68Ga-FAPI-04 PET/CT in Non-Small Cell Lung Cancer: Accurate Evaluation of Lymph Node Metastasis and Correlation with Fibroblast Activation Protein Expression

Fibroblast activation protein (FAP) is a promising diagnostic and therapeutic target in various solid tumors. This study aimed to assess the diagnostic efficiency of 68Ga-labeled FAP inhibitor (FAPI)-04 PET/CT for detecting lymph node metastasis in non-small cell lung cancer (NSCLC) and to investigate the correlation between tumor 68Ga-FAPI-04 uptake and FAP expression. Methods: We retrospectively enrolled 136 participants with suspected or biopsy-confirmed NSCLC who underwent 68Ga-FAPI-04 PET/CT for initial staging. The diagnostic performance of 68Ga-FAPI-04 for the detection of NSCLC was evaluated. The final histopathology or typical imaging features were used as the reference standard. The SUVmax and SUVmean, 68Ga-FAPI-avid tumor volume (FTV), and total lesion FAP expression (TLF) were measured and calculated. FAP immunostaining of tissue specimens was performed. The correlation between 68Ga-FAPI-04 uptake and FAP expression was assessed using the Spearman correlation coefficient. Results: Ninety-one participants (median age, 65 y [interquartile range, 58-70 y]; 69 men) with NSCLC were finally analyzed. In lesion-based analysis, the diagnostic sensitivity and positive predictive value of 68Ga-FAPI-04 PET/CT for detection of the primary tumor were 96.70% (88/91) and 100% (88/88), respectively. In station-based analysis, the diagnostic sensitivity, specificity, and accuracy for the detection of lymph node metastasis were 72.00% (18/25), 93.10% (108/116), and 89.36% (126/141), respectively. Tumor 68Ga-FAPI-04 uptake (SUVmax, SUVmean, FTV, and TLF) correlated positively with FAP expression (r = 0.470, 0.477, 0.582, and 0.608, respectively; all P ≤ 0.001). The volume parameters FTV and TLF correlated strongly with FAP expression in 31 surgical specimens (r = 0.700 and 0.770, respectively; both P < 0.001). Conclusion: 68Ga-FAPI-04 PET/CT had excellent diagnostic efficiency for detecting lymph node metastasis, and 68Ga-FAPI-04 uptake showed a close association with FAP expression in participants with NSCLC.

A multicomponent triformylphoroglucinol-based covalent organic framework for overall hydrogen peroxide photosynthesis

A multicomponent covalent organic framework (COF-Tfp-BpyDaaq) integrating bipyridine with diaminoanthraquinone through a triformylphoroglucinol linkage was synthesized for the first time as a photocatalyst for overall H2O2 photosynthesis. It exhibits enhanced photo-charge separation and H2O2 production rate over its two-component counterparts, demonstrating the pivotal role of multicomponent synthesis in designing efficient photocatalysts.

Temporally Decoupled Ammonia Splitting by a Zn-NH3 Battery with an Ammonia Oxidation/Hydrogen Evolution Bifunctional Electrocatalyst as a Cathode

Ammonia splitting to hydrogen is a decisive route for hydrogen economy but is seriously limited by the complex device and low efficiency. Here, we design and propose a new rechargeable Zn-NH3 battery based on temporally decoupled ammonia splitting to achieve efficient NH3-to-H2 conversion. In this system, ammonia is oxidized into nitrogen during cathodic charging (2NH3 + 6OH- → N2 + 6H2O + 6e-) with external electrical energy conversion and storage, while during cathodic discharging, water is reduced to hydrogen (2H2O + 2e- → H2 + 2OH-) with electrical energy generation. In this loop, continuous and efficient H2 production without separation and purification is achieved. With the help of the ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) bifunctional catalyst of Mo2C/NiCu@C, a rechargeable Zn-NH3 battery is realized that exhibits a high NH3-to-H2 FE of 91.6% with outstanding durability for 900 cycles (300 h) at 20 mA/cm2, enabling efficient and continuous NH3-to-H2 conversion.

FLASH radiotherapy for the treatment of symptomatic bone metastases in the thorax (FAST-02): protocol for a prospective study of a novel radiotherapy approach

BACKGROUND

FLASH therapy is a treatment technique in which radiation is delivered at ultra-high dose rates (≥ 40 Gy/s). The first-in-human FAST-01 clinical trial demonstrated the clinical feasibility of proton FLASH in the treatment of extremity bone metastases. The objectives of this investigation are to assess the toxicities of treatment and pain relief in study participants with painful thoracic bone metastases treated with FLASH radiotherapy, as well as workflow metrics in a clinical setting.

