Population pharmacokinetic model for oral ORIN1001 in Chinese patients with advanced solid tumors

Background: ORIN1001, a first-in-class oral IRE1-α endoribonuclease inhibitor to block the activation of XBP1, is currently in clinical development for inhibiting tumor growth and enhancing the effect of chemical or targeted therapy. Early establishment of a population pharmacokinetic (PopPK) model could characterize the pharmacokinetics (PK) of ORIN1001 and evaluate the effects of individual-specific factors on PK, which will facilitate the future development of this investigational drug. Methods: Non-linear mixed effect model was constructed by Phoenix NLME software, utilizing the information from Chinese patients with advanced solid tumors in a phase I clinical trial (Register No. NCT05154201). Statistically significant PK covariates were screened out by a stepwise process. The final model, after validating by the goodness-of-fit plots, non-parametric bootstrap, visual predictive check and test of normalized prediction distribution errors, was further applied to simulate and evaluate the impact of covariates on ORIN1001 exposure at steady state up to 900 mg per day as a single agent. Results: A two-compartment model with first-order absorption (with lag-time)/elimination was selected as the best structural model. Total bilirubin (TBIL) and lean body weight (LBW) were considered as the statistically significant covariates on clearance (CL/F) of ORIN1001. They were also confirmed to exert clinically significant effects on ORIN1001 steady-state exposure after model simulation. The necessity of dose adjustments based on these two covariates remains to be validated in a larger population. Conclusion: The first PopPK model of ORIN1001 was successfully constructed, which may provide some important references for future research.

New insights into micro-algal astaxanthin's effect on deoxynivalenol-induced spleen lymphocytes pyroptosis in Cyprinus carpio: Involving mitophagy and mtROS-NF-κB-dependent NLRP3 inflammasome

Deoxynivalenol (DON) is one of the most common sources of fungal toxins in fish feed, posing a significant risk to the immune and reproductive systems of fish. Microalgal astaxanthin (MIA), a potent antioxidant derived from microalgae, confers multifarious advantages upon piscine organisms, notably encompassing its anti-inflammatory and antioxidant prowess. Herein, we investigated the potential of MIA in ameliorating the immunotoxicity of DON on carp (Cyprinus carpio L.) based on spleen lymphocytes treated with DON (1.5 ng/ml) and/or MIA (96 μM). Firstly, CCK8 results showed that DON resulted in excessive death of spleen lymphocytes. Secondly, spleen lymphocytes treated with DON had a higher proportion of pyroptosis, and the mRNA and protein levels of pyroptosis (NLRP3, IL-1β and ASC) in spleen lymphocytes were increased. Thirdly, the relative red fluorescence intensity of JC-1 and DCFH-DA showed decreased mitochondrial membrane potential and increased ROS in spleen lymphocytes treated with DON. Mitochondrial ATP, DNA and NADPH/NADP+ analysis revealed decreased mitochondrial ATP, DNA and NADPH/NADP+ levels in DON-treated lymphocytes, corroborating the association between DON exposure and elevated intracellular ATP, DNA and NADPH/NADP+ in lymphocytes. DON exposure resulted in the downregulation of mitophagy-related genes and proteins (PINK1, Parkin and LC3) in lymphocytes. Notably, these effects were counteracted by treatment with MIA. Furthermore, DON led to the elevated secretion of inflammatory factors (TNF-α, IL-4 and IFN-γ), thereby inducing immune dysfunction in spleen lymphocytes. Encouragingly, MIA treatment effectively mitigated the immunotoxic effects induced by DON, demonstrating its potential in ameliorating pyroptosis, mitochondrial dysfunction and mitophagy impairment via regulating the mtROS-NF-κB axis in lymphocytes. This study sheds light on safeguarding farmed fish against agrobiological threats posed by DON, highlighting the valuable applications of MIA in aquaculture.

Effect of High-Fat Food on the Pharmacokinetic Profile and Safety of SAF-189s, an ALK/ROS1 Inhibitor, in Healthy Chinese Adults

BACKGROUND AND OBJECTIVES

This study was conducted to investigate the effect of high-fat meals on the pharmacokinetics (PK) and safety profile of SAF-189s, a novel ALK/ROS1 inhibitor.

METHODS

This was a single-center, phase I, open-label, crossover study in which healthy adults (≥18 years) were randomized (1:1) to two sequences of SAF-189s administration (fasted-fed or fed-fasted) separated by a 14-day washout. After a ≥10-h overnight fast, volunteers received SAF-189s 160 mg orally in a fasted state or 30 min after a high-fat, high-calorie meal. Similarity of pharmacokinetic parameters was concluded if the 90% CI for the geometric mean ratio (GMR) between the fed and fasted group fell within the predefined range of 0.80-1.25.

RESULTS

In total, 24 subjects were enrolled and 23 completed the study. SAF-189s maximum plasma concentration (Cmax; GMR: 109.1% [90% CI 103.1-115.4]) was comparable under fed (high-fat meal, n = 24) versus fasted (n = 23) conditions, with no effect on area under the plasma concentration-time curve from time 0 to t (AUC0-t; GMR: 105.1% [90% CI 100.3-110.2]) and AUC from time 0 to infinity (AUC0-∞; GMR: 105.5% [90% CI, 100.6-110.6]). In both groups, the median time to maximum plasma concentration (tmax) was around 6 h and mean plasma half-life (t½) was around 35 h. Fed administration led to a lower incidence of treatment-emergent adverse events (TEAEs; 29.2% vs 54.2%), including gastrointestinal disorders (4.2% vs 41.7%) and headache (0.0% vs 12.5%), versus fasted administration.

CONCLUSIONS

A high-fat meal had minimal effect on the pharmacokinetic profile of SAF-189s compared with a fasted state following a single dose of 160 mg. Administration with a high-fat meal led to a lower incidence of TEAEs.

Micro-algal astaxanthin ameliorates polystyrene microplastics-triggered necroptosis and inflammation by mediating mitochondrial Ca2+ homeostasis in carp's head kidney lymphocytes (Cyprinus carpio L.)

Polystyrene microplastics (PM) is a pressing global environmental concern, posing substantial risks to aquatic ecosystems. Microalgal astaxanthin (MA), a heme pigment, safeguards cells against oxidative damage induced by free radicals, which contributes to various health conditions, including aging, inflammation and chronic diseases. Herein, we investigated the potential of MA in ameliorating the immunotoxicity of PM on carp (Cyprinus carpio L.) based on head kidney lymphocytes treated with PM (250 μM) and/or MA (100 μM). Firstly, CCK8 results showed that PM resulted in excessive death of head kidney lymphocytes. Secondly, head kidney lymphocytes treated with PM had a higher proportion of necroptosis, and the levels of necroptosis-related genes in head kidney lymphocytes were increased. Thirdly, the relative red fluorescence intensity of JC-1 and MitoSox showed decreased mitochondrial membrane potential and increased mtROS in head kidney lymphocytes treated with PM. MitoTracker® Green FM fluorescence analysis revealed enhanced mitochondrial Ca2+ levels in PM-treated lymphocytes, corroborating the association between PM exposure and elevated intracellular Ca2+ dynamics. PM exposure resulted in upregulation of calcium homeostasis-related gene (Orail, CAMKIIδ and SLC8A1) in lymphocytes. Subsequent investigations revealed that PM exposure reduced miR-25-5p expression while increasing levels of MCU, MICU1, and MCUR1. Notably, these effects were counteracted by treatment with MA. Furthermore, PM led to the elevated secretion of inflammatory factors (IFN-γ, IL-1β, IL-2 and TNF-α), thereby inducing immune dysfunction in head kidney lymphocytes. Encouragingly, MA treatment effectively mitigated the immunotoxic effects induced by PM, demonstrating its potential in ameliorating necroptosis, mitochondrial dysfunction and immune impairment via regulating the miR-25-5p/MCU axis in lymphocytes. This study sheds light on safeguarding farmed fish against agrobiological threats posed by PM, highlighting the valuable applications of MA in aquaculture.

