Cholera toxin B subunit(CTB)can enhance antigen presentation and promote T cell pro-liferation,B cell differentiation and B cell isotype conversion.Moreover,woodchuck hepatitis virus post transcriptional regulatory element(WPRE)can enhance gene expression efficiency by optimi-zing RNA polyadenylation,denuclearization and/or translation.In order to construct porcine epi-demic diarrhea virus like particles(VLPs)chimerized with CTB and WPRE and evaluate their im-munogenicity,the G Ⅱ type PEDV S gene,combined with the elements promoting the protein ex-pression and enhancing immune effects,was synthesized by the company and cloned into pET32a(+).Af-ter double enzyme digestion and gel recovery,the gene named as TSCW was cloned into pFastBacl to construct the recombinant plasmid pFastBac-TSCW.pFastBac-TSCW was further transformed into DH10Bac competent cells to obtain recombinant bacmid Bacmid-TSCW.Subsequently,the Bacmid-TSCW was transfected into sf9 cells to obtain recombinant baculovirus BV-TSCW.After co-infection of BV-TSCW and BV-M into sf9 cells,viral like particles VLP-TSCW was obtained and used to immunize mice to evaluate its immunogenicity.The results showed that the recombi-nant plasmid pFastBac-TSCW and bacmid Bacmid-TSCW were successfully constructed.After transfection of sf9 cells with recombinant baculovirus,significant cytopathic effects were observed.PCR and Western blot results showed that the recombinant baculoviruses existed stably in sf9 cells and the target proteins was also expressed stably.In addition,the electron microscopy results showed that BV-TSCW and BV-M successfully assembled into viral like particles VLP-TSCW.Furthermore,ELISA results indicated that VLP-TSCW induced high level specific antibodies.The above results laid the foundation for further optimization,design and development of PEDV VLPs subunit vaccines.

Cholera toxin B subunit(CTB)can enhance antigen presentation and promote T cell pro-liferation,B cell differentiation and B cell isotype conversion.Moreover,woodchuck hepatitis virus post transcriptional regulatory element(WPRE)can enhance gene expression efficiency by optimi-zing RNA polyadenylation,denuclearization and/or translation.In order to construct porcine epi-demic diarrhea virus like particles(VLPs)chimerized with CTB and WPRE and evaluate their im-munogenicity,the G Ⅱ type PEDV S gene,combined with the elements promoting the protein ex-pression and enhancing immune effects,was synthesized by the company and cloned into pET32a(+).Af-ter double enzyme digestion and gel recovery,the gene named as TSCW was cloned into pFastBacl to construct the recombinant plasmid pFastBac-TSCW.pFastBac-TSCW was further transformed into DH10Bac competent cells to obtain recombinant bacmid Bacmid-TSCW.Subsequently,the Bacmid-TSCW was transfected into sf9 cells to obtain recombinant baculovirus BV-TSCW.After co-infection of BV-TSCW and BV-M into sf9 cells,viral like particles VLP-TSCW was obtained and used to immunize mice to evaluate its immunogenicity.The results showed that the recombi-nant plasmid pFastBac-TSCW and bacmid Bacmid-TSCW were successfully constructed.After transfection of sf9 cells with recombinant baculovirus,significant cytopathic effects were observed.PCR and Western blot results showed that the recombinant baculoviruses existed stably in sf9 cells and the target proteins was also expressed stably.In addition,the electron microscopy results showed that BV-TSCW and BV-M successfully assembled into viral like particles VLP-TSCW.Furthermore,ELISA results indicated that VLP-TSCW induced high level specific antibodies.The above results laid the foundation for further optimization,design and development of PEDV VLPs subunit vaccines.

Objective:This study collected a real-world data on survival and efficacy of gemcitabine-containing therapy in advanced breast cancer. Aimed to find the main reasons of affecting the duration of gemcitabine-base therapy in advanced breast cancer patients.Methods:Advanced breast cancer patients who received gemcitabine-base therapy from January 2017 to January 2019 were enrolled(10 hospitals). The clinicopathological data, the number of chemotherapy cycles and the reasons for treatment termination were collected and analyzed. To identify the reasons related with continuous treatment for advanced breast cancer and the factors which affect the survival and efficacy.Results:A total of 224 patients with advanced breast cancer were enrolled in this study, with a median age of 52 years (26-77 years), 55.4%(124/224) was postmenopausal. Luminal type were 83 cases, TNBC were 97 cases, and human epidermal growth factor receptor 2 (HER's-2) overexpression were 44. At the analysis, 224 patients who received the gemcitabine-based regimens were evaluated, included 5 complete reponse (CR), 77 partial response (PR), 112 stable disease (SD) and 27 progressive disease (PD). The objective response rate (ORR) was 36.6%(82/224). Seventy patients had serious adverse diseases, including leukopenia (9), neutrophilia (49), thrombocytopenia (15), and elevated transaminase (2). The median follow-up time was 41 months (26~61 months), and the median PFS was 5.6 months. The reasons of termination treatment were listed: disease progression were 90 patients; personal reasons were 51 patients; adverse drug reactions were 18 patients; completed treatment were 65 patients. It was found that progression-free survival (PFS) was significantly longer in patients receiving >6 cycles than that in patients with ≤6 cycles (8.2 months vs 5.4 months, HR=2.474, 95% CI: 1.730-3.538, P＜0.001). Conclusions:Gemcitabine-based regimen is generally well tolerated in the Chinese population and has relatively ideal clinical efficacy in the real world. The median PFS is significantly prolonged when the number of treatment cycles are appropriately increased.