METHODS

This single-arm clinical trial is being conducted under an FDA investigational device exemption (IDE) approved for 10 patients with 1-3 painful bone metastases in the thorax, excluding bone metastases in the spine. Treatment will be 8 Gy in a single fraction administered at ≥ 40 Gy/s on a FLASH-enabled proton therapy system delivering a single transmission proton beam. Primary study endpoints are efficacy (pain relief) and safety. Patient questionnaires evaluating pain flare at the treatment site will be completed for 10 consecutive days post-RT. Pain response and adverse events (AEs) will be evaluated on the day of treatment and on day 7, day 15, months 1, 2, 3, 6, 9, and 12, and every 6 months thereafter. The outcomes for clinical workflow feasibility are the occurrence of any device issues as well as time on the treatment table.

DISCUSSION

This prospective clinical trial will provide clinical data for evaluating the efficacy and safety of proton FLASH for palliation of bony metastases in the thorax. Positive findings will support the further exploration of FLASH radiation for other clinical indications including patient populations treated with curative intent.

REGISTRATION

ClinicalTrials.gov NCT05524064.

Body mass index's effect on CRSwNP extends to pathological endotype and recurrence

BACKGROUND

Elevated body mass index (BMI) has been recognized as an important contributor to corticosteroid insensitivity in chronic rhinosinusitis with nasal polyps (CRSwNP). We aimed to delineate the effects of elevated BMI on immunological endotype and recurrence in CRSwNP individuals.

METHODOLOGY

A total of 325 patients with CRSwNP undergoing FESS were recruited and stratified by BMI. H&E staining was employed for histological evaluation. Characteristics of inflammatory patterns were identified by immunohistochemical staining. The predictive factors for recurrence were determined and evaluated by multivariable logistic regression analysis and the receiver operating characteristic (ROC) curves across all subjects and by weight group.

RESULTS

In all patients with CRSwNP, 26.15% subjects were classified as overweight/obese group across BMI categories and exhibited a higher symptom burden. The upregulated eosinophil/neutrophil-dominant cellular endotype and amplified type 2/ type 3 coexisting inflammation was present in overweight/obese compared to underweight/normal weight controls. Additionally, a higher recurrent proportion was shown in overweight/obese patients than that in underweight/normal weight cohorts. Multivariable logistic regression analysis identified BMI as an independent predictor for recurrence. The predictive capacity of each conventional parameter (tissue eosinophil and CLCs count, and blood eosinophil percentage) alone or in combination was poor in overweight/obese subjects.

CONCLUSIONS

Overweight/obese CRSwNP stands for a unique phenotype and endotype. Conventional parameters predicting recurrence are compromised in overweight/obese CRSwNP, and there is an urgent need for novel biomarkers that predict recurrence for these patients.

Use of survival support vector machine combined with random survival forest to predict the survival of nasopharyngeal carcinoma patients

Background

The Cox regression model is not sufficiently accurate to predict the survival prognosis of nasopharyngeal carcinoma (NPC) patients. It is impossible to calculate and rank the importance of impact factors due to the low predictive accuracy of the Cox regression model. So, we developed a system. Using the SEER (The Surveillance, Epidemiology, and End Results) database data on NPC patients, we proposed the use of random survival forest (RSF) and survival-support vector machine (SVM) from the machine learning methods to develop a survival prediction system specifically for NPC patients. This approach aimed to make up for the insufficiency of the Cox regression model. We also used the Cox regression model to validate the development of the nomogram and compared it with machine learning methods.

Methods

A total of 1,683 NPC patients were extracted from the SEER database from January 2010 to December 2015. We used R language for modeling work, established the nomogram of survival prognosis of NPC patients by Cox regression model, ranked the correlation of influencing factors by RSF model VIMP (variable important) method, developed a survival prognosis system for NPC patients based on survival-SVM, and used C-index for model evaluation and performance comparison.

Results

Although the Cox regression models can be developed to predict the prognosis of NPC patients, their accuracy was lower than that of machine learning methods. When we substituted the data for the Cox model, the C-index for the training set was only 0.740, and the C-index for the test set was 0.721. In contrast, the C index of the survival-SVM model was 0.785. The C-index of the RSF model was 0.729. The importance ranking of each variable could be obtained according to the VIMP method.

Conclusions

The prediction results from the Cox model are not as good as those of the RSF method and survival-SVM based on the machine learning method. For the survival prognosis of NPC patients, the machine learning method can be considered for clinical application.

