Analysis of spatial correlation networks of carbon emissions in emerging economies.

Studies have shown that energy consumption from economic development leads to an increase in carbon emissions. Emerging economies, as important sources of carbon emissions with high growth potential, play a crucial role in global decarbonisation efforts. However, the spatial pattern and evolution trend of carbon emissions in emerging economies have not been studied in depth. Therefore, this paper uses the improved gravitational model and carbon emission data from 2000 to 2018 to construct a spatial correlation network of carbon emissions in 30 emerging economies around the world, aiming to reveal the spatial characteristics and influencing factors of carbon emissions at the national level. The results show that the spatial network structure of carbon emissions in emerging economies is closely linked, forming a "big network" of interconnection. Amongst them, Argentina, Brazil, Russia, Estonia, etc. are at the centre of the network and play a leading role. Geographical distance, economic development level, population density, and scientific and technological level have a significant impact on the formation of spatial correlation between carbon emissions. Further use of GeoDetector shows that the explanatory power of two-factor interaction on centrality is greater than that of a single factor, indicating that a single economic development cannot well enhance the influence of countries in the carbon emission network, and needs to be combined with factors such as industrial structure and scientific and technological level. These results are helpful to understand the correlation between carbon emissions between countries from the perspective of the whole and part and provide a reference for optimizing the carbon emission network structure in the future.

Monomethyl auristatin E-conjugated anti-EGFR antibody inhibits the growth of human EGFR-positive non-small cell lung cancer.

PURPOSE: Epidermal growth factor receptor (EGFR) is highly expressed on non-small cell lung cancers (NSCLC) and a valuable therapeutic target. This study aimed at producing and characterizing monomethyl auristatin E (MMAE)-conjugated anti-EGFR antibody as a novel EGFR-targeting therapy for NSCLC. METHODS: A humanized anti-EGFR monoclonal antibody (named RC68) was purified and conjugated with MMAE using a MC-VC-PAB or PY-VC-PAB linker. The in vitro and in vivo antitumor activity of RC68-MC-VC-PAB-MMAE and RC68-PY-VC-PAB-MMAE were characterized. RESULTS: The RC68 was generated from RC68-expressing cells and had a purity of > 99.0%. The RC68 recognized EGFR on tumor cells, particularly for higher EGFR expressing H125, A431, HCC827 and H1975 cells. The RC68 was conjugated with an average of 4 MMAE molecules to generate RC68-MC-VC-PAB-MMAE and RC68-PY-VC-PAB-MMAE, respectively. The RC68-MC-VC-PAB-MMAE, RC68-PY-VC-PAB-MMAE and RC68 displayed similar binding affinity to EGFR on tumor cells, and RC68-MC-VC-PAB-MMAE and RC68-PY-VC-PAB-MMAE were effectively internalized by H125 cells. The RC68-MC-VC-PAB-MMAE and RC68-PY-VC-PAB-MMAE inhibited the growth of H125 cells in vitro with an IC50 7.37-8.04 ng/mL and implanted H125 tumors in vivo, but did not affect body weights of mice. The antitumor effect of RC68-MC-VC-PAB-MMAE was stronger than RC68-PY-VC-PAB-MMAE, which was also stronger than docetaxel in vivo. CONCLUSIONS: These novel antibody-drug conjugates, particularly for RC68-MC-VC-PAB-MMAE, may be a potential candidate for treatment of EGFR + NSCLC.

Development of a Novel EGFR-Targeting Antibody-Drug Conjugate for Pancreatic Cancer Therapy.

BACKGROUND: Overexpression of epidermal growth factor receptor (EGFR) is common in pancreatic cancer and associated with the poor prognosis of this malignancy. OBJECTIVE: To develop anti-EGFR antibody-drug conjugates (ADCs) for use in a novel EGFR-targeting approach to treat pancreatic cancer. METHODS: A humanized anti-EGFR monoclonal antibody (RC68) was generated by mouse immunization and complementary-determining region grafting technology. Two RC68-based ADCs, RC68-MC-VC-PAB-MMAE and RC68-PY-VC-PAB-MMAE, were synthesized by conjugating monomethyl auristatin E (MMAE), a small-molecule cytotoxin, to RC68 through two distinct linkers (MC and PY). Internalization of the RC68-based ADCs was examined by flow cytometry. The in vitro and in vivo antitumor activities of RC68-based ADCs were evaluated in human pancreatic cancer cells and in a BXPC-3 xenograft nude mouse model, respectively. RESULTS: The RC68-based ADCs bound to EGFR on the surface of tumor cells and were effectively internalized, resulting in the death of EGFR-positive cancer cell lines. The RC68-based ADCs (at 5 or 10 mg/kg) were more potent than gemcitabine hydrochloride (60 mg/kg) at inhibiting the growth of BXPC-3 xenografts. Moreover, RC68-PY-VC-PAB-MMAE was found to have superior stability in human plasma compared with RC68-MC-VC-PAB-MMAE. CONCLUSION: A novel EGFR-targeting ADC, RC68-PY-VC-PAB-MMAE, shows promise as an effective, selective, and safe therapeutic agent for EGFR-positive pancreatic cancer.

