[Current status of diagnosis and treatment of chronic lymphocytic leukemia in China: A national multicenter survey research]

Objective: To understand the current status of diagnosis and treatment of chronic lymphocytic leukemia (CLL) /small lymphocytic lymphoma (SLL) among hematologists, oncologists, and lymphoma physicians from hospitals of different levels in China. Methods: This multicenter questionnaire survey was conducted from March 2021 to July 2021 and included 1,000 eligible physicians. A combination of face-to-face interviews and online questionnaire surveys was used. A standardized questionnaire regarding the composition of patients treated for CLL/SLL, disease diagnosis and prognosis evaluation, concomitant diseases, organ function evaluation, treatment selection, and Bruton tyrosine kinase (BTK) inhibitor was used. Results: ①The interviewed physicians stated that the proportion of male patients treated for CLL/SLL is higher than that of females, and the age is mainly concentrated in 61-70 years old. ②Most of the interviewed physicians conducted tests, such as bone marrow biopsies and immunohistochemistry, for patient diagnosis, in addition to the blood test. ③Only 13.7% of the interviewed physicians fully grasped the initial treatment indications recommended by the existing guidelines. ④In terms of cognition of high-risk prognostic factors, physicians' knowledge of unmutated immunoglobulin heavy-chain variable and 11q- is far inferior to that of TP53 mutation and complex karyotype, which are two high-risk prognostic factors, and only 17.1% of the interviewed physicians fully mastered CLL International Prognostic Index scoring system. ⑤Among the first-line treatment strategy, BTK inhibitors are used for different types of patients, and physicians have formed a certain understanding that BTK inhibitors should be preferentially used in patients with high-risk factors and elderly patients, but the actual use of BTK inhibitors in different types of patients is not high (31.6%-46.0%). ⑥BTK inhibitors at a reduced dose in actual clinical treatment were used by 69.0% of the physicians, and 66.8% of the physicians had interrupted the BTK inhibitor for >12 days in actual clinical treatment. The use of BTK inhibitors is reduced or interrupted mainly because of adverse reactions, such as atrial fibrillation, severe bone marrow suppression, hemorrhage, and pulmonary infection, as well as patients' payment capacity and effective disease progression control. ⑦Some differences were found in the perceptions and behaviors of hematologists and oncologists regarding the prognostic assessment of CLL/SLL, the choice of treatment options, the clinical use of BTK inhibitors, etc. Conclusion: At present, a gap remains between the diagnosis and treatment of CLL/SLL among Chinese physicians compared with the recommendations in the guidelines regarding the diagnostic criteria, treatment indications, prognosis assessment, accompanying disease assessment, treatment strategy selection, and rational BTK inhibitor use, especially the proportion of dose reduction or BTK inhibitor discontinuation due to high adverse events.

Cytological and genetic effects of rye chromosomes 1RS and 3R on the wheat-breeding founder parent Chuanmai 42 from southwestern China

Rye (Secale cereale L.) is an important genetic resource for improving the disease resistance of wheat. An increasing number of rye chromosome segments have been transferred into modern wheat cultivars via chromatin insertions. In this study, 185 recombinant inbred lines (RILs) derived from a cross between a wheat accession containing rye chromosomes 1RS and 3R and a wheat-breeding founder parent Chuanmai 42 from southwestern China were used to decipher the cytological and genetic effects of 1RS and 3R via fluorescence/genomic in situ hybridization and quantitative trait locus (QTL) analyses. Chromosome centromere breakage and fusion were detected in the RIL population. Additionally, the recombination of chromosomes 1BS and 3D from Chuanmai 42 was completely suppressed by 1RS and 3R in the RIL population. In contrast to chromosome 3D of Chuanmai 42, rye chromosome 3R was significantly associated with white seed coats and decreased yield-related traits, as revealed by QTL and single marker analyses, whereas it had no effect on stripe rust resistance. Rye chromosome 1RS did not affect yield-related traits and it increased the susceptibility of plants to stripe rust. Most of the detected QTLs that positively affected yield-related traits were from Chuanmai 42. The findings of this study suggest that the negative effects of rye-wheat substitutions or translocations, including the suppression of the pyramiding of favorable QTLs on paired wheat chromosomes from different parents and the transfer of disadvantageous alleles to filial generations, should be considered when selecting alien germplasm to enhance wheat-breeding founder parents or to breed new varieties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11032-023-01386-0.

