Efficacy, Safety, and Population Pharmacokinetics of MW032 Compared With Denosumab for Solid Tumor-Related Bone Metastases: A Randomized, Double-Blind, Phase 3 Equivalence Trial.

Importance: The bioequivalence of denosumab biosimilar has yet to be studied in a 53-week, multicenter, large-scale, and head-to-head trial. A clinically effective biosimilar may help increase access to denosumab in patients with solid tumor-related bone metastases. Objectives: To establish the biosimilarity of MW032 to denosumab in patients with solid tumor-related bone metastases based on a large-scale head-to-head study. Design, Setting, and Participants: In this 53-week, randomized, double-blind, phase 3 equivalence trial, patients with solid tumors with bone metastasis were recruited from 46 clinical sites in China. Overall, 856 patients were screened and 708 eligible patients were randomly allocated to receive either MW032 or denosumab. Interventions: Patients were randomly assigned (1:1) to receive MW032 or reference denosumab subcutaneously every 4 weeks until week 49. Main Outcomes and Measures: The primary end point was percentage change from baseline to week 13 of natural logarithmic transformed urinary N-telopeptide/creatinine ratio (uNTx/uCr). Results: Among the 701 evaluable patients (350 in the MW032 group and 351 in the denosumab group), the mean (range) age was 56.1 (22.0-86.0) years and 460 patients were women (65.6%). The mean change of uNTx/uCr from baseline to week 13 was -72.0% (95% CI, -73.5% to -70.4%) in the MW032 group and -72.7% (95% CI, -74.2% to -71.2%) in the denosumab group. These percent changes corresponded to mean logarithmic ratios of -1.27 and -1.30, or a difference of 0.02. The 90% CI for the difference (-0.04 to 0.09) was within the equivalence margin (-0.13 to 0.13); the mean changes of uNTx/uCr and bone-specific alkaline phosphatase (s-BALP) at each time point were also similar during 53 weeks. The differences of uNTx/uCr change were 0.015 (95% CI, -0.06 to 0.09), -0.02 (95% CI, -0.09 to 0.06), -0.05 (95% CI, -0.13 to 0.03) and 0.001 (95% CI, -0.10 to 0.10) at weeks 5, 25, 37, and 53, respectively. The differences of s-BALP change were -0.006 (95% CI, 0.06 to 0.05), 0.00 (95% CI, -0.07 to 0.07), -0.085 (95% CI, -0.18 to 0.01), -0.09 (95% CI, -0.20 to 0.02), and -0.13 (95% CI, -0.27 to 0.004) at weeks 5, 13, 25, 37 and 53, respectively. No significant differences were observed in the incidence of skeletal-related events (-1.4%; 95% CI, -5.8% to 3.0%) or time to first on-study skeletal-related events (unadjusted HR, 0.86; P = .53; multiplicity adjusted HR, 0.87; P = .55) in the 2 groups. Conclusions and Relevance: MW032 and denosumab were biosimilar in efficacy, population pharmacokinetics, and safety profile. Availability of denosumab biosimilars may broaden the access to denosumab and reduce the drug burden for patients with advanced tumors. Trial Registration: ClinicalTrials.gov Identifier: NCT04812509.

A HER2-targeted antibody-novel DNA topoisomerase I inhibitor conjugate induces durable adaptive antitumor immunity by activating dendritic cells.

We designed and developed a novel DNA topoisomerase I inhibitor MF-6, which was a more potent cytotoxin and a more potent inducer of immunogenic cell death compared with DXd. To utilize MF-6's ability to induce antitumor immunity, a human epidermal growth factor receptor 2 (HER2)-targeted antibody-drug conjugate (ADC) trastuzumab-L6 that included a cleavable linker and MF-6 was developed. Different from traditional cytotoxic ADC, the antitumor activity of trastuzumab-L6 was assessed by inducing tumor cell immunogenic cell death, activating dendritic cells and cytotoxic CD8+ T cells to acquire durable adaptive immune memory. Tumor cells treated with trastuzumab-L6 were committed to immunogenic cell death, with upregulation of damage-associated molecular patterns and antigen presentation molecules. In a syngeneic tumor model with a mouse cell line that expressed human HER2, immunocompetent mice showed greater antitumor efficacy compared with nude mice. The trastuzumab-L6-cured immunocompetent mice acquired adaptive antitumor memory and rejected subsequent tumor cell challenge. The trastuzumab-L6 efficacy was abrogated when cytotoxic CD8+ T cells were depleted and enhanced when regulatory CD4+ T cells were depleted. The combination of trastuzumab-L6 with immune checkpoint inhibitors significantly increased antitumor efficacy. Enhanced T cell infiltration, dendritic cell activation, and decreased type M2 macrophages in tumor post trastuzumab-L6 administration confirmed the immune-activating responses. In conclusion, trastuzumab-L6 was considered to be an immunostimulatory agent, rather than a traditional cytotoxic ADC, and its antitumor efficacy was enhanced when combined with an anti-PD-L1 and anti-CTLA-4 antibody, which suggested a potential therapeutic strategy.

