CD38 x ICAM-1 Bispecific Antibody Is a Novel Approach for Treating Multiple Myeloma and Lymphoma.

The cluster of differentiation 38 (CD38) is a well-validated target for treating multiple myeloma. Although anti-CD38 mAbs have demonstrated outstanding initial responses in patients with multiple myeloma, nearly all patients eventually develop resistance and relapse. In addition, currently approved CD38 targeting therapies have failed to show monotherapy efficacy in lymphomas, where CD38 expression is present but at lower levels. To effectively target CD38 on tumor cells, we generated an antibody-dependent cellular cytotoxicity (ADCC) enhanced bispecific CD38 x intercellular cell adhesion molecule 1 (ICAM-1) antibody, VP301. This bispecific antibody targets unique epitopes on CD38 and ICAM-1 on tumor cells with reduced red blood cell binding compared with the benchmark CD38 antibody daratumumab. VP301 demonstrated potent ADCC and antibody-dependent cellular phagocytosis activities on a selected set of myeloma and lymphoma cell lines even those with low CD38 expression. In an ex vivo drug sensitivity assay, we observed responses to VP301 in multiple myeloma primary samples from relapsed/refractory patients. Moreover, VP301 demonstrated potent tumor inhibition activities in in vivo myeloma and lymphoma models. Interestingly, combination of VP301 with the immunomodulatory drug, lenalidomide, led to synergistic antitumor growth activity in an in vivo efficacy study. In conclusion, the CD38 x ICAM-1 bispecific antibody VP301 demonstrated promising efficacy and specificity toward CD38+ and ICAM-1+ tumor cells and represents a novel approach for treating multiple myeloma and lymphoma.

Target arm affinities determine preclinical efficacy and safety of anti-HER2/CD3 bispecific antibody.

Systemic cytokine release and on-target/off-tumor toxicity to normal tissues are the main adverse effects limiting the clinical utility of T cell-redirecting therapies. This study was designed to determine how binding affinity for CD3 and tumor target HER2 impact the efficacy and nonclinical safety of anti-HER2/CD3 T cell-dependent antibodies (TDBs). Affinity was found to be a major determinant for the overall tolerability. Higher affinity for CD3 associated with rapidly elevated peripheral cytokine concentrations, weight loss in mice, and poor tolerability in cynomolgus monkeys. A TDB with lower CD3 affinity was better tolerated in cynomolgus monkeys compared with a higher CD3-affinity TDB. In contrast to tolerability, T cell binding affinity had only limited impact on in vitro and in vivo antitumor activity. High affinity for HER2 was critical for the tumor-killing activity of anti-HER2/CD3 TDBs, but higher HER2 affinity also associated with a more severe toxicity profile, including cytokine release and damage to HER2-expressing tissues. The tolerability of the anti-HER2/CD3 was improved by implementing a dose-fractionation strategy. Fine-tuning the affinities for both the tumor target and CD3 is likely a valuable strategy for achieving maximal therapeutic index of CD3 bispecific antibodies.

Anti-CD20/CD3 T cell-dependent bispecific antibody for the treatment of B cell malignancies.

Bispecific antibodies and antibody fragments in various formats have been explored as a means to recruit cytolytic T cells to kill tumor cells. Encouraging clinical data have been reported with molecules such as the anti-CD19/CD3 bispecific T cell engager (BiTE) blinatumomab. However, the clinical use of many reported T cell-recruiting bispecific modalities is limited by liabilities including unfavorable pharmacokinetics, potential immunogenicity, and manufacturing challenges. We describe a B cell-targeting anti-CD20/CD3 T cell-dependent bispecific antibody (CD20-TDB), which is a full-length, humanized immunoglobulin G1 molecule with near-native antibody architecture constructed using "knobs-into-holes" technology. CD20-TDB is highly active in killing CD20-expressing B cells, including primary patient leukemia and lymphoma cells both in vitro and in vivo. In cynomolgus monkeys, CD20-TDB potently depletes B cells in peripheral blood and lymphoid tissues at a single dose of 1 mg/kg while demonstrating pharmacokinetic properties similar to those of conventional monoclonal antibodies. CD20-TDB also exhibits activity in vitro and in vivo in the presence of competing CD20-targeting antibodies. These data provide rationale for the clinical testing of CD20-TDB for the treatment of CD20-expressing B cell malignancies.

