446P CDK4/6 inhibitors in the first-line treatment of postmenopausal women with HR+/HER2- advanced or metastatic breast cancer: An updated network meta-analysis and cost-effectiveness analysis

Recently updated results of clinical trials have confirmed that palbociclib, ribociclib and abemaciclib plus letrozole/anastrozole significantly prolonged survival compared to placebo plus letrozole/anastrozole in the first-line treatment for postmenopausal women with HR+/HER2- metastatic breast cancer. However, the high cost of CDK4/6 inhibitors imposes a huge financial burden on patients and healthcare systems. Studies estimating CDK4/6 inhibitors plus NSAI for HR+/HER2- ABC were searched. A network meta-analysis was made with the main outcomes HRs of OS and PFS. The costs and efficacy of four first-line therapies for HR+/HER2- ABC were evaluated by Markov model. The main outcomes in the cost-effectiveness analysis were incremental cost-utility ratios (ICURs), incremental monetary benefit (INMB), and incremental net-health benefit (INHB). The robustness of the model was assessed by one-way, three-way, and probabilistic sensitivity analyses. Seven studies involving 5347 patients were included in the NMA. The three first-line CDK4/6 inhibitors plus NSAI groups provided significant PFS and OS superiority to NSAI alone. Abem+NSAI represented a significant statistical advantage on PFS and indicated a trend in best OS benefit compared to the Placebo+NSAI group. Abem+NSAI, Palbo+NSAI, and Ribo+NSAI groups resulted in additional costs of $12,602, $20,391, and $81,258, with additional effects of 0.38, 0.31, and 0.30 QALYs, respectively, leading to an ICUR of $33,163/QALY, $65,777/QALY, and $270,860/QALY. Additional pairwise comparisons showed Abem+NSAI was the only cost-effective option in three CDK4/6 inhibitors plus NSAI groups. The sensitivity analyses showed that the proportion of receiving subsequent CDK4/6 inhibitors and the cost of abemaciclib significantly influenced the results of Abem+NSAI. From the Chinese payers'perspective, Abem+NSAI was a cost-effective treatment compared with Placebo+NSAI at the willingness-to-pay of $38,029/QALY. The Palbo+NSAI and Ribo+NSAI groups were cost-effective unless adjusting drug prices to 50% or 10% of current prices is probably cost-effective.