Recent Patents on Anti-Cancer Drug Discovery - Volume 16, Issue 3, 2021

Background: Epidermal growth factor receptor and anaplastic lymphoma kinase play key roles in tumorigenesis and disease progression. Currently, targeted therapy is a better approach for cancer therapy compared with traditional chemotherapy. EGFR-based/ALK-based target therapies are key targets for drug development in cancer therapy. Objective: The objective of this study was to show a recent trend in research and development of EGFR-based/ALK-based targets and to better understand the Intellectual Property surrounding EGFR-based and ALK-based targets. Methods: EGFR-based and ALK-based targets were analyzed by comprehensive US patent analysis. US patents of EGFR-based/ALK-based targets were analyzed from September 2001 to September 2020. Results: The results indicated that the key technologies and methods of EGFR-based/ALK-based targets were developed by large global pharmaceutical companies or American companies/universities. Small molecular inhibitors showed a higher percentage in the number of patents of EGFRbased targets. In addition, the present study also showed recent small molecular targeted drugs approved by FDA. Conclusion: Global large pharmaceutical companies and American companies/universities have obvious advantages in the research and development of targeted drugs. EGFR-based target was still an attractive target for research and drug development in the past 10 years. Also, large global pharmaceutical companies prefer to complete key technology research and development by independent innovation instead of collaboration.

Background: Camrelizumab, which was launched in China on May 29, 2019, is a humanized anti-programmed cell death-1 (PD-1) antibody. It is used for the treatment of complicated or refractory classic Hodgkin's lymphoma with at least second-line chemotherapy. On March 4, 2020, camrelizumab was approved as a second-line drug in China for the treatment of advanced hepatocellular carcinoma. Currently, camrelizumab is undergoing clinical research for advanced solid tumors such as liver cancer, gastric cancer, esophageal cancer, and lung cancer, and all have shown clinical efficacy. Objective: This review describes preclinical studies on camrelizumab and its efficacy and safety in clinical studies in various tumors. Methods: A literature search was conducted on basic research and clinical trials of camrelizumab determined its pharmacology, toxicology, pharmacokinetic properties, and current clinical research status. We also analyzed the difference between camrelizumab and other PD-1 antibodies. Results: The results of preclinical studies show that camrelizumab binds to the PD-1 receptor and has stable anti-tumor activity in a dose-dependent manner. Clinical studies show that camrelizumab has therapeutic effects on a variety of tumors. The incidence of adverse reactions with camrelizumab is low, with most being mild, reversible, and predictable. Conclusion: This review summarizes the current status of preclinical and clinical studies on camrelizumab. Current research confirms that camrelizumab alone or in combination with other drugs shows significant anti-cancer activity and a low incidence of adverse reactions. However, further studies are needed to verify the application potential of camrelizumab in a variety of tumors.

Background: Pemetrexed is a folate analogue metabolic inhibitor for mammalian cells. Pemetrexed is toxic to several cancer cells by interfering with their new biosynthesis of nucleotides, thus causing cell apoptosis. Presently, Pemetrexed is given to patients with Non-Small Cell Lung Cancer (NSCLC). Objective: This review focuses on the recent patents of Pemetrexed. This assessment includes patents grouped in segments like crystalline form patent, composition related patents, product patents, as well as a method of treatment. The aim of this review is to simplify inventors with existing patents in a single place. Methods: Data were searched from several available databases, including paid databases which include Orbit® and SciFinder®. Free databases include Worldwide Espacenet® (EPO), Patentscope® (WIPO), InPASS (Indian patent database) and Google Patents. Results: Some new polymorph and composition-related inventions of Pemetrexed have been recently patented as its orange-book listed patents will soon expire in May 2022. Further, because of the problem of oxidation through the development and continuing storage of Pemetrexed composition, several excipients are experimented with within these patents to stabilize the same. Nevertheless, there is a need for further development of an improved composition of Pemetrexed with improved characteristics. Conclusion: Wide research has been conducted on different processes for preparing Pemetrexed and formulation thereof. Such type of active research may clear the track for the generic companies in the United States, producing the formulation at low prices and providing universal health care at economical prices.