[Clinical and genetic characteristics of young patients with myeloproliferative neoplasms]

Objectives: To investigate the clinical and genetic features of young Chinese patients with myeloproliferative neoplasms (MPN). Methods: In this cross-sectional study, anonymous questionnaires were distributed to patients with MPN patients nationwide. The respondents were divided into 3 groups based on their age at diagnosis: young (≤40 years) , middle-aged (41-60 years) , and elderly (>60 years) . We compared the clinical and genetic characteristics of three groups of MPN patients. Results: 1727 assessable questionnaires were collected. There were 453 (26.2%) young respondents with MPNs, including 274 with essential thrombocythemia (ET) , 80 with polycythemia vera (PV) , and 99 with myelofibrosis. Among the young group, 178 (39.3%) were male, and the median age was 31 (18-40) years. In comparison to middle-aged and elderly respondents, young respondents with MPN were more likely to present with a higher proportion of unmarried status (all P<0.001) , a higher education level (all P<0.001) , less comorbidity (ies) , fewer medications (all P<0.001) , and low-risk stratification (all P<0.001) . Younger respondents experienced headache (ET, P<0.001; PV, P=0.007; MF, P=0.001) at diagnosis, had splenomegaly at diagnosis (PV, P<0.001) , and survey (ET, P=0.052; PV, P=0.063) . Younger respondents had fewer thrombotic events at diagnosis (ET, P<0.001; PV, P=0.011) and during the survey (ET, P<0.001; PV, P=0.003) . JAK2 mutations were found in fewer young people (ET, P<0.001; PV, P<0.001; MF, P=0.013) ; however, CALR mutations were found in more young people (ET, P<0.001; MF, P=0.015) . Furthermore, mutations in non-driver genes (ET, P=0.042; PV, P=0.043; MF, P=0.004) and high-molecular risk mutations (ET, P=0.024; PV, P=0.023; MF, P=0.001) were found in fewer young respondents. Conclusion: Compared with middle-aged and elderly patients, young patients with MPN had unique clinical and genetic characteristics.

Development and cytological characterization of wheat-Thinopyrum intermedium translocation lines with novel stripe rust resistance gene

Wheat stripe rust is a destructive disease in many cool and temperate regions around the world. Exploiting novel sources of resistance can provide wheat cultivars with robust and durable resistance to stripe rust. The wheat-Thinopyrum intermedium addition line TAI-14 was proven to carry a stripe rust resistance gene (named as YrT14) on the alien Th. intermedium chromosome. In order to transfer the resistance gene to wheat, wheat-Th. intermedium translocation lines were created by irradiating the pollen of the line TAI-14. We totally obtained 153 wheat-Th. intermedium translocation lines, among which the long alien segmental translocation line Zhongke 78 and the intercalary translocation line Zhongke 15 not only showed good integrated agronomic traits but also were identified as highly resistant to stripe rust in both seedling and adult plant stages. The alien chromatin in Zhongke 15 was identified as an insertion into the satellite of chromosome 6B, a type of translocation never reported before in chromosome engineering. By screening Simple Sequence Repeat (SSR) and Expressed Sequence Tag (EST) markers as well as the markers developed from RNA-sequencing (RNA-Seq) data, 14 markers were identified specific for the alien chromosome and a physical map was constructed. Both Zhongke 78 and Zhongke 15 could be used as a novel source of stripe rust resistance for wheat breeding, and the linked marker T14K50 can be used for molecular marker-assisted breeding. Finally, based on the karyotype, reaction to stripe rust, and genome resequencing data of different wheat-Th. intermedium translocation lines, the stripe rust resistance gene YrT14 was located to an 88.1 Mb interval from 636.7 to 724.8 Mb on Th. intermedium chromosome 19 corresponding to 7J or 7J^s.

Assessment of a compounded synthetic adrenocorticotropic hormone product in 17 healthy dogs

OBJECTIVES

Synthetic adrenocorticotropic hormone or tetracosactide is routinely used in the diagnosis of hypoadrenocorticism and frequently in the diagnosis and treatment of hyperadrenocorticism. There have been repeated shortages of tetracosactide in recent years in Australia. This study investigated the agreement of serum cortisol after a compounded tetracosactide (Bova Aus), compared to commercial tetracosactide (Synacthen®) in healthy dogs.

