COST-UTILITY OF IMMUNOGLOBULIN REPLACEMENT THERAPY VERSUS NO IMMUNOGLOBULIN REPLACEMENT THERAPY FOR INFECTION PROPHYLAXIS IN MULTIPLE MYELOMA: A THRESHOLD EFFECTIVENESS AND TREATMENT DURATION ANALYSIS
Author(s)
Rainier Arnolda, MPH1, Adam Irving, PhD2, Laura Fanning, MPH, PhD2, Aleece MacPhail, MBBS3, Georgia McCaughan, MBBS4, Philip Crispin, MBBS5, Erica Wood, MBBS3, Zoe McQuilten, MBBS3, Andrew Spencer, MBBS6, Dennis Petrie, PhD1.
1Centre for Health Economics, Monash University, Melbourne, Australia, 2Centre for Health Economics & School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia, 3Transfusion Research Unit, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia, 4Department of Haematology & School of Clinical Medicine, Faculty of Medicine and Health, St Vincent's Hospital Sydney & University of New South Wales, Sydney, Australia, 5Department of Haematology & Medical School, Canberra Hospital & Australian National University, Canberra, Australia, 6Australian Centre for Blood Diseases & Malignant Haematology and Stem Cell Transplantation, Alfred Health–Monash University, Melbourne, Australia.
1Centre for Health Economics, Monash University, Melbourne, Australia, 2Centre for Health Economics & School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia, 3Transfusion Research Unit, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia, 4Department of Haematology & School of Clinical Medicine, Faculty of Medicine and Health, St Vincent's Hospital Sydney & University of New South Wales, Sydney, Australia, 5Department of Haematology & Medical School, Canberra Hospital & Australian National University, Canberra, Australia, 6Australian Centre for Blood Diseases & Malignant Haematology and Stem Cell Transplantation, Alfred Health–Monash University, Melbourne, Australia.
OBJECTIVES: Multiple myeloma (MM) confers a substantial risk of infection, and immunoglobulin replacement therapy (IgRT) is commonly prescribed for prevention, but its effectiveness is uncertain. Owing to limited supply and high cost, targeting IgRT at high-risk individuals during high-risk periods is critical. We aimed to determine the threshold IgRT effectiveness and treatment duration at which prophylaxis becomes cost-effective.
METHODS: We conducted the economic evaluation from the perspective of the Australian healthcare system. We extended the established Monash Myeloma Model, a discrete-event simulation model parameterised using risk equations derived from a national clinical registry, to incorporate infections and death due to infections, both estimated from linked administrative data. We varied the assumed IgRT comparative effectiveness (infection reduction, 5-65%) and IgRT durations after infections (1-12 months). We stratified by chronic kidney disease (CKD) and anticancer treatment status, both established predictors of infection risk. We assessed quality-adjusted life-years (QALYs) and costs over a lifetime horizon, discounting both at 5% annually. Non-parametric bootstrapping was used to quantify the parameter uncertainty.
RESULTS: In the best-case scenario, patients on anticancer treatment, 65% IgRT effectiveness, 1-month IgRT treatment duration and prescribed for patients with CKD were associated with 0.02 incremental QALYs (95% confidence interval [CI] -0.03, 0.08) and -A$2,117 incremental costs (95% CI -$6,739, $5,314). For patients without CKD, the same scenario yielded 0.006 incremental QALYs (95% CI -0.04, 0.05) and -A$520 incremental costs (95% CI -$4,576, $4,180). At thresholds of A$50,000 and A$300,000 per QALY, prescribing IgRT for patients with CKD had an 88% and 87% chance of being cost-effective, respectively, versus 70% and 63% for patients without CKD.
CONCLUSIONS: Prophylactic IgRT is only likely to be cost-effective if associated with a substantial reduction in infection risk. Cost-effective prescribing requires careful patient selection and, likely, a short IgRT treatment duration. All scenarios yielded small QALY gains with substantial uncertainty.
METHODS: We conducted the economic evaluation from the perspective of the Australian healthcare system. We extended the established Monash Myeloma Model, a discrete-event simulation model parameterised using risk equations derived from a national clinical registry, to incorporate infections and death due to infections, both estimated from linked administrative data. We varied the assumed IgRT comparative effectiveness (infection reduction, 5-65%) and IgRT durations after infections (1-12 months). We stratified by chronic kidney disease (CKD) and anticancer treatment status, both established predictors of infection risk. We assessed quality-adjusted life-years (QALYs) and costs over a lifetime horizon, discounting both at 5% annually. Non-parametric bootstrapping was used to quantify the parameter uncertainty.
RESULTS: In the best-case scenario, patients on anticancer treatment, 65% IgRT effectiveness, 1-month IgRT treatment duration and prescribed for patients with CKD were associated with 0.02 incremental QALYs (95% confidence interval [CI] -0.03, 0.08) and -A$2,117 incremental costs (95% CI -$6,739, $5,314). For patients without CKD, the same scenario yielded 0.006 incremental QALYs (95% CI -0.04, 0.05) and -A$520 incremental costs (95% CI -$4,576, $4,180). At thresholds of A$50,000 and A$300,000 per QALY, prescribing IgRT for patients with CKD had an 88% and 87% chance of being cost-effective, respectively, versus 70% and 63% for patients without CKD.
CONCLUSIONS: Prophylactic IgRT is only likely to be cost-effective if associated with a substantial reduction in infection risk. Cost-effective prescribing requires careful patient selection and, likely, a short IgRT treatment duration. All scenarios yielded small QALY gains with substantial uncertainty.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EE699
Topic
Economic Evaluation, Health Technology Assessment, Real World Data & Information Systems
Disease
Infectious Disease (non-vaccine), Oncology, Urinary/Kidney Disorders