Pembrolizumab: a novel antiprogrammed death 1 (PD-1) monoclonal antibody for treatment of metastatic melanoma

Global trends in the health economics field of PD-1/PD-L1 inhibitors: A bibliometric and visualized study

Inhibitors of programmed cell death protein 1 and its associated ligand (PD-L1) are widely used in cancer treatment. However, medical costs and benefits of PD-1/PD-L1 inhibitors need attention owing to differences in response rates among individuals. This study explored global trends in the health economics field of PD-1/PD-L1 inhibitors to enhance their worldwide development. Bibliometric analysis of all documents currently indexed in Web of Science Core Collection from inception to 2022 was performed. Publication year, authors, countries, institutes, and journals were analyzed by Bibliometrix package (version 3.2.1) in R (version 4.1.3). CiteSpace (version 6.1.R6) and VOSviewer (version 1.6.18) were used to analyze burst words, co-authorship of institutes, co-cited journals, and co-cited references, while figures were mainly drawn by Ggplot2 package (version 3.3.5) in R (version 4.1.3) and SCImago Graphica Beta (version 1.0.23). A total of 2020 documents related to the health economics of PD-1/PD-L1 inhibitors were identified, and 1,204 documents met the selection criteria for inclusion in the study. A rapid increase in the number of publications since 2019 was observed, but this increase stopped in 2022, revealing research saturation in the field. Value in Health (166 publications, 13.79% of total documents) had the most publications, while New England Journal of Medicine (2,890 co-citations) was the most co-cited journal. The United States was the leading contributor in this field with 506 publications and the top two productive institutes globally. The main hot topics included the cost-effectiveness of treatment with PD-1 and/or PD-L1 inhibitors, and the comparison between the cost-effectiveness of PD-/PD-L1 inhibitors and other drugs. There were substantial differences between developed and developing countries in the health economics field of PD-1 and/or PD-L1 inhibitors. The cost-effectiveness analysis of combined treatment with PD-1/PD-L1 inhibitors and other drugs warrants further attention. Findings from this study may provide governments and pharmaceutical companies with a strong reference for future research.

Development of Novel Ecto-Nucleotide Pyrophosphatase/Phosphodiesterase 1 (ENPP1) Inhibitors for Tumor Immunotherapy

The cyclic guanosine monophosphate–adenosine monophosphate synthase–stimulator of interferon genes–TANK-binding kinase 1–interferon regulating factor 3 (cGAS-STING-TBK1-IRF3) axis is now acknowledged as the major signaling pathway in innate immune responses. However, 2′,3′-cGAMP as a STING stimulator is easily recognized and degraded by ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which reduces the effect of tumor immunotherapy and promotes metastatic progression. In this investigation, the structure-based virtual screening strategy was adopted to discover eight candidate compounds containing zinc-binding quinazolin-4(3H)-one scaffold as ENPP1 inhibitors. Subsequently, these novel inhibitors targeting ENPP1 were synthesized and characterized by NMR and high-resolution mass spectra (HRMS). In bioassays, 7-fluoro-2-(((5-methoxy-1H-imidazo[4,5-b]pyridin-2-yl)thio)methyl)quina-zolin-4(3H)-one(compound 4e) showed excellent activity against the ENPP1 at the molecular and cellular levels, with IC₅₀ values of 0.188 μM and 0.732 μM, respectively. Additionally, compound 4e had superior selectivity towards metastatic breast cancer cells (4T1) than towards normal cells (LO2 and 293T) in comparison with cisplatin, indicating that compound 4e can potentially be used in metastatic breast cancer therapy. On the other hand, compound 4e upgraded the expression levels of IFN-β in vivo by preventing the ENPP1 from hydrolyzing the cGAMP to stimulate a more potent innate immune response. Therefore, this compound might be applied to boost antitumor immunity for cancer immunotherapy. Overall, our work provides a strategy for the development of a promising drug candidate targeting ENPP1 for tumor immunotherapy.