METHODS

Prospective crossover study using 20 dogs. Ten dogs received 5 μg/kg Synacthen® on day 1 and 5 μg/kg compounded tetracosactide on Day 2. The other 10 dogs received the reverse order. Cortisol concentrations in each dog 1 h after injection were compared for agreement, which was defined as the limits of agreement of the Bland-Altman ratio to be within a range of 0.8-1.25. Passing-Bablok regression analysis examined for constant and proportional biases.

RESULTS

Three dogs were excluded with post-stimulation serum cortisol concentrations markedly outside reference interval. For the remaining 17 dogs, Bland-Altman ratio analysis of cortisol concentration (tetracosactide/Synacthen®) at 1 h found virtually no constant bias (mean of ratios 1.01;95% CI 0.97-1.05) and 95% limits of agreement were 0.88 (95% CI 0.78-0.90) and 1.17 (95% CI 1.13-1.25). This met our criteria for agreement between cortisol concentrations. Bias of the Bland-Altman difference was 2.8 nmol/L (95% CI -7.2 to 12.8); 95% limits of agreement -35.2 nmol/L (95% CI -57.0 to -26.1) and 40.8 nmol/L (95% CI 31.7-62.6). Passing-Bablok regression analysis did not identify bias.

CONCLUSION

In healthy dogs, cortisol concentrations were in agreement after compounded tetracosactide compared to commercial tetracosactide, Synacthen®.

Reperfusion strategy and late clinical outcomes of patients with ST-elevation myocardial infarction (STEMI) in the absence of standard modifiable risk factors (SMuRFs)

Introduction

There is growing evidence that patients presenting with STEMI in the absence of standard modifiable cardiovascular risk factors (SMuRFs; smoking, hypertension, hypercholesterolemia, diabetes) have poorer outcomes compared to those with atleast one SMuRF. It has been hypothesised that this may be in part due to decreased administration of pharmacotherapies in the post-infarct period due to perceived low risk. Long term outcomes of patients without SMuRFs based on reperfusion strategy received during the index admission have not been investigated.

Purpose

We sought to analyse late clinical outcomes of STEMI patients with and without SMuRFs based on reperfusion strategy received during the index admission.

Methods

All patients who underwent PCI between 2003 and 2014 were identified from a PCI centre STEMI database. Late clinical outcomes of patients with and without SMuRFs were analysed overall and based on reperfusion strategy [primary PCI (pPCI) vs pharmaco-invasive PCI (PI-PCI)]. Propensity matching was used to account for differences in baseline characteristics between the groups.

Results

Amongst 2,091 STEMI patients, 531 (25%) had no SMuRFs (51% pPCI, 49% PI-PCI) and 1560 (75%) had ≥1 SMuRF (52% pPCI, 48% PI-PCI). Unadjusted late mortality in SMuRF-less patients was 13.4% (18.8% pPCI, 7.7% PI-PCI) and for those with ≥1 SMuRF was 9.7% (11.0% pPCI, 8.4% PI-PCI). After propensity-matching clinical and angiographic characteristics, 5 year mortality rates were significantly higher for patients without SMuRFs compared to those with SMuRFs [HR 1.36, CI: 1.03–1.81, p=0.031]. This difference was attenuated for patients who underwent pPCI [HR 1.72, CI: 1.22–2.43, p=0.002]. Interestingly, this discrepancy was not observed amongst individuals who underwent pharmaco-invasive PCI [HR 1.13, CI: 0.53–1.48, p=0.638], as SMuRF-less patients had similar mortality rates to their counterparts. Long term rates of reinfarction, stent thrombosis and target vessel revascularisation were similar between the groups. Additionally, there was no significant difference in rates of stroke and major bleeding amongst all 4 subgroups.

Conclusion

Patients presenting with STEMI in the absence of SMuRFs have increased overall late mortality compared to those with at least one SMuRF. However, this difference was not observed in patients who underwent a pharmaco-invasive strategy, whereby patients without SMuRFs had similar outcomes to those with SMuRFs after adjusting for confounders. Our findings suggest the use of a pharmaco-invasive strategy in appropriate SMuRF-less patients presenting with STEMI.

Funding Acknowledgement

Type of funding sources: None.

