Appropriate PD-L1 Cutoff Value for Gastric Cancer Immunotherapy: A Systematic Review and Meta-Analysis

BackgroundImmunotherapy dramatically changed the treatment landscape of gastric cancer in recent years. PD-L1 expression was proposed as a biomarker; however, the treatment strategy according to PD-L1 is still uncertain. Here, we aimed to find the appropriate cutoff value of PD-L1 expression for gastric cancer immunotherapy.MethodsWe did a systematic electronic research of prospective clinical trials of gastric cancer immunotherapy across databases. Studies that provided subgroup analysis results stratified by PD-L1 expression were included. Objective response rate (ORR), disease control rate (DCR), hazard ratio (HR), and 95% confidential interval (CI) of progression-free survival (PFS) and overall survival (OS) at different PD-L1 cutoff values were extracted.ResultsTwelve studies and 6,488 patients in total were finally included for pooled analysis. ORR in allover, PD-L1-negative, combined positive score (CPS) ≥1, CPS ≥5, and CPS ≥10 population was 10%, 3%, 13%, 20%, and 23%, respectively. Immune checkpoint inhibitor (ICI) monotherapy failed to show survival advantage in allover and PD-L1-negative patients. Single-agent ICI therapy prolonged OS (HR = 0.84, 95% CI: 0.74–0.96) but not PFS (HR = 1.38, 95% CI: 0.91–2.09) in PD-L1 CPS ≥1 patients. For combined immunotherapy, ORR in allover, PD-L1-negative, CPS ≥1, CPS ≥5, and CPS ≥10 population was 64%, 57%, 48%, 60%, and 58%, respectively. Allover population could gain survival benefit from combined immunotherapy based on the results from Checkmate-649. OS (HR = 0.81, 95% CI: 0.71–0.92) and PFS (HR = 0.77, 95% CI: 0.69–0.86) were significantly prolonged in PD-L1 CPS ≥1 patients receiving combined immunotherapy.ConclusionEfficacy and survival advantages improved with PD-L1 CPS. CPS ≥1 was the cutoff value for ICI monotherapy to gain survival benefit. Combined immunotherapy prolonged PFS and OS in allover population but needs further study to confirm it.

EFFICACY OF COMBINED IMMUNOTHERAPY WITH PROPES AND INFLAMAFERTIN IN SELECTIVE DEFICIENCY OF NK AND NKT CELLS IN CHILDREN WITH AUTISM SPECTRUM DISORDERS ASSOCIATED WITH GENETIC DEFICIENCY OF THE FOLATE CYCLE

Objectives. The results of previous small clinical trials indicate the potential benefit of combination immunotherapy with Propes and Inflamafertin to compensate for NK and NKT cell deficiency due to genetic deficiency of the folate cycle in children with autism spectrum disorders. The purpose of the research was to study the effectiveness of combined immunotherapy with Propes and Inflamafertin in NK and NKT cell deficiency in children with autism spectrum disorders associated with genetic deficiency of the folate cycle. Material and methods. This single-center, prospective, controlled, nonrandomized clinical trial included 96 children aged 2 to 10 years with autism spectrum disorders associated with a genetic folate deficiency (study group, SG). Children of SG received Propes at a dose of 2 ml IM every other day for 3 consecutive months (45 injections), and Inflamafertin at a dose of 2 ml IM every other day for 3 months in a row, alternating with Propes (45 injections). The control group (CG) consisted of 32 children of similar age and gender distribution who suffered from autism spectrum disorders associated with genetic deficiency of the folate cycle, but who did not receive immunotherapy. Outcomes. The number of NK cells reached the lower limit of normal in 39 out of 53 patients (74% of cases), with the resulting deficiency of these lymphocytes, and the average number of NK cells in the blood in SG almost doubling during the 3-month course of immunotherapy (р ˂ 0.05; Z ˂ Z0.05). However, it returned to almost initial level in the 2 months following the discontinuation of immunotherapeutic agents (р˃0.05; Z˃Z0.05). The number of NKT cells was normalized in 78 out of 87 patients (89% of cases) with an initial deficiency of these cells, and the average number of NKT cells in the blood in the DG increased during the course of immunotherapy by half (р ˂ 0.05; Z ˂ Z0.05) and continued to grow for the next 2 months after the discontinuation of immunotropic drugs (р ˂ 0.05; Z ˂ Z0.05). There was a link between immunotherapy and normalization of NK - (χ2 = 18.016; OR = 13.929; 95%CI = 3.498-55.468) and NKT-cells (χ2 = 60.65; OR = 46.800; 95%CI = 14.415-151.937) in the blood with a strong association between these processes (criterion φ = 0.504 and 0.715 respectively; С = 0.450 and 0.581 respectively). Conclusions. Combination immunotherapy with Propes and Inflamafertin is an effective strategy for the treatment of immunodeficiency caused by genetic deficiency of the folate cycle in children with autism spectrum disorders.