[Sedum sarmentosun bunge extraction ameliorated severe acute pancreatitis-induced lung injury: an experimental research]].

OBJECTIVE: To explore the effect of Sedum sarmentosum Bunge Extract (SSBE) on severe acute pancreatitis (SAP) induced acute lung injury (ALI) model rats and their excessive inflammatory reactions. METHODS: Forty-two healthy adult male Sprague-Dawley (SD) rats were randomly divided into 3 groups, the sham-operated control group (C), the SAP group (SAP), and the SSBE treated group (SSBE), 14 in each group. SAP induced ALl rat model was induced by retrograde injection of 5% sodium taurocholate (1 mL/kg) into the pancreatic duct. SSBE (100 m/kg) was administrated subcutaneously after the establishment of the SAP model. Equal dose of SSBE was injected again 12 h later. Equal volume of normal saline was administrated in the same way for rats in the C group and the SAP group. Rats were sacrificed after successful modeling and samples taken at 12 and 24 h. Pathological changes in the pancreas and the lung tissue were observed under light microscope. The ascites, serum amylase (AMS), wet/dry proportion (W/D) of the lung tissue, activities of myeloperoxidase (MPO), interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF-alpha) were also measured. RESULTS: Ascites and serum AMS activities significantly increased; MPO, IL-1, IL-6, TNF-alpha contents, and W/D ratio also significantly increased in the SAP group, when compared with the C group (P<0.05). Compared with the SAP group, those parameters were all attenuated in the SSBE group at 12 and 24 h (P<0.05, P<0.01). Pathological changes in the pancreas and the lung tissue were alleviated in the SSBE group under light microscope. The injury degree ranged between that of the C group and the SAP group. CONCLUSION: SSBE could relieve the ALl in SAP model rats, which could be achieved through alleviating inflammation responses of SAP rats.

Static headspace-multicapillary column with gas chromatography coupled to ion mobility spectrometry as a simple approach for the discrimination of crude and processed traditional Chinese medicines.

The processing procedure can alter the nature and chemical transformation of traditional Chinese medicine to accommodate different clinical dispensing and preparation requirements. In this study, static headspace-multicapillary column with gas chromatography coupled to ion mobility spectrometry was developed for the rapid and sensitive discrimination of crude and processed traditional Chinese medicine. Using Radix Paeoniae Alba as a traditional Chinese medicine model, the combined power of this approach was illustrated by classifying the crude and processed Radix Paeoniae Alba samples into two main categories. The contents of the main components in Radix Paeoniae Alba varied significantly. The established method could promote the use of ion mobility spectrometry in intrinsic quality control and differentiation of herbal medicines from other processed products or preparations.

Codon 104 variation of p53 gene provides adaptive apoptotic responses to extreme environments in mammals of the Tibet plateau.

Mutational changes in p53 correlate well with tumorigenesis. Remarkably, however, relatively little is known about the role that p53 variations may play in environmental adaptation. Here we report that codon asparagine-104 (104N) and glutamic acid-104 (104E), respectively, of the p53 gene in the wild zokor (Myospalax baileyi) and root vole (Microtus oeconomus) are adaptively variable, meeting the environmental stresses of the Tibetan plateau. They differ from serine-104 (104S) seen in other rodents, including the lowland subterranean zokor Myospalax cansus, and from serine 106 (106S) in humans. Based on site-directed mutational analysis in human cell lines, the codon 104N variation in M. baileyi is responsible for the adaptive balance of the transactivation of apoptotic genes under hypoxia, cold, and acidic stresses. The 104E p53 variant in Microtus oeconomus suppresses apoptotic gene transactivation and cell apoptosis. Neither 104N nor 104E affects the cell-cycle genes. We propose that these variations in p53 codon 104 are an outcome of environmental adaptation and evolutionary selection that enhance cellular strategies for surviving the environmental stresses of hypoxia and cold (in M. baileyi and M. oeconomus) and hypercapnia (in M. baileyi) in the stressful environments of the Qinghai-Tibet plateau.