Preclinical Evaluation of 9MW2821, a Site-Specific Monomethyl Auristatin E-based Antibody-Drug Conjugate for Treatment of Nectin-4-expressing Cancers.

Overexpression of nectin cell adhesion protein 4 correlates with cancer progression and poor prognosis in many human malignancies. Enfortumab vedotin (EV) is the first nectin-4-targeting antibody-drug conjugate (ADC) approved by the FDA for the treatment of urothelial cancer. However, inadequate efficacy has limited progress in the treatment of other solid tumors with EV. Furthermore, ocular, pulmonary, and hematologic toxic side effects are common in nectin-4-targeted therapy, which frequently results in dose reduction and/or treatment termination. Thus, we designed a second generation nectin-4-specific drug, 9MW2821, based on interchain-disulfide drug conjugate technology. This novel drug contained a site specifically conjugated humanized antibody and the cytotoxic moiety monomethyl auristatin E. The homogenous drug-antibody ratio and novel linker chemistry of 9MW2821 increased the stability of conjugate in the systemic circulation, enabling highly efficient drug delivery and avoiding off-target toxicity. In preclinical evaluation, 9MW2821 exhibited nectin-4-specific cell binding, efficient internalization, bystander killing, and equivalent or superior antitumor activity compared with EV in both cell line-derived xenograft and patient-derived xenograft (PDX) models. In addition, 9MW2821 demonstrated a favorable safety profile; the highest nonseverely toxic dose in monkey toxicologic studies was 6 mg/kg, with milder adverse events compared with EV. Overall, 9MW2821 is a nectin-4-directed, investigational ADC based on innovative technology that endowed the drug with compelling preclinical antitumor activity and a favorable therapeutic index. The 9MW2821 ADC is being investigated in a phase I/II clinical trial (NCT05216965 and NCT05773937) in patients with advanced solid tumors.

Antibody-dependent enhancement (ADE) of SARS-CoV-2 pseudoviral infection requires FcγRIIB and virus-antibody complex with bivalent interaction.

Understanding the underlying molecular mechanisms behind ADE of SARS-CoV-2 is critical for development of safe and effective therapies. Here, we report that two neutralizing mAbs, MW01 and MW05, could enhance the infection of SARS-CoV-2 pseudovirus on FcγRIIB-expressing B cells. X-ray crystal structure determination and S trimer-binding modeling showed that MW01 and MW05 could bind to RBDs in S trimer with both "up" and "down" states. While, the neutralizing mAb MW07, which has no ADE activity only binds to RBD in S trimer with "up" state. Monovalent MW01 and MW05 completely diminished the ADE activity compared with their bivalent counterparts. Moreover, both macropinocytosis and endocytosis are confirmed involving in ADE of SARS-CoV-2 pseudoviral infection. Blocking endosome transportation and lysosome acidification could inhibit the ADE activity mediated by MW05. Together, our results identified a novel ADE mechanism of SARS-CoV-2 pseudovirus in vitro, FcγRIIB-mediated uptake of SARS-CoV-2/mAb complex with bivalent interaction.

CoVac501, a self-adjuvanting peptide vaccine conjugated with TLR7 agonists, against SARS-CoV-2 induces protective immunity.

