Meplazumab in hospitalized adults with severe COVID-19(DEFLECT):a multicenter,seamless phase 2/3,randomized,third-party double-blind clinical trial

Meplazumab,a humanized CD147 antibody,has shown favourable safety and efficacy in our previous clinical studies.In DEFLECT(NCT04586153),167 patients with severe COVID-19 were enroled and randomized to receive three dosages of meplazumab and a placebo.Meplazumab at 0.12 mg/kg,compared to the placebo group,showed clinical benefits in significantly reducing mortality by 83.6%(2.4%vs.14.6%,p=0.0150),increasing the proportion of patients alive and discharged without supplemental oxygen(82.9%vs.70.7%,p=0.0337)and increasing the proportion of patients who achieved sustained clinical improvement(41.5%vs.31.7%).The response rate in the 0.2 mg/kg group was relatively increased by 16.0%compared with the placebo group(53.7%vs.46.3%).Meplazumab also reduced the viral loads and multiple cytokine levels.Compare with the placebo group,the 0.3 mg/kg significantly increased the virus negative rate by 40.6%(p=0.0363)and reduced IL-8 level(p=0.0460);the 0.2 mg/kg increased the negative conversion rate by 36.9%,and reduced IL-4(p=0.0365)and IL-8 levels(p=0.0484).In this study,the adverse events occurred at a comparable rate across the four groups,with no unexpected safety findings observed.In conclusion,meplazumab promoted COVID-19 convalescence and reduced mortality,viral load,and cytokine levels in severe COVID-19 population with good safety profile.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells

In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.

CD 147 receptor is essential for TFF3-mediated signaling regulating colorectal cancer progression

Major gaps in understanding the molecular mechanisms of colorectal cancer(CRC)progression and intestinal mucosal repair have hampered therapeutic development for gastrointestinal disorders.Trefoil factor 3(TFF3)has been reported to be involved in CRC progression and intestinal mucosal repair;however,how TFF3 drives tumors to become more aggressive or metastatic and how TFF3 promotes intestinal mucosal repair are still poorly understood.Here,we found that the upregulated TFF3 in CRC predicted a worse overall survival rate.TFF3 deficiency impaired mucosal restitution and adenocarcinogenesis.CD147,a membrane protein,was identified as a binding partner for TFF3.Via binding to CD147,TFF3 enhanced CD147-CD44s interaction,resulting in signal transducer and activator of transcription 3(STAT3)activation and prostaglandin G/H synthase 2(PTGS2)expression,which were indispensable for TFF3-induced migration,proliferation,and invasion.PTGS2-derived PGE2 bound to prostaglandin E2 receptor EP4 subtype(PTGER4)and contributed to TFF3-stimulated CRC progression.Solution NMR studies of the TFF3-CD147 interaction revealed the key residues critical for TFF3 binding and the induction of PTGS2 expression.The ability of TFF3 to enhance mucosal restitution was weakened by a PTGS2 inhibitor.Blockade of TFF3-CD147 signaling using competitive inhibitory antibodies or a PTGS2 inhibitor reduced CRC lung metastasis in mice.Our findings bring strong evidence that CD147 is a novel receptor for TFF3 and PTGS2 signaling is critical for TFF3-induced mucosal restitution and CRC progression,which widens and deepens the understanding of the molecular function of trefoil factors.

Safety and efficacy of meplazumab in healthy volunteers and COVID-19 patients: a randomized phase 1 and an exploratory phase 2 trial

Recent evidence suggests that CD147 serves as a novel receptor for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.Blocking CD147 via anti-CD147 antibody could suppress the in vitro SARS-CoV-2 replication.Meplazumab is a humanized anti-CD147 IgG_(2) monoclonal antibody,which may effectively prevent SARS-CoV-2 infection in coronavirus disease 2019(COVID-19)patients.Here,we conducted a randomized,double-blinded,placebo-controlled phase 1 trial to evaluate the safety,tolerability,and pharmacokinetics of meplazumab in healthy subjects,and an open-labeled,concurrent controlled add-on exploratory phase 2 study to determine the efficacy in COVID-19 patients.In phase 1 study,59 subjects were enrolled and assigned to eight cohorts,and no serious treatment-emergent adverse event(TEAE)or TEAE grade≥3 was observed.The serum and peripheral blood Cmax and area under the curve showed non-linear pharmacokinetic characteristics.No obvious relation between the incidence or titer of positive anti-drug antibody and dosage was observed in each cohort.The biodistribution study indicated that meplazumab reached lung tissue and maintained>14 days stable with the lung tissue/cardiac blood-pool ratio ranging from 0.41 to 0.32.In the exploratory phase 2 study,17 COVID-19 patients were enrolled,and 11 hospitalized patients were involved as concurrent control.The meplazumab treatment significantly improved the discharged(P=0.005)and case severity(P=0.021),and reduced the time to virus negative(P=0.045)in comparison to the control group.These results show a sound safety and tolerance of meplazumab in healthy volunteers and suggest that meplazumab could accelerate the recovery of patients from COVID-19 pneumonia with a favorable safety profile.