Modeling the effect of gut microbiome on therapeutic efficacy of immune checkpoint inhibitors against cancer

Immune checkpoint inhibitors have been shown to be highly successful against some solid metastatic malignancies, but only for a subset of patients who show durable clinical responses. The overall patient response rate is limited due to the interpatient heterogeneity. Preclinical and clinical studies have recently shown that the therapeutic responses can be improved through the modulation of gut microbiome. However, the underlying mechanisms are not fully understood. In this paper, we explored the effect of favorable and unfavorable gut bacteria on the therapeutic efficacy of anti-PD-1 against cancer by modeling the tumor-immune-gut microbiome interactions, and further examined the predictive markers of responders and non-responders to anti-PD-1. The dynamics of the gut bacteria was fitted to the clinical data of melanoma patients, and virtual patients data were generated based on the clinical patient survival data. Our simulation results show that low initial growth rate and low level of favorable bacteria at the initiation of anti-PD-1 therapy are predictive of non-responders, while high level of favorable bacteria at the initiation of anti-PD-1 therapy is predictive of responders. Simulation results also confirmed that it is possible to promote patients' response rate to anti-PD-1 by manipulating the gut bacteria composition of non-responders, whereby achieving long-term progression-free survival.

Small molecules targeting the innate immune cGAS‒STING‒TBK1 signaling pathway

Multiple cancer immunotherapies including chimeric antigen receptor T cell and immune checkpoint inhibitors (ICIs) have been successfully developed to treat various cancers by motivating the adaptive anti-tumor immunity. Particularly, the checkpoint blockade approach has achieved great clinic success as evidenced by several U.S. Food and Drug Administration (FDA)-approved anti-programmed death receptor 1/ligand 1 or anti-cytotoxic T lymphocyte associated protein 4 antibodies. However, the majority of cancers have low clinical response rates to these ICIs due to poor tumor immunogenicity. Indeed, the cyclic guanosine monophosphate-adenosine monophosphate synthase‒stimulator of interferon genes‒TANK-binding kinase 1 (cGAS‒STING‒TBK1) axis is now appreciated as the major signaling pathway in innate immune response across different species. Aberrant signaling of this pathway has been closely linked to multiple diseases, including auto-inflammation, virus infection and cancers. In this perspective, we provide an updated review on the latest progress on the development of small molecule modulators targeting the cGAS‒STING‒TBK1 signaling pathway and their preclinical and clinical use as a new immune stimulatory therapy. Meanwhile, highlights on the clinical candidates, limitations and challenges, as well as future directions in this field are also discussed. Further, small molecule inhibitors targeting this signaling axis and their potential therapeutic use for various indications are discussed as well.

Biopharmaceutical Potential of Selegiline Loaded Chitosan Nanoparticles in the Management of Parkinson's Disease

BACKGROUND

Selegiline hydrochloride, a hydrophilic anti-Parkinson' moiety, undergoes extensive first-pass metabolism and has low bioavailability. A process to obtain of selegiline (SH) loaded chitosan nanoparticles was attempted to circumvent the above problem, through intranasal delivery.

METHODS

SH loaded polymeric nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate, and stabilized by tween 80/ poloxamer 188. The resulting nanoparticles (NPs) were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, entrapment efficiency, particle size, zeta potential and surface morphology by scanning electron microscopy. Further, they were schematically evaluated for mucoadhesive strength, in-vitro drug release, release kinetics, pharmacokinetics, catalepsy, akinesia, in-vivo lipid peroxidation, nitrite levels, glutathione, catalase enzyme levels in brain and physicochemical stability parameters.

