Main Session
Sep 29
QP 03 - Right Care, Right Cost: Access and Utilization in Oncology

1013 - Cost-Effectiveness of Memantine for Patients Undergoing Whole Brain Radiation Therapy (WBRT)

03:55pm - 04:00pm ET
Room 109

Presenter(s)

Alexandra Bennett, MD - Mayo Clinic College of Medicine and Science Rochester, Rochester, MN

A. C. Kessel1, H. Kim2, E. L. McKone1, P. D. Brown1, E. J. Lehrer1, N. N. Laack II1, E. S. Yan1, S. Schultz3, S. Kizilbash4, B. J. Neth5, U. Sener5, M. R. Waddle1, W. Breen1, R. O. Kowalchuk1, and A. K. Bennett1; 1Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 2Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA, 3Department of Pharmacy, Mayo Clinic, Rochester, MN, 4Department of Medical Oncology, Mayo Clinic, Rochester, MN, 5Department of Neurology, Mayo Clinic, Rochester, MN

Purpose/Objective(s):

WBRT is a common treatment for patients with metastatic intracranial disease; however, radiation-induced cognitive decline is a well-recognized complication. Memantine, an NMDA receptor antagonist, has been shown to delay the onset of cognitive failure in the phase 3 setting. However, SEER database evaluation identifies memantine use in WBRT to be less than 10%1. The objective of this study was to evaluate the cost-effectiveness of adding memantine to standard WBRT.

Materials/Methods:

We used data from two phase 3 trials - RTOG 06142 and NRG CC0013 to select model parameters. Using a decision tree with an integrated Markov model, patients could exist in one of three states: mild cognitive decline, moderate cognitive decline, or death. Due to lack of exact clinical data, mild and moderate cognitive decline were assumed to be similar to mild and moderate dementia for quality of life and costs. Transition between these states was based on rate of cognitive failure from RTOG 0614. Memantine was assumed to start at WBRT treatment until 24 weeks after. Costs were measured from a healthcare system perspective, including drug cost, grade 3+ toxicity burden, and management of cognitive decline. Utility values were assigned based on health states. Outcomes were expressed as incremental cost-effectiveness ratios (ICERs) per quality-adjusted life-year (QALY) gained. Treatment is considered cost effective if it meets the commonly accepted willingness-to-pay threshold of $100,000 per QALY gained.

Results:

Per the Veteran Affairs Federal Supply Schedule and assuming a 121% cost increase for the general population, the cost of a 24-week course of memantine, including titration and maintenance is $79.58. Using 12-month cycles, memantine demonstrated an ICER of -$13,063 per QALY compared to the placebo. Memantine was the dominant strategy, improving QALY while also reducing costs.

Based on RTOG 0614, there was no significant increase in grade 3+ toxicity for patients receiving memantine versus the placebo. With low drug cost and similar toxicity cost, model outcomes were driven primarily based on improved quality of life and decreased burden of healthcare costs. Results were sensitive to assumptions about utility decrement associated with cognitive decline.

Conclusion:

Using this model, the addition of memantine to WBRT is cost-saving and improves quality of life for patients who are at risk of radiation-induced cognitive dysfunction. While direct cost-utility studies in WBRT populations are lacking, the best available data was used. Based on recent reports, memantine is substantially underutilized clinically. Our results suggest that memantine has the potential to improve quality of life and reduce cost of care in patients treated with WBRT.

Citations:

  1. Lamba N, et al. J Neuroonc. 2020. PMID:32468331
  2. Brown PD, et al. Neuro-Onc. 2013. PMID: 23956241
  3. Brown PD, et al. JCO. 2020. PMID: 32058845