Model-informed dose selection for an investigational human epidermal growth factor receptor 2 antibody-drug conjugate FS-1502 in patients with human epidermal growth factor receptor 2-expressing advanced malignant solid tumours

AIMS

The dose-escalation phase (phase Ia study) of a novel human epidermal growth factor receptor 2 (HER2) antibody-drug conjugate (ADC) FS-1502 included a dose range from 0.1 to 3.5 mg/kg in HER2-expressing advanced malignant solid tumours. However, the defined maximum tolerated dose was not reached. This model-informed approach integrated population pharmacokinetic (PopPK) modelling and exposure-response (E-R) analysis to facilitate dose selection for phase II.

METHODS

The PopPK model was constructed using PK data from 109 Chinese patients who received doses of 0.1-3.5 mg/kg FS-1502 every 3 (Q3W) or 4 weeks during a phase I dose-escalation and dose expansion trial. The structural model consisted of compartment models for FS-1502 and unconjugated monomethyl auristatin F. E-R was explored for the percentage change in tumour size, overall response rate and treatment-related adverse events.

RESULTS

A semi-mechanistic 2-analyte PopPK model was developed. The FS-1502 PK data were best described by a 2-compartment PK model with parallel linear and nonlinear Michaelis-Menten eliminations. The PK of unconjugated monomethyl auristatin F was described by a 2-compartment model with first-order elimination. E-R analysis supported the clinically meaningful efficacy of FS-1502 at 2.3 mg/kg and above. However, 2.3 mg/kg Q3W was considered to have a better benefit-risk balance due to a lower incidence of safety events without a significant reduction in efficacy compared to 3.0 mg/kg Q3W.

CONCLUSION

This PopPK and E-R analysis guided the recommended phase II dose selection of 2.3 mg/kg Q3W and supported body weight-based dosing for an investigational HER2 ADC FS-1502.

A Portable Nucleic Acid Sensor Based on PCR for Simple, Rapid, and Sensitive Testing of Botrytis cinerea in Ginseng

Botrytis cinerea is a ubiquitous pathogen that can infect at least 200 dicotyledonous plant species including many agriculturally and economically important crops. In Ginseng, the fungus may cause ginseng gray mold disease, causing great economic losses in the ginseng industry. Therefore, the early detection of B. cinerea in the process of ginseng production is necessary for the disease prevention and control of the pathogen's spread. In this study, a polymerase chain reaction-nucleic acid sensor (PCR-NAS) rapid detection technique was established, and it can be used for field detection of B. cinerea through antipollution design and portable integration. The present study showed that the sensitivity of PCR-NAS technology is 10 times higher than that of traditional PCR-electrophoresis, and there is no need for expensive detection equipment or professional technicians. The detection results of nucleic acid sensors can be read by the naked eye in under 3 min. Meanwhile, the technique has high specificity for the detection of B. cinerea. The testing of 50 field samples showed that the detection results of PCR-NAS were consistent with those of the real-time quantitative PCR (qPCR) method. The PCR-NAS technique established in this study can be used as a novel nucleic acid field detection technique, and it has a potential application in the field detection of B. cinerea to achieve early warning of the pathogen infection.

Cryo-EM of α-tubulin isotype-containing microtubules revealed a contracted structure of α4A/β2A microtubules

Microtubules are hollow α/β-tubulin heterodimeric polymers that play critical roles in cells. In vertebrates, both α- and β-tubulins have multiple isotypes encoded by different genes, which are intrinsic factors in regulating microtubule functions. However, the structures of microtubules composed of different tubulin isotypes, especially α-tubulin isotypes, remain largely unknown. Here, we purify recombinant tubulin heterodimers composed of different mouse α-tubulin isotypes, including α1A, α1C and α4A, with the β-tubulin isotype β2A. We further assemble and determine the cryo-electron microscopy (cryo-EM) structures of α1A/β2A, α1C/β2A, and α4A/β2A microtubules. Our structural analysis demonstrates that α4A/β2A microtubules exhibit longitudinal contraction between tubulin interdimers compared with α1A/β2A and α1C/β2A microtubules. Collectively, our findings reveal that α-tubulin isotype composition can tune microtubule structures, and also provide evidence for the "tubulin code" hypothesis.

Effect of tip winglet position on tip flow and noise of axial flow fan

In order to investigate the impact of blade tip winglet position on the internal flow and noise characteristics of axial flow fans,three different blade tip winglets,namely the TSW blade, the SSW blade, and the PSW blade,were hereby proposed. The accuracy of the simulation model was verified through experiments, and the circumferential internal flow characteristics and noise characteristics of these different blades were studied by numerical simulation using the blade tip partition method. The calculation results indicated the high-level efficiency of TSW, SSW and PSW blades in reducing the blade tip leakage flow in Z1 and Z2 regions and suppressing its circumferential propagation in the Z3 region. Besides, it was found that SSW blade and PSW blade had larger total pressure loss relative to Ori blade, and that TSW had higher total pressure difference at low blade height. Additionally TSW blades performed the best in improving the blade tip blockage,while TSW, SSW and PSW blades effectively reduced the leakage flow against the main stream, and blade tip winglet blades could effectively improve the fan discrete noise, SSW had the most significant noise reduction effect in the total sound pressure level, and in the overall blade,Z1, Z2 and Z3 were reduced by 2.16 dB,1.68 dB,2.24 dB and 3.74 dB.

Phase 1 dose-escalation study to evaluate the safety, tolerability, pharmacokinetics, and anti-tumor activity of FCN-159 in adults with neurofibromatosis type 1-related unresectable plexiform neurofibromas

BACKGROUND

Surgery is a common treatment strategy for patients with neurofibromatosis type 1 (NF1)-related plexiform neurofibroma (PN) and has limited efficacy. FCN-159 is a novel anti-tumorigenic drug via selective inhibition of MEK1/2. This study assesses the safety and efficacy of FCN-159 in patients with NF1-related PN.

METHODS

This is a multicenter, open-label, single-arm, phase I dose-escalation study. Patients with NF1-related PN that was non-resectable or unsuitable for surgery were enrolled; they received FCN-159 monotherapy daily in 28-day cycles.

RESULTS

Nineteen adults were enrolled in the study, 3 in 4 mg, 4 in 6 mg, 8 in 8 mg, and 4 in 12 mg. Among patients included in dose-limiting toxicity (DLT) analysis, DLTs (grade 3 folliculitis) were reported in 1 of 8 patients (16.7%) receiving 8 mg and 3 of 3 (100%) patients receiving 12 mg. The maximum tolerated dose was determined to be 8 mg. FCN-159-related treatment-emergent adverse events (TEAEs) were observed in 19 patients (100%); most of which were grade 1 or 2. Nine (47.4%) patients reported grade 3 study-drug-related TEAEs across all dose levels, including four experiencing paronychia and five experiencing folliculitis. Of the 16 patients analyzed, all (100%) had reduced tumor size and six (37.5%) achieved partial responses; the largest reduction in tumor size was 84.2%. The pharmacokinetic profile was approximately linear between 4 and 12 mg, and the half-life supported once daily dosing.

CONCLUSIONS

FCN-159 was well tolerated up to 8 mg daily with manageable adverse events and showed promising anti-tumorigenic activity in patients with NF1-related PN, warranting further investigation in this indication.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04954001. Registered 08 July 2021.