Development of novel anti-CD19 antibody-drug conjugates for B-cell lymphoma treatment.

B-cell lymphoma remains one of the most refractory tumors, and as such the development of novel treatment approaches, such as antibody-drug conjugates (ADCs), is required. To improve the stability and homogeneity of the ADCs, a humanized anti-CD19 monoclonal antibody (RC58) was developed in the present study. RC58 was based on the CD19 antigen as a potential molecular target of human B-cell lymphomas. RC58 has high CD19-binding affinity and can be internalized in CD19-positive cells through endocytosis. Furthermore, three types of RC58-based ADCs (ADC-1, ADC-2, and ADC-3) were generated using three kinds of Maleimide-PEG-based linkers with two different cytotoxins. The anti-tumor activities of the ADCs were confirmed by in vitro and in vivo experiments. The stability of the ADCs was also evaluated by incubation in human plasma for 10 days. In vitro experiments showed that the three ADCs had distinct inhibitory effects on several B-lymphoma cell lines. Meanwhile, a close correlation between efficacy and drug concentration was found in a nude mouse xenograft model of human B-cell lymphoma, after treatment with RC58-based ADCs. Our results suggest that ADC-1, with high efficiency, could be used as a potential therapeutic agent for human B-cell malignancies.

Dual blockade of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF-2) exhibits potent anti-angiogenic effects.

Both vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF or FGF-2) are potent pro-angiogenic factors and play a critical role in cancer development and progression. Clinical anti-VEGF therapy trials had a major challenge due to upregulated expression of other pro-angiogenic factor, like FGF-2. This study developed a novel chimeric decoy receptor VF-Trap fusion protein to simultaneously block activity of both VEGF and FGF pathways in order to achieve an additive or synergistic anti-tumor effect. Our in vitro data showed that VF-Trap potently blocked proliferation and migration of both VEGF- and FGF-2-induced vascular endothelial cells. In animal models, treatment of xenograft tumors with VF-Trap resulted in significant inhibition of tumor growth compared to blockage of the single molecule, like VEGF or FGF blocker. In addition, VF-Trap was also more potent in inhibition of ocular angiogenesis in a mouse oxygen-induced retinopathy (OIR) model. These data demonstrated the potent anti-angiogenic effects of this novel VF-Trap fusion protein on blockage of VEGF and FGF-2 activity in vitro and in animal models. Further study will assess its effects in clinic as a therapeutic agent for angiogenesis-related disorders, such as cancer and ocular vascular diseases.

An anti-HER2 antibody conjugated with monomethyl auristatin E is highly effective in HER2-positive human gastric cancer.

Antibody-drug conjugate (ADC) is a novel class of therapeutics for cancer target therapy. This study assessed antitumor activity of ADC with an antimitotic agent, monomethyl auristatin E (MMAE) and a humanized monoclonal anti-HER2 antibody, hertuzumab, in gastric cancer. The efficacy of hertuzumab-MC-Val-Cit-PAB-MMAE (hertuzumab-vcMMAE) on human epidermal growth factor receptor 2 (HER2) positive human gastric cancer cells, NCI-N87, was evaluated in vitro and in vivo. The cytotoxicity of hertuzumab was significantly enhanced after conjugation with MMAE. Compared to trastuzumab, hertuzumab had a higher affinity to HER2 and had more potent antibody-dependent cell-mediated cytotoxicity (ADCC) activity in vitro. After conjugation with MMAE, the binding specificity for HER2 was not affected. Furthermore, the internalization of hertuzumab-vcMMAE in HER2 positive gastric cancer cells was verified. Although the conjugation of hertuzumab and MMAE decreased the ADCC effect, the overall cytotoxicity was dramatically increased in HER2 positive gastric cancer cells. In vitro data on this hertuzumab-vcMMAE has exerted much stronger antitumor activity compared to trastuzumab-DM1 in HER2 positive gastric cancer cells. A single administration of hertuzumab-vcMMAE at 5 or 10 mg/kg showed high potency and a sustained tumor inhibitory effect on NCI-N87 xenografts in mice. In conclusion, hertuzumab-vcMMAE conjugate is a highly effective anti-HER2 targeted therapy for HER2-positive gastric cancer.

