Effectiveness of osimertinib plus chemotherapy and avastin for untreated EGFR-mutated advanced non-small cell lung cancer.

Abstract

e21178 Background: Osimertinib is recommended as a novel first-line standard treatment for advanced Non-Small-Cell Lung Cancer (NSCLC) patients with EGFR mutation. However, there are also patients with concurrent mutation or/and metastases have limited benefits. According to the current remission rate, regression depth and PFS data, the main mechanism of the benefit of combined anti-angiogenesis or chemotherapy is to reduce tumor load and heterogeneous reserve to a greater extent, so as to extend the remission time, that is, to delay the occurrence of drug resistance to extend PFS. This prospective study aims to investigate the efficacy and safety of Osimertinib plus chemotherapy and Avastin for Untreated EGFR-Mutated advanced NSCLC. Methods: The study enrolled 22 patients diagnosed with untreated advanced NSCLC and tested with EGFR mutation, who received osimertinib ( 80mg QD) plus pemetrexed (500mg/m2), cisplatin (75mg/m2) and bevacizumab (7.5mg/kg) for 6 cycles, then maintained with osimertinib/pemetrexed/bevacizumab. The primary endpoint was progression free survival (PFS). The secondary endpoint was objective response rate (ORR). Treatment was continued until disease progression and the tumor response was determined according to the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1. The toxicity was determined according to CTCAE 4.0. Results: From February, 2018 to July, 2020, 22 patients enrolled. All the patients were evaluated and showed partial response(PR) when make efficacy evaluation at the first time. The target lesions reduction were shown. The average reduction is 48%, ranged from 32% of Pt12 to 71% of Pt11. Up to January, 2021, all the patients are still under the treatment. Especially for Pt7 who has already benefited from the treatment protocol by 35months. The toxicities associated with this protocols were manageable. Only 1 patient was 3/4-grade Anemia, 1 patient was 3/4-grade Diarrhea and 3 patients was 3/4-grade Lymphopenia. Conclusions: Osimertinib in combination with chemotherapy and Bevacizumab. exhibits superior activity and generally manageable toxicities for the naive advanced NSCLC patients with EGFR mutant, especially for the patients with concurrent mutation or/and metastases. It may provide a new and effective therapy strategy for them, but large sample and additional clinical trials are also needed.