Safe, effective, and economical vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to achieve adequate herd immunity and end the pandemic. We constructed a novel SARS-CoV-2 vaccine, CoVac501, which is a self-adjuvanting peptide vaccine conjugated with Toll-like receptor 7 (TLR7) agonists. The vaccine contains immunodominant peptides screened from the receptor-binding domain (RBD) and is fully chemically synthesized. It has been formulated in an optimized nanoemulsion formulation and is stable at 40 °C for 1 month. In non-human primates (NHPs), CoVac501 elicited high and persistent titers of protective neutralizing antibodies against multiple RBD mutations, SARS-CoV-2 original strain, and variants (B.1.1.7 and B.1.617.2). Specific peptides booster immunization against the B.1.351 variant has also been shown to be effective in improving protection against B.1.351. Meanwhile, CoVac501 elicited the increase of memory T cells, antigen-specific CD8+ T-cell responses, and Th1-biased CD4+ T-cell immune responses in NHPs. Notably, at an extremely high SARS-CoV-2 challenge dose of 1 × 107 TCID50, CoVac501 provided near-complete protection for the upper and lower respiratory tracts of cynomolgus macaques.

Safety, tolerability, pharmacokinetic characteristics, and immunogenicity of MW33: a Phase 1 clinical study of the SARS-CoV-2 RBD-targeting monoclonal antibody.

MW33 is a fully humanized IgG1κ monoclonal neutralizing antibody, and may be used for the prevention and treatment of coronavirus disease 2019 (COVID-19). We conducted a randomized, double-blind, placebo-controlled, single-dose, dose-escalation Phase 1 study to evaluate the safety, tolerability, pharmacokinetics (PK), and immunogenicity of MW33. Healthy adults aged 18-45 years were sequentially enrolled into the 4, 10, 20, 40, and 60 mg/kg dose groups and infused with MW33 over 60 ± 15 min and followed for 85 days. All 42 enrolled participants completed the MW33 infusion, and 40 participants completed the 85-day follow-up period. 34 participants received a single infusion of 4 (n = 2), 10 (n = 8), 20 (n = 8), 40 (n = 8), and 60 mg/kg (n = 8) of MW33. 27 subjects in the test groups experienced 78 adverse events (AEs) post-dose, with an incidence of 79.4% (27/34). The most common AEs included abnormal laboratory test results, vascular and lymphatic disorders, and infectious diseases. The severity of AEs was mainly Grade 1 (92 AEs), and three Grade 2 and one Grade 4. The main PK parameters, maximum concentration (Cmax), and area under the concentration-time curve (AUC0-t, and AUC0-∞) in 34 subjects showed a linear kinetic relationship in the range of 10-60 mg/kg. The plasma half-life was approximately 25 days. The positive rates of serum ADAs and antibody titres were low with no evidence of an impact on safety or PK. In conclusion, MW33 was well-tolerated, demonstrated linear PK, with a lower positive rate of serum ADAs and antibody titres in healthy subjects.Trial registration: ClinicalTrials.gov identifier: NCT04427501.Trial registration: ClinicalTrials.gov identifier: NCT04533048.Trial registration: ClinicalTrials.gov identifier: NCT04627584.

Characterization of neutralizing antibody with prophylactic and therapeutic efficacy against SARS-CoV-2 in rhesus monkeys.

Efficacious interventions are urgently needed for the treatment of COVID-19. Here, we report a monoclonal antibody (mAb), MW05, with SARS-CoV-2 neutralizing activity by disrupting the interaction of receptor binding domain (RBD) with angiotensin-converting enzyme 2 (ACE2) receptor. Crosslinking of Fc with FcγRIIB mediates antibody-dependent enhancement (ADE) activity by MW05. This activity is eliminated by introducing the LALA mutation to the Fc region (MW05/LALA). Potent prophylactic and therapeutic effects against SARS-CoV-2 are observed in rhesus monkeys. A single dose of MW05/LALA blocks infection of SARS-CoV-2 in prophylactic treatment and clears SARS-CoV-2 in three days in a therapeutic treatment setting. These results pave the way for the development of MW05/LALA as an antiviral strategy for COVID-19.

Study on the Heterogeneity of T-DM1 and the Analysis of the Unconjugated Linker Structure under a Stable Conjugation Process.

