OBJECTIVES:To evaluate the progression-free survival and its associated factors among non-squamous NSCLC patients with first-line pemetrexed therapy before and after CDI policy implementation in Zhejiang province.

METHODS: A total of 353 Zhejiang residents, who were diagnosed with stage IIIb/IV non-squamous NSCLC, initiating their first-line pemetrexed therapy between 1/1/2010 and 31/10/2016, were included. All subjects were followed till 7/18/2018. CDI status were described as before CDI (before 12/2014) and after CDI (01/2015-11/2016). Pemetrexed adherence was measured by treatment cycles and used >4 cycles as the cut-off point. Survival analyses were used to assess factors associated with PFS.

RESULTS: Percentage of patients with pemetrexed treatment >4 cycles was significantly higher (p<0.0001) after CDI (39.08 %) compared to before CDI implementation (17.39%). The median PFS of the entire study population was 9.4 months (95%CI: 8.6-12.7). The median PFS of the entire study population did not differ significantly between patients before CDI (median: 8.6 months, 95%CI: 6.8-11.8) and after CDI (median: 10.8 months, 95%CI: 8.7-14.6) (HR: 0.827, p=0.2281). Among patients who used CDI-covered pemetrexed, the median PFS of those before CDI and after CDI was 8.7 months (95%CI: 6.4-12.7) and 14.2 months (95%CI: 9.4-20.7) respectively. There was no significant difference between two groups (HR: 0.759, p=0.2124). The median PFS among patients with pemetrexed treatment >4 cycles (median: 14.6 months, 95%CI: 10.8-35.7) was significantly longer than the PFS among patients with pemetrexed treatment ≤4 cycles (median: 7.2 months, 95%CI: 5.1-9.2) (HR: 0.464, p<0.0001). Multivariate Cox regression analysis showed a statistically significant association only between pemetrexed adherence and PFS (HR: 0.488, p<0.0179)

CONCLUSIONS:Zhejiang CDI policy has a positive impact on improving the pemetrexed adherence for advanced non-squamous NSCLC patients. While better pemetrexed adherence (treatment cycles >4 cycles) is significantly associated with longer PFS, the direct association between CDI policy implementation and PFS is inconclusive.