Background: Ovarian cancer is a disease with the highest mortality in gynecologic malignancies. Activation of STAT3 pathway is well known to be associated with tumor progression and metastasis in a number of cancers, including ovarian cancer. Therefore, STAT3 may be an ideal target for ovarian cancer treatment. Objective: The present study aims to determine the antitumor activity of STAT3 inhibitor Napabucasin as a single agent or in combination with proteasome inhibitor MG-132 in ovarian cancer cells. Methods: MTT was performed to determine the anti-proliferative effect of Napabucasin on ovarian cancer SKOV-3 cells. The involved anti-tumor mechanism was explored by flow cytometry, qRTPCR and western blot. MDC staining and tandem mRFP-GFP-LC3 fluorescence microscopy were used to analyze the autophagy-inducing capability of Napabucasin with or without MG-132. The combinational anticancer effect of Napabucasin and MG-132 was evaluated according to Chou and Talalay’s method (1984). Results: Napabucasin showed obvious tumor-inhibitory effects against SKOV-3 cells. Treatment by Napabucasin arrested cell cycle progression in G2/M phase. Mechanistically, elevated expression of p21 may contribute to the blockade of the cell cycle. Moreover, we demonstrated that Napabucasin induced autophagy in SKOV-3 cells by using various assays, including MDC staining, autophagic flux examination, and detection of the autophagy markers. In addition, a combination of Napabucaisin with MG-132 exhibited a significant synergistic anti-proliferative effect, probably by inducing apoptosis through a mitochondria-dependent pathway. The two compounds induced pro-survival autophagies, and co-treatment with autophagy inhibiter might further enhance their antitumor effects. Conclusion: Napabucasin alone or in combination with MG-132 might be promising treatment strategy for ovarian cancer patients.

Background: m6A-methyltransferase METTL3 and demethylase FTO regulate gene expression by dynamically modifying RNA methylation. However, their clinical relevance in renal Clear Cell Carcinoma (CCRCC) has not been well elucidated. Objective: This study aims to investigate prognostic values of FTO and METTL3 mRNA and DNA methylation, their differential expression and associations with chemokines and inflammation-related genes in CCRCC. Methods: Kaplan-Meier survival curves and multivariate cox regression were performed for survival analyses, and random-effects meta-analysis was conducted for differential expression of FTO and METTL3 in CCRCC. Results: A significantly negative correlation was observed between mRNA and DNA methylation for both FTO and METTL3. Survival analysis showed a superior survival in patients with either high FTO mRNA or low DNA methylation, or low METTL3 mRNA or high DNA methylation. The adjusted hazard ratios were 0.67 (95% CI: 0.49-0.91, p = 0.01) for high vs. low FTO mRNA, 2.17 (1.38-3.42, p = 0.0008) for high vs. low FTO DNA methylation, 1.97 (1.45-2.68, p < 0.0001) for high vs. low METTL3 mRNA, and 0.49 (0.31-0.79, p = 0.003) for high vs. low METTL3 DNA methylation, respectively. There was a significant interaction between FTO and METTL3 mRNA levels (p = 0.024). Upregulation of FTO and METTL3 with 1.64 folds (95% CI: 1.43-1.89) and 1.17 folds (1.02-1.35), respectively, was observed in CCRCC vs. normal kidney tissues. FTO and METTL3 mRNA showed opposite expressions of CD8+ T cell migration-related chemokines. Conclusion: Dysregulated FTO and METTL3 may be involved in the disease development and progression, affecting immune response in CCRCC. FTO and METTL3 expression and DNA methylation are potential prognostic markers of CCRCC.

