341P - Cost-effectiveness analysis of first-line atezolizumab for patients with stage IV non-small cell lung cancer whose tumours have a high-programmed death ligand 1 expression in Thailand

Background

Atezolizumab treatment provided significantly longer overall survival than pemetrexed/gemcitabine plus platinum based chemotherapy as a first-line treatment for stage IV non-small cell lung cancer (NSCLC) whose tumours have a high programmed death ligand 1 (PD-L1) expression as shown in the phase III IMpower110 trial. There is no study examining cost-effectiveness of atezolizumab monotherapy to inform policy making in Thailand.

Methods

A cost-effectiveness analysis used a partitioned survival model and was conducted from a payer perspective. Costs and outcomes of atezolizumab and gemcitabine plus platinum based chemotherapy, which is a standard of care in Thailand, were estimated over a 35-year time horizon. Clinical outcomes were derived from the IMpower110 trial assuming the clinical equivalence of gemcitabine and pemetrexed since pemetrexed was used for non-squamous population in the trial, however only gemcitabine is being used in Thailand. Costs were obtained from literature from the Thai setting. All outcomes and costs were discounted at 3% annually. Sensitivity analyses were performed to assess robustness of the results. The Thai willingness-to-pay threshold was set at $4,520/QALY.

Results

The atezolizumab treatment resulted in 3.78 life-years (LY) and 2.70 quality-adjusted life-years (QALY) gained at an additional cost of $44,770 compared with chemotherapy. The incremental cost-effectiveness ratio (ICER) were $11,841/LY and $16,553/QALY. Key factors influencing a change in ICER were discount rates for outcomes and costs.

Conclusions

Although atezolizumab has clinical benefits more than twice compared to standard chemotherapy, the ICER is still higher than the current threshold. To enhance patients’ access to this life-extending treatment at the end of life, alternative financing strategies and a concept of QALY shortfall could be considered to support policy decision-making.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

K. Kittrongsiri, S. Abogunrin, H. Celik, S. Sangroongruangsri: Financial Interests, Institutional, Full or part-time Employment: Roche.