Influence of Eastern Cooperative Oncology Group performance status (ECOG PS), tumor size and age on patient outcomes after anlotinib treatment: A subgroup analysis based on ALTER01031 trial for medullary thyroid carcinoma (MTC).

Abstract

6527 Background: Anlotinib is a newly developed TKI achieved a nearly 2-fold PFS prolongation in a randomized, placebo-controlled phase 2b trial (NCT02586350) for MTC, the results of which were firstly published in 2019 ASCO annual meeting. This subanalysis examined the influence of baseline demographic (ECOG PS score, age) and tumor size on efficacy in this study. Methods: Kaplan-Meier method was applied to estimate the median PFS (mPFS) for subgroups of patients (pts) received anlotinib or placebo based on ECOG PS score (0 vs. 1), median tumor lesion diameter ( < 67 vs. ≥67mm) and age ( < 55 vs. ≥55 years old). Results: 91 eligible pts were randomly assigned in a 2:1 ratio to receive anlotinib or placebo. The numbers of pts in each subgroup were summarized in the table below. In placebo arm, mPFS did not differ significantly between pts with ECOG PS 0 and 1 (11.3 vs. 11.1months; HR = 0.895 [95% CI 0.347, 2.312], P = 0.821) or between pts with tumor lesion diameter < 67mm and ≥ 67mm (7.0 vs. 11.1 months; HR = 1.168 [95% CI 0.463, 2.945], P = 0.737). Conversely, pts in anlotinib arm with ECOG PS 0 obtained more PFS benefits (34.6 vs. 14.0 months; HR = 0.331 [95% CI 0.163, 0.671], P = 0.002). Similarly, anlotinib treated pts with tumor lesion diameters < 67mm achieved a longer mPFS (Not reached vs. 14.0 months, HR = 0.567 [95% CI 0.280, 1.147], P = 0.111). Consistent with that has been verified in differentiated thyroid cancer, high age predicted poor prognosis as mPFS were 14.3 months and 6.8 months in pts < 55 and ≥ 55 years old respectively in placebo arm (HR = 0.322 [95% CI 0.116, 0.893], P = 0.007).). Anlotinib treatment exhibited PFS improvement to pts in both age groups but higher PFS prolongation was observed in pts < 55 years old (22.4 vs. 14.0 months; HR = 0.720 [95% CI 0.321, 1.614], P = 0.381). Conclusions: This analysis showed that for pts in placebo arm, PFS was similar regardless of functional status (ECOG PS) or tumor size while older pts had higher progression risk. Treatment with anlotinib exhibited greater PFS benefits for pts with better functional status (ECOG PS = 0), younger age or lower tumor burden. These results indicated that it is reasonable to start anlotinib treatment at a relative earlier disease stage before the worsen of ECOG PS, increase of tumor size or ageing. Clinical trial information: NCT02586350 . [Table: see text]