Safety and Pharmacokinetics of PSD502 in Healthy Chinese Male and Female Volunteers: Two Randomized, Double-Blind, Placebo-Controlled, Phase I Trials

BACKGROUND AND OBJECTIVE

PSD502 is a metered-dose spray for premature ejaculation. The two trials aimed to evaluate the safety and pharmacokinetics of PSD502 in healthy Chinese male and female individuals.

METHODS

Two phase I, randomized, double-blind, placebo-controlled trials were conducted in men (Trial 1) and women (Trial 2). The participants were randomized 3:1 to receive PSD502 (7.5 mg of lidocaine and 2.5 mg of prilocaine per spray) or a placebo. For male individuals, a single dose (three sprays) once daily was applied to the glans penis for 21 days except for nine sprays (three doses) on days 7 and 14, 4 h apart for each dose. For female individuals, two sprays were applied to the vagina and one to the cervix once daily for 7 days. The primary endpoint was safety. Pharmacokinetics analysis was also performed.

RESULTS

Twenty-four male and 24 female individuals were recruited. Treatment-emergent adverse events occurred in 38.9% (7/18) of male individuals and 66.7% (12/18) of female individuals in the PSD502 group, respectively. Both trials reported 50.0% (3/6) treatment-emergent adverse events for the placebo. No grade ≥ 3 treatment-emergent adverse events, serious adverse events, or treatment-emergent adverse events leading to early withdrawal or discontinuation occurred. After consecutive applications, lidocaine and prilocaine cleared rapidly in both trials. Plasma concentrations exhibited high inter-individual variability. The maximum plasma concentrations of active ingredients were far below the anticipated minimum toxic concentrations. The area under the plasma concentration-time curve of metabolites were ≤ 20% of the parent drugs. No clinically significant accumulations were observed in the two trials.

CONCLUSIONS

PSD502 was well tolerated and showed low plasma concentrations in healthy Chinese male and female individuals.

The distinct initiation sites and processing activities of TTLL4 and TTLL7 in glutamylation of brain tubulin

Mammalian brain tubulins undergo a reversible posttranslational modification-polyglutamylation-which attaches a secondary polyglutamate chain to the primary sequence of proteins. Loss of its erasers can disrupt polyglutamylation homeostasis and cause neurodegeneration. Tubulin tyrosine ligase like 4 (TTLL4) and TTLL7 were known to modify tubulins, both with preference for the β-isoform, but differently contribute to neurodegeneration. However, differences in their biochemical properties and functions remain largely unknown. Here, using an antibody-based method, we characterized the properties of a purified recombinant TTLL4 and confirmed its sole role as an initiator, unlike TTLL7, which both initiates and elongates the side chains. Unexpectedly, TTLL4 produced stronger glutamylation immunosignals for α-isoform than β-isoform in brain tubulins. Contrarily, the recombinant TTLL7 raised comparable glutamylation immunoreactivity for two isoforms. Given the site selectivity of the glutamylation antibody, we analyzed modification sites of two enzymes. Tandem mass spectrometry analysis revealed their incompatible site selectivity on synthetic peptides mimicking carboxyl termini of α1- and β2-tubulins and a recombinant tubulin. Particularly, in the recombinant α1A-tubulin, a novel region was found glutamylated by TTLL4 and TTLL7, that again at distinct sites. These results pinpoint different site specificities between two enzymes. Moreover, TTLL7 exhibits less efficiency to elongate microtubules premodified by TTLL4, suggesting possible regulation of TTLL7 elongation activity by TTLL4-initiated sites. Finally, we showed that kinesin behaves differentially on microtubules modified by two enzymes. This study underpins the different reactivity, site selectivity, and function of TTLL4 and TTLL7 on brain tubulins and sheds light on their distinct role in vivo.

Comparison of tyrosine kinase inhibitors in the treatment of metastatic renal cell carcinoma with rhabdoid and sarcomatoid differentiations

OBJECTIVE

To investigate the efficacy of tyrosine kinase inhibitors (TKIs) in the treatment of metastatic renal cell carcinoma (mRCC) with rhabdoid (mRCC-R) and sarcomatoid (mRCC-S) differentiations.

MATERIALS AND METHODS

In this single-institutional cohort study, we included patients with RCC with rhabdoid (RCC-R) and sarcomatoid (RCC-S) differentiation, who were treated with TKIs after metastasis at our institute from 2013 to 2021. Patient characteristics, treatments, and clinical outcomes were recorded and analyzed.

RESULTS

We identified 111 patients with RCC-R or RCC-S differentiations, of which 23 patients were included in the final analysis. Of the 23 patients, 10 (43.5%) were grouped as mRCC-R and 13 (56.5%) as mRCC-S. At a median follow-up of 40 months, mRCC-R and mRCC-S progressed in 7 of 10 and 12 of 13 patients, respectively. In addition, four and eight patients died in the mRCC-R and mRCC-S groups, respectively. The median progression-free survival (PFS) of the two groups was 19 months (mRCC-R: 95% confidence interval [CI] 4.08-33.92) and 7 months (mRCC-S: 95% CI 2.03-11.96), while the median overall survival (OS) was 32 months and 21 months, respectively. mRCC-S had a worse prognosis than mRCC-R. Based on the univariate Cox regression model, single metastasis or multiple metastasis of tumor, rhabdoid differentiation, and sarcomatoid differentiation were predictors of PFS but not OS.

CONCLUSION

The efficacy of TKIs in the treatment of mRCC-R and mRCC-S may be different.

Endoscopic manifestations of jejunal choriocarcinoma

Choriocarcinoma, a malignant tumor deriving from the trophoblastic tissue, is mostly associated with adverse pregnancy. Early metastasis is very common in patient with choriocarcinoma, but the cases of intestinal metastasis are definitely rare. Herein, we reported a case of jejunal choriocarcinoma revealed by endoscopy. Segmental resection of the jejunum as well as biopsy of liver nodules were performed. The patient was classified as super high-risk choriocarcinoma and received chemotherapy and surgical treatment. Unfortunately, the patient ultimately died of liver rupture.

Pathway and mechanism of tubulin folding mediated by TRiC/CCT along its ATPase cycle revealed using cryo-EM

The eukaryotic chaperonin TRiC/CCT assists the folding of about 10% of cytosolic proteins through an ATP-driven conformational cycle, and the essential cytoskeleton protein tubulin is the obligate substrate of TRiC. Here, we present an ensemble of cryo-EM structures of endogenous human TRiC throughout its ATPase cycle, with three of them revealing endogenously engaged tubulin in different folding stages. The open-state TRiC-tubulin-S1 and -S2 maps show extra density corresponding to tubulin in the cis-ring chamber of TRiC. Our structural and XL-MS analyses suggest a gradual upward translocation and stabilization of tubulin within the TRiC chamber accompanying TRiC ring closure. In the closed TRiC-tubulin-S3 map, we capture a near-natively folded tubulin-with the tubulin engaging through its N and C domains mainly with the A and I domains of the CCT3/6/8 subunits through electrostatic and hydrophilic interactions. Moreover, we also show the potential role of TRiC C-terminal tails in substrate stabilization and folding. Our study delineates the pathway and molecular mechanism of TRiC-mediated folding of tubulin along the ATPase cycle of TRiC, and may also inform the design of therapeutic agents targeting TRiC-tubulin interactions.