Identification of chromosomal copy number variations and novel candidate loci in hereditary nonpolyposis colorectal cancer with mismatch repair proficiency.

The pathogenesis of microsatellite stable hereditary non-polyposis colorectal cancers (MSS HNPCC) is unclear. To identify genomic regions that might be involved in MSS HNPCC pathogenesis, we selected 20 pairs of MSS HNPCC for a genome-wide study using copy number variation targeted (CNV-targeted) CytoScan HD Array. A remarkably increased frequency of 20q gain (70%) and high levels of copy-neutral loss of heterozygosity (40%) were observed. The most frequent tumor-specific CNVs included amplifications (7p21.3-15.1, 8q13.3-24.3, 13q14.1-33.3 and 20q12-13.33) and deletions (8p11.23-23.1, 15q11.2-26.1, 17p13.1-13.3 and 18q11.2-21.33). In addition, 10 novel CNVs were discovered and led to identification of WDR16 and RAPGEF5 as candidate genes involved in tumorigenesis, displaying a robust correlation between expression and genomic alterations. Moreover, WDR16 and RAPGEF5 exhibited altered protein expression levels as assessed by immunohistochemistry (IHC) in 41 other independent samples. Finally, high consistencies (68-84%) were observed between CNVs by Array and quantitative PCR. These findings are important for further elucidating MSS HNPCC pathogenesis.

Evidence for SNARE zippering during Ca2+-triggered exocytosis in PC12 cells.

SNAREs (soluble NSF attachment protein receptors) are membrane proteins that catalyze membrane fusion. SNAREs are defined by a characteristic 70 residue sequence called the SNARE motif. During synaptic vesicle fusion, the single SNARE motif of the synaptic vesicle SNARE protein synaptobrevin/VAMP associates into a four-helical bundle with SNARE motifs from the plasma membrane SNARE proteins syntaxin 1 and SNAP-25. The four SNARE motifs (one each from synaptobrevin and syntaxin, and two from SNAP-25) assume a parallel orientation in the complex, suggesting that formation of the complex initiates fusion by forcing the membranes containing the SNAREs into close proximity. It has been proposed that SNARE complexes assemble in an N- to C-terminal progression, a process referred to as zippering, but little direct evidence for zippering exists. Furthermore, the SM protein Munc18-1, which binds to syntaxin 1 and is essential for synaptic fusion, is thought to prepare SNAREs for complex formation by an unknown mechanism, possibly by nucleating zippering. We now show that fragments containing the N- and C-terminal regions of the SNARE motif from syntaxin 1A bind SNAP-25 similarly. However, in permeabilized PC12 cells which are used as a biochemical model system to study synaptic fusion, only fragments containing the N-terminal region are powerful inhibitors of fusion. Furthermore, mutations in the N-terminal part of the Syntaxin SNARE motif have only a moderate effect on SNAP-25 binding but abolish the inhibitory activity of the SNARE motif. Finally, larger fragments of syntaxin 1A that strongly bind to Munc18-1 but do not readily assemble into SNARE complexes had no effect on exocytosis in permeabilized PC12 cells. Together these results suggest that Munc18-1 acts before SNARE complex assembly, and is no longer required at the stage of fusion assayed in permeabilized PC12 cells. The selective effect of the N-terminal half of the syntaxin 1A SNARE motif on PC12 cell exocytosis shows that the SNARE motif is functionally polarized, and supports the notion that SNARE complexes assemble in an N- to C-terminal zippering reaction during fusion without a stable, partially assembled intermediate.