Background: Bee venom is a promising agent for cancer treatment due to its selective cytotoxic potential for cancer cells through apoptotic pathways. However, there is no evidence for changes in the epigenome and mitochondrial DNA copy numbers after bee venom application. The purpose of this study was to determine the impact of bee venom on cytosine modifications and mitochondrial DNA copy number variation. Methods: A broad range of methods was applied to elucidate the impact of bee venom on neoplastic cells. These included MTT assay for detection of cytotoxicity, immunostaining of cytosine modifications and mitochondria, assessment of cellular morphology by flow cytometry, and quantification of mitochondrial DNA copy numbers using QPCR. Results: Bee venom-induced cell death was selective for cancer cells, where it triggered a response characterized by alteration of cytosine modification. In contrast, normal cells were more resistant to DNA modifications. Furthermore, application of the venom resulted in variation of mitochondrial membrane permeability and mitochondrial DNA copy numbers, together with alterations in cell morphology, manifesting as reduced affected cell size. Conclusion: The study findings suggest that bee venom can be used as a selective DNA (de)methylating agent in cancer. Various agents (such as decitabine and 5-azacytidine) have been synthesized and developed for cancer treatment, and a range of syntheses and preparation and application methods have been described for these patented drugs. However, to the best of our knowledge, no previous research has investigated the use of bee venom or any component thereof for epigenetic therapy in cancer cells.

Background: ATP-Binding Cassette subfamily G member 2 (ABCG2) is a semi-transport protein that plays a key role in human diseases, including bladder cancer and lung cancer, and maybe resistant to chemotherapy drugs. Objective: The present study aimed to determine the role and underlying mechanisms of breast cancer resistance protein (ABCG2) in breast cancer and to study the reversal effect of inhibiting ABCG2 expression on the drug resistance of breast cancer cells and provide new ideas for gene-targeted therapy of breast cancer. Methods: The structure and genomic alterations of ABCG2 were systematically investigated using GeneCards and cBioPortal to reveal the genetic alterations (including amplification and deep deletions) of ABCG2. We performed the correlation between ABCG2 expression and clinicopathological parameters using the data in bc-GenExMiner 4.4. Then, the protein-protein interaction and functional enrichment analysis of ABCG2 were performed based on the STRING, bc-GenExMiner 4.4, and Enrichr databases. Besides, we analyzed the pathway activity of genes that interact with ABCG2 using GSCALite and PharmGKB. Using magnetic nanoparticles polyMAG as the carrier of ABCG2-siRNA, polyMAG-ABCG2-siRNA was transfected into the Doxorubicin (DOX)-resistant breast cancer cell line MCF-7/ADR and directly into the tumors in nude mice. Patent US20150328485 points out that magnetic nanoparticles can be attached to an anti-cancer drug, such as an antibody-based anti-cancer drug. Results: We found a statistically significant correlation between ABCG2 expression and clinicopathological parameters, such as Estrogen Receptor (ER), Progesterone Receptor (PR), and human epidermal growth factor receptor-2 (HER2), and nodal status in breast cancer patients. ABCG2 is closely related to SLC2A9, KIT, ABCG1, and MRPS7, which suggests that these proteins may be functional partners of breast cancer. The expression of ABCG2 is correlated with the activation or inhibition of multiple oncogenic pathways. Moreover, we found that ABCG2 is involved in the DOX signaling pathway. The small interfering RNA (siRNA) carried by magnetic nanoparticles can reduce the expression of ABCG2, thereby significantly improving the therapeutic effect of DOX on tumors. Conclusion: Our findings provide a more in-depth understanding of ABCG2 as a biomarker for predicting DOX-resistance and insights into the development of related therapeutic targets in breast cancer.

