoma in the United kingdom

Abstract

In the phase III PALETTE trial, pazopanib improved progression-free survival (PFS) compared with placebo in patients with advanced/metastatic soft tissue sarcomas (mSTS) who had received prior chemotherapy. We used a multistate model to estimate expected PFS, overall survival (OS), lifetime STS treatment costs, and quality-adjusted life-years (QALYs) for patients receiving pazopanib, placebo, trabectedin, ifosfamide, or gemcitabine plus docetaxel as second-line mSTS therapies. The cost-effectiveness of pazopanib was expressed as the incremental costs per QALY gained. Estimates of PFS/OS, adverse events, and utilities for pazopanib and placebo were from the PALETTE trial. Estimates of relative effectiveness of the other comparators were from an unadjusted indirect comparison versus pazopanib. Costs were from published sources. Pazopanib is estimated to increase QALYs by 0.128 and costs by £7,976 versus placebo; cost per QALY gained with pazopanib versus placebo is estimated to be £62,000. Compared with the other chemotherapies, pazopanib provides similar QALYs at a lower cost. Pazopanib may not be cost-effective versus placebo but may be cost-effective versus the most commonly used active treatments, although this conclusion is uncertain. Given the unmet need for effective treatments for mSTS, pazopanib may be an appropriate alternative to some currently used medications in the United Kingdom.

Figure 1

Weibull versus Kaplan-Meier survival distributions for (a) progression-free survival and (b) overall survival of pazopanib and placebo for patients in the PALETTE trial.

Figure 2

Tornado diagram showing result of deterministic sensitivity analysis for the direct comparison of cost-effectiveness of pazopanib versus placebo. Parameters were varied by 0.5 or 1.5 and shown on either side of the graph. AE: adverse events; CI: confidence interval; OS: overall survival; PFS: progression-free survival; PPS: postprogression survival; PTACT: posttreatment anticancer therapy.

Figure 3

(a) Probabilistic sensitivity analyses for comparison of cost-effectiveness of pazopanib versus placebo. (b) Acceptability curve for comparison of cost-effectiveness of pazopanib versus placebo. QALYs: quality-adjusted life-years.