Cost savings to hospital of rituximab use in severe autoimmune acquired thrombotic thrombocytopenic purpura

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Global Health Resource Utilization and Cost-Effectiveness of Therapeutics and Diagnostics in Immune Thrombotic Thrombocytopenic Purpura (TTP)

In this review, we examine the current landscape of health resource utilization and cost-effectiveness data in the care of patient populations with immune thrombotic thrombocytopenic purpura. We focus on the therapeutic (therapeutic plasma exchange, glucocorticoids, rituximab, caplacizumab) and diagnostic (ADAMTS13 assay) health technologies employed in the care of patients with this rare disease. Health resource utilization and cost-effectiveness data are limited to the high-income country context. Measurement of TTP-specific utility weights in the high-income country context and collection of health resource utilization data in the low- and middle-income country settings would enable an evaluation of country-specific quality-adjusted life expectancy and cost-effectiveness of these therapeutic and diagnostic health technologies. This quantification of value is one way to mitigate cost concerns where they exist.

Long-term risk of relapse in immune-mediated thrombotic thrombocytopenic purpura and the role of anti-CD20 therapy

Disease relapse is recognized as a risk in immune-mediated thrombotic thrombocytopenic purpura (iTTP) after treatment of the acute presenting episode. Identification of patients at risk of relapse and its patterns are yet to be clearly established. We reviewed patients with iTTP having had >3 years of follow-up over 10 years in the United Kingdom to identify patient characteristics for relapse, assess relapse rates and patterns, and response to anti-CD20 therapy in those with a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) relapses (ADAMTS13 activity of <20% without thrombocytopenia). We identified 443 patients demonstrating relapse rates of 40% at 5-year follow-up. At 10-year follow-up, no difference in relapse was observed irrespective of whether rituximab was used at acute presentation (P = .39). Black Caribbean ethnicity increased the risk of disease relapse in the British population. There was a distinct population of patients (6%) that relapsed early with subsequent frequent relapses occurring on average within 2 years (average time to relapse in subgroup, 1.7 years). Overall, nearly 60% of relapses described were ADAMTS13 relapses, with subsequent treatment reducing the risk of progression to clinical relapses. We demonstrate that iTTP diagnosed in the latter part of the study period had lower rates of clinical relapses (22.6% vs 11.1%, P = .0004) with the advent of regular monitoring and preemptive rituximab. In ADAMTS13 relapses, 96% responded to anti-CD20 therapy, achieving ADAMTS13 activity of >20%. Anti-CD20 therapy was demonstrated to be an effective long-term treatment regardless of relapse pattern and there was no loss of this treatment response after subsequent treatment episodes.

Cost-effectiveness of second-line therapies in adults with chronic immune thrombocytopenia

Major options for second-line therapy in adults with chronic immune thrombocytopenia (ITP) include splenectomy, rituximab, and thrombopoietin receptor agonists (TRAs). The American Society of Hematology guidelines recommend rituximab over splenectomy, TRAs over rituximab, and splenectomy or TRAs while noting a lack of evidence on the cost-effectiveness of these therapies. Using prospective, observational, and meta-analytic data, we performed the first cost-effectiveness analysis of second-line therapies in chronic ITP, from the perspective of the U.S. health system. Over a 20-year time-horizon, our six-strategy Markov model shows that a strategy incorporating early splenectomy, an approach at odds with current guidelines and clinical practice, is the cost-effective strategy. All four strategies utilizing TRAs in the first or second position cost over $1 million per quality-adjusted life-year, as compared to strategies involving early use of splenectomy and rituximab. In a probabilistic sensitivity analysis, early use of splenectomy and rituximab in either order was favored in 100% of 10 000 iterations. The annual cost of TRAs would have to decrease over 80% to begin to become cost-effective in any early TRA strategy. Our data indicate that effectiveness of early TRA and late TRA strategies is similar with the cost significantly greater with early TRA strategies. Contrary to current practice trends and guidelines, early use of splenectomy and rituximab, rather than TRAs, constitutes cost-effective treatment in adults with chronic ITP.

Economic impact of a rapid, on‐demand ADAMTS‐13 activity assay for the diagnosis of thrombotic thrombocytopenic purpura

Background

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening thrombotic microangiopathy (TMA), characterized by ADAMTS-13 activity <10%. ADAMTS-13 activity assays are typically performed in reference laboratories with a turnaround time of several days. First-line treatment for TTP, therapeutic plasma exchange (TPE), typically starts while results are pending. The automated, on-demand HemosIL AcuStar ADAMTS-13 Activity assay provides results in under an hour, which could reduce unnecessary TPE use and associated costs.