Ultrathin Mo2S3 Nanowire Network for High-Sensitivity Breathable Piezoresistive Electronic Skins

Flexible piezosensing electronic skins (e-skins) have attracted considerable interest owing to their applications in real-time human-health monitoring, human-machine interactions, and soft bionic robot perception. However, the fabrication of piezosensing e-skins with high sensitivity, biological affinity, and good permeability at the same time is challenging. Herein, we designed and synthesized Mo₂S₃ nanowires by inserting _∞¹[Mo²⁺S] chains between MoS₂ interlayers. The resulting Mo₂S₃ nanowires feature high conductivity (4.9 × 10⁴ S m^-1) and a high aspect ratio (∼200). An ultrathin (∼500 nm) Mo₂S₃ nanowire network was fabricated using a simple liquid/liquid interface self-assembly method, showing high piezoresistive sensitivity (5.65 kPa^-1), a considerably low pressure detection limit (0.08 Pa), and gratifying air permeability. Moreover, this nanowire network can be directly attached to human skin for real-time human pulse detection, finger movement monitoring, and sign language recognition, exhibiting excellent potential for health monitoring and human-machine interactions.

Effect of Food (Low and High Fat) on Pharmacokinetics of FCN-159, a Selective MEK Inhibitor, in Healthy Chinese Males

INTRODUCTION

FCN-159 is a novel, oral, potent, selective MEK1/2 inhibitor in clinical development for the treatment of NRAS-mutant advanced melanoma and neurofibromatosis type 1. We investigated the effect of food on the pharmacokinetics (PK), safety, and tolerability of FCN-159.

METHODS

In this single-center, open-label, phase 1 study with a three-period, three-sequence, crossover design, healthy Chinese male subjects (n = 24) were randomized (1:1:1) to receive a single, oral 8 mg dose of FCN-159 in the fasted state (overnight, > 10 h), and with a low-fat and a high-fat meal, separated by a 10-day washout. PK parameters including time to maximum plasma concentration (C_max) and area under the concentration-time curve (AUC) were compared using geometric least-squares mean ratios (GLSMR), with the fasted state as the reference. A 90% CI for the GLSMR within 80-125% indicated no significant food effect.

RESULTS

A low-fat meal (n = 23) did not affect the PK profile of FCN-159: G LSMR for AUC from time 0 to t (AUC_0-t), 106.9% (90% CI 99.9-114.4%); AUC from time 0 to infinity (AUC_0-∞), 106.8% (90% CI 100.0-114.0%); C_max, 96.4% (90% CI 83.9-110.8%). A high-fat meal (n = 24) did not affect exposure to FCN-159 (GLSMR for AUC_0-t, 99.4%; 90% CI 99.0-106.3%; AUC_0-∞, 99.5 5%; 90% CI 93.2-106.1%), but modestly reduced C_max by 15% (GLSMR 84.9%; 90% CI 74.0-97.3%). Both the low-fat and high-fat meals slightly prolonged the median time to C_max by 0.5 h (90% CI 0.5-1.0 h). FCN-159 was generally well tolerated, with a lower incidence of treatment-emergent adverse events following administration in the fasted state than with a low-fat or high-fat meal (20.8%, 39.1%, and 37.5%, respectively).

CONCLUSION

Food did not affect the PK profile of FCN-159 to a clinically meaningful extent compared with administration in the fasted state.

Abstract P4-01-07: FS-1502, an anti-HER2 ADC, in Patients with HER2-Expressing Advanced Solid Tumors: A Phase 1a Dose-Escalation Study

Background: FS-1502 is a HER2-targeting antibody drug-conjugate with a cleavable β-glucuronide linker and an antimitotic agent (monomethyl auristatin F) which showed promising antitumor activity in preclinical studies. We are evaluating the safety and tolerability of FS-1502 in patients with HER2-expressing advanced solid tumors (NCT03944499). Methods: Patients with HER2-expresssing advanced solid tumors who had failed prior standard of care therapies were enrolled in a single-arm, open-label, dose-escalation phase Ia study in China. FS-1502 was given IV once in 21-day or 28-day cycles. The primary endpoint was incidence of dose-limiting toxicity (DLT). Adverse events (AEs), objective response rate (ORR) and duration of response (DoR) were also assessed. Data cutoff was December 30, 2021. Results: A total of 67 patients, 64 with breast cancer and 3 with other solid tumors, with median 3 prior therapies (range 1-10), were enrolled in 5 sites and treated with FS-1502 at doses of 0.1-3.5 mg/kg. Two DLTs, as defined by the protocol, were observed, with one G2 decrease in creatinine clearance at 3.0 mg/kg and one G3 thrombocytopenia with hemorrhage at 3.5 mg/kg. No Grade 4/5 events were observed. Grade 3 TRAEs were observed in 24 (35.8%) patients with the most common AEs of hypokalemia (14.9%) and decreased platelet count (9.0%). ORRs were observed at doses at or above 1.0 mg/kg with an ORR of 66.7% (4/6) at the recommended phase 2 dose (RP2D) of 2.3 mg/kg. Median duration of response (DoR) across all dose levels was 9.2 months (95%CI 5.6-NR). ORR for HER2-low patients was 42.9% (3/7). Plasma concentration and exposure (AUC) based on total ADC and total antibody increased dose proportionally at ≥1.0 mg/kg, with a T1/2 of 2.4-4.9 days. The incidence and magnitude of immunogenicity were low. While no MTD was determined, the 2.3mg/kg dose once in a 21-day cycle was selected as the RP2D based on safety, antitumor activity and PK data. Conclusions: FS-1502 was well-tolerated and demonstrated encouraging antitumor activity in both HER2-high and -low patients. Phase Ib and phase II clinical trials with FS-1502 are currently ongoing in various solid tumor indications including breast, gastric, and colorectal cancer.

Citation Format: Qiao Li, Xian Wang, Ying Cheng, Yunjiang Liu, Jianhua Chang, Zhuo Wang, Chunjiao Wu, Mingxia Wang, Ai-Min Hui, Zhuli Wu, Yongli Jin, Xin Huang, Liping Zhong, Lei Diao, Han Zhao, Binghe Xu. FS-1502, an anti-HER2 ADC, in Patients with HER2-Expressing Advanced Solid Tumors: A Phase 1a Dose-Escalation Study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-01-07.

Abstract P4-01-21: Phase 2 Study of the CDK4/6 Inhibitor FCN-437c in Combination With Fulvestrant or Letrozole and Goserelin in Patients With HR+, HER2– Advanced Breast Cancer

Background: FCN-437c is a second-generation CDK4/6 inhibitor. Phase 1b clinical results indicated improved antitumor activity in patients (pts) with HR+, HER2– advanced breast cancer (ABC), treated with FCN-437c + letrozole.

Methods: This Phase 2, multicenter, open-label clinical study evaluated the antitumor activity, pharmacokinetics (PK), and safety of FCN-437c + fulvestrant in post-menopausal pts (Cohort 1, treatment-naïve or 2L), FCN-437c + letrozole + goserelin in pre-menopausal pts (Cohort 2, treatment-naïve). Pts received FCN-437c (200 mg QD) in a 21-day-on and 7-day-off schedule either in combination with fulvestrant (500 mg D1) or letrozole (2.5 mg QD) + goserelin (3.6 mg once per cycle) in 28-day cycles. The primary endpoint was overall response rate (ORR) and secondary endpoints were progression-free survival (PFS), overall survival (OS), PK, and safety.