Trastuzumab emtansine (T-DM1) is a target-specific anticancer antibody-drug conjugate (ADC). In the present study, critical quality attributes for different manufactured products, such as the drug to antibody ratio (DAR), conjugation site, and site conjugation ratio, are similar, which is contrary to the traditional view that conjugation at lysine sites is randomly assigned. To investigate this result, a series samples with different DARs were prepared. Site conjugation ratios of the 27 different conjugation sites (corresponding to 54 potential sites) were analyzed. We found that the correlation coefficients of the 26 site conjugation ratio and the DAR were R 2 > 0.9, and the remaining one was R 2 > 0.7. By comparing three batches of samples with a DAR value of ∼3.3 in a stability study, we found that degradation rates of conjugation sites of the samples incubated at 40 °C were basically the same. These data show that the conjugation ratio and the conjugation stability of each site may remain consistent if the process parameters are stable. LC/MS/MS was used to study the unconjugated linker of the crosslink byproducts produced by a two-step method. We determined four forms of unconjugated linkers: (N-maleimidomethyl) cyclohexane-1-carboxylate (MCC) unconjugated to DM1, hydrolyzed MCC unconjugated to DM1, lys-MCC-lys, and lys-MCC-cys. We believe that the current study can provide an effective guide for the processing of ADCs, control of product quality, and reduction of side reaction products.

The influence of YS-1 on the Dll4-Notch1 signaling pathway.

In this study, we investigated the role and molecular mechanism of p43 and YS-1 (recombinant human p43 protein) in Dll4-Notch1 signaling pathway. Active, small interfering RNA and recombinant plasmid targeting of p43 protein were used to infect human umbilical vein endothelial cells (HUVECs). Three-dimensional sprouting model, endothelial cell migration assay, and sprouting and tube formation assay were used to deduce the function of p43 and YS-1 in angiogenesis. Semi-quantitative reverse transcription-polymerase chain reaction and western blot analysis were performed to detect the efficiency of p43 in Dll4-Notch1 signaling in HUVECs. It was found that silencing and overexpression of p43 could upregulate Dll4-Notch and stimulate angiogenesis. p43 plays a complex role in angiogenesis. When the concentration is under 100 nM, it promotes angiogenesis; instead, when the concentration is over 100 nM, it inhibits angiogenesis. In this study, we found that the expression level of p43 was under 60 nM. However, recombinant human p43 protein, YS-1, inhibited endothelial cell sprouting, and 500 µg/ml of YS-1 attenuated the activation of Dll4-Notch1 signaling. These results suggested that YS-1 could directly inhibit angiogenesis through Dll4-Notch1 signal transduction pathway, while p43 plays a modulating role in this signaling pathway.

Genome Sequence of the Bacterium Bifidobacterium longum Strain CMCC P0001, a Probiotic Strain Used for Treating Gastrointestinal Disease.

Bifidobacterium longum subsp. longum CMCC P0001, a standard probiotic strain in China, has been widely used in clinical medicine for more than 20 years. Here we report the genome features of B. longum strain CMCC P0001.

Characterization of a novel humanized anti-CD20 antibody with potent anti-tumor activity against non-Hodgkin's lymphoma.

BACKGROUND: Rituximab, a mouse Fab and human Fc chimeric antibody, has been widely used to treat Non-Hodgkin's lymphoma (NHL). However, only 48% of patients respond to the treatment and complete response rate is below 10%. Also, immunogenicity was reported in 17-20% patients receiving the treatment, making it unsuitable for long term diseases such as autoimmune disorders. It has been a hot research field to "humanize" rituximab toward improved efficacy and reduced immunogenicity. METHODS: In this study, an advanced antibody humanization technology was applied to the sequence of the anti-CD20 antibody 2B8, its sequence of which was based on the original murine monoclonal antibody of rituximab in Roche. The complementarity-determining regions (CDRs) of the humanized antibodies were further optimized through computer-aided molecular dock. RESULTS: Five novel humanized anti-CD20 antibodies 1-5(1635, 1534, 3637, 1634 and 1536) were generated and their immunogenicity was significantly decreased when compared to rituximab. The novel humanized anti-CD20 antibodies 1-5 retained the binding activity of their murine counterpart, as demonstrated by the fluorescence-activated cell-sorting analysis (FACS). When compared to rituximab, the humanized antibodies still have the similar properties on both complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC). Furthermore, its anti-tumor efficacy in xenograft model is comparable to that of rituximab. CONCLUSION: The humanized anti-CD20 antibodies 1-5 have lower immunogenicity than rituximab. And at the same time, they still retain the anti-tumor effect both in vitro and vivo.

