In clinical development,adequate and well-controlled randomised clinical trials are usually conducted to evaluate the safety and efficacy of test treatment under investigation.The purpose is to ensure that there is an...In clinical development,adequate and well-controlled randomised clinical trials are usually conducted to evaluate the safety and efficacy of test treatment under investigation.The purpose is to ensure that there is an accurate and reliable assessment of test treatment under study.In practice,however,some controversial issues inevitably appear despite the compliance of good clinical practice.These debatable issues include,but are not limited to,(1)appropriateness of hypotheses for clinical investigation,(2)feasibility of power calculation for sample size requirement,(3)integrity of randomisation/blinding,(4)strategy for clinical endpoint selection,(5)demonstrating effectiveness or ineffectiveness,(6)impact of protocol amendments and(7)independence of independent data monitoring committee.In this article,these controversial issues are discussed.The impact of these issues in evaluating the safety and efficacy of the test treatment under investigation is also assessed.Recommendations regarding possible resolutions to these issues are provided whenever possible.展开更多
We evaluated novel Chlamydial vaccines, consisting of major outer membrane protein (MOMP) alone or in combination with polymorphic membrane proteins D (PmpD) and G (PmpG) using a C57BL/6 mouse model. Native MOMP (nMOM...We evaluated novel Chlamydial vaccines, consisting of major outer membrane protein (MOMP) alone or in combination with polymorphic membrane proteins D (PmpD) and G (PmpG) using a C57BL/6 mouse model. Native MOMP (nMOMP) isolated from <em>C</em>. <em>muridarum</em> elementary bodies (EBs) and recombinant PmpD and PmpG proteins were adjuvanted with Monophosphoryl lipid A (MPLA), with either lipid nanoparticles (LNPs) or the cationic lipid dimethyldioctadecylammonium bromide (DDA). Antibody titers to <em>C</em>. <em>muridarum</em> nMOMP, and EBs were evaluated by ELISA, and T-cell responses were analyzed by intracellular cytokine staining (ICS). Protection from challenge was determined by qPCR. Vaccine immunized mice showed significantly higher antibody titers to nMOMP (P < 0.001) and <em>C</em>. <em>muridarum</em> EBs (P < 0.001), when compared to the adjuvant alone group. Antibody titers in vaccine groups with Monophosphoryl lipid A (MPLA) + LNP were higher as compared to the MPLA + DDA group (P < 0.001) except for (Cm nMOMP + PmpG + PmpD p73 + PmpD p82 + MPLA + DDA) vs (Cm nMOMP + PmpG + PmpD p73 + PmpD p82 + MPLA + LNP) for both <em>C</em>. <em>muridarum</em> EBs and PmpG. ICS analysis showed more robust CD4 + T-cell responses (IFN-<em>γ</em>/IL-2/TNF-a) in the DDA and LNP groups compared to the adjuvant alone group. The DDA + MPLA gave robust Th17 responses in comparison to MPLA and LNP group. Mice immunized with <em>Chlamydia</em> antigens also showed protection from <em>C</em>. <em>muridarum</em> challenge, by reduction in bacterial shedding for all groups (P < 0.003) compared to shedding from the adjuvant control. Both vaccine formulations generated robust immunological responses, and both were protective by reducing bacterial shedding after challenge. This data indicates equal protection can be achieved without the induction of Th17 responses.展开更多
AIM: to evaluate addition of boceprevir to peginterferon/ribavirin(PR) in Russian patients with chronic hepatitis C virus(HCV).METHODS: treatment-naive(t N) and treatmentexperienced(t E) patients(who had failed prior ...AIM: to evaluate addition of boceprevir to peginterferon/ribavirin(PR) in Russian patients with chronic hepatitis C virus(HCV).METHODS: treatment-naive(t N) and treatmentexperienced(t E) patients(who had failed prior treatment with PR for ≥ 12 wk) with chronic HCV genotype 1 infection were enrolled in this placebocontrolled, double-blind study. All patients initially received PR for 4 wk. Patients randomized to control treatment then received PR for an additional 44 wk. t N patients randomized to triple therapy received boceprevir(800 mg three times daily) plus PR for 24 wk and then further therapy according to treatment week 8(t W8) HCV RNA levels. t E patients received boceprevir plus PR for 32 wk and then further therapy according to t W8 HCV RNA levels. treatment was discontinued for t N patients with detectable HCV RNA at t W24 and t E patients with detectable HCV RNA at t W12 because of futility. the primary efficacy end point was sustained virologic response(SVR) defined as undetectable HCV RNA 24 wk after completing all study therapy.RESULTS: SVR was 74.8% in the boceprevir plus PR arm compared with 46.2% in the control arm, with a stratification-adjusted treatment difference of 29.2%(95%CI: 16.4-41.5; P < 0.0001). Rates of SVR were higher in the boceprevir arm in both t N and t E patient groups(t N 78.4% vs 56.3%; t E 69.4% vs 30.0%). Within t E patients, the rates of SVR were higher with boceprevir plus PR compared with PR, regardless of treatment failure type(null responder, partial responder, and relapser). Most patients receiving boceprevir plus PR in both t N(86%) and t E(71%) populations were eligible for reduced treatment duration. Anemia was increased in patients receiving boceprevir plus PR vs PR alone(47.2% vs 24.4%); there was a corresponding increase in ribavirin dose reduction and erythropoietin use. Among patients receiving boceprevir plus PR, SVR rates were similar in patients with anemia(< 10 g/d L) and those without anemia(71.2% vs 77.4%).CONCLUSION: Regulatory approval has been obtained for boceprevir plus PR in Russian patients with HCV genotype 1 infection based on the results of this study.展开更多