RESULTS

Selegiline nanoparticles (SP18) produced were in size of 63.1 nm, polydispersity index of 0.201, zeta potential of +35.2 mV, mucoadhesion of 65.4% and entrapment efficiency of 74.77%. Selegiline showed biphasic release from nanoparticles, over a period of 36 h, with Fickian diffusion controlled release profile. Maximum concentration of SH in plasma was recognized as 52.71 ng/ml at 2 h for SP18, 20.09 ng/ml at 1 h for marketed formulation, and 21.69 ng/ ml for drug solution. SH loaded NPs showed a reversive effect in catalepsy and akinesia behaviour. This effect was especially pronounced in rats receiving SH loaded CS-NPs. Significant decrease in lipid peroxidation and nitrite concentration; increase in reduced glutathione and catalase enzyme levels were obtained due to antioxidant characteristics of SH, which turned to be useful to treat Parkinson's disease.

CONCLUSION

Selegiline loaded chitosan nanoparticles form an effective non-invasive drug delivery system of direct nose to brain targeting in Parkinson's disease.

Mitoribosome Defect in Hepatocellular Carcinoma Promotes an Aggressive Phenotype with Suppressed Immune Reaction

Mitochondrial ribosomes (mitoribosomes), the specialized translational machinery for mitochondrial genes, exclusively encode the subunits of the oxidative phosphorylation (OXPHOS) system. Although OXPHOS dysfunctions are associated with hepatic disorders including hepatocellular carcinoma (HCC), their underlying mechanisms remain poorly elucidated. In this study, we aimed to investigate the effects of mitoribosome defects on OXPHOS and HCC progression. By generating a gene signature from HCC transcriptome data, we developed a scoring system, i.e., mitoribosome defect score (MDS), which represents the degree of mitoribosomal defects in cancers. The MDS showed close associations with the clinical outcomes of patients with HCC and with gene functions such as oxidative phosphorylation, cell-cycle activation, and epithelial-mesenchymal transition. By analyzing immune profiles, we observed that mitoribosomal defects are also associated with immunosuppression and evasion. Taken together, our results provide new insights into the roles of mitoribosome defects in HCC progression.

•

A set of down-regulated MRPs in HCC cause mitoribosomal defects

•

Mitoribosomal defects are linked to aggressive molecular features and poor prognosis

•

Mitoribosomal defects in HCC are associated with immunosuppression and evasion

•

TGF-β signaling pathway is a crucial mechanism to mediate mitoribosomal defects in HCC

Reactive Oxygen Species Regulate T Cell Immune Response in the Tumor Microenvironment

Reactive oxygen species (ROS) produced by cellular metabolism play an important role as signaling messengers in immune system. ROS elevated in the tumor microenvironment are associated with tumor-induced immunosuppression. T cell-based therapy has been recently approved to be effective for cancer treatment. However, T cells often become dysfunctional after reaching the tumor site. It has been reported that ROS participate extensively in T cells activation, apoptosis, and hyporesponsiveness. The sensitivity of T cells to ROS varies among different subsets. ROS can be regulated by cytokines, amino acid metabolism, and enzymatic activity. Immunosuppressive cells accumulate in the tumor microenvironment and induce apoptosis and functional suppression of T cells by producing ROS. Thus, modulating the level of ROS may be important to prolong survival of T cells and enhance their antitumor function. Combining T cell-based therapy with antioxidant treatment such as administration of ROS scavenger should be considered as a promising strategy in cancer treatment, aiming to improve antitumor T cells immunity.

Molecular Imaging of Immunotherapy Targets in Cancer

Immunotherapy has emerged as a promising alternative in the arsenal against cancer by harnessing the power of the immune system to specifically target malignant tissues. As the field of immunotherapy continues to expand, researchers will require newer methods for studying the interactions between the immune system, tumor cells, and immunotherapy agents. Recently, several noninvasive imaging strategies have been used to map the biodistribution of immune checkpoint molecules, monitor the efficacy and potential toxicities of the treatments, and identify patients who are likely to benefit from immunotherapies. In this review, we outline the current applications of noninvasive techniques for the preclinical imaging of immunotherapy targets and suggest future pathways for molecular imaging to contribute to this developing field.