CD147 contributes to SARS-CoV-2-induced pulmonary fibrosis

COVID‐19 patients can develop clinical and histopathological features associated with fibrosis,but the pathogenesis of fibrosis remains poorly understood.CD147 has been identified as a universal receptor for SARS-CoV-2 and its variants,which could initiate COVID-19-related cytokine storm.Here,we systemically analyzed lung pathogenesis in SARS-CoV-2-and its delta variant-infected humanized CD147 transgenic mice.Histopathology and Transmission Electron Microscopy revealed inflammation,fibroblast expansion and pronounced fibrotic remodeling in SARS-CoV-2-infected lungs.Consistently,RNA-sequencing identified a set of fibrosis signature genes.Furthermore,we identified CD147 as a crucial regulator for fibroblast activation induced by SARS-CoV-2.We found conditional knockout of CD147 in fibroblast suppressed activation of fibroblasts,decreasing susceptibility to bleomycin-induced pulmonary fibrosis.Meplazumab,a CD147 antibody,was able to inhibit the accumulation of activated fibroblasts and the production of ECM proteins,thus alleviating the progression of pulmonary fibrosis caused by SARS-CoV-2.In conclusion,we demonstrated that CD147 contributed to SARS-CoV-2-triggered progressive pulmonary fibrosis and identified CD147 as a potential therapeutic target for treating patients with post-COVID-19 pulmonary fibrosis.

PDGFA-associated protein 1 is a novel target of c-Myc and contributes to colorectal cancer initiation and progression

Background:The mechanism underlying colorectal cancer(CRC)initiation and progression remains elusive,and overall survival is far from satisfactory.Previous studies have shown that PDGFA-associated protein 1(PDAP1)is upregulated in several cancers including CRC.Here,we aimed to identify the cause and consequence of PDAP1 dysregulation in CRC and evaluate its role as a potential therapeutic target.Methods:Multi-omics data analysis was performed to identify potential key players in CRC initiation and progression.Immunohistochemistry(IHC)staining was applied to determine the expression pattern of PDAP1 in CRC tissues.Pdap1 conditional knockout mice were used to establish colitis and CRC mouse models.RNA sequencing,a phosphoprotein antibody array,western blotting,histological analysis,5-bromo-2′-deoxyuridine(BrdU)incorporation assay,and interactome analysis were applied to identify the underlying mechanisms of PDAP1.A human patient-derived xenograft(PDX)model was used to assess the potential of PDAP1 as a therapeutic target.Results:PDAP1 was identified as a potential key player in CRC development using multi-omics data analysis.PDAP1 was overexpressed in CRC cells and correlated with reduced overall survival.Further investigation showed that PDAP1 was critical for the regulation of cell proliferation,migration,invasion,and metastasis.Significantly,depletion of Pdap1in intestinal epithelial cells impaired mucosal restitution in dextran sulfate sodium salt-induced colitis and inhibited tumor initiation and growth in colitis-associated cancers.Mechanistic studies showed that c-Myc directly transactivated PDAP1,which contributed to the high PDAP1 expression in CRC cells.PDAP1 interacted with the juxtamembrane domain of epidermal growth factor receptor(EGFR)and facilitated EGFRmitogen-activated protein kinase(MAPK)signaling activation,which resulted in FOS-related antigen 1(FRA-1)expression,thereby facilitating CRC progression.Notably,silencing of PDAP1 could hinder the growth of patient-derived xenografts that sustain high PDAP1 levels.Conclusions:PDAP1 facilitates mucosal restitution and carcinogenesis in colitis-associated cancer.c-Myc-driven upregulation of PDAP1 promotes proliferation,migration,invasion,and metastasis of CRC cells via the EGFRMAPK-FRA-1 signaling axis.These findings indicated that PDAP1 inhibition is warranted for CRC patients with PDAP1 overexpression.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells

In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.