Low-density lipoprotein cholesterol levels and long-term bleeding in patients undergoing percutaneous coronary intervention: 5-year outcomes from a large cohort study

Aims

Recent research reported that lower low-density lipoprotein cholesterol (LDL-C) is associated with more in-hospital bleeding in acute coronary syndrome (ACS) patients. However, the association between lower LDL-C levels and long-term bleeding in percutaneous coronary intervention (PCI) patients remains unclear.

Methods

A total of 10724 patients treated with PCI enrolled in ourhospital from January 2013 to December 2013. The primary endpoint was the Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding at 5 years. The secondary endpoint was intracranial hemorrhage. Taking the LDL-C value of 1.8 mmol/L (70 mg/dL) or 1.4 mmol/L (55 mg/dL) as cut-off points, patients were grouped to analyse, respectively.

Results

Among 9697 PCI patients treated with dual antiplatelet therapy finally enrolled, a total of 411 BARC type 2, 3 or 5 bleedings and 42 intracranial hemorrhage were recorded during a follow-up of 5 years. With LDL-C value of 1.8 mmol/L as cut-off point, multivariate Cox regression showed that lower LDL-C level was not associated with the risk for bleeding [hazard ratio (HR): 1.166, 95% confidence interval (CI): 0.879–1.549]. The result was consistent (HR: 1.185; 95% CI: 0.713–1.968) in a 1:4 propensity-score matching cohort (n=1285). For further study, we performed subgroup analysis which showed that lower LDL-C was not associated with the risk for bleeding in ACS (HR: 1.140; 95% CI: 0.846–1.535) or non-ACS patients (HR: 1.284; 95% CI: 0.909–1.813). With LDL-C value of 1.4 mmol/L as cut-off point, Cox regression showed that lower LDL-C level was not associated with the risk for bleeding in total population, ACS or non-ACS patients (P&gt;0.05). The result was consistent in a 1:4 propensity-score matching cohort (n=760) (P&gt;0.05). As for secondary endpoint, lower LDL-C level was not associated with the risk for intracranial hemorrhage whether the LDL-C value is 1.8 or 1.4 mmol/L as the cut-off point (P&gt;0.05).

Conclusions

To the best of our knowledge, we firstly report lower LDL-C level (whether the LDL-C value is 1.8 or 1.4 mmol/L as the cut-off point) was not the independent risk factor of long-term bleeding in PCI population and ACS or non-ACS subgroup populations.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): CAMS Innovation Fund for Medical Sciences (CIFMS); Young and middle-aged talents in the XPCC Science and Technology Project

Atomistic deformation mechanism of silicon under laser-driven shock compression

Silicon (Si) is one of the most abundant elements on Earth, and it is the most widely used semiconductor. Despite extensive study, some properties of Si, such as its behaviour under dynamic compression, remain elusive. A detailed understanding of Si deformation is crucial for various fields, ranging from planetary science to materials design. Simulations suggest that in Si the shear stress generated during shock compression is released via a high-pressure phase transition, challenging the classical picture of relaxation via defect-mediated plasticity. However, direct evidence supporting either deformation mechanism remains elusive. Here, we use sub-picosecond, highly-monochromatic x-ray diffraction to study (100)-oriented single-crystal Si under laser-driven shock compression. We provide the first unambiguous, time-resolved picture of Si deformation at ultra-high strain rates, demonstrating the predicted shear release via phase transition. Our results resolve the longstanding controversy on silicon deformation and provide direct proof of strain rate-dependent deformation mechanisms in a non-metallic system.

Understanding the how silicon deforms under pressure is important for several fields, including planetary science and materials design. Laser-driven shock compression experiments now confirm that shear stress generated during compression is released via a high-pressure phase transition.

Wheat glutamine synthetase TaGSr-4B is a candidate gene for a QTL of thousand grain weight on chromosome 4B

