Summary and interpretation of results
anaemia, diarrhoea, hypokalaemia, neutropenia
ANAEMIA, DISEASE PROGRESSION, NEUTROPENIA
5-FU in combination with either oxaliplatin or irinotecan (± VEGF or EGFR inhibitor) is an established treatment for mCRC, with good clinical efficacy at an acceptable cost [Pembrolizumab was the first and only PD-1 inhibitor approved by the NMPA in China as the first-line therapy for patients with dMMR/MSI-H mCRC based on the results of the KEYNOTE-177 trial. The trial demonstrated that pembrolizumab treatment significantly prolonged survival compared with standard chemotherapy. In the Chinese context, given the incremental benefit and cost related to this treatment, we conducted the first study, to our knowledge, detecting the cost-effectiveness of pembrolizumab as the first-line regimen in patients with dMMR/MSI-H advanced or metastatic CRC. On the basis of our model, pembrolizumab was projected to extend patient life expectancy to a point not previously seen in this patient population. For instance, in the pembrolizumab arm, life expectancy was projected to reach nearly 9 years, approximately 1.5 times that of the chemotherapy group (increase patients’ survival by 3 years with discounting), despite the high proportion of crossover in the control group after disease progression. In addition, from the perspective of safety, the incidence of AEs (Grade ≥ 3), such as diarrhoea, anaemia, hypokalaemia and neutropenia, in Group P was lower than that in Group C, which, to some extent, reduced the cost and improved the quality of life for patients. The associated incremental cost per QALY gained was U.S.$30,330.15. While there is no single established ICER threshold for cost-effectiveness in China, the World Health Organization has referenced a threshold of 3 times the estimated per capita GDP with respect to disability-adjusted life years, which in China for in 2022 would correspond to U.S.$38,142.56/QALY [In univariable sensitivity analyses, the most influential driver of the ICER was the consideration of PAP. The PAP called “Key to Life” was approved in China on July 8, 2021 [