Results: At study cutoff (Feb 7, 2022), 36 pts were enrolled in Cohort 1 and 31 pts were in Cohort 2; 42 (62.7%) pts had visceral metastases and 9 (13.4%) pts had bone-only metastases. In Cohort 1, 18 pts were treatment-naïve, 15 pts had received 1L treatment, and 3 pts had received ≥2L treatment. In Cohort 2, 25 pts were treatment-naïve and 6 pts had received 1L treatment. Overall, 27 pts in the per-protocol set achieved partial response (PR), resulting in an ORR of 40.9% (95% CI, 29.0-53.7). Median follow-up was 12.8 months, and median PFS (mPFS), OS, and DOR were not reached. However, at 12 months, the PFS rate was 67.7% (95% CI, 53.2-78.6) and the OS rate was 95.9% (95% CI, 84.5-99.0); the 6-month DOR rate was 96.0% (95% CI, 74.8-99.4). In Cohort 1 (n=35), 11 pts achieved PR: the ORR was 31.4% (16.9-49.3%) and mPFS was 12.9 months (95% CI, 9.2-NR); the 6-month DOR rate was 100%. In Cohort 2 (n=31), 16 pts achieved PR: the ORR was 51.6% (95% CI, 33.1-69.9%). mPFS, OS, and DOR were not reached; the 6-month DOR rate was 92.9% (95% CI, 59.08-98.96) (Table). Treatment-emergent adverse events (TEAEs) were observed in all pts. Majority of AE were G1 or 2 except for hematological TEAE. 58 (86.6%) pts reported grade ≥3 TEAEs, mainly neutropenia (74.6%), leukopenia (49.3%), hypertriglyceridemia (6.0%), lymphocyte count decrease (4.5%), and γ-glutamyltransferase increase (3.0%): most were reversed through dose interruption and symptomatic therapy. Steady-state PK parameters were analyzed after 15-21 days of QD administration: Cohort 1: median Tmax was 3 h, geomean T1/2 was 44.6 h, geomean Cmax was 1650.7 ng/mL, and geomean AUC0-24h was 29,148.08 h*ng/mL; the geomean accumulation ratios of AUC0-24h and RCmax were 2.18 and 1.74, respectively, compared with first dose. Cohort 2: median Tmax was 4 h, geomean T1/2 was 35.7 h, geomean Cmax was 1314.34 ng/mL, and geomean AUC0-24h was 22,889.96 h*ng/mL; the geomean accumulation ratios of AUC0-24h and RCmax were 1.95 and 1.63, respectively, compared with first dose.

Conclusion: FCN-437c in combination with fulvestrant or letrozole + goserelin demonstrates antitumor activity and safety and is well tolerated in pts with HR+, HER2– ABC. This combination therapy will be further investigated in 2 ongoing Phase 3 trials (NCT05438810 and NCT05439499).

Clinical trial number: NCT05004142. Research Sponsor: Avanc Pharmaceutical Co., Ltd

Table. Clinical outcomes for patients in the per-protocol set.

Citation Format: JiaJie Shi, Wei Li, Zhongsheng Tong, Aimin Zang, Xiaohua Zeng, Shui Wang, Tao Huang, Ying Wang, Yanqiu Song, Lihua Kang, Zheng Lv, Yehui Shi, Hua Yang, Jing Wu, Yongmei Yin, Yan Liang, Jie Tan, Jie Ming, Yaping Yang, Simin Luo, Xiujuan Gui, Ai-Min Hui, Zhuli Wu, Ling Tian, Yuchen Yang, Lei Diao, Wenjing Zhang, Yongjiao Zhang, Yunjiang Liu. Phase 2 Study of the CDK4/6 Inhibitor FCN-437c in Combination With Fulvestrant or Letrozole and Goserelin in Patients With HR+, HER2– Advanced Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-01-21.

Population pharmacokinetics of FCN-159, a MEK1/2 inhibitor, in adult patients with advanced melanoma and neurofibromatosis type 1 (NF1) and model informed dosing recommendations for NF1 pediatrics

Objective: FCN-159 is a highly active mitogen-activated extracellular signal-regulated kinase 1/2 (MEK1/2) inhibitor in patients with advanced melanoma and neurofibromatosis type 1 (NF1). We report a population pharmacokinetic (PopPK) model-based analysis of FCN-159 and its application to inform dose selection for NF1 pediatric trials. Methods: PK data collected from patients with advanced melanoma and NF1 in two clinical studies (NCT03932253 and NCT04954001) were analyzed using a non-linear mixed effects model. The adult model was adapted by incorporating allometric scaling for PK projection in 2-17 years old children. Pediatric exposure in different body surface area (BSA) bins was simulated to identify nominal doses (i.e., dose amounts given as integers) and BSA bin cutoffs to achieve exposure comparable to adults' optimal exposure across the entire pediatric BSA range. Results: The final dataset consisted of 45 subjects with a total of 1030 PK samples. The PK of FCN-159 was well-described by a 2-compartment model with first-order linear elimination and delayed first-order absorption. Covariates, including BSA, age, sex, albumin, total protein, and cancer type, were identified as statistically significant predictors of FCN-159 disposition. Simulations based on the final model projected daily doses of 4 mg/m2 QD with optimized BSA bin cutoffs would allow fixed nominal doses within each bin and result in steady state exposure approximating the adult exposure observed at the recommended phase 2 dose (RP2D) in NF1, which is 8 mg QD. Conclusion: The developed population PK model adequately described the PK profile of FCN-159, which was adapted using allometric scaling to inform dose selection for NF1 pediatric trials.

Use of PARP inhibitors in prostate cancer: from specific to broader application

Prostate cancer (PC) is one of the major health issues of elderly men in the word. It is showed that there were approximately 1.414 million patients with PC in 2020 worldwide, with a high mortality rate in metastatic cases. In the present choices of treatment in PC, androgen deprivation therapy has long been as a backbone of them. But the clinical outcomes of patients with metastatic castration-resistant prostate cancer (mCRPC) were not ideal because of their poor prognosis, more effective therapeutic approaches are still necessary to further improve this problem. Poly (ADP-ribose) polymerase (PARP) inhibitors lead to the single-strand DNA breaks and/or double-strand DNA breaks, and result in synthetic lethality in cancer cells with impaired homologous recombination genes. It is estimated that approximately 20~25% of patients with mCRPC have a somatic or germinal DNA damage repair gene mutation. Furthermore, in "BRCAness" cases, which has been used to describe as tumors that have not arisen from a germline BRCA1 or BRCA2 mutation, there were also a number of studies sought to extend these promising results of PARP inhibitors. It is worth noting that an interaction between androgen receptor signaling and synthetic lethality with PARP inhibitors has been proposed. In this review, we discussed the mechanism of action and clinical research of PARP inhibitors, which may benefit population from "specific" to the "all-comer" in patients with PC when combined with novel hormonal therapies.

A first-in-human, phase 1a dose-escalation study of the selective MEK1/2 inhibitor FCN-159 in patients with advanced NRAS-mutant melanoma

BACKGROUND

A phase 1a first-in-human study evaluated the safety/tolerability, preliminary antitumour activity and pharmacokinetics of the oral MEK1/2 inhibitor FCN-159 in Chinese patients with advanced, NRAS-mutant melanoma.

PATIENTS AND METHODS

Patients received a single FCN-159 dose at assigned levels, proceeding to continuous dosing (once daily [QD] for 28-day cycles) if no dose-limiting toxicities (DLTs) occurred within the next 3 days. Dose escalation was initiated after review of data for the previous dose level. The primary end-point was incidence of DLTs after the first dose.

RESULTS

Thirty-three patients were enrolled across nine FCN-159 dose groups (0.2-15 mg QD). One DLT occurred: grade 3 folliculitis in the 15-mg group. There was one grade >3 treatment-emergent adverse event (TEAE), death of unknown aetiology (not FCN-159 related). The most common FCN-159-related TEAE was rash (36.4%), and the incidence of grade ≥3 FCN-159-related TEAEs was 15.2%. Antitumour activity at QD doses <6 mg was limited; therefore, efficacy data are presented only for doses ≥6 mg (n = 21). The objective response and clinical benefit rates were 19.0% (four partial responses) and 52.4%, respectively. Median (95% confidence interval) duration of response and progression-free survival were 4.8 months (2.8-not reached) and 3.8 months (1.8-5.6), respectively. FCN-159 exposure increased dose-proportionately; geometric mean terminal half-life was 29.9-56.9 h.