Glutamine synthetase TaGSr-4B is a candidate gene for a QTL of thousand grain weight on 4B, and the gene marker is ready for wheat breeding. A QTL for thousand grain weight (TGW) in wheat was previously mapped on chromosome 4B in a DH population of Westonia × Kauz. For identifying the candidate genes of the QTL, wheat 90 K SNP array was used to saturate the existing linkage map, and four field trials plus one glasshouse experiment over five locations were conducted to refine the QTL. Three nitrogen levels were applied to two of those field trials, resulting in a TGW phenotype data set from nine environments. A robust TGW QTL cluster including 773 genes was detected in six environments with the highest LOD value of 13.4. Based on differentiate gene expression within the QTL cluster in an RNAseq data of Westonia and Kauz during grain filling, a glutamine synthesis gene (GS: TaGSr-4B) was selected as a potential candidate gene for the QTL. A SNP on the promoter region between Westonia and Kauz was used to develop a cleaved amplified polymorphic marker for TaGSr-4B gene mapping and QTL reanalysing. As results, TGW QTL appeared in seven environments, and in four out of seven environments, the TGW QTL were localized on the TaGSr-4B locus and showed significant contributions to the phenotype. Based on the marker, two allele groups of Westonia and Kauz formed showed significant differences on TGW in eight environments. In agreement with the roles of GS genes on nitrogen and carbon remobilizations, TaGSr-4B is likely the candidate gene of the TGW QTL on 4B and the TaGSr-4B gene marker is ready for wheat breeding.

O-235 ACLY entry into the nucleus to bind with EP300 and regulate the genomic DNA and ribosomal DNA transcription during early embryonic development

Study question

ATP citrate lyase (ACLY) is one of the key enzymes to produce acetyl coenzyme A. What is its role in early embryonic development?

Summary answer

ACLY affected by activation of T447, S451 and S455 sites into nucleus and band with EP300 to affect genomic DNA and ribosomal DNA transcription.

What is known already

ACLY is one of the key enzymes to produce acetyl coenzyme A, which participates in fatty acid metabolism and regulates acetylation. Studies have found that ACLY knockout cells can survive, while the cell proliferation capacity will be weakened. ACLY is highly expressed in the cytoplasm of Hela cells colon cancer cells and other somatic cells. When AKT phosphorylates S455 site, ACLY enters the nucleus and participates in DNA damage repair. Its localization and role in embryos have not been studied. The only thing we know is homozygous mice could not be detected at E8.5 days after implantation.

Study design, size, duration

Twenty-four human day 6 developmentally arrested embryos were used to detect ACLY localization. Dozens of ACLY heterozygous female mice were used to test the time points of ACLY homozygous lethality after mating with heterozygous male mice. After zygotes were taken from wild-type C57BL6 mice, microinjection technology was used to explore the effects of knocking down ACLY, changing ACLY location or mutating ACLY. HeLa cells were used to explore at the molecular level.

Participants/materials, setting, methods

In this experiment, we used human abandoned or donated embryos, gene knockout mice, wild-type C57BL6 mice and Hela cell.

The experimental techniques used include in vitro embryo culture, EU staining, plasmid transfection, immunoprecipitation, western blot analysis, in vitro transcription, microinjection, immunofluorescence, RT-PCR and RNA-seq.

Main results and the role of chance

Firstly, our study found its special nuclear localization in early embryos for the first time and proved that its localization was related to embryonic development potential.

Secondly, the specific period of ACLY homozygous death was identified by ACLY heterozygous mice. And by knocking down ACLY or adding inhibitor SB204990, It was found that ACLY played an important role in cell proliferation, blastocyst formation and lineage differentiation of early embryo development.

Thirdly, we proved that ACLY nucleation played an important role in the development of early embryos. and the activated form of T447, S451 and S455 three sites led to ACLY nucleation.

Finally, we found that ACLY affected the level of histone acetylation and UBF acetylation. And then genomic DNA and ribosomal DNA transcription level were decreased. We further explored how the acetyl group produced by ACLY regulated transcription. The interaction between ACLY and EP300 was confirmed by immunofluorescence and COIP experiments. After knocking down EP300 in embryos or inhibiting its function with inhibitor c646, the results are consistent with knocking down ACLY. The above experimental data prove that ACLY affects histone acetylation level and regulates gene opening through the interaction with EP300.

Limitations, reasons for caution

We need to further explore the factors that promote ACLY into the nucleus, so as to add it to in vitro culture to enhance the embryonic development potential.

Wider implications of the findings

The study provides a new mechanism for insulin or lysophosphatidic acid to promote embryo development, and helps to improve the quality of embryo development in the process of embryo culture in vitro.

