Abstract Background: Coronavirus disease 2019 (COVID-19) has posed a great challenge for the treatment of cancer patients. COVID-19 presents as a severe respiratory infection in aging individuals, including lung cancer patients. COVID-19 may be linked to the progression of aggressive lung cancer. Conversely, the side effects of chemotherapy, such as chemotherapy resistance and the acceleration of cellular senescence could worsen COVID-19. Considering the above-mentioned facts, our present work aimed to investigate the role of paclitaxel (a chemotherapy drug) in the cell proliferation, apoptosis, and cellular senescence of gefitinib-resistant NSCLC cells (PC9-MET) and to reveal the underlying mechanisms. Methods: PC9-MET cells were treated with paclitaxel for 72 h and were then evaluated by a cell viability assay, DAPI staining, Giemsa staining, apoptosis assay, ROS assay, SA-β-Gal staining, TUNEL assay and Western blotting.Results: Our results revealed that paclitaxel significantly reduced the viability of PC9-MET cells and induced morphological signs of apoptosis. The apoptotic effects of paclitaxel were observed by increased levels of cleaved caspase-3, cleaved caspase-9 and cleaved PARP. Additionally, paclitaxel increased ROS production, leading to DNA damage. Importantly, paclitaxel eliminated cellular senescence, which was observed by SA-β-Gal staining.Conclusion: In light of these findings, paclitaxel could be a promising anticancer drug and could offer a new therapeutic strategy for gefitinib-resistant NSCLC during the COVID-19 pandemic. Citation Format: Md Mohiuddin, Hideharu Kimura, Takashi Sone, Satoshi Watanabe, Hiroki Matsuoka, Keigo Saeki, Nanao Terada, Miki Abo, Kazuo Kasahara. The growth inhibitory effect of paclitaxel on gefitinib-resistant non-small cell lung cancer (NSCLC) cells during the COVID-19 pandemic [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB073.