CONCLUSIONS

FCN-159 was well tolerated and demonstrated promising antitumour activity at doses ≥6 mg QD in patients with advanced, NRAS-mutant melanoma. The recommended phase 2 dose was 12 mg QD.

CLINICALTRIALS

GOV IDENTIFIER

NCT03932253. https://clinicaltrials.gov/ct2/show/NCT03932253.

OUP accepted manuscript

The pathways of gametogenesis encompass elaborate cellular specialization accompanied by precise partitioning of the genome content in order to produce fully matured spermatozoa and oocytes. Transcription factors are an important class of molecules that function in gametogenesis to regulate intrinsic gene expression programs, play essential roles in specifying (or determining) germ cell fate and assist in guiding full maturation of germ cells and maintenance of their populations. Moreover, in order to reinforce or redirect cell fate in vitro, it is transcription factors that are most frequently induced, over-expressed or activated. Many reviews have focused on the molecular development and genetics of gametogenesis, in vivo and in vitro, in model organisms and in humans, including several recent comprehensive reviews: here, we focus specifically on the role of transcription factors. Recent advances in stem cell biology and multi-omic studies have enabled deeper investigation into the unique transcriptional mechanisms of human reproductive development. Moreover, as methods continually improve, in vitro differentiation of germ cells can provide the platform for robust gain- and loss-of-function genetic analyses. These analyses are delineating unique and shared human germ cell transcriptional network components that, together with somatic lineage specifiers and pluripotency transcription factors, function in transitions from pluripotent stem cells to gametes. This grand theme review offers additional insight into human infertility and reproductive disorders that are linked predominantly to defects in the transcription factor networks and thus may potentially contribute to the development of novel treatments for infertility.

Low-volume regimen without additional liquids or adjunctive agents versus standard bowel preparation in non-constipated patients: a propensity score matching analysis

AIMS

Split-dose, 4-L polyethylene glycol (PEG, HSD) is currently the first-line choice for unselected or difficult colon preparations. Almost all low-volume bowel preparations (BPs) include a large volume of additional liquid and adjunctive agents to improve cleansing efficiency. However, neither HSD nor additional liquids or adjunctive agents of low-volume regimens may be necessary for low-risk patients. The aim of this study was to compare the cleansing efficiency between split-dose, low-volume (2-L) PEG without additional liquids or adjunctive agents (LSD) and HSD in non-constipated patients.

METHODS

A retrospective study was performed from January 2013 to December 2015. Consecutive non-constipated patients who received LSD or HSD BPs were enrolled into LSD and HSD groups. Propensity score matching (PSM) was used to reduce selection bias and potential confounders. The primary outcome was bowel cleansing quality, as evaluated by the Boston Bowel Preparation Scale (BBPS). The adenoma detection rate (ADR), the most important secondary outcome, was also recorded. Follow-up was conducted in 2016.

RESULTS

After excluding those participants who meet exclusion criteria or lost follow-up, 1656 non-constipated patients underwent LSD (n = 999) or HSD (n = 657) BP. Most patients had a BBPS score ≥6 (LSD vs. HSD, 93.6 vs. 92.9%, p = .166). The segmental BBPS scores were ≥2 in 92 and 91.9% in the LSD and HSD groups, respectively. The overall ADR was 16.7% in the LSD group and 17.5% in the HSD group (p = .334).

CONCLUSION

For non-constipated patients, LSD is not inferior to HSD in cleansing efficiency, while more willing to repeat the same BP.

Roles of Spermatogonial Stem Cells in Spermatogenesis and Fertility Restoration

Spermatogonial stem cells (SSCs) are a group of adult stem cells in the testis that serve as the foundation of continuous spermatogenesis and male fertility. SSCs are capable of self-renewal to maintain the stability of the stem cell pool and differentiation to produce mature spermatozoa. Dysfunction of SSCs leads to male infertility. Therefore, dissection of the regulatory network of SSCs is of great significance in understanding the fundamental molecular mechanisms of spermatogonial stem cell function in spermatogenesis and the pathogenesis of male infertility. Furthermore, a better understanding of SSC biology will allow us to culture and differentiate SSCs in vitro, which may provide novel stem cell-based therapy for assisted reproduction. This review summarizes the latest research progress on the regulation of SSCs, and the potential application of SSCs for fertility restoration through in vivo and in vitro spermatogenesis. We anticipate that the knowledge gained will advance the application of SSCs to improve male fertility. Furthermore, in vitro spermatogenesis from SSCs sets the stage for the production of SSCs from induced pluripotent stem cells (iPSCs) and subsequent spermatogenesis.

α1A and α1C form microtubules to display distinct properties mainly mediated by their C-terminal tails

Microtubules consisting of α/β-tubulin dimers play critical roles in cells. More than seven genes encode α-tubulin in vertebrates. However, the property of microtubules composed of different α-tubulin isotypes is largely unknown. Here, we purified recombinant tubulin heterodimers of mouse α-tubulin isotypes including α1A and α1C with β-tubulin isotype β2A. In vitro microtubule reconstitution assay detected that α1C/β2A microtubules grew faster and underwent catastrophe less frequently than α1A/β2A microtubules. Generation of chimeric tail-swapped and point-mutation tubulins revealed that the carboxyl-terminal (C-terminal) tails of α-tubulin isotypes largely accounted for the differences in polymerization dynamics of α1A/β2A and α1C/β2A microtubules. Kinetics analysis showed that in comparison to α1A/β2A microtubules, α1C/β2A microtubules displayed higher on-rate, lower off-rate, and similar GTP hydrolysis rate at the plus-end, suggesting a contribution of higher plus-end affinity to faster growth and less frequent catastrophe of α1C/β2A microtubules. Furthermore, EB1 had a higher binding ability to α1C/β2A microtubules than to α1A/β2A ones, which could also be attributed to the difference in the C-terminal tails of these two α-tubulin isotypes. Thus, α-tubulin isotypes diversify microtubule properties, which, to a great extent, could be accounted by their C-terminal tails.

Retracted: AIB1 induces epithelial-mesenchymal transition in gastric cancer via the PI3K/AKT signaling

Amplified in breast cancer 1 (AIB1) is overexpression in various cancers and promotes tumor cell proliferation, survival, and invasiveness. However, the role of AIB1 in the regulation of gastric cancer (GC) cell epithelial-mesenchymal transition (EMT) is still largely unclear. In the present study, immunohistochemistry showed that AIB1 was upregulated in our cohort of patients with GC and correlated with poor survival. Knockdown of AIB1 reduced the invasive ability of GC cells, downregulated the expression of epithelial cell marker E-cadherin, and upregulated mesenchymal cell marker vimentin. AIB1 overexpression elicited the opposite effect. PI-103, the inhibitor of the PI3K/AKT signaling, partially reversed AIB1 overexpression mediated a decrease in E-cadherin and an increase in vimentin. The present data demonstrated that AIB1 augmented the EMT via activation of PI3K/AKT signaling. In conclusion, our results suggested a novel role of AIB1 in GC invasion and EMT and raised the possibility of using this molecule as an indicator for GC treatment.

