Background

Relapsed or refractory (R/R) Hodgkin Lymphoma (HL) following autologous stem cell transplant (ASCT) carries an unfavorable prognosis with a median overall survival of less than 2 years and is extremely costly to treat. Novel agents that both reduce the risk of progression and the need for further treatment, including allogeneic stem cell transplant, offer the potential to be both clinically effective and cost-effective. To address this issue, we constructed a decision model evaluating the potential cost-effectiveness of brentuximab vedotin (BV) vs. best supportive care (BSC) in the treatment of patients at risk of relapse following ASCT.

Methods

Adult patients with R/R HL ÒenterÓ the model immediately after receiving ASCT, and are either treated with BV plus BSC (hereafter ÒBVÓ) or BSC alone. Following treatment, the cohort of patients is tracked through five health states in monthly cycles (remission, relapse/salvage therapy, relapse/palliative care, 2nd remission, death). Transition probabilities were derived from peer-reviewed literature, bone marrow transplant registry data, and U.S. life tables. Drug cost was based on average sales price plus 6%. Other inputs were based on literature review and 2013 Center for Medicare and Medicaid reimbursements. In the base case, we evaluated outcomes with the expected relapse hazard ratio of 0.667 for BV vs. BSC among post-ASCT patients (regardless of risk factors) based on the phase 3 AETHERA trial design. We also provide a plausible range of values for the relapse hazard ratio to evaluate the range of potential cost-effectiveness. The model uses the perspective of a U.S. health insurer and a lifetime time horizon.

Results

In the base case, total life years, QALYs, and costs (discounted) were 16.7, 13.4, and $308,000 for the BV strategy vs. 14.3, 10.9, and$140,000 for the BSC strategy. The corresponding BV cost per life year gained and cost per QALY gained were $70,000 and$67,200, respectively. The table below reports economic outcomes across a range of potential hazard ratios for relapse after BV vs. BSC.

Table
BV Relapse Hazard Ratio vs. BSC
0.5 0.6 0.7 0.8
Incremental Life Years 3.8 2.9 2.1 1.3
Incremental QALYs 4.1 3.1 2.3 1.4
Incremental Cost $155,000$162,000 $169,000$176,000
ICER: Cost Per Life Year Gained $40,789$55,862 $80,476$135,384
ICER: Cost Per QALY Gained $37,804$52,258 $73,478$125,714
BV Relapse Hazard Ratio vs. BSC
0.5 0.6 0.7 0.8
Incremental Life Years 3.8 2.9 2.1 1.3
Incremental QALYs 4.1 3.1 2.3 1.4
Incremental Cost $155,000$162,000 $169,000$176,000
ICER: Cost Per Life Year Gained $40,789$55,862 $80,476$135,384
ICER: Cost Per QALY Gained $37,804$52,258 $73,478$125,714

In addition to the impact of BV on the relapse hazard ratio, the results were most sensitive to monthly drug cost and the duration of treatment (cycles). At a hazard ratio of 0.667, probabilistic sensitivity analysis showed a 92.6% likelihood of BV being cost-effective at a societal willingness to pay threshold of \$100,000 per QALY.

Conclusions

When used following ASCT to prevent progression, BV has the potential to be cost-effective vs. BSC in adults with relapsed or refractory HL. The results of the forthcoming phase 3 AETHERA trial will provide definitive evidence of the efficacy of BV in this setting, and thus more precise evidence of the cost-effectiveness of this strategy.

Disclosures

Roth:Seattle Genetics: Consultancy. Carlson:Seattle Genetics: Consultancy. Ramsey:Seattle Genetics: Consultancy.

## Author notes

*

Asterisk with author names denotes non-ASH members.