Objectives

To estimate the hospital budget impact in the United States, United Kingdom, and France of using a rapid ADAMTS-13 activity assay.

Methods

We compared routine use of a rapid assay in adults with TMA with a scenario in which results take 3 days. Model structure and variables were based on published literature, plus survey and interviews of five clinicians from the three countries. Costs for the ADAMTS-13 activity assays and TPE were included.

Results

Model results suggest that if an on-demand, rapid ADAMTS-13 activity assay is used, US, UK, and French hospitals could save $18 million, £1.2 million, and €1.6 million annually, respectively. This equates to $10 788, £3497, and €4700 saved per patient with TMA in the United States, United Kingdom, and France. The model is most sensitive to the exact split of diagnoses of TMA cases, as savings accrue from non-TTP diagnoses.

Conclusions

In patients with TMA, use of a rapid, on-demand ADAMTS-13 activity assay such as the HemosIL AcuStar ADAMTS-13 Activity assay has the potential to be cost saving for hospitals.

Predictors of relapse and preventative strategies in immune thrombotic thrombocytopenic purpura

INTRODUCTION

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare autoimmune blood disorder, which presents with microangiopathic hemolytic anemia, thrombocytopenia, and microvascular thrombosis and is caused by severe deficiency of ADAMTS13. iTTP may result in both acute and chronic complications and is rapidly fatal without expedient treatment. Life-time risk of relapse is approximately 40%.

AREAS COVERED

A number of predictors of relapse has been described in the literature. The most well-studied predictor of relapse is persistent ADAMTS13 deficiency; however, it is not a perfect marker. Relapse can be prevented by treatment with immunosuppressive medications, with rituximab being the most studied.

EXPERT OPINION

Patients who recover from iTTP should be regularly assessed, including with ADAMTS13 activity testing. The optimal frequency of assessments has not been established, but every 3 months is recommended. Considering the potential for significant organ damage and mortality associated with iTTP relapse, patients in remission and with persistent ADAMTS13 activity of 10-20% should be prophylactically treated with immunosuppression. Additional markers to precisely identify patients at higher risk of relapse are needed.

Best practices and recommendations for drug regimens and plasma exchange for immune thrombotic thrombocytopenic purpura

INTRODUCTION

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening thrombotic microangiopathy characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ injury. TTP pathophysiology is based on a severe ADAMTS13 deficiency, and is a medical emergency with fatal outcome if appropriate treatment is not initiated promptly.

AREAS COVERED

Authors will review the best options currently available to minimize mortality, prevent relapses, and obtain the best clinical response in patients with immune TTP (iTTP). Available bibliography about iTTP treatment has been searched in Library's MEDLINE/PubMed database from January 1990 until April 2021.

EXPERT OPINION

The generalized use of plasma exchange marked a paradigm in the management of iTTP. In recent years, strenuous efforts have been done for a better understanding of the pathophysiology of this disease, improve diagnosis, optimize treatment, reduce mortality, and prevent recurrences. The administration of front-line rituximab and, more recently, the availability of caplacizumab, the first targeted therapy for iTTP, have been steps toward a further reduction in early mortality and for the prevention of relapses.

Cost effectiveness of caplacizumab in acquired thrombotic thrombocytopenic purpura

Acquired thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease characterized by thrombotic microangiopathy leading to end-organ damage. The standard of care (SOC) treatment is therapeutic plasma exchange (TPE) alongside immunomodulation with steroids, with increasing use of rituximab ± other immunomodulatory agents. The addition of caplacizumab, a nanobody targeting von Willebrand factor, was shown to accelerate platelet count recovery and reduce TPE treatments and hospital length of stay in TTP patients treated in 2 major randomized clinical trials. The addition of caplacizumab to SOC also led to increased bleeding from transient reductions in von Willebrand factor and increased relapse rates. Using data from the 2 clinical trials of caplacizumab, we performed the first-ever cost-effectiveness analysis in TTP. Over a 5-year period, the projected incremental cost-effectiveness ratio (ICER) in our Markov model was $1 482 260, significantly above the accepted 2019 US willingness-to-pay threshold of $195 300. One-way sensitivity analyses showed the utility of the well state and the cost of caplacizumab to have the largest effects on ICER, with a reduction in caplacizumab cost demonstrating the single greatest impact on lowering the ICER. In a probabilistic sensitivity analysis, SOC was favored over caplacizumab in 100% of 10 000 iterations. Our data indicate that the addition of caplacizumab to SOC in treatment of acquired TTP is not cost effective because of the high cost of the medication and its failure to improve relapse rates. The potential impact of caplacizumab on health system cost using longer term follow-up data merits further study.