Pharmacokinetics, pharmacodynamics, short term efficacy and safety of RCT-18, a novel BLyS/APRIL fusion protein, in patients with rheumatoid arthritis.

AIM: RCT-18 is a recombinant fusion protein that interferes with the selection and survival of mature B-lymphocytes by inhibiting B-lymphocyte stimulator and a proliferation-inducing ligand. METHODS: This single blind, randomized, placebo controlled, clinical pharmacological study explored the short term efficacy and safety of RCT-18 in 21 rheumatoid arthritis (RA) patients with three different dosing regimens. The pharmacological behaviour of RCT-18 was also characterized through a six level biomarker cascade approach to identify potential predictors for clinical responses. RESULTS: Nine out of 10 patients (>80%) experienced moderate to good EULAR response at the end of 3 months with once or twice weekly doses of 180 mg RCT-18, whereas weekly administration of 360 mg RCT-18 or placebo, however, only resulted in moderate improvement in one patient in each group. Absence of IgM-type rheumatoid factor reduction, recovery of IgM 2 weeks after drug cessation, lack of decrease in the count of CD27(+) B-lymphocytes and a DAS28 change from baseline <6 in 4-6 weeks after the treatment initiation may indicate poor clinical response. No anti-drug antibody of RCT-18 was detected. The active treatments were well tolerated, although more mild to moderate infections were reported in patients receiving RCT-18. CONCLUSION: The study results support further development of RCT-18 in RA patients and provide important information for future dose selection.

Pharmacokinetics, Pharmacodynamics, Safety, and Clinical Activity of Multiple Doses of RCT-18 in Chinese Patients With Systemic Lupus Erythematosus.

RCT-18 is a novel recombinant fusion protein that blocks the activity of a B-lymphocyte stimulator and a proliferation-inducing ligand. This was a randomized, single-blind, and placebo-controlled phase 1 study in 12 patients with systemic lupus erythematosus. Eligible patients were randomized 3:1 to receive multiple subcutaneous doses of RCT-18 for 4 weeks (180 mg, once weekly) or placebo and monitored over an 84-day observation period for pharmacokinetics, pharmacodynamics, immunogenicity, safety, and clinical activity. After multiple-dose RCT-18, the maximal serum concentration (Cmax ) of total and free RCT-18 was reached within 1 to 2 days. Mean elimination half-life for total RCT-18 and free RCT-18 was 11.4 to 26.4 days and 2.4 to 26.5 days, respectively. Slight accumulation was found after multiple subcutaneous administrations. The average accumulation ratios of AUC and Cmax after the fourth administration of RCT-18 were 2.0 and 1.7 for total RCT-18, and 1.8 and 1.6 for free RCT-18. The formation and elimination of BLyS-RCT-18 complex were much slower, with a time to Cmax of 14 to 46 days. Pharmacokinetic characteristics of RCT-18 in SLE patients were similar to those in patients with rheumatoid arthritis. No positive reaction was detected in the immunogenicity assessments. RCT-18 was biologically active, according to serum immunoglobulin and B-cell levels. Treatment-related IgM and IgA reduction was found during this study. CD19(+) , IgD(+) , and CD27(+) B-cell counts were increased after administration and decreased subsequently. SLE patients treated with RCT-18 were more prone to infections, including moderate and severe infections. Lower dosages of RCT-18 should be considered in further clinical development.

A novel humanized anti-HER2 antibody conjugated with MMAE exerts potent anti-tumor activity.