Trial registration number

not applicable

Pentaploidization Enriches the Genetic Diversity of Wheat by Enhancing the Recombination of AB Genomes

Allohexaploidization and continuous introgression play a key role in the origin and evolution of bread wheat. The genetic bottleneck of bread wheat resulting from limited germplasms involved in the origin and modern breeding may be compensated by gene flow from tetraploid wheat through introgressive hybridization. The inter-ploidy hybridization between hexaploid and tetraploid wheat generates pentaploid hybrids first, which absorbed genetic variations both from hexaploid and tetraploid wheat and have great potential for re-evolution and improvement in bread wheat. Therefore, understanding the effects of the pentaploid hybrid is of apparent significance in our understanding of the historic introgression and in informing breeding. In the current study, two sets of F2 populations of synthetic pentaploid wheat (SPW1 and SPW2) and synthetic hexaploid wheat (SHW1 and SHW2) were created to analyze differences in recombination frequency (RF) of AB genomes and distorted segregation of polymorphic SNP markers through SNP genotyping. Results suggested that (1) the recombination of AB genomes in the SPW populations was about 3- to 4-fold higher than that in the SHW populations, resulting from the significantly (P < 0.01) increased RF between adjacent and linked SNP loci, especially the variations that occurred in a pericentromeric region which would further enrich genetic diversity; (2) the crosses of hexaploid × tetraploid wheat could be an efficient way to produce pentaploid derivatives than the crosses of tetraploid × hexaploid wheat according to the higher germination rate found in the former crosses; (3) the high proportion of distorted segregation loci that skewed in favor of the female parent genotype/allele in the SPW populations might associate with the fitness and survival of the offspring. Based on the presented data, we propose that pentaploid hybrids should increasingly be used in wheat breeding. In addition, the contribution of gene flow from tetraploid wheat to bread wheat mediated by pentaploid introgressive hybridization also was discussed in the re-evolution of bread wheat.

[Gene expression signature analysis of peripheral blood mononuclear cells from patients with for high altitude pulmonary hypertension and value for potential drug selection]

Objective: To investigate the gene expression characteristics of peripheral blood mononuclear cells from patients with high altitude pulmonary hypertension (HAPH) in Naxi residents living in Lijiang, Yunnan, and to explore the underlying pathogenesis and value for potential drug selection. Methods: This is a case-control study. Six patients with HPAH (HPAH group) and 4 normal subjects (control group) were selected from the Naxi residents who originally lived in Lijiang, Yunnan Province. The general clinical data of the two groups were collected, and the related indexes of pulmonary artery pressure were collected. Peripheral blood mononuclear cells of the subjects were collected for RNA sequencing. The differences on gene expression, regulatory network of transcription factors and drug similarity between the two groups were compared. The results were compared with the public data of idiopathic pulmonary arterial hypertension (IPAH). Biological processes and signal pathways were analyzed and compared between HPAH and IPAH patients. Results: The age of 6 patients with HAPH was (68.1±8.3) years old, and there were 2 males (2/6). The age of 4 subjects in the control group was (62.3±10.9) years old, and there were 2 males (2/4). Tricuspid regurgitation velocity, tricuspid pressure gradient and pulmonary systolic pressure in HAPH group were significantly higher than those in control group (all P<0.05). The results of RNA sequencing showed that compared with the control group, 174 genes were significantly upregulated and 169 genes were downregulated in peripheral blood mononuclear cells of HAPH group. These differentially expressed genes were associated with 220 biological processes, 52 molecular functions and 23 cell components. A total of 21 biological processes and 2 signal pathways differed between HPAH and IPAH groups, most of which were related to inflammation and immune response. ZNF384, SP1 and STAT3 were selected as highly correlated transcription factors by transcription factor prediction analysis. Trichostatin A and vorinostat were screened out as potential drugs for the treatment of HAPH by drug similarity analysis. Conclusions: There are significant differences in gene expression in peripheral blood monocytes between HAPH patients and normal population, and inflammation and immune dysfunction are the main pathogenic factors. Trichostatin A and Vorinostat are potential drugs for the treatment of HAPH.