Protective effects of selenium yeast against cadmium-induced necroptosis through miR-26a-5p/PTEN/PI3K/AKT signaling pathway in chicken kidney

Cadmium (Cd) is a ubiquitous environmental pollutant of increasing worldwide concern to both humans and animals. Selenium yeast (Se-Y) is an organic selenium source that has been shown an advantage in antagonizing Cd-induced liver necroptosis in chicken. Herein, we described the discovery path of Se-Y antagonism in Cd-induced renal necroptosis in chicken through targeting miR-26a-5p/PTEN/PI3K/AKT signaling pathway. We set up four groups of chickens at random: control group (0.5 mg/kg Na₂SeO₃), Se-Y group (0.5 mg/kg Se-Y), Se-Y+Cd group (0.5 mg/kg Se-Y and 150 mg/kg CdCl₂) and Cd group (150 mg/kg CdCl₂ and 0.5 mg/kg Na₂SeO₃). Interestingly, we found Se-Y, but not Na₂SeO₃, significantly blocked Cd accumulation in the kidney and alleviated Cd-induced necroptosis through inhibiting the expression of RIP1, RIP3 and MLKL. Se-Y, activated miR-26a-5p expression, thereby down-regulated the expression of PTEN, resulting in the up-regulation of PI3K/AKT signaling pathway and the inhibition of oxidative stress in both Se-Y and Cd treated chickens. Besides that, Se-Y could also specifically reduce the expression levels of heat shock protein 60 (HSP60), HSP70 and HSP90 in Se-Y and Cd co-treated chickens. Taken together, our results showed that Se-Y has an added value to antagonize Cd-induced necroptosis in chicken kidney by regulating the miR-26a-5p/PTEN/PI3K/AKT signaling pathway and HSPs, indicating that Se-Y could serve as an effective antagonist on Cd-induced renal necroptosis in chickens.

P–371 Clinical value assessment between endometrial receptivity array and immune profiling in patients with implantation failure

Study question

To evaluate whether the pregnancy outcomes could be improved in implantation failure patients by endometrial receptivity array, endometrial immune profiling, or a combination of both.

Summary answer

There was no statistical difference between different endometrial receptivity evaluation and treatment in improving the clinical pregnancy rate.

What is known already

Both endometrial receptivity array and endometrial immune profiling were promised to improve the endometrial receptivity and subsequent clinical pregnancy. However, less is known about the efficiency between each other and whether the combination could further enhance their clinical value.

Study design, size, duration

Between November 2019 and September 2020, 143 women with a history of at least two or more consecutive implantation failure in IVF/ICSI treatment in Chengdu Xinan Gynecology Hospital were included. They were divided into three groups: ‘ERA + Immune Profiling’ (n = 70), ‘Immune Profiling’ (n = 41), and ‘ERA’ (n = 32).

Participants/materials, setting, methods

Inclusion criteria were age ≤ 38, with normal uterus and uterine cavity. All patients were suggested to evaluate endometrial receptivity by ERA test (Igenomix, Valencia, Spain) and endometrial immune profiling based on immunohistochemistry simultaneously, who would be free to choose each or both evaluation approaches. Personal Embryo Transfer and/or personal medical care were adopted according to evaluation results. Clinical pregnancy was confirmed by gestational sacs observed under ultrasonography.

Main results and the role of chance

The overall prevalence of displaced window of implantation (WOI) is 84.3%, and nearly 74.8% (83/111) patients were diagnosed as endometrial immune dysregulation. Clinical Pregnancy rate and embryonic implantation rate decreased in the ‘Immune Test’ groups, but without a statistical difference (P = 0.311, and 0.158, respectively). Multivariable logistic regression analysis showed that different endometrial receptivity evaluation and treatment was not associated the clinical pregnancy rate, suggesting the performance of different endometrial receptivity evaluation and treatment is similar in improving the clinical pregnancy rate. Neither the immune profiling (CD56, P = 0.591; FOXP3, P = 0.195; CD68, P = 0.820; CD163, P = 0.926; CD1a, P = 0.561; CD57, P = 0.221; CD8, P = 0.427; CD138 CE, P = 0.372) nor histologic endometrial dating defined by Noyes criteria (P = 0.374) were associated with ERA phases.

Limitations, reasons for caution

Although the selection of evaluation approaches was based on patients’ willingness, the variances of baseline characteristics and immune profiling existed in different groups. The immunological treatment efficacy based on immune profiling was not evaluated before embryo transfer.

Wider implications of the findings: To our knowledge, this is the first study comparing the pregnancy outcomes after two typical endometrial receptivity evaluation approaches. The findings highlight the unsubstitutability for each assessment, indicating that both asynchronous and pathological WOI contribute to implantation failure.

Trial registration number

X2019004

α-TubK40me3 is required for neuronal polarization and migration by promoting microtubule formation

Tri-methylation on lysine 40 of α-tubulin (α-TubK40me3) is a recently identified post-translational modification involved in mitosis and cytokinesis. However, knowledge about α-TubK40me3 in microtubule function and post-mitotic cells remains largely incomplete. Here, we report that α-TubK40me3 is required for neuronal polarization and migration by promoting microtubule formation. α-TubK40me3 is enriched in mouse cerebral cortex during embryonic day (E)14 to E16. Knockdown of α-tubulin methyltransferase SETD2 at E14 leads to the defects in neuronal migration, which could be restored by overexpressing either a cytoplasm-localized SETD2 truncation or α-TubK40me3-mimicking mutant. Furthermore, α-TubK40me3 is preferably distributed on polymerized microtubules and potently promotes tubulin nucleation. Downregulation of α-TubK40me3 results in reduced microtubule abundance in neurites and disrupts neuronal polarization, which could be rescued by Taxol. Additionally, α-TubK40me3 is increased after losing α-tubulin K40 acetylation (α-TubK40ac) and largely rescues α-TubK40ac function. This study reveals a critical role of α-TubK40me3 in microtubule formation and neuronal development.

Post-translational modifications of tubulins regulate microtubule properties and neural development. Here, the authors report that one such post-translational modification, α-TubK40me3, is required for neuronal polarization and migration by promoting microtubule formation.

5'-UTR SNP of FGF13 causes translational defect and intellectual disability

The congenital intellectual disability (ID)-causing gene mutations remain largely unclear, although many genetic variations might relate to ID. We screened gene mutations in Chinese Han children suffering from severe ID and found a single-nucleotide polymorphism (SNP) in the 5′-untranslated region (5′-UTR) of fibroblast growth factor 13 (FGF13) mRNA (NM_001139500.1:c.-32c>G) shared by three male children. In both HEK293 cells and patient-derived induced pluripotent stem cells, this SNP reduced the translation of FGF13, which stabilizes microtubules in developing neurons. Mice carrying the homologous point mutation in 5′-UTR of Fgf13 showed delayed neuronal migration during cortical development, and weakened learning and memory. Furthermore, this SNP reduced the interaction between FGF13 5′-UTR and polypyrimidine-tract-binding protein 2 (PTBP2), which was required for FGF13 translation in cortical neurons. Thus, this 5′-UTR SNP of FGF13 interferes with the translational process of FGF13 and causes deficits in brain development and cognitive functions.

Population Pharmacokinetic Analysis of Recombinant Factor VIII Fc Fusion Protein in Subjects With Severe Hemophilia A: Expanded to Include Pediatric Subjects

Recombinant factor VIII Fc fusion protein (rFVIIIFc) has been indicated for adults and children with hemophilia A. The objective of this article was to build a population pharmacokinetic (PK) model using adult and pediatric data sets and explore relevant dosing scenarios across all ages. The activity-time profiles of rFVIIIFc from 3 clinical studies (all trials registered at https://www.clinicaltrials.gov: NCT01027377, NCT01181128, and NCT01458106) were characterized, and covariates that determine variability of rFVIIIFc PK in children and adults were identified and implemented. Data sets were pooled to estimate population PK parameters. Simulations were conducted to generate activity-time profiles at steady state (SS). The proportion of subjects maintaining SS trough >1 and >3 IU/dL and time >10 IU/dL were estimated. The rFVIIIFc model was a two-compartment model that identified weight and von Willebrand factor as significant covariates. Model-predicted SS peaks and troughs of rFVIIIFc activity-time profiles confirmed the necessity of modifying dosing in pediatric subjects. The model also predicted that the average subject in the adult and adolescent group dosed with 40 IU/kg every 2 days maintained factor VIII activity >10 IU/dL for the entire duration. Children aged <6 years and aged 6 to <12 years receiving this dose maintained factor VIII activity of >10 IU/dL for nearly two-thirds and three-quarters of their time, respectively. In conclusion, these population PK analyses characterize activity-time profiles for rFVIIIFc among pediatric and adult subjects. The model was used for simulation of clinically relevant dosing scenarios, which can provide better protection and better clinical outcomes.