Background: N6-Methyladenosine (m6A) RNA methylation is the most universal mRNA modification in eukaryotic cells. M6A mRNA modification affects almost every phases of RNA processing, including splicing, decay, export, translation and expression. Several patents have reported the application of m6A mRNA modification in cancer diagnosis and treatment. Ovarian cancer is the leading cause of death among all gynecological cancers. It is urgent to identify new biomarkers for early diagnosis and prognosis of ovarian cancer. Objective: In the current study, we aimed to evaluate the m6A RNA methylation regulators and m6A related genes and establish a new gene signature panel for the prognosis of ovarian cancer. Methods: We downloaded the mutations data, FPKM data and corresponding clinical information of 373 patients with Ovarian Cancer (OC) from the TCGA database. We performed LASSO regression analysis and multivariate cox regression analysis to develop a risk-identifying gene signature panel. Results: A total of 317 candidate m6A RNA methylation related genes were obtained. Finally, 12 - genes (WTAP, LGR6, ZC2HC1A, SLC4A8, AP2A1, NRAS, CUX1, HDAC1, CD79A, ACE2, FLG2 and LRFN1) were selected to establish the signature panel. We analyzed the genetic alterations of the selected 12 -genes in OC using cBioPortal database. Among the 373 patients, 368 patients have mutations. The results showed that all queried genes were altered in 137 of 368 cases (37.23%). The 12-gene signature panel was confirmed as an independent prognostic indicator (P =2.29E-18, HR = 1.699, 95% CI = 1.508-1.913). Conclusion: We established an effective m6A-related gene signature panel consisted of 12 -genes, which can predict the outcome of patients with OC. The high risk score indicates unfavorable survival. Our study provided novel insights into the relationship between m6A and OC. This gene signature panel will be helpful in identifying poor prognostic patients with OC and could be a promising prognostic indicator in clinical practice.

Background: Oral Lichen Planus (OLP) is one of the most common oral mucosal diseases. However, the current diagnostic method for OLP has limitations, and sometimes it is easy to be misdiagnosed. Salivary metabolomics may provide new ideas for the diagnosis of OLP. Objective: To identify the biomarkers for the early detection of OLP. Methods: A non-targeted metabolomic analysis method was established based on UHPLC-Q-Orbitrap HRMS (Ultra-performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry) to analyze the differential metabolites in saliva samples of patients with OLP and healthy subjects. Saliva samples were collected from 120 OLP patients and 125 healthy subjects. Results: A total of 19 differential metabolites were identified, including 6 amino acid metabolites, 2 carnitines, 2 lipid metabolites and 9 other metabolites. The integrated biomarkers were constructed by 3 metabolites according to Receiver Operating Characteristic (ROC). Meanwhile, multiple metabolic pathways were found to be involved in the occurrence and development of OLP. Conclusion: Metabolomics can be used to characterize the characteristics of metabolic disorders in patients with OLP, which is also helpful to the early diagnosis of OLP and reveal the pathological process of OLP.

Background: According to the special physiological and pharmacological activities of natural compounds, many drugs with special therapeutic effects have been developed. The Triptolide (TP) is a natural anti-tumor drug with a world patent, but its target and mechanism are yet unknown. Objective: The study aims to explore and predict the target and mechanism of TP on Non-Small Cell Lung Cancer (NSCLC), Pancreatic Cancer (PC) and Colorectal Cancer (CC) through network pharmacology technology. Methods: We screened the core targets of TP with NSCLC, PC and CC, respectively, and carried out network analysis, enrichment analysis and ligand-receptor docking to clarify its potential pharmacological mechanism. Results: By screening the core genes between TP with NSCLC, PC and CC, respectively, it was found that PTGS2 was the common target gene in the three cancers. NSCLC, CCL2, IL6, HMOX1 and COL1A1 are the specific target genes, while MMP2, JUN, and CXCL8 are the specific target genes in PC. In CC, the specific target genes includeERBB2, VEGFA, STAT1 and MAPK8. In enrichment analysis, it was found that the NF- ΚB, toll-like receptors and IL-17 signaling pathway were mainly involved in TP for these cancers. The binding energy of TP to the core target is less than that of cyclophosphamide. Conclusion: This study preliminarily revealed that TP may prevent and treat cancers\ through multiple targets and pathways. The possible mechanisms of TP include regulating immune and inflammatory responses, promoting apoptosis and inhibiting tumor development. It shows that TP may have potential in treating kinds of tumors.

