Avatrombopag and lusutrombopag for thrombocytopenia in people with chronic liver disease needing an elective procedure: a systematic review and cost-effectiveness analysis.

BACKGROUND: There have been no licensed treatment options in the UK for treating thrombocytopenia in people with chronic liver disease requiring surgery. Established management largely involves platelet transfusion prior to the procedure or as rescue therapy for bleeding due to the procedure. OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of two thrombopoietin receptor agonists, avatrombopag (Doptelet®; Dova Pharmaceuticals, Durham, NC, USA) and lusutrombopag (Mulpleta®; Shionogi Inc., London, UK), in addition to established clinical management compared with established clinical management (no thrombopoietin receptor agonist) in the licensed populations. DESIGN: Systematic review and cost-effectiveness analysis. SETTING: Secondary care. PARTICIPANTS: Severe thrombocytopenia (platelet count of < 50,000/µl) in people with chronic liver disease requiring surgery. INTERVENTIONS: Lusutrombopag 3 mg and avatrombopag (60 mg if the baseline platelet count is < 40,000/µl and 40 mg if it is 40,000-< 50,000/µl). MAIN OUTCOME MEASURES: Risk of platelet transfusion and rescue therapy or risk of rescue therapy only. REVIEW METHODS: Systematic review including meta-analysis. English-language and non-English-language articles were obtained from several databases including MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials, all searched from inception to 29 May 2019. ECONOMIC EVALUATION: Model-based cost-effectiveness analysis. RESULTS: From a comprehensive search retrieving 11,305 records, six studies were included. Analysis showed that avatrombopag and lusutrombopag were superior to no thrombopoietin receptor agonist in avoiding both platelet transfusion and rescue therapy or rescue therapy only, and mostly with a statistically significant difference (i.e. 95% confidence intervals not overlapping the point of no difference). However, only avatrombopag seemed to be superior to no thrombopoietin receptor agonist in reducing the risk of rescue therapy, although far fewer patients in the lusutrombopag trials than in the avatrombopag trials received rescue therapy. When assessing the cost-effectiveness of lusutrombopag and avatrombopag, it was found that, despite the success of these in avoiding platelet transfusions prior to surgery, the additional long-term gain in quality-adjusted life-years was very small. No thrombopoietin receptor agonist was clearly cheaper than both lusutrombopag and avatrombopag, as the cost savings from avoiding platelet transfusions were more than offset by the drug cost. The probabilistic sensitivity analysis showed that, for all thresholds below £100,000, no thrombopoietin receptor agonist had 100% probability of being cost-effective. LIMITATIONS: Some of the rescue therapy data for lusutrombopag were not available. There were inconsistencies in the avatrombopag data. From the cost-effectiveness point of view, there were several additional important gaps in the evidence required, including the lack of a price for avatrombopag. CONCLUSIONS: Avatrombopag and lusutrombopag were superior to no thrombopoietin receptor agonist in avoiding both platelet transfusion and rescue therapy, but they were not cost-effective given the lack of benefit and increase in cost. FUTURE WORK: A head-to-head trial is warranted. STUDY REGISTRATION: This study is registered as PROSPERO CRD42019125311. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 51. See the NIHR Journals Library website for further project information.

