Low-dose Gemcitabine Combined With Nivolumab for Second-line and Above Line Treatment of NSCLC

In recent years, immunotherapy research has made great progress, especially the immunocheckpoint inhibitors represented by anti-pd-1 antibody have shown good efficacy in the treatment of malignant tumors, and some patients can achieve long-term survival. However, despite the encouraging clinical data, only a small number of people have benefited. Therefore, how to further improve the efficacy of immunotherapy and expand the benefit population has become the focus of this field. Conventional view holds that chemotherapeutic drugs work by directly killing tumor cells. In recent years, with the in-depth understanding of immunity, people have realized that the anti-cancer effect of chemotherapy drugs depends on the body's sound immune system, and chemotherapy drugs have been more and more recognized as an immune regulator. However, it should be noted that the combination of drugs may not achieve the desired results, or even the opposite. The applicant was previously published in Oncoimmunology (2017; E1331807) pointed out in the above article: MDSC is a group of immunosuppressive cells, the number of this group of cells in the body of cancer patients is more than normal, its presence affects the proliferation, activation and function of T cells, is one of the important factors affecting the efficacy of immunocheckpoint inhibitors. Therefore, ideal drugs used in combination with immunocheckpoint inhibitors should meet the following conditions: first, they can kill or inactivate tumor cells to release tumor-specific or associated antigens; Second, MDSC and other immunosuppressive cells can be eliminated. Third, the number and function of T cells were not affected. Gemcitabine is a synthetic antimetabolic tumor drug widely used in the treatment of locally advanced or metastatic non-small cell lung cancer. Myelosuppression is the dose - limiting toxicity of gemcitabine, which includes lymphocytopenia. Therefore, if the commonly used clinical dose gemcitabine is used in combination with pd-1 antibody, the effect of pd-1 antibody will be affected due to the reduction of lymphocytes caused by gemcitabine. Therefore, we speculated that the reduced-dose treatment of gemcitabine combined with pd-1 antibody might have synergistic anti-tumor effect on the second-line and above second-line treatment of non-small cell lung cancer with negative driver gene, and the adverse reactions were relatively mild. This study is a phase IV, open, non-randomized, single-arm, single-center study to investigate the safety and efficacy of half-dose gemcitabine combined with pd-1 antibody in second-line and above treatment of non-small cell lung cancer patients with negative driver genes. Fifty subjects will be enrolled in this study. The primary endpoint of the study was objective efficiency (ORR), while secondary endpoints included disease control rate (DCR), disease-free progression (PFS), and overall survival (OS).