Synthesis and Biological Evaluation of Enantiomerically Pure (R)- and (S)-[18F]OF-NB1 for Imaging the GluN2B Subunit-Containing NMDA Receptors

GluN2B subunit-containing N-methyl-d-aspartate (NMDA) receptors have been implicated in various neurological disorders. Nonetheless, a validated fluorine-18 labeled positron emission tomography (PET) ligand for GluN2B imaging in the living human brain is currently lacking. The aim of this study was to develop a novel synthetic approach that allows an enantiomerically pure radiosynthesis of the previously reported PET radioligands (R)-[18F]OF-NB1 and (S)-[18F]OF-NB1 as well as to assess their in vitro and in vivo performance characteristics for imaging the GluN2B subunit-containing NMDA receptor in rodents. A novel synthetic approach was successfully developed, which allows for the enantiomerically pure radiosynthesis of (R)-[18F]OF-NB1 and (S)-[18F]OF-NB1 and the translation of the probe to the clinic. While both enantiomers were selective over sigma2 receptors in vitro and in vivo, (R)-[18F]OF-NB1 showed superior GluN2B subunit specificity by in vitro autoradiography and higher volumes of distribution in the rodent brain by small animal PET studies.

Evaluation of [18F]RoSMA-18-d6 as a CB2 PET Radioligand in Nonhuman Primates

The cannabinoid type 2 receptor (CB2) has been implicated in a variety of central and peripheral inflammatory diseases, prompting significant interest in the development of CB2-targeted diagnostic and therapeutic agents. A validated positron emission tomography (PET) radioligand for imaging CB2 in the living human brain as well as in peripheral tissues is currently lacking. As part of our research program, we have recently identified the trisubstituted pyridine, [18F]RoSMA-18-d6, which proved to be highly suitable for in vitro and in vivo mapping of CB2 in rodents. The aim of this study was to assess the performance characteristics of [18F]RoSMA-18-d6 in nonhuman primates (NHPs) to pave the way for clinical translation. [18F]RoSMA-18-d6 was synthesized from the respective tosylate precursor according to previously reported procedures. In vitro autoradiograms with NHP spleen tissue sections revealed a high binding of [18F]RoSMA-18-d6 to the CB2-rich NHP spleen, which was significantly blocked by coincubation with the commercially available CB2 ligand, GW405833 (10 μM). In contrast, no specific binding was observed by in vitro autoradiography with NHP brain sections, which was in agreement with the notion of a CB2-deficient healthy mammalian brain. In vitro findings were corroborated by PET imaging experiments in NHPs, where [18F]RoSMA-18-d6 uptake in the spleen was dose-dependently attenuated with 1 and 5 mg/kg GW405833, while no specific brain signal was observed. Remarkably, we observed tracer uptake and retention in the NHP spinal cord, which was reduced by GW405833 blockade, pointing toward a potential utility of [18F]RoSMA-18-d6 in probing CB2-expressing cells in the bone marrow. If these observations are substantiated in NHP models of enhanced leukocyte proliferation in the bone marrow, [18F]RoSMA-18-d6 may serve as a valuable marker for hematopoietic activity in various pathologies. In conclusion, [18F]RoSMA-18-d6 proved to be a suitable PET radioligand for imaging CB2 in NHPs, supporting its translation to humans.

Development of Novel 11C-Labeled Selective Orexin-2 Receptor Radioligands for Positron Emission Tomography Imaging

Orexin 2 receptors (OX2R) represent a vital subtype of orexin receptors intricately involved in the regulation of wakefulness, arousal, and sleep-wake cycles. Despite their importance, there are currently no positron emission tomography (PET) tracers available for imaging the OX2R in vivo. Herein, we report [11C]1 ([11C]OX2-2201) and [11C]2 ([11C]OX2-2202) as novel PET ligands. Both compounds 1 (Ki = 3.6 nM) and 2 (Ki = 2.2 nM) have excellent binding affinity activities toward OX2R and target selectivity (OX2/OX1 > 600 folds). In vitro autoradiography in the rat brain suggested good to excellent in vitro binding specificity for [11C]1 and [11C]2. PET imaging in rat brains indicated that the low brain uptake of [11C]2 may be due to P-glycoprotein and/or breast cancer resistance protein efflux interaction and/or low passive permeability. Continuous effort in medicinal chemistry optimization is necessary to improve the brain permeability of this scaffold.

