409P - Preliminary results of bevacizumab plus raltitrexed-based chemotherapy as second-line therapy in patients with metastatic colorectal cancer (mCRC): A multicenter phase II trial

Background

There are limited treatment options after failure of first-line fluoropyrimidine-based chemotherapy in mCRC.The study aimed to evaluate the efficacy and safety of bevacizumab plus raltitrexed-based (Saiweijian®) chemotherapy as second-line therapy in Chinese patients with mCRC.

Methods

This is a prospective,open-label,multicenter, phase II trial. One hundred patients were required. Enrolled patients were treated with BEV+SALIRI(bevacizumab 7.5mg/kg d1, raltitrexed 3mg/m² d1, irinotecan 200 mg ⁄m² d1,q3w) or BEV+SALOX(bevacizumab 7.5mg/kg d1,raltitrexed 3mg/m² d1, oxaliplatin 130mg⁄m² d1,q3w)(depending on first-line regimen). Patients treated for 6 cycles with efficacy evaluation SD or above were followed by maintenance therapy(bevacizumab7.5 mg/kg d1, raltitrexed 3 mg/m² d1,q3w) until disease progression or intolerable toxicity. The primary endpoint was PFS, and the secondary endpoints were ORR, DCR, OS, QOL and safety.

Results

Between 12/2016 and 10/2021, 100 patients were enrolled, and 94 patients were treated with BEV+SALIRI, the others accept BEV+SALOX. The median age was 56 years(range:19-77), ECOG PS 1 scored 89.0%. A total of 620 cycles were completed and 31 patients recieved maintenance therapy. ORR was 26.0%, DCR was 87.0%; Overall median PFS was 7.3m (95%CI：5.1-9.4), median OS was not observed yet.COX multivariate regression analysis showed that PFS was significantly associated with age, cycless and response evaluation. Adverse events (AE) were mostly grade 1/2, and no SAE occurred. The main treatment-related AEs were glutamyltransferase increased(52.0%), alanine aminotransferase increased (40.0%), aspartate aminotransferase increased(40.0%), elevated alkaline phosphatase(21%), neutropenia (19.0%), leukopenia (12.0%), fatigue (14.0%), nausea (10.0%) and diarrhea (10.0%). The treatment regimen was well tolerated.

Conclusions

The results suggest that the combination of bevacizumab and raltitrexed-based chemotherapy could be an effective and safe regimen for the second-line treatment in Chinese patients with mCRC, which is worth further exploration.

Clinical trial identification

NCT03126071.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.