Efficacy and safety of anti-PD-1/anti-PD-L1 antibody therapy in treatment of advanced gastric cancer or gastroesophageal junction cancer: A meta-analysis

BACKGROUND Faced with limited and inadequate treatment options for patients with advanced gastric cancer or gastroesophageal junction cancer(GC/GEJC), researchers have turned toward, with the support of promising clinical trials, anti-PD-1/anti-PD-L1 antibody therapy. But there are also different clinical trial results. To better assess its efficacy and safety, we integrated data from 13 eligible studies for a systematic review and meta-analysis.AIM To comprehensively evaluate the efficacy and safety of anti-PD-1/anti-PD-L1 antibody therapy in the treatment of advanced GC/GEJC patients.METHODS PubMed, Web of Science, Cochrane Library,and EMBASE databases were searched to identify eligible articles with outcomes including objective response rate(ORR), disease control rate(DCR), overall survival(OS), progression-free survival(PFS), and adverse events(AEs) of anti-PD-1/anti-PD-L1 antibody therapy.RESULTS Our study encompassed a total of 13 trials totaling 1618 patients. The outcomes showed a pooled ORR and DCR of 15%(95% confidence interval [CI]: 14%-18%) and 40%(95%CI: 33%-46%), respectively. The pooled 6-mo OS and PFS were 54%(95%CI: 45%-64%) and 26%(95%CI: 20%-32%), respectively, and the 12-mo OS and PFS were 42%(95%CI: 21%-62%) and 11%(95%CI: 8%-13%), respectively. In addition, the incidence of any-grade AEs and grade ≥ 3 AEs was 64%(95%CI: 54%-73%) and 18%(95%CI: 16%-20%), respectively. Most importantly, PD-L1 positive patients exhibited a higher ORR rate than PD-L1 negative patients(odds ratio = 2.54, 95%CI: 1.56-4.15).CONCLUSION Anti-PD-1/anti-PD-L1 antibody therapy has shown promising anti-tumor efficacy with manageable AEs in advanced GC/GEJC patients, with PD-L1 overexpressing patients exhibiting a higher ORR. What is more, the clinical efficacy of anti-PD-1/PD-L1 combined with traditional chemotherapy drugs is even better, although the occurrence of AEs still causes considerate concerns.

Immunotherapy in gastric cancer

Gastric cancer is the second most common of cancerrelated deaths worldwide.In the majority of cases gastric cancer is advanced at diagnosis and although medical and surgical treatments have improved,survival rates remain poor.Cancer immunotherapy has emerged as a powerful and promising clinical approach for treatment of cancer and has shown major success in breast cancer,prostate cancer and melanoma.Here,we provide an overview of concepts of modern cancer immunotherapy including the theory,current approaches,remaining hurdles to be overcome,and the future prospect of cancer immunotherapy in the treatment of gastric cancer.Adaptive cell therapies,cancer vaccines,gene therapies,monoclonal antibody therapies have all been used with some initial successes in gastric cancer.However,to date the results in gastric cancer have been disappointing as current approaches often do not stimulate immunity efficiently allowing tumors continue to grow despite the presence of a measurable immune response.Here,we discuss the identification of targets for immunotherapy and the role of biomarkers in prospectively identifying appropriate subjects or immunotherapy.We also discuss the molecular mechanisms by which tumor cells escape host immunosurveillance and produce an immunosuppressive tumor microenvironment.We show how advances have provided tools for overcoming the mechanisms of immunosuppression including the use of monoclonal antibodies to block negative regulators normally expressed on the surface of T cells which limit activation and proliferation of cytotoxic T cells.Immunotherapy has greatly improved and is becoming an important factor in such fields as medical care and welfare for human being.Progress has been rapid ensuring that the future of immunotherapy for gastric cancer is bright.

Antibody Therapies Targeting Complex Membrane Proteins

In analyses of protein families that may serve as drug targets,membrane-associated G-protein-coupled receptors(GPCRs)dominate,followed by ion channels,transporters,and—to a lesser extent—membrane-bound enzymes.However,various challenges put such membrane proteins among key groups of underutilized opportunities for the application of therapeutic antibodies.Antibodies hold the promise of exquisite specificity,as they are able to target even specific conformations of a particular membrane protein,as well as adaptability through engineering into various antibody formats.However,the ease of raising and isolating specific,effective antibodies targeting membrane proteins depends on many factors.In particular,the generation of specific antibodies is easier when targeting larger,simpler,extracellular domains with greater uniqueness of amino acid sequence.The rareness of such ideal conditions is illustrated by the limited number of approved biologics for targeting GPCRs and other complex membrane proteins.Challenges in developing antibodies to complex membrane proteins such as GPCRs,ion channels,transporters,and membrane-bound enzymes can be addressed by the design of the antigen,antibody-generation strategies,lead optimization technologies,and antibody modalities.A better understanding of the membrane proteins being targeted would facilitate mechanism-based drug discovery.This review describes the advantages and challenges of targeting complex membrane proteins with antibodies and discusses the preparation of membrane protein antigens and antibody generation,illustrated by select examples of success.