Efficacy of Postoperative Radiotherapy for Patients with New N2 Descriptors of Subclassification in Completely Resected Non-Small Cell Lung Cancer: A Real-World Study

PURPOSE/OBJECTIVE(S)

Patients with N2 non-small cell lung cancer (NSCLC) were heterogeneous groups and required further stratification. The International Society for the Study of Lung Cancer (IASLC) added new descriptors of three sub-stages for stage N2 NSCLC: N2 at a single station without N1 involvement (N2a1), N2 at a single station with N1 involvement (N2a2), and N2 at multiple stations (N2b). This study aimed to investigate the efficacy of postoperative radiotherapy (PORT) for patients with these N2 descriptors.

MATERIALS/METHODS

Patients with histologically confirmed NSCLC after complete resection and divided into PORT group and non-PORT group. The primary endpoint was DFS. The second endpoints were overall survival (OS) and locoregional recurrence-free survival (LRFS). Propensity-score matching (PSM) of baseline characteristics between the PORT and non-PORT groups was used for validation.

RESULTS

Totally 1832 patients were enrolled, including 308 N2a1 patients, 682 N2a2 patients, and 842 N2b patients. The median follow-up time was 50.1 months. The survival outcomes of the PORT and non-PORT groups before PSM were shown in Table 1. For patients with N2a1, PORT could not improve the DFS (median DFS of the PORT group and the non-PORT group: not reached vs. 46.8 months, P = 0.41), OS (P = 0.85), or LRFS (P = 0.32), which were consistent with the multivariate analysis and data after the PSM. For patients with N2a2, PORT significantly improved the DFS (median DFS 29.7 vs. 22.2 months, P = 0.02), OS (P = 0.03), and LRFS (P = 0.01). The multivariate analysis and data after the PSM confirmed the benefits in DFS and LRFS, but no benefit was observed in OS (multivariate analysis: HR 0.79, P = 0.18; median OS after PSM: 103.7 vs. 63.1 months, P = 0.34). For patients with N2b, PORT could not improve the DFS (median DFS 20.6 vs. 21.2 months, P = 0.39) but significantly improved the OS (P<0.001) and LRFS (P<0.001). However, the multivariate analysis showed that PORT significantly improved DFS (HR 0.81, P = 0.03), consistent with the data after the PSM (median DFS 20.6 and 17.6 months, P = 0.04).

CONCLUSION

PORT significantly improved the DFS and LRFS in patients with N2a2 and significantly improved the DFS, LRFS, and OS in patients with N2b. Patients with N2a1 could not benefit from PORT.

Self-supervised dual-head attentional bootstrap learning network for prostate cancer screening in transrectal ultrasound images

Current convolutional neural network-based ultrasound automatic classification models for prostate cancer often rely on extensive manual labeling. Although Self-supervised Learning (SSL) have shown promise in addressing this problem, those data that from medical scenarios contains intra-class similarity conflicts, so using loss calculations directly that include positive and negative sample pairs can mislead training. SSL method tends to focus on global consistency at the image level and does not consider the internal informative relationships of the feature map. To improve the efficiency of prostate cancer diagnosis, using SSL method to learn key diagnostic information in ultrasound images, we proposed a self-supervised dual-head attentional bootstrap learning network (SDABL), including Online-Net and Target-Net. Self-Position Attention Module (SPAM) and adaptive maximum channel attention module (CAAM) are inserted in both paths simultaneously. They captures position and inter-channel attention and of the original feature map with a small number of parameters, solve the information optimization problem of feature maps in SSL. In loss calculations, we discard the construction of negative sample pairs, and instead guide the network to learn the consistency of the location space and channel space by drawing closer to the embedding representation of positive samples continuously. We conducted numerous experiments on the prostate Transrectal ultrasound (TRUS) dataset, experiments show that our SDABL pre-training method has significant advantages over both mainstream contrast learning methods and other attention-based methods. Specifically, the SDABL pre-trained backbone achieves 80.46% accuracy on our TRUS dataset after fine-tuning.

Chemoradiotherapy Combined with Nab-Paclitaxel plus Cisplatin in Patients with Locally Advanced Borderline Resectable or Unresectable Esophageal Squamous Cell Carcinoma: A Phase I/II Study

PURPOSE/OBJECTIVE(S)

To evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) plus cisplatin as the regimen of conversional chemoradiotherapy (cCRT) in locally advanced borderline resectable or unresectable esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Patients with locally advanced ESCC (cT3-4, Nany, M0-1, M1 was limited to lymph node metastasis in the supraclavicular area) were enrolled. All the patients received the cCRT of nab-PTX plus cisplatin. After the cCRT, those resectable patients received esophagectomy; those unresectable patients continued to receive the definitive chemoradiotherapy (dCRT). The locoregional control (LRC), overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), pathological complete response (pCR), R0 resection rate and adverse events (AEs) were calculated.

