1718P - Impact of the economic status of the patient's country of residence on the outcome of oncology clinical trials

Background

Prolongation of overall survival (OS) is commonly evaluated as a primary endpoint in confirmative oncology clinical trials; however, it is potentially affected by the healthcare environment, which often varies from country to country. We compared progression-free survival (PFS) and OS between the Organisation for Economic Co-operation and Development (OECD) and non-OECD countries. We also investigated the causes of the survival difference.

Methods

Individual patient data from industry-sponsored multi-regional phase III oncology trials were obtained from the Project Data Sphere. Cox regression analysis was conducted to estimate the hazard ratio (HR) for PFS and OS between the different subgroups such as race and country in each trial, and summary HR was estimated. Patients’ demographic data such as performance status (PS) and ratio of the elderly were compared between the subgroups by calculating the odds ratio. The incidence of serious adverse events (SAEs) was calculated by the subgroups, and median survival time in patients with SAEs was estimated using the Kaplan-Meier method. The rate of post treatment in each subgroup was calculated.

Results

Eleven arms from 10 clinical trials were eligible for the analysis. No statistically significant difference was observed in PFS and OS between races. A prolongation of OS was observed in patients enrolled in the OECD, while no statistically significant difference was observed in PFS. Patients enrolled in the OECD were older and showed favorable PS. Although incidence of SAEs was higher in the OECD, the median PFS and OS in patients with SAEs were longer in the OECD. The rate of post treatment was higher in the OECD.

Conclusions

The economic status and healthcare environment of countries where patients were enrolled had an impact on the outcome of OS. Differences were observed in patients' demographic data such as PS and age as well as in the management of SAEs depending on the patients’ country of residence. Clinical trial sponsors are recommended to consider carefully how to design and conduct oncology clinical trials including the selection of countries, provision of appropriate AE management guidelines and related training, and data management of subsequent treatments.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

S. Nishiyama: Financial Interests, Personal, Full or part-time Employment: Chugai Pharmaceutical Co., Ltd. All other authors have declared no conflicts of interest.