OBJECTIVES: Regarding the low penetration of biosimilars drugs in the French market, the government introduce two incentives to increase biosimilar use. First, the “general case” redirects 20% of the price difference between reference product and its biosimilar to hospitals for every biosimilar delivered in community pharmacy from these hospital’s prescriptions. Second, the “experimental case” increases the premium to 30% by specifically targeting prescribing hospital clinical units for every biosimilar delivered in community pharmacy from these clinical unit’s prescriptions. The experimentation started in October-2018 and concerned etanercept and insulin glargine. It was then extended to adalimumab in April-2019. Our study aimed to compare the efficacy of both incentives for adalimumab biosimilars after 19 months.

METHODS: We used IQVIA Xponent data to evaluate public hospitals’ prescriptions. The number of adalimumab boxes delivered in retail pharmacies was given on a monthly basis and was linked to the corresponding hospital’s prescription. The comparison between hospitals in the experimentation and the others was assessed by a double difference method.

RESULTS: Among the 39 hospitals studied in the “experimental case”, 95% were public. They were compared to 208 other hospitals (“general case”) of which 83% were public. Before the experiment, in March 2019, the mean rate of adalimumab biosimilars was 10.3% for hospitals in the experimental case and 8.3% for those in the general case. These mean rates continuously increased and were respectively of 38.6% and 29.8% in October 2020. The double difference estimator (6.2%) was not significant.

CONCLUSION: Contrary to the same experiment for etanercept¹, we cannot conclude to an advantage of incentivising clinical care units to increase the use of adalimumab biosimilars. However, both experimentation and marketing of adalimumab’s biosimilars is more recent and there is still room for improvement. A new assessment should be done in May-2022 at the end of the experimentation.