SUMOylation of α-tubulin is a novel modification regulating microtubule dynamics

Microtubules (MTs) are regulated by a number of known posttranslational modifications (PTMs) on α/β-tubulin to fulfill diverse cellular functions. Here, we showed that SUMOylation is a novel PTM on α-tubulin in vivo and in vitro. The SUMOylation on α-tubulin mainly occurred at Lys 96 (K96), K166, and K304 of soluble α-tubulin and could be removed by small ubiquitin-related modifier (SUMO)-specific peptidase 1. In vitro experiments showed that tubulin SUMOylation could reduce interprotofilament interaction, promote MT catastrophe, and impede MT polymerization. In cells, mutation of the SUMOylation sites on α-tubulin reduced catastrophe frequency and increased the proportion of polymerized α-tubulin, while upregulation of SUMOylation with fusion of SUMO1 reduced α-tubulin assembly into MTs. Additionally, overexpression of SUMOylation-deficient α-tubulin attenuated the neurite extension in Neuro-2a cells. Thus, SUMOylation on α-tubulin represents a new player in the regulation of MT properties.

Protective effects of hypericin against infectious bronchitis virus induced apoptosis and reactive oxygen species in chicken embryo kidney cells

Avian infectious bronchitis virus (IBV), a coronavirus, causes infectious bronchitis leading to enormous economic loss in the poultry industry worldwide. Hypericin (HY) is an excellent compound that has been investigated in antiviral, antineoplastic, and antidepressant. To investigate the inhibition effect of HY on IBV infection in chicken embryo kidney (CEK) cells, 3 different experimental designs: pre-treatment of cells prior to IBV infection, direct treatment of IBV-infected cells, and pre-treatment of IBV prior to cell infection were used. Quantitative real-time PCR (qRT-PCR), immunofluorescence assay (IFA), flow cytometry, and fluorescence microscopy were performed and virus titer was determined by TCID50. The results revealed that HY had a good anti-IBV effect when HY directly treated the IBV-infected cells, and virus infectivity decreased in a dose-dependent manner. Furthermore, HY inhibited IBV-induced apoptosis in CEK cells, and significantly reduced the mRNA expression levels of Fas, FasL, JNK, Bax, Caspase 3, and Caspase 8, and significantly increased Bcl-2 mRNA expression level in CEK cells. In addition, HY treatment could decrease IBV-induced reactive oxygen species (ROS) generation in CEK cells. These results suggested that HY showed potential antiviral activities against IBV infection involving the inhibition of apoptosis and ROS generation in CEK cells.

α-Tubulin Acetylation Restricts Axon Overbranching by Dampening Microtubule Plus-End Dynamics in Neurons

Axon growth is tightly controlled to establish functional neural circuits during brain development. Despite the belief that cytoskeletal dynamics is critical for cell morphology, how microtubule acetylation regulates axon development in the mammalian central nervous system remains unclear. Here, we report that loss of α-tubulin acetylation by ablation of MEC-17 in mice predisposes neurons to axon overbranching and overgrowth. Introduction of MEC-17F183A lacking α-tubulin acetyltransferase activity into MEC-17-deficient neurons failed to rescue axon defects. Moreover, loss of α-tubulin acetylation led to increases in microtubule debundling, microtubule invasion into filopodia and growth cones, and microtubule plus-end dynamics along the axon. Taxol application dampened microtubule hyperdynamics and suppressed axon overbranching and overgrowth in MEC-17-deficient neurons. Thus, our study reveals that α-tubulin acetylation acts as a brake for axon overbranching and overgrowth by dampening microtubule dynamics, providing insight into the role of microtubule post-translational modifications in regulating neural development.

Antiviral Activity Against Infectious Bronchitis Virus and Bioactive Components of Hypericum perforatum L

Hypericum perforatum L., also known as Saint John’s Wort, has been well studied for its chemical composition and pharmacological activity. In this study, the antiviral activities of H. perforatum on infectious bronchitis virus (IBV) were evaluated in vitro and in vivo for the first time. The results of in vitro experiments confirmed that the antiviral component of H. perforatum was ethyl acetate extraction section (HPE), and results showed that treatment with HPE significantly reduced the relative messenger ribonucleic acid (mRNA) expression and virus titer of IBV, and reduced positive green immunofluorescence signal of IBV in chicken embryo kidney (CEK) cells. HPE treatment at doses of 480–120 mg/kg for 5 days, reduced IBV induced injury in the trachea and kidney, moreover, reduced the mRNA expression level of IBV in the trachea and kidney in vivo. The mRNA expression levels of IL-6, tumor necrosis factor alpha (TNF-α), and nuclear factor kappa beta (NF-κB) significantly decreased, but melanoma differentiation-associated protein 5 (MDA5), mitochondrial antiviral signaling gene, interferon alpha (IFN-α), and interferon beta (IFN-β) mRNA levels significantly increased in vitro and in vivo. Our findings demonstrated that HPE had significant anti-IBV effects in vitro and in vivo, respectively. In addition, it is possible owing to up-regulate mRNA expression of type I interferon through the MDA5 signaling pathway and down-regulate mRNA expression of IL-6 and TNF-α via the NF-κB signaling pathway. Moreover, the mainly active compositions of HPE analyzed by high-performance liquid chromatography/electrospray ionization–mass spectroscopy (ESI-MS) are hyperoside, quercitrin, quercetin, pseudohypericin, and hypericin, and a combination of these compounds could mediate the antiviral activities. This might accelerate our understanding of the antiviral effect of H. perforatum and provide new insights into the development of effective therapeutic strategies.

Pharmacometric Applications and Challenges in the Development of Therapeutic Antibodies in Immuno-Oncology

Purpose of review

Monoclonal antibodies targeting key checkpoints in immune stimulatory pathways have over the last years become the mainstay of cancer immunotherapy. This article provides a brief review of the application and key impact of pharmacometrics and quantitative clinical pharmacology approaches in the development of these novel biologics.

Recent findings

The clinical development and selection of optimal dosing regimens for monoclonal antibodies used in immune-oncology has been facilitated by an extensive application of pharmacometric approaches to characterize the exposure-response relationship for major efficacy and safety endpoints. These analysis techniques were applied for the anti CTLA-4 antibody ipilimumab, as well as the anti PD1/PD-L1 antibodies nivolumab, pembrolizumab, avelumab, atezolizumab and durvalumab. The utilization of quantitative clinical pharmacology, including model-based analyses, did not only support the identification of efficacious doses with acceptable safety limits, but was also able to address complicating challenges such as time- and response-dependent changes in antibody clearance as observed for most compounds.

Summary

A widespread and systematic application of pharmacometric approaches has provided key aspects in elucidating, interpreting and integrating preclinical, biochemical and clinical data in support of the development of safe and efficacious dosing regimens of monoclonal antibodies used in immuno-oncology, thereby facilitating the clinical use of this promising new class of biologics in cancer patients with unmet medical needs.