Symptom burden in patients with idiopathic multicentric Castleman disease and its impact on daily life: an international patient and caregiver survey

Background

Idiopathic Multicentric Castleman Disease (iMCD) is a rare inflammatory lymphoproliferative disorder with heterogenous clinical presentations. The symptomatology in iMCD patients remains poorly understood. The aim of this study was to identify the type, frequency and severity of iMCD-related symptoms and the impact of these on the daily lives of iMCD patients and informal-caregivers.

Methods

We conducted two bespoke 45-question online surveys for iMCD patients and informal-caregivers of patients recruited from the US, UK, Australia and Canada between April 14 and November 8, 2021. Descriptive data was collected, and a Likert scale was used to quantify the impact of symptoms on various aspects of daily life. Ordinal logistic regression analysis was used to determine associations between age, gender, employment status and symptom burden with aspects of daily life.

Findings

Eligible respondents included 51 iMCD patients and 11 informal-caregivers. Patients reported up to 27 unique symptoms, the mean number of symptoms experienced by a patient was 6.7 (range 0-22 symptoms). Most symptoms had a moderate to severe impact on patients' daily lives, with 'pain/discomfort', 'ability to travel', and 'sexual functioning' being the most impacted. iMCD patient characteristics such as being 40 years or older, female, and either disabled or unemployed was significantly associated with adverse impact on several aspects of daily life. Among caregivers, the aspects of daily life that were disproportionately affected was their own social life and freedom, emotional wellbeing, travel/relocation, and work.

Interpretation

iMCD patients have widely varied and unappreciated symptomatology. High symptom burden adversely impacts several aspects of patient daily lives as well as their caregivers.

Funding

Funding was provided by EUSA Pharma.

Cost-Effectiveness Analysis of Siltuximab for Australian Public Investment in the Rare Condition Idiopathic Multicentric Castleman Disease

OBJECTIVES

This paper presents an Australian model that formed part of the health technology assessment for public investment in siltuximab for the rare condition of idiopathic Multicentric Castleman Disease (iMCD) in Australia.

METHODS

Two literature reviews were conducted to identify the appropriate comparator and model structure. Survival gain based on available clinical trial data were modelled using an Excel-based model semi-Markov model including time-varying transition probabilities, an adjustment for trial crossover and long-term data. A 20-year horizon was taken, and an Australian healthcare system perspective was adopted, with both benefits and costs discounted at 5%. The model was informed with an inclusive stakeholder approach that included a review of the model by an independent economist, Australian clinical expert opinion and feedback from the Pharmaceutical Benefits Advisory Committee (PBAC). The price used in the economic evaluation reflects a confidential discounted price, which was agreed to with the PBAC.

RESULTS

An incremental cost-effectiveness ratio of A$84,935 per quality-adjusted life-year (QALY) gained was estimated. At a willingness-to-pay threshold of A$100,000 per QALY, siltuximab has a 72.1% probability of being cost-effective compared with placebo and best supportive care. Sensitivity analyses results were most sensitive to the length of interval between administrations (from 3- to 6-weekly) and crossover adjustments.

CONCLUSION

Within a collaborative and inclusive stakeholder framework, the model submitted to the Australian PBAC found siltuximab to be cost-effective for the treatment of iMCD.

Emerging morbidities and health care resource utilization in idiopathic multicentric Castleman disease patients: A population-level analysis using health claims-based dataset