Early response to caplacizumab and rituximab after anaphylaxis to Octaplas plasma in a patient with thrombotic thrombocytopenic purpura

Management of aTTP in patients who refuse or are intolerant to plasma remains challenging, but new drugs can be implemented with success. A 39-year-old woman presented to the Emergency department for bruises at the upper and lower limbs together with worsening anemia and thrombocytopenia; PLASMIC score was seven, indicative of high risk to have a thrombotic microangiopathy due to severe ADAMTS-13 deficiency: indeed, it was 1.4%. We immediately started Plasma Exchange, but after the third procedure she developed severe anaphylaxis to Octaplas plasma, so PEXs were discontinued. We proceeded to a salvage strategy with rituximab and caplacizumab that was rapidly effective to resolve symptoms and hemolysis. It has been already reported a case in which a patient developed severe reactions to fresh-frozen plasma that required discontinuation of PEX. Differently from this case, our patient was already using the less immunogenic pooled plasma units Octaplas, therefore a strategy with caplacizumab was the only available option. Moreover, rituximab is associated with a shorter time to obtain a durable remission in aTTP and a faster time (15 days) to final ADAMTS13 activity recovery >10%. To our knowledge, this is the first case of early discontinuation of caplacizumab in a patient allergic to PEX by actively monitoring ADAMTS13 activity, allowing optimization of healthcare resources during COVID-19 pandemic.

Burden of illness among Medicare and non-Medicare US populations with acquired thrombotic thrombocytopenic purpura

BACKGROUND

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare hematologic disorder that can lead to serious life-threatening medical complications.

OBJECTIVE

The aim of this study was to describe aTTP-related hospital resource utilization, cost, complications, and overall survival among US Medicare and non-Medicare populations following aTTP episodes prior to the US approval of caplacizumab.

METHODS

This retrospective study utilized administrative claims data for Medicare Fee-for-Service (FFS) beneficiaries (100% sample) and a sample of commercial, managed Medicaid [MM], Medicare Advantage [MA] plan members from the Inovalon MORE² Registry. aTTP patients ages 18+ were identified between 2010 and 2018 using a published validated algorithm: ≥1 hospitalization for thrombotic microangiopathy + therapeutic plasma exchange (TPE). 2,279 patients were identified; 65.2% were enrolled in Medicare FFS, 13.6% in commercial, 15.7% in MM, and 5.4% in MA. Mean hospitalization days for aTTP index episode ranged between 12 and 17 days; ∼60% of patients required intensive care. Mean payments for index hospitalization varied by payer [Medicare FFS: $29,024; MA: $12,860; commercial: $9,996 and MM: $10,470]. Among FFS patients, 15.7% died during initial hospitalization and 21.0% died within first 30 days of the event. During follow-up, 11.6-19.6% experienced aTTP-related exacerbation. Incidence rate of relapse and complications per 100 person-years was 5.6 [Medicare FFS: 3.6; MA: 8.7; commercial: 10.4 and MM: 14.7] and 16.7 [FFS: 15.5; MA: 20.5; commercial: 21.7 and MM: 19.1], respectively. Among Medicare patients with and without aTTP, mortality risk was 2.9 (95 % CI: 2.4-3.4) times higher for aTTP vs. non-aTTP patients.

CONCLUSION

This is the first real-world study evaluating burden of illness among aTTP patients in the US across payer types. Despite being treated with TPE, patients with aTTP have lower survival rates in comparison to a matched cohort without aTTP. These findings highlight the need for more effective and novel therapies to reduce disease burden for this population.Key pointsIn US Medicare and managed care populations with aTTP between 2010 and 2018, aTTP can lead to significant utilization of ICU services due to clinical complications, and/or relapse following hospital discharge.Despite treatment with therapeutic plasma exchange, acute mortality remains high (15.7%) indicating the need for more effective and novel treatments.