Abstract:

Objective To compare the efficacy and safety of programmed death-1 (PD-1) inhibitors monotherapy and combined with chemotherapy/targeted therapy in the treatment of advanced malignant tumors. Methods The clinical data of 52 patients with advanced malignant tumors treated with PD-1 inhibitors from January 2017 to August 2018 in Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College were analyzed. All the patients were divided into monotherapy group (n=23) and combined therapy group (n=29) according to the therapeutic regimen. The monotherapy group received only PD-1 inhibitors and the combined therapy group received PD-1 inhibitors combined with chemotherapy/targeted therapy. The therapeutic effects and adverse reactions of the two groups were compared. Results Of the 52 patients, 38 were evaluated according to the imaging results, including 15 in the monotherapy group and 23 in the combined therapy group. The overall response rates of the monotherapy group and combined therapy group were 33.33% (5/15) and 34.78% (8/23) respectively, with no significant difference (P=0.604). The disease control rates of the monotherapy group and combined therapy group were 80.00% (12/15) and 73.91% (17/23), with no significant difference (P=0.490). The median overall survival (OS) of the monotherapy group was 6.0 months, and that of the combined therapy group was 5.0 months, with no significant difference (χ ²=0.790, P=0.374). The median progression-free survival (PFS) of the monotherapy group was 6.0 months, and that of the combined therapy group was 5.0 months, with no significant difference (χ ²=0.371, P=0.542). The incidence of abdominal pain and diarrhea was lower in the monotherapy group [grade 1-2: 8.7% (2/23), grade 3 and above: 0] than that in the combined therapy group [grade 1-2: 27.59% (8/29), grade 3 and above: 6.90% (2/29); Z=2.211, P=0.027]. There were no significant differences in the incidence of bone marrow suppression, nausea and vomiting, rash, liver and kidney function impairment or treatment-related pneumonia between the two groups (all P>0.05). Conclusion For patients with advanced malignant tumors, there is no significant difference in OS and PFS whether PD-1 inhibitors are taken separately or together, but the incidence of abdominal pain and diarrhea in patients treated with PD-1 inhibitors alone is lower than that in patients treated with combined therapy.

Key words: Immunosuppressive agents, Antineoplastic combined chemotherapy protocols, Treatment outcome, Adverse effects