Thrombocytopenia, which is a reduction in platelet numbers in the blood, is a common complication of chronic liver disease. It increases the risk of bleeding during procedures including liver biopsy and transplantation. It can delay or prevent procedures, leading to illness and death. Established treatment largely involves platelet transfusion before the procedure or as rescue therapy for bleeding. This report aims to systematically review the clinical effectiveness and estimate the cost-effectiveness of the first two recently licensed treatments, thrombopoietin receptor agonists avatrombopag (Doptelet^®; Dova Pharmaceuticals, Durham, NC, USA) (60 mg if platelet count is < 40,000/µl and 40 mg if platelet count is 40,000­< 50,000/µl) and lusutrombopag (Mulpleta^®; Shionogi Inc., London, UK) (3 mg if platelet count is < 50,000/µl), compared with established treatment. From a comprehensive search, six studies were included. Clinical effectiveness analysis showed that avatrombopag and lusutrombopag were superior to no thrombopoietin receptor agonist in avoiding both platelet transfusion and rescue therapy. Only avatrombopag seemed superior to no thrombopoietin receptor agonist in reducing rescue therapy alone. Cost-effectiveness analysis found that lusutrombopag and avatrombopag were more expensive than no thrombopoietin receptor agonist over a lifetime, as the savings from avoiding platelet transfusions were exceeded by the drug cost, and without long-term health benefits. The probabilistic sensitivity analysis, which examined the effect of uncertainty, showed that no thrombopoietin receptor agonist had 100% probability of being cost-effective. Uncertainty about the price of avatrombopag and the content and costs of platelet transfusions and the potential under-reporting of use to estimate platelet transfusion-specific mortality had the greatest impact on results. If the price of avatrombopag was (confidential information has been removed) below the price of lusutrombopag, avatrombopag would become cost saving in the 40,000­< 50,000/µl subgroup. However, although in some scenarios avatrombopag costs could decrease in the 40,000­< 50,000/µl subgroup to around 10% more than the cost of no thrombopoietin receptor agonist, there would be negligible health benefits and the incremental cost-effectiveness ratios would remain very high, meaning that lusutrombopag and avatrombopag would still not be considered cost-effective.

Obinutuzumab in Combination with Chemotherapy for the First-Line Treatment of Patients with Advanced Follicular Lymphoma : An Evidence Review Group Evaluation of the NICE Single Technology Appraisal.

The National Institute for Health and Care Excellence (NICE), as part of the institute's single technology appraisal (STA) process, invited the company that makes obinutuzumab (Roche Products Limited) to submit evidence of the clinical and cost effectiveness of the drug in combination with chemotherapy, with or without obinutuzumab as maintenance therapy for adult patients with untreated, advanced follicular lymphoma (FL) in the UK. Kleijnen Systematic Reviews Ltd (KSR), in collaboration with Erasmus University Rotterdam, was commissioned to act as the Evidence Review Group (ERG). This paper describes the company's submission, the ERG review, and NICE's subsequent decisions. The clinical evidence was derived from two phase III, company-sponsored, randomised, open-label studies. Most evidence on obinutuzumab was based on the GALLIUM trial that compared obinutuzumab in combination with chemotherapy as induction followed by obinutuzumab maintenance monotherapy with rituximab in combination with chemotherapy as induction followed by rituximab maintenance monotherapy in previously untreated patients with FL (grades 1-3a). Long-term clinical evidence was based on the PRIMA trial, studying the benefit of two years of rituximab maintenance after first-line treatment in patients with FL. The cost-effectiveness evidence submitted by the company relied on a partitioned survival cost-utility model, implemented in Microsoft® Excel. The base-case incremental cost-effectiveness ratio (ICER) presented in the company submission was <£20,000 per quality-adjusted life-year (QALY) gained. Although the ERG concluded that the economic model met the NICE reference case to a reasonable extent, some errors were identified and several assumptions made by the company were challenged. A new base-case scenario produced by the ERG suggested an ICER that was higher than the company base case, but still below £30,000 per QALY gained. However, some ERG scenario analyses were close to or even above the threshold. This was the case in particular for assuming a treatment effect that did not extend beyond trial follow-up. These results led to an initial negative recommendation by the appraisal committee. Subsequently, the company submitted a revised base case focusing on patients at intermediate or high risk of premature mortality. Simultaneously, a further price discount for obinutuzumab was granted. In addition to the company's revised base case, the ERG suggested a restriction of the treatment effect to 5 years and implemented biosimilar uptake and cheaper prices for rituximab. All of these adjustments did not exceed £30,000 per QALY gained and therefore the use of obinutuzumab for patients with advanced FL and a Follicular Lymphoma International Predictive Index (FLIPI) score of two or more could be recommended.