POS0397 SSD6453, A NOVEL AND HIGHLY SELECTIVE BTK/JAK3 DUAL INHIBITOR IS EFFICACIOUS IN MULTIPLE PRE-CLINICAL MODELS OF INFLAMMATION

Background

The mechanism of inflammatory diseases is complicated and dysfunction of multiple immune cells is thought to be directly related to the pathogenesis. Targeting either JAK-STAT or BCR signaling has been proved solid clinical efficacy in multiple inflammatory diseases, such as rheumatoid arthritis (RA) and multiple sclerosis (MS). And the combination of BTK and JAK inhibitors demonstrated synergistic effects for the treatment of inflammation models in pre-clinic. JAK3 expression is largely restricted to leukocytes and involves functions in JAK1/JAK3 heterodimer in signal transduction, it might be a more effective and safer target. Meanwhile, both BTK and JAK3 possess a cysteine residue in their active site and this feature makes it possible to design a dual inhibitor. SSD6453 is a highly selective and irreversible JAK3/BTK dual inhibitor which may have synergistic effects for the treatment of RA and other inflammatory diseases such as MS.

Objectives

To develop a potent, oral, highly selective JAK3/BTK inhibitor for treatment of multiple inflammatory diseases.

Methods

ADP-GLO based biochemical assays were performed to determine the enzymatic inhibitory effect and selectivity for JAK family. The target engagement was evaluated by IgM induced pBTK and IL-2 induced pSTAT5 in human PBMCs. In vivo efficacy was evaluated by rat collagen-induced arthritic (CIA) model and mice experimental autoimmune encephalomyelitis (EAE) models induced by MOG1-125 or MOG35-55, respectively. BTK occupancy in spleens post last dose 24h and IL-2 induced pSTAT5 in whole blood post last dose 0.5h were used to evaluate targets inhibitions. Osteoclast was stained by IHC in pathological section of rat paws.

Results

In biochemical assays, SSD6453 inhibited BTK and JAK3 with the IC50 values of 3.4 nM and 1.1 nM, respectively. Notably, SSD6453 displayed high selectivity against JAK1 (510 fold), JAK2 (75 fold) and TYK2 (525 fold). In cellular assays, SSD6453 inhibited anti-IgM induced pBTK and IL-2 induced pSTAT5 in human PBMCs with the IC50 values of 18.8 nM and 168.8 nM, respectively. SSD6453 demonstrated favorable PK properties in broad pre-clinical species. Single oral administration of SSD6453 in rat or mouse, resulted in dose-dependent inhibition of BTK and JAKs concurrently. In the rat CIA model in which disease development was accompanied by a robust T-cell and B-cell inflammation response to collagen, SSD6453 dose-dependently inhibited paw edema. And SSD6453 at 10mpk achieved complete (95%) BTK occupancy and JAK3 inhibition and superior efficacy in comparison of tofacitinib (JAK@10 mpk) or evobrutinib (BTK @30mpk) alone, suggesting that concurrent inhibition of JAK3 and BTK lead to synergistic anti-inflammation effects. In addition, ED-1+ osteoclast count decrease was observed in paws, suggesting the prevention of SSD6453 in joint destruction. In two EAE models either induced by MOG1-125 or MOG35-55, which represented T or B dominant inflammation model, respectively, SSD6453 robustly ameliorated disease in both two models. In comparison, BTK inhibitor is efficacious only in the MOG1-125 induced model.

Conclusion

SSD6453 is a novel and high selective BTK/JAK3 dual inhibitor, and demonstrated synergistic efficacy in multiple pre-clinic inflammation models. SSD6453 showed good pharmacokinetic characteristics and well-tolerant in multiple pre-clinical species, and is moving to IND in 2022.

Disclosure of Interests

Feng Zhou Shareholder of: I own the shares of Simcere, Grant/research support from: The work is financially support by Simcere, Employee of: Simcere, Lei Jiang Shareholder of: I own the shares of Simcere, Grant/research support from: The work is financially supported by Simcere, Employee of: I am employee of Simcere, Yuxi Yan Grant/research support from: The work is financially supported by Simcere, Employee of: I am employee of Simcere, Wenqing Yang Shareholder of: I own the shares of Simcere, Grant/research support from: the work is financially supported by Simcere, Employee of: I am employee of Simcere, Feng Tang Shareholder of: I own the shares of Simcere, Grant/research support from: The work is financially supported by Simcere, Employee of: I am employee of simcere, Ping Chen Shareholder of: I own the shares of Simcere, Grant/research support from: The work is financially supported by Simcere, Employee of: I am employee of Simcere, Renhong Tang Shareholder of: I own the shares of Simcere, Grant/research support from: The work is financially supported by Simcere, Employee of: I am employee of Simcere.