Background: The combination of anti-VEGF or anti-EGFR targeted drugs with chemotherapy is the standard first-line therapy for metastatic colorectal cancer (mCRC), and the followed maintenance treatment is an optional approach to balance the efficacy and toxicity. However, studies regarding the maintenance strategies based on antiangiogenic TKIs are limited currently. Anlotinib, a novel oral multi-target TKI which can inhibit both tumor angiogenesis and tumor cell proliferation simultaneously, substantially prolonged the PFS with manageable toxicity for refractory mCRC in the phase III ALTER0703 clinical trial. Here we report an update of efficacy and safety results which provide a longer follow up and increased number of patients. Methods: In this open label, single-arm, multi-center, phase II clinical trial, 29 mCRC patients without prior systemic treated, aged 18-75 and an ECOG performance status of 0 or 1 were planned to recruit. Eligible patients received capecitabine (1000 mg/m², po, d1-14, q3w) and oxaliplatin (130 mg/m², iv, d1, q3w) plus anlotinib (10mg, po, d1̃14, q3w) treatment for 6 cycles. After 6 cycles of inducing therapy, patients would receive anlotinib (12mg, po, d1̃14, q3w) as maintenance therapy until disease progression or intolerable adverse events (AEs). The primary endpoint was PFS; Secondary endpoints included ORR, DCR, DOR and safety. Results: At data cut-off date (January 18, 2022), the total 29 patients were enrolled, of which 23 patients were available for efficacy assessment. In best overall response assessment, there were 56.5% PR (13/23), 34.8% SD (8/23) and 8.7% PD (2/23). The ORR was 56.5% (95% CI, 34.5-76.8%) and DCR was 91.3% (95% CI, 72.0-98.9%). The longest duration of treatment was 17.5 months. The median PFS was not reached. The most common treatment related adverse events (TRAEs) of any grade (≥30%) were hypertension, leukopenia, nausea/vomiting, hypertriglyceridemia, neutropenia, hypohemoglobinemia, hypoalbuminemia. Grade 3/4 TRAEs (≥10%) were neutropenia (13.8%), hypertension (13.8%) and hypertriglyceridemia (10.3%). One grade 5 TRAE was pancytopenia that occurred at 2.7 months. Conclusions: The update results suggested that anlotinib combined with XELOX as first line regimen followed by anlotinib monotherapy showed favorable anti-tumor activity and manageable safety for patients with mCRC. And the conclusions needed to be confirmed in randomized study continued subsequently. Clinical trial information: ChiCTR1900028417.