Definition of peptide inhibitors from a synthetic peptide library by targeting gelatinase B/matrix metalloproteinase-9 (MMP-9) and TNF-α converting enzyme (TACE/ADAM-17).

Gelatinase B/matrix metalloproteinase-9 (MMP-9) is a regulatory and effector metalloproteinase in inflammation. TNF-α is an important proinflammatory cytokine and is released by the action of a Zn(2+)-containing converting enzyme (TACE/ADAM-17). Both metallo-enzymes play important roles during the development of shock syndromes. Combinatorial chemical synthesis and subsequent library deconvolution were previously used to define a peptide inhibitor (Regasepin1) acting, almost to the same degree, on neutrophil collagenase/MMP-8 and MMP-9 in vitro, and protecting mice against lethal endotoxinemia in vivo. We have now extended this approach by incorporating D-form amino acids and residues preferred by TACE. A new peptide library was designed and synthesized, and by deconvolution new peptide inhibitors were defined. These included a TACE-specific inhibitor, an MMP-9- specific inhibitor, and inhibitors for both enzymes.

A reference proteomic database of Lactobacillus plantarum CMCC-P0002.

Lactobacillus plantarum is a widespread probiotic bacteria found in many fermented food products. In this study, the whole-cell proteins and secretory proteins of L. plantarum were separated by two-dimensional electrophoresis method. A total of 434 proteins were identified by tandem mass spectrometry, including a plasmid-encoded hypothetical protein pLP9000_05. The information of first 20 highest abundance proteins was listed for the further genetic manipulation of L. plantarum, such as construction of high-level expressions system. Furthermore, the first interaction map of L. plantarum was established by Blue-Native/SDS-PAGE technique. A heterodimeric complex composed of maltose phosphorylase Map3 and Map2, and two homodimeric complexes composed of Map3 and Map2 respectively, were identified at the same time, indicating the important roles of these proteins. These findings provided valuable information for the further proteomic researches of L. plantarum.

[Over-expression in Escherichia coli and characterization of apolipoprotein AI].

Apolipoprotein AI (apo AI), the major protein component of human high-density lipoprotein (HDL), is a single-chain polypeptide of 243 amino acids. Several epidemiological studies have shown that the plasma concentrations of HDL has the role of reverse cholesterol transport (RCT) and inversely correlated with the incidence of coronary artery disease. Because apo AI lacks post-translational modifications, it is convenient to express human apo AI in Escherichia coli expression system. However, there is a poor stability of the mRNA and the apo AI protein in E. coli, it is difficult to express mature apo AI in recombinant bacteria, moreover, even as a fusion protein, apo AI is still sensitive to degradation and can not be cleaved efficiently from the fusion tags. In contrast, proapolipoprotein AI (proapo AI, having an additional polypeptide containing the amino acids Arg-His-Phe-Trp-Gln-Gln at the amino-teminal of the mature protein) proved stable and undegraded in Escherichia coli, and therefore, in this research, an expression system of E. coli including a plasmid of P(R)P(L) tandem promoter was adapted to produce proapo AI. Furthermore, site-directed mutagenesis of the proapo AI cDNA was performed to generate a Clu8Asp mutation in the amino-terminal sequence of proapo AI which created an acid labile Asp-Pro peptide bond between amino acid 8 and 9, and permitted specific chemical cleavage to remove pro-peptide. After inducing with a shift of temperature, yields of recombinant proapo AI achieved about 40% of total cell protein and the recombinant proapo AI expressed proved as a form of inclusion body in cells, so protein need to renature. First of all, the protein was dissolved in buffer with denaturant, and renaturation was carried out on a hydrophobic interaction column (Phenyl Sepharose), ion-exchange chromatography and gel-filtration chromatography were then used to further purify the protein. The purified recombinant apo AI was detected by a set of tests including Western-blotting, Circular dichroism spectra and lipid-binding test, the results shown that recombinant apo AI has similar structural and lipid-binding properties identical to those of native plasma apo AI, which facilitates further research and application.