Human epidermal growth factor receptor-2 (HER2) is a validated therapeutic target for breast cancer and trastuzumab (Herceptin), a humanized anti-HER2 antibody, has significant anti-cancer effects in the clinic. However, breast cancer patients often experience disease progression after prolonged Herceptin treatment. To develop a more effective therapy, we generated humanized monoclonal antibody hertuzumab and hertuzumab-drug conjugates as novel breast cancer therapies. The hertuzumab was conjugated with small molecule cytotoxic agents monomethylauristatin E (MMAE) or monomethylauristatin F (MMAF) with various linkers to generate antibody-drug conjugates (ADCs), which were evaluated for their in vitro and in vivo anti-cancer activities. Among these ADCs, hertuzumab-vc-MMAE can be effectively internalized and potently kill HER2 over-expressing tumor cells. In xenograft tumor models, hertuzumab-vc-MMAE showed a more potent anti-tumor activity than T-DM1, a FDA-approved ADC drug. More importantly, this novel ADC drug also showed superior anti-tumor activity than T-DM1 in trastuzumab- and lapatinib-resistant xenograft tumor models, suggesting its potential as an improved therapy for HER2-positive breast cancers. The novel ADC, hertuzumab-vc-MMAE, is an effective and selective agent for the treatment of HER2-positive breast tumors.

Pharmacokinetics, pharmacodynamics, and tolerability of single ascending doses of RCT-18 in Chinese patients with rheumatoid arthritis.

BACKGROUND AND OBJECTIVES: RCT-18 is a novel recombinant fusion protein that targets and neutralizes B-lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL). This first in-human study investigated the safety, tolerability, pharmacokinetics, immunogenicity, and pharmacodynamics of RCT-18 in patients with rheumatoid arthritis (RA). METHODS: This was a single-center, randomized, single-blind, placebo-controlled study in 28 RA patients. Eligible patients were randomized 3:1 to receive single subcutaneous doses of RCT-18 (1.2, 6, 18, 60, 180, 360, 540 mg) or placebo. A 71-day observation period was scheduled for each patient, during which serial blood sampling for pharmacokinetic, pharmacodynamic, and immunogenicity assessments was performed. Safety was assessed throughout the study. RESULTS: RCT-18 was well tolerated, although mild infections and skin irritation occurred more frequently in patients receiving this drug. After single-dose RCT-18, the maximal serum concentration (C max) of total and free RCT-18 was reached within 1-2 days, followed by a multi-exponential decline. Mean elimination half-life for total RCT-18 and free RCT-18 was 5.7-12.8 days and 3.2-11.3 days at 6-60 mg, and 15.1-17.5 days and 18.8-36.8 days with 180-540 mg RCT-18. The formation and elimination of BLyS-RCT-18 complex were much slower, with a time to C max of 5-29 days and the elimination half-life mounting from 13.3 to 32.8 days with dose escalation. No positive reaction was detected in the immunogenicity assessments. Substantial IgM reduction was only evidenced with 540 mg RCT-18, while the response profiles of IgM/IgG were distinguishable from placebo after 180, 360, or 540 mg RCT-18. CONCLUSION: RCT-18 was safe and well tolerated up to 540-mg single doses. The serum exposure of total and free RCT-18 is linearly correlated to the weight-normalized doses of RCT-18 in dose groups receiving 180-540 mg RCT-18. The elimination half-life of BLyS-RCT-18 increased with RCT-18 doses, suggesting a shift from target-mediated disposition in 1.2-18 mg RCT-18 groups to non-specific clearance in 60-540 mg RCT-18 groups. Assuming the concentration of BLyS-RCT-18 complex and the IgM/IgG ratio are surrogate biomarkers for clinical effects of RCT-18, the dose-response relationship suggests 180-540 mg are pharmacodynamically effective doses in RCT-18 for RA patients, but the effect profile of 540 mg RCT-18 on IgM is similar to that of atacicept at pharmacodynamically effective but clinically ineffective doses.

A fusion fragment from Flt-1 and KDR, acted as VEGF decoy receptor and exhibited anti-tumor function.

Angiogenesis is important in tumor development. Vascular endothelial growth factor (VEGF) is involved in this process. In this report, we constructed a recombinant protein (called FK) by fusing the second immunoglobulin-like (Ig-like) domain of a human fms-like tyrosine kinase (Flt-1) with the third Ig-like domain of human kinase insert domain-containing receptor (KDR). FK bound to VEGF(165) in a dose-dependent manner with a disocciation constant (Kd) of 2.7 pM. In addition, FK specifically inhibited the proliferation of human microvascular endothelial cell (HMEC) and human umbilical vein endothelial Cell (HUVEC) stimulated by VEGF(165). Subsequent studies also demonstrate that FK efficaciously suppresses growth of a variety of tumors, which could make FK a potential drug candidate in anti-tumor therapy.