RESULTS

A total of 45 patients with ESCC treated from October 2019 to May 2021 were finally included. The median follow-up time was 30.3 months. The LRC, OS, EFS, DMFS at 1and 2 years were 81.5%, 86.6%, 64.3%, 73.2% and 72.4%, 68.8%, 44.8%, 52.7% respectively. 21 patients (46.7%) received conversional chemoradiotherapy plus surgery (cCRT+S). The pCR rate and R0 resection rate were 47.6% and 84.0%. The LRC rate at 1 and 2 years were 95.0%, 87.1% in cCRT+S patients and 69.3%, 58.7% in dCRT patients respectively (HR, 5.14; 95% CI, 1.10-23.94; P = 0.021). The OS rate at 1 and 2 years were 95.2% and 84.2% in resectable patients compared to 78.8% and 54.4% in unresectable patients (HR, 3.41; 95% CI, 1.10-10.61; P = 0.024). The toxicities during chemoradiotherapy were tolerated, the most common grade 3-4 toxicities were radiation esophagitis (15.6%).

CONCLUSION

Nab-PTX plus cisplatin were effective and safe as the regimen of conversional chemoradiotherapy of ESCC. The patients receiving conversional chemoradiotherapy plus surgery (cCRT+S) were prone to have a better survival.

Clinical Outcomes with Thoracic Radiotherapy for Extensive-Stage Small-Cell Lung Cancer in the Era of Immunotherapy: A Retrospective Analysis

PURPOSE/OBJECTIVE(S)

Chemo-immunotherapy has shown significant benefits for extensive-stage small-cell lung cancer (ES-SCLC), which prolonged overall survival (OS) of nearly 2-4.5 months compared with platinum-based chemotherapy alone. However, thoracic radiotherapy (TRT), was not allowed to be used in previous trials. This retrospective study aimed to evaluate the safety and efficiency of TRT for ES-SCLC patients in the era of Immunotherapy.

MATERIALS/METHODS

We retrospectively reviewed ES-SCLC patients treated with chemo-immunotherapy between 2017 and 2021 in our center. Patients who accepted consolidative or salvage TRT were included. The overall survival, progression-free survival (PFS), local progression-free survival (LPFS), and distant progression free-survival (DPFS) were calculated using the Kaplan-Meier method. Toxicity was recorded based on CTCAE 5.0 scale.

RESULTS

We finally enrolled 30 patients in our study. The median follow-up time was 26.0 months (95% confidence interval, 18.2-33.8 months). 26(86.7%) patients have undergone first-line chemotherapy and immunotherapy, while 4(13.3%) have undergone immunotherapy as a second-line agent. 23(76.6%) patients achieved CR/PR/SD to initial systematic therapy. All patients were treated with TRT with a median dose of 51 Gy (24-60.2 Gy). The median interval between TRT and immunotherapy was 35 days. Median OS was 26 months (95% confidence interval, 17.8-34.2 months) and median PFS was 8 months (95% confidence interval, 5.3-10.7 months). 2-year OS, PFS, and DPFS were 51.4%, 21.4%, and 27.4%, respectively. 18 months LPFS was 59.6%. There was no ≥ G3 radiation-related adverse event except 2(6.7%) G3 esophagitis. G1-2 pneumonitis was reported in 8(26.7%) patients.

CONCLUSION

TRT is well-tolerated and effective for selected ES-SCLC patients in the modern era of immunotherapy. Prospective trials are still needed to further evaluate the combination of TRT and immunotherapy for patients with ES-SCLC.

Regionally distinct progenitor cells in the lower airway give rise to neuroendocrine and multiciliated cells in the developing human lung

Using scRNA-seq and microscopy, we describe a cell that is enriched in the lower airways of the developing human lung and identified by the unique coexpression of SCGB3A2/SFTPB/CFTR. To functionally interrogate these cells, we apply a single-cell barcode-based lineage tracing method, called CellTagging, to track the fate of SCGB3A2/SFTPB/CFTR cells during airway organoid differentiation in vitro. Lineage tracing reveals that these cells have a distinct differentiation potential from basal cells, giving rise predominantly to pulmonary neuroendocrine cells and a subset of multiciliated cells distinguished by high C6 and low MUC16 expression. Lineage tracing results are supported by studies using organoids and isolated