Cost-effectiveness of Esketamine versus Real-world Treatments for Patients with Treatment-resistant Depression: A Multi-armed Modelling Study
Author(s)
Yifan Li, MSc1, Vivien K Y Chan, PhD1, Franco W. Cheng, RPh1, Hei Hang Edmund Yiu, PhD1, Esther W Chan, PhD1, Sandra Sau Man Chan, FHKCPsych2, Xue Li, BEc, MPhil, PhD1;
1The University of Hong Kong, Hong Kong, Hong Kong, 2The Chinese University of Hong Kong, Hong Kong, Hong Kong
1The University of Hong Kong, Hong Kong, Hong Kong, 2The Chinese University of Hong Kong, Hong Kong, Hong Kong
OBJECTIVES: Treatment-resistant depression (TRD) is the failure to respond to at least two antidepressant (AD) regimens administered at an effective dose for a sufficient duration. Esketamine nasal spray is a novel rapid-onset treatment for TRD, but current economic studies only compared it with unrealistic comparators such as AD monotherapy. We assessed the cost-effectiveness of esketamine compared with six usual care strategies and identify the most cost-effective option(s) for TRD from the healthcare payer’s perspective.
METHODS: We adopted a Markov cohort model to derive the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY) of esketamine adjunctive to oral AD, indirectly compared to other third-line treatment strategies: 1) AD monotherapy (common referent), 2) Combination AD therapy 3) AD augmented with an antipsychotic, 4) Psychotherapy alone, 5) Psychotherapy adjunctive to oral AD, and 6) Unilateral rTMS adjunctive to oral AD. Additional scenarios of esketamine dose reduction, varying cycle length and repetitive use of esketamine in subsequent lines were assumed. A 5-year horizon and 2.5% annual discount rate were used. Willingness-to-pay threshold of US$50,000/QALY was adopted. Deterministic and probabilistic sensitivity analyses, and cost-effectiveness acceptability curves (CEAC) were performed.
RESULTS: The base-case ICERs of adjunctive esketamine ranged between $43,208/QALY to $725,639/QALY, showing that it was not cost-effective compared to all strategies except adjunctive rTMS. Dose reduction lowered the cost by 22% but did not change the conclusion. The model was particularly sensitive to clinical efficacy. CEAC showed only a 0.8% probability for esketamine to be the most cost-effective at the current threshold. Among all options, the combination strategy had the highest probability to be cost-effective below the threshold of $150,000/QALY, beyond which adjunctive psychotherapy started to take over.
CONCLUSIONS: Despite promising clinical evidence of esketamine, it is unlikely to be cost-effective unless compared to adjunctive rTMS. Combination and adjunctive psychotherapy could be cost-effective options depending on WTP threshold.
METHODS: We adopted a Markov cohort model to derive the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY) of esketamine adjunctive to oral AD, indirectly compared to other third-line treatment strategies: 1) AD monotherapy (common referent), 2) Combination AD therapy 3) AD augmented with an antipsychotic, 4) Psychotherapy alone, 5) Psychotherapy adjunctive to oral AD, and 6) Unilateral rTMS adjunctive to oral AD. Additional scenarios of esketamine dose reduction, varying cycle length and repetitive use of esketamine in subsequent lines were assumed. A 5-year horizon and 2.5% annual discount rate were used. Willingness-to-pay threshold of US$50,000/QALY was adopted. Deterministic and probabilistic sensitivity analyses, and cost-effectiveness acceptability curves (CEAC) were performed.
RESULTS: The base-case ICERs of adjunctive esketamine ranged between $43,208/QALY to $725,639/QALY, showing that it was not cost-effective compared to all strategies except adjunctive rTMS. Dose reduction lowered the cost by 22% but did not change the conclusion. The model was particularly sensitive to clinical efficacy. CEAC showed only a 0.8% probability for esketamine to be the most cost-effective at the current threshold. Among all options, the combination strategy had the highest probability to be cost-effective below the threshold of $150,000/QALY, beyond which adjunctive psychotherapy started to take over.
CONCLUSIONS: Despite promising clinical evidence of esketamine, it is unlikely to be cost-effective unless compared to adjunctive rTMS. Combination and adjunctive psychotherapy could be cost-effective options depending on WTP threshold.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
EE418
Topic
Economic Evaluation
Disease
SDC: Mental Health (including addition)