e18792

Background: Idiopathic multicentric Castleman disease (iMCD) is a hematologic disorder characterized by systemic inflammation, polyclonal lymphoproliferation, and multi-organ dysfunction due to hypercytokinemia often including interleukin-6 (IL-6). iMCD patients have had historically poor outcomes, particularly prior to the advent of anti-IL-6 therapy. We recently found that ̃90% of iMCD patients did not have any claims for anti-IL-6 therapy. One potential reason for inadequate treatment is limited understanding of associated morbidities that can be controlled with therapy. We aimed to assess emergent morbidities in iMCD patients using a large administrative claims database. Methods: An iMCD cohort was identified using an administrative health claims dataset that enrolled 30.7 million US patients between January 1, 2017 and December 2, 2020. This is an updated analysis from a previously published health claims study ( Mukherjee et al, 2022). iMCD patients were identified based on CD-specific ICD-10 diagnosis code (D47·Z2), negative HHV-8 and HIV status, and diagnostic or laboratory claims for ≥2 minor criteria. Post-diagnosis hospitalizations, emergency room (ER) visits, and emergent morbidities in iMCD patients were identified in claims data and compared to non-iMCD cohort matched (1:50) by age group (0-17, 18-44, 45-54, 55-64, > 65 years), sex, insurance type, database history, and region. The iMCD cohort was further stratified by age (0-44 years, 45-60 years, > 60 years) or treatment (iMCD-directed therapy, steroid only, and no treatment) for subgroup analyses of morbidity rates. Results: We identified 271 individuals likely to have iMCD (iMCD patients) (mean age: 50·8 years; 59·4% female), including 191 patients previously reported (ASH, 2021). We found significantly higher odds of organ dysfunction (n = 116, OR = 6·5, 95% CI = 4·9, 8·5) and thrombotic events (n = 79, OR = 4·8, 95% CI = 3·4, 6·7) in iMCD patients compared to a matched non-iMCD cohort. We observed increasing proportions of morbidities with advancing age in iMCD and matched non-iMCD cohorts. Similar morbidity trends were observed in all three iMCD treatment cohorts. A high proportion of iMCD patients required an ER visit (47.8% and 42.6% in the year before and after initial diagnosis), dropping to 13.5% in the second year after diagnosis. A similar pattern was observed in inpatient stays, with a marked increase in patients hospitalized for > 5 days increasing from 6·2% two years prior to diagnosis to 34·3% and 15·6% in the two subsequent years. Conclusions: We report high odds of organ dysfunction and thrombotic events in iMCD patients from this population analysis of patient-claims data. In this iMCD cohort with previously reported low use of iMCD-directed therapies, a high proportion of patients required ER visits and inpatient hospitalizations.

Annual public health and economic benefits of seasonal influenza vaccination: a European estimate

BACKGROUND

Vaccination is currently the most effective means of preventing influenza infection. Yet evidence of vaccine performance, and the impact and value of seasonal influenza vaccination across risk groups and between seasons, continue to generate much discussion. Moreover, vaccination coverage is below recommended levels.

METHODS

A model was generated to assess the annual public health benefits and economic importance of influenza vaccination in 5 WHO recommended vaccination target groups (children 6 - 23 months of age; persons with underlying chronic health conditions; pregnant women; health care workers; and, the elderly, 65 years of age) in 27 countries of the European Union. Model estimations were based on standard calculation methods, conservative assumptions, age-based and country-specific data.

RESULTS

Out of approximately 180 million Europeans for whom influenza vaccination is recommended, only about 80 million persons are vaccinated. Seasonal influenza vaccination currently prevents an annual average of between 1.6 million and 2.1 million cases of influenza, 45,300 to 65,600 hospitalizations, and 25,200 to 37,200 deaths. To reach the 75% vaccination coverage target set by the EU Council Recommendation in 2009, an additional 57.4 million person would need to be vaccinated in the elderly and other risk groups. By achieving the 75% target rate set in EU-27 countries, average annual influenza- related events averted would increase from current levels to an additional +1.6 to +1.7 million cases, +23,800 to +31,400 hospitalization, +9,800 to +14,300 deaths, +678,500 to +767,800 physician visits, and +883,800 to +1,015,100 lost days of work yearly. Influenza-related costs averted because of vaccination would increase by an additional + €190 to + €226 million yearly, in vaccination target groups.

CONCLUSIONS

Full implementation of current influenza vaccination recommendations of 75% vaccination coverage rate (VCR) in Europe by the 2014-2015 influenza season could immediately reduce an important public health and economic burden.