Background: Oxidative stress and inflammation are the predominant cause of chronic diseases, including multiple forms of cancers. Prevention of oxidative stress and inflammation is considered to be a target for preventing these disorders due to their significant roles in various degenerative diseases. Various natural products and plant extracts prevent the process of free radical- induced damages. Objective: The present study evaluated the biological properties of Thottea siliquosa, belonging to the family Aristolochiaceae, which is a traditionally used Ayurvedic plant. Methods: Antioxidant assays carried out were DPPH, FRAP, hydrogen peroxide scavenging, and hemolysis inhibition assay; nitric oxide and lipoxygenase inhibition assays were used for anti-inflammatory studies. Anticancer activity was evaluated using human endometrial and breast cancer cells by MTT assay. Bioactive compounds present in T. siliquosa were identified by LCMS and each was docked with various cancer targets, including EGFR, VEGFR, GST, COX2, and Lipooxygenase. Results: The results of the present study showed antioxidant properties of the methanolic crude extract of T. siliquosa as DPPH radical scavenging (110.40 ± 4.5 μg/mL), FRAP capacity (41.1 ± 6.2), and peroxide scavenging (233.4 ± 14.2 μg/mL). Besides, anti-inflammatory properties were also evident in terms of nitric oxide radical scavenging (28.76± 3.9 μg/mL) and lipoxygenase inhibition (39.2 ± 3.2 μg/mL) assays. In silico analysis confirmed the inhibitory potential of the bioactive compounds of T. siliquosa against cancer drug targets such as EGFR, VEGFR, and inflammatory enzymes cyclooxygenase as well as lipooxygenase. Further, the anticancer activity of the extract has been identified against human endometrial and breast cancer cells. The possible mechanism of anticancer action of the extract is mediated through the apoptosis induction mechanism acting through increased caspase and APAF-1 expressions. Conclusion: The study thus concludes that T. siliquosa showed significant antioxidant, anti-inflammatory and anticancer properties. Further studies together with a bioassay-guided fractionation may identify possible bioactive compounds.

Background: Chronic myeloid leukemia is characterized by the presence of the Philadelphia chromosome, which is caused by the breakpoint cluster region-Abelson fusion or joined gene. A high concentration of BCR-ABL transcripts level can strongly forecast cytogenetic and hematologic reversion in CML patients. However, the molecular test for BCR-ABL is costly and hardly available in developing countries with low and middle-income. Owing to this, it is required to examine other cost-effective and best diagnostic (prognostic) biomarkers. Objective: The present study aimed to estimate the total LDH and uric acid level as compared to BCR-ABL transcript level among treated and treatment-naive Chronic Myeloid Leukemia (CML) patients. Methods: A comparative cross-sectional study design was used to include eighty-one (81) CML patients tested for BCR-ABL by GeneXpert RT-PCR transcript level at Tikur Anbessa Specialized Hospital. The current study correlates LDH with BCR-ABL and hematological parameters using the spearman correlation, Mann-Whitney U test, and roc curve data analysis tool. Results: A total of 81 CML patients were assayed; 46(56.8%) of them were in the medically treated group, and the remaining 35 (43.2%) were treatment-naive patients. Significant positive correlations were observed between LDH and BCR-ABL (r=0.79, P<0.001).The correlation coefficient value of uric acid (r=0.295, p<0.008) with BCR-ABL showed a weak correlation between the two test parameters. There was a statistically noteworthy (p<0.05) difference in the median level of BCR-ABL and LDH among patients in the treatment group (median=21%, 350 U/L) and the treatment- naive group (median=57%, 1246 U/L), respectively. For uric acid, there was no statistically significant (p<0.542) difference between the study group. The AUC for LDH, Basophil, and WBC was 0.881, 0.889, and 0.748, respectively, which showed better performance for the follow-up of patients with CML than uric acid (0.695) and platelets (0.70). Conclusion: The CML LDH value strongly correlated with BCR-ABL transcript level, whereas uric acid was weakly correlated with BCR-ABL. Hence, in parallel with the BRC-ABL transcript level, these findings could be a patent for confirming the capability of LDH as an alternative cost-- effective diagnostic, prognostic biomarker, and a novel therapeutic target in CML disease.