Recent advances in treatment of nodal and gastrointestinal follicular lymphoma

Follicular lymphoma(FL)is the most common low-grade lymphoma,and although nodal FL is highly responsive to treatment,the majority of patients relapse repeatedly,and the disease has been incurable with a poor prognosis.However,primary FL of the gastrointestinal tract has been increasingly detected in Japan,especially due to recent advances in small bowel endoscopy and increased opportunities for endoscopic examinations and endoscopic diagnosis.However,many cases are detected at an early stage,and the prognosis is good in many cases.In contrast,in Europe and the United States,gastrointestinal FL has long been considered to be present in 12%-24%of Stage-IV patients,and the number of advanced gastrointestinal cases is expected to increase.This editorial provides an overview of the recent therapeutic advances in nodal FL,including antibody-targeted therapy,bispecific antibody therapy,epigenetic modulation,and chimeric antigen receptor T-cell therapy,and reviews the latest therapeutic manuscripts published in the past year.Based on an understanding of the therapeutic advances in nodal FL,we also discuss future possibilities for gastroenterologists to treat gastrointestinal FL,especially in advanced cases.

Nanoparticles(NPs)-mediated systemic mRNA delivery to reverse trastuzumab resistance for effective breast cancer therapy

Monoclonal antibody-based therapy has achieved great success and is now one of the most crucial therapeutic modalities for cancer therapy.The first monoclonal antibody authorized for treating human epidermal growth receptor 2(HER2)-positive breast cancer is trastuzumab.However,resistance to trastuzumab therapy is frequently encountered and thus significantly restricts the therapeutic outcomes.To address this issue,tumor microenvironment(TME)pH-responsive nanoparticles(NPs)were herein developed for systemic mRNA delivery to reverse the trastuzumab resistance of breast cancer(BCa).This nanoplatform is comprised of a methoxyl-poly(ethylene glycol)-b-poly(lactic-co-glycolic acid)copolymer with a TME pH-liable linker(Meo-PEG-Dlinkm-PLGA)and an amphiphilic cationic lipid that can complex PTEN mRNA via electrostatic interaction.When the long-circulating mRNA-loaded NPs build up in the tumor after being delivered intravenously,they could be efficiently internalized by tumor cells due to the TME pH-triggered PEG detachment from the NP surface.With the intracellular mRNA release to up-regulate PTEN expression,the constantly activated PI3K/Akt signaling pathway could be blocked in the trastuzumab-resistant BCa cells,thereby resulting in the reversal of trastuzumab resistance and effectively suppress the development of BCa.

Chinese Medicine Amygdalin and β-Glucosidase Combined with Antibody Enzymatic Prodrug System As A Feasible Antitumor Therapy

Amarogentin is an efficacious Chinese herbal medicine and a component of the bitter apricot kernel.It is commonly used as an expectorant and supplementary anti-cancer drug.β-Glucosidase is an enzyme that hydrolyzes the glycosidic bond between aryl and saccharide groups to release glucose.Upon their interaction,β-glucosidase catalyzes amarogentin to produce considerable amounts of hydrocyanic acid,which inhibits cytochrome C oxidase,the terminal enzyme in the mitochondrial respiration chain,and suspends adenosine triphosphate synthesis,resulting in cell death.Hydrocyanic acid is a cell-cycle-stage-nonspecific agent that kills cancer cells.Thus,β-glucosidase can be coupled with a tumor-specific monoclonal antibody.β-Glucosidase can combine with cancer-cell-surface antigens and specifically convert amarogentin to an active drug that acts on cancer cells and the surrounding antibodies to achieve a kil ing effect.β-Glucosidase is injected intravenously and recognizes cancer-cel-surface antigens with the help of an antibody.The prodrug amarogentin is infused after β-glucosidase has reached the target position.Coupling of cell membrane peptides with β-glucosidase allows the enzyme to penetrate capillary endothelial cells and clear extracellular deep solid tumors to kill the cells therein.The Chinese medicine amarogentin and β-glucosidase will become an important treatment for various tumors when an appropriate monoclonal antibody is developed.

Broad strategies for neutralizing SARS-CoV-2 and other human coronaviruses with monoclonal antibodies

Antibody therapeutics and vaccines for coronavirus disease 2019(COVID-19)have been approved in many countries,with most being developed based on the original strain of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).SARS-CoV-2 has an exceptional ability to mutate under the pressure of host immunity,especially the immune-dominant spike protein of the virus,which is the target of both antibody drugs and vaccines.Given the continuous evolution of the virus and the identification of critical mutation sites,the World Health Organization(WHO)has named 5 variants of concern(VOCs):4 are previously circulating VOCs,and 1 is currently circulating(Omicron).Due to multiple mutations in the spike protein,the recently emerged Omicron and descendent lineages have been shown to have the strongest ability to evade the neutralizing antibody(NAb)effects of current antibody drugs and vaccines.The development and characterization of broadly neutralizing antibodies(bNAbs)will provide broad strategies for the control of the sophisticated virus SARS-CoV-2.In this review,we describe how the virus evolves to escape NAbs and the potential neutralization mechanisms that associated with bNAbs.We also summarize progress in the development of bNAbs against SARS-CoV-2,human coronaviruses(CoVs)and other emerging pathogens and highlight their scientific and clinical significance.

Letter to the editor: Neutralizing antibodies for the treatment of COVID-19

To the Editor:Coronavirus disease 2019(COVID-19)is a global epidemic caused by the infection of severe acute respiratory coronavirus 2(SARS-Co V-2)and its mortality rate was up to 20 times higher than that of influenza.The virus is infectious,strange and variable.