The novel coronavirus(COVID-19)pandemic that emerged from Wuhan city in December 2019 overwhelmed health systems and paralyzed economies around the world.It became the most important public health challenge facing man...The novel coronavirus(COVID-19)pandemic that emerged from Wuhan city in December 2019 overwhelmed health systems and paralyzed economies around the world.It became the most important public health challenge facing mankind since the 1918 Spanish flu pandemic.Various theoretical and empirical approaches have been designed and used to gain insight into the transmission dynamics and control of the pandemic.This study presents a primer for formulating,analysing and simulating mathematical models for understanding the dynamics of COVID-19.Specifically,we introduce simple compartmental,Kermack-McKendrick-type epidemic models with homogeneously-and heterogeneously-mixed populations,an endemic model for assessing the potential population-level impact of a hypothetical COVID-19 vaccine.We illustrate how some basic non-pharmaceutical interventions against COVID-19 can be incorporated into the epidemic model.A brief overview of other kinds of models that have been used to study the dynamics of COVID-19,such as agent-based,network and statistical models,is also presented.Possible extensions of the basic model,as well as open challenges associated with the formulation and theoretical analysis of models for COVID-19 dynamics,are suggested.展开更多
Drug metabolism and pharmacokinetics(DMPK) is an important branch of pharmaceutical sciences.The nature of ADME(absorption,distribution,metabolism,excretion) and PK(pharmacokinetics) inquiries during drug discovery an...Drug metabolism and pharmacokinetics(DMPK) is an important branch of pharmaceutical sciences.The nature of ADME(absorption,distribution,metabolism,excretion) and PK(pharmacokinetics) inquiries during drug discovery and development has evolved in recent years from being largely descriptive to seeking a more quantitative and mechanistic understanding of the fate of drug candidates in biological systems.Tremendous progress has been made in the past decade,not only in the characterization of physiochemical properties of drugs that influence their ADME,target organ exposure,and toxicity,but also in the identification of design principles that can minimize drug-drug interaction(DDI) potentials and reduce the attritions.The importance of membrane transporters in drug disposition,efficacy,and safety,as well as the interplay with metabolic processes,has been increasingly recognized.Dramatic increases in investments on new modalities beyond traditional small and large molecule drugs,such as peptides,oligonucleotides,and antibody-drug conjugates,necessitated further innovations in bioanalytical and experimental tools for the characterization of their ADME properties.In this review,we highlight some of the most notable advances in the last decade,and provide future perspectives on potential major breakthroughs and innovations in the translation of DMPK science in various stages of drug discovery and development.展开更多
Although mechanisms of telomere protection are well-defined in differentiated cells,how stem cells sense and respond to telomere dysfunction,in particular telomeric double-strand breaks(DSBs),is poorly characterized.H...Although mechanisms of telomere protection are well-defined in differentiated cells,how stem cells sense and respond to telomere dysfunction,in particular telomeric double-strand breaks(DSBs),is poorly characterized.Here,we report the DNA damage signaling,cell cycle,and transcriptome changes in human induced pluripotent stem cells(iPSCs)in response to telomere-internal DSBs.We engineer human iPSCs with an inducible TRF1-FokI fusion protein to acutely induce DSBs at telomeres.Using this model,we demonstrate that TRF1-FokI DSBs activate an ATR-dependent DNA damage response,which leads to p53-independent cell cycle arrest in G2.Using CRISPR–Cas9 to cripple the catalytic domain of telomerase reverse transcriptase,we show that telomerase is largely dispensable for survival and lengthening of TRF1-FokI-cleaved telomeres,which instead are effectively repaired by robust homologous recombination(HR).In contrast to HR-based telomere maintenance in mouse embryonic stem cells,where HR causes ZSCAN4-dependent extension of telomeres beyond their initial lengths,HR-based repair of telomeric breaks is sufficient to maintain iPSC telomeres at a normal length,which is compatible with sustained survival of the cells over several days of TRF1-FokI induction.Our findings suggest a previously unappreciated role for HR in telomere maintenance in telomerase-positive iPSCs and reveal distinct iPSC-specific responses to targeted telomeric DNA damage.展开更多
文摘In clinical development,adequate and well-controlled randomised clinical trials are usually conducted to evaluate the safety and efficacy of test treatment under investigation.The purpose is to ensure that there is an accurate and reliable assessment of test treatment under study.In practice,however,some controversial issues inevitably appear despite the compliance of good clinical practice.These debatable issues include,but are not limited to,(1)appropriateness of hypotheses for clinical investigation,(2)feasibility of power calculation for sample size requirement,(3)integrity of randomisation/blinding,(4)strategy for clinical endpoint selection,(5)demonstrating effectiveness or ineffectiveness,(6)impact of protocol amendments and(7)independence of independent data monitoring committee.In this article,these controversial issues are discussed.The impact of these issues in evaluating the safety and efficacy of the test treatment under investigation is also assessed.Recommendations regarding possible resolutions to these issues are provided whenever possible.
文摘We evaluated novel Chlamydial vaccines, consisting of major outer membrane protein (MOMP) alone or in combination with polymorphic membrane proteins D (PmpD) and G (PmpG) using a C57BL/6 mouse model. Native MOMP (nMOMP) isolated from <em>C</em>. <em>muridarum</em> elementary bodies (EBs) and recombinant PmpD and PmpG proteins were adjuvanted with Monophosphoryl lipid A (MPLA), with either lipid nanoparticles (LNPs) or the cationic lipid dimethyldioctadecylammonium bromide (DDA). Antibody titers to <em>C</em>. <em>muridarum</em> nMOMP, and EBs were evaluated by ELISA, and T-cell responses were analyzed by intracellular cytokine staining (ICS). Protection from challenge was determined by qPCR. Vaccine immunized mice showed significantly higher antibody titers to nMOMP (P < 0.001) and <em>C</em>. <em>muridarum</em> EBs (P < 0.001), when compared to the adjuvant alone group. Antibody titers in vaccine groups with Monophosphoryl lipid A (MPLA) + LNP were higher as compared to the MPLA + DDA group (P < 0.001) except for (Cm nMOMP + PmpG + PmpD p73 + PmpD p82 + MPLA + DDA) vs (Cm nMOMP + PmpG + PmpD p73 + PmpD p82 + MPLA + LNP) for both <em>C</em>. <em>muridarum</em> EBs and PmpG. ICS analysis showed more robust CD4 + T-cell responses (IFN-<em>γ</em>/IL-2/TNF-a) in the DDA and LNP groups compared to the adjuvant alone group. The DDA + MPLA gave robust Th17 responses in comparison to MPLA and LNP group. Mice immunized with <em>Chlamydia</em> antigens also showed protection from <em>C</em>. <em>muridarum</em> challenge, by reduction in bacterial shedding for all groups (P < 0.003) compared to shedding from the adjuvant control. Both vaccine formulations generated robust immunological responses, and both were protective by reducing bacterial shedding after challenge. This data indicates equal protection can be achieved without the induction of Th17 responses.
文摘AIM: to evaluate addition of boceprevir to peginterferon/ribavirin(PR) in Russian patients with chronic hepatitis C virus(HCV).METHODS: treatment-naive(t N) and treatmentexperienced(t E) patients(who had failed prior treatment with PR for ≥ 12 wk) with chronic HCV genotype 1 infection were enrolled in this placebocontrolled, double-blind study. All patients initially received PR for 4 wk. Patients randomized to control treatment then received PR for an additional 44 wk. t N patients randomized to triple therapy received boceprevir(800 mg three times daily) plus PR for 24 wk and then further therapy according to treatment week 8(t W8) HCV RNA levels. t E patients received boceprevir plus PR for 32 wk and then further therapy according to t W8 HCV RNA levels. treatment was discontinued for t N patients with detectable HCV RNA at t W24 and t E patients with detectable HCV RNA at t W12 because of futility. the primary efficacy end point was sustained virologic response(SVR) defined as undetectable HCV RNA 24 wk after completing all study therapy.RESULTS: SVR was 74.8% in the boceprevir plus PR arm compared with 46.2% in the control arm, with a stratification-adjusted treatment difference of 29.2%(95%CI: 16.4-41.5; P < 0.0001). Rates of SVR were higher in the boceprevir arm in both t N and t E patient groups(t N 78.4% vs 56.3%; t E 69.4% vs 30.0%). Within t E patients, the rates of SVR were higher with boceprevir plus PR compared with PR, regardless of treatment failure type(null responder, partial responder, and relapser). Most patients receiving boceprevir plus PR in both t N(86%) and t E(71%) populations were eligible for reduced treatment duration. Anemia was increased in patients receiving boceprevir plus PR vs PR alone(47.2% vs 24.4%); there was a corresponding increase in ribavirin dose reduction and erythropoietin use. Among patients receiving boceprevir plus PR, SVR rates were similar in patients with anemia(< 10 g/d L) and those without anemia(71.2% vs 77.4%).CONCLUSION: Regulatory approval has been obtained for boceprevir plus PR in Russian patients with HCV genotype 1 infection based on the results of this study.
基金One of the authors(ABG)acknowledge the support,in part,of the Simons Foundation(Award#585022)the National Science Foundation(Award#1917512)CNN acknowledges the support of the Simons Foundation(Award#627346).
文摘The novel coronavirus(COVID-19)pandemic that emerged from Wuhan city in December 2019 overwhelmed health systems and paralyzed economies around the world.It became the most important public health challenge facing mankind since the 1918 Spanish flu pandemic.Various theoretical and empirical approaches have been designed and used to gain insight into the transmission dynamics and control of the pandemic.This study presents a primer for formulating,analysing and simulating mathematical models for understanding the dynamics of COVID-19.Specifically,we introduce simple compartmental,Kermack-McKendrick-type epidemic models with homogeneously-and heterogeneously-mixed populations,an endemic model for assessing the potential population-level impact of a hypothetical COVID-19 vaccine.We illustrate how some basic non-pharmaceutical interventions against COVID-19 can be incorporated into the epidemic model.A brief overview of other kinds of models that have been used to study the dynamics of COVID-19,such as agent-based,network and statistical models,is also presented.Possible extensions of the basic model,as well as open challenges associated with the formulation and theoretical analysis of models for COVID-19 dynamics,are suggested.
基金supported in part by grants from the National Institutes of Health (CA023074,CA092596,ES004940,ES006694,and ES020867,USA)。
文摘Drug metabolism and pharmacokinetics(DMPK) is an important branch of pharmaceutical sciences.The nature of ADME(absorption,distribution,metabolism,excretion) and PK(pharmacokinetics) inquiries during drug discovery and development has evolved in recent years from being largely descriptive to seeking a more quantitative and mechanistic understanding of the fate of drug candidates in biological systems.Tremendous progress has been made in the past decade,not only in the characterization of physiochemical properties of drugs that influence their ADME,target organ exposure,and toxicity,but also in the identification of design principles that can minimize drug-drug interaction(DDI) potentials and reduce the attritions.The importance of membrane transporters in drug disposition,efficacy,and safety,as well as the interplay with metabolic processes,has been increasingly recognized.Dramatic increases in investments on new modalities beyond traditional small and large molecule drugs,such as peptides,oligonucleotides,and antibody-drug conjugates,necessitated further innovations in bioanalytical and experimental tools for the characterization of their ADME properties.In this review,we highlight some of the most notable advances in the last decade,and provide future perspectives on potential major breakthroughs and innovations in the translation of DMPK science in various stages of drug discovery and development.
基金supported by the NIH(R01HL148821 and F31CA260918)University of Pennsylvania Abramson Cancer Center(Patel Scholar Award)Pennsylvania Department of Health(Health Research Formula Fund).
文摘Although mechanisms of telomere protection are well-defined in differentiated cells,how stem cells sense and respond to telomere dysfunction,in particular telomeric double-strand breaks(DSBs),is poorly characterized.Here,we report the DNA damage signaling,cell cycle,and transcriptome changes in human induced pluripotent stem cells(iPSCs)in response to telomere-internal DSBs.We engineer human iPSCs with an inducible TRF1-FokI fusion protein to acutely induce DSBs at telomeres.Using this model,we demonstrate that TRF1-FokI DSBs activate an ATR-dependent DNA damage response,which leads to p53-independent cell cycle arrest in G2.Using CRISPR–Cas9 to cripple the catalytic domain of telomerase reverse transcriptase,we show that telomerase is largely dispensable for survival and lengthening of TRF1-FokI-cleaved telomeres,which instead are effectively repaired by robust homologous recombination(HR).In contrast to HR-based telomere maintenance in mouse embryonic stem cells,where HR causes ZSCAN4-dependent extension of telomeres beyond their initial lengths,HR-based repair of telomeric breaks is sufficient to maintain iPSC telomeres at a normal length,which is compatible with sustained survival of the cells over several days of TRF1-FokI induction.Our findings suggest a previously unappreciated role for HR in telomere maintenance in telomerase-positive iPSCs and reveal distinct iPSC-specific responses to targeted telomeric DNA damage.