Background and purpose:For patients with human epidermal growth factor receptor 2(HER2)-positive metastatic breast cancer,trastuzumab treatment can prolong the overall survival and significantly improve the prognosis of patients.However,the reference original research trastuzumab(Herceptin?)is more expensive.Biosimilars have comparable efficacy and safety profiles while increasing patient access to treatment.This clinical trial aimed to evaluate the efficacy,pharmacokinetics,safety and immunogenicity of the trastuzumab biosimilar AK-HER2 compared to trastuzumab(Herceptin?)in patients with HER2-positive metastatic breast cancer.Methods:This multi-center,randomised,double-blind phase Ⅲ clinical trial was conducted in 43 subcenters in China.This study complied with the research protocol,the ethical principles stated in the Declaration of Helsinki and the quality management standards for drug clinical trials.It was approved by the hospital's medical ethics committee.The clinical trial registration agency is the State Food and Drug Administration(clinical trial approval number:2015L04224;clinical trial registration number:CTR20170516).Written informed consent was obtained from subjects before enrollment.Enrolled patients were randomly assigned to the AK-HER2 group and the control group,respectively receiving AK-HER2 or trastuzumab(initial loading dose 8 mg/kg,maintenance dose 6 mg/kg,every 3 weeks as a treatment cycle,total treatment time is 16 cycles)in combination with docetaxel(75 mg/m2,treatment duration is at least 9 cycles).The primary endpoint of this clinical trial was the objective response rate(ORR9)between the AK-HER2 group and the control group in the 9th cycle.Secondary efficacy endpoints included ORR16,disease control rate(DCR),clinical benefit rate(CBR),progression-free survival(PFS)and 1-year survival rate.In this study,100 subjects(AK-HER2 group to control group=1:1)were randomly selected for blood sample collection after the 6th cycle of medication,The collection time points were 45 minutes after infusion(the end of administration),4,8,24,72,120,168,336,and 504 hours after the end of administration.After collection,blood samples were analyzed by PK parameter set(PKPS).Other evaluation parameters included safety and immunogenicity assessment.Results:A total of 550 patients with HER2-positive metastatic breast cancer were enrolled in this clinical trial between Sep.2017 and Mar.2021.In the AK-HER2 group(n=237),129 subjects in the experimental group achieved complete response(CR)or partial response(PR),and the ORR9 was 54.4%.There were 134 subjects in the control group(n=241)who achieved CR or PR,and the ORR9 was 55.6%.The ORR9 ratio between the AK-HER2 group and the control group was 97.9%[90%confidence interval(CI):85.4%-112.2%,P=0.784],which was not statistically significant.In all secondary efficacy endpoints,no statistically significant differences were observed between the two groups.We conducted a mean ratio analysis of pharmacokinetics(PK)parameters between the AK-HER2 group and the control group,and the results suggested that the pharmacokinetic characteristics of the two drugs are similar.The incidence of treatment emergent adverse event(TEAE)leading to drug reduction or suspension during trastuzumab treatment was 3.6%(10 cases)in the AK-HER2 group and 8.1%(22 cases)in the control group.There was statistically significant difference between the two groups(P=0.027).The incidence rate was significantly lower in the AK-HER2 group than in the control group,and there was no statistically significant difference among the other groups.The differences in the positive rates of anti-drug antibodies(ADA)and neutralizing antibodies(NAB)between groups were of no statistical significance(P=0.385 and P=0.752).Conclusion:In patients with HER2-positive metastatic breast cancer,AK-HER2 was comparable to the trastuzumab(Herceptin?)in terms of drug efficacy,pharmacokinetics,safety and immunogenicity.

Objective:This study collected a real-world data on survival and efficacy of gemcitabine-containing therapy in advanced breast cancer. Aimed to find the main reasons of affecting the duration of gemcitabine-base therapy in advanced breast cancer patients.Methods:Advanced breast cancer patients who received gemcitabine-base therapy from January 2017 to January 2019 were enrolled(10 hospitals). The clinicopathological data, the number of chemotherapy cycles and the reasons for treatment termination were collected and analyzed. To identify the reasons related with continuous treatment for advanced breast cancer and the factors which affect the survival and efficacy.Results:A total of 224 patients with advanced breast cancer were enrolled in this study, with a median age of 52 years (26-77 years), 55.4%(124/224) was postmenopausal. Luminal type were 83 cases, TNBC were 97 cases, and human epidermal growth factor receptor 2 (HER's-2) overexpression were 44. At the analysis, 224 patients who received the gemcitabine-based regimens were evaluated, included 5 complete reponse (CR), 77 partial response (PR), 112 stable disease (SD) and 27 progressive disease (PD). The objective response rate (ORR) was 36.6%(82/224). Seventy patients had serious adverse diseases, including leukopenia (9), neutrophilia (49), thrombocytopenia (15), and elevated transaminase (2). The median follow-up time was 41 months (26~61 months), and the median PFS was 5.6 months. The reasons of termination treatment were listed: disease progression were 90 patients; personal reasons were 51 patients; adverse drug reactions were 18 patients; completed treatment were 65 patients. It was found that progression-free survival (PFS) was significantly longer in patients receiving >6 cycles than that in patients with ≤6 cycles (8.2 months vs 5.4 months, HR=2.474, 95% CI: 1.730-3.538, P＜0.001). Conclusions:Gemcitabine-based regimen is generally well tolerated in the Chinese population and has relatively ideal clinical efficacy in the real world. The median PFS is significantly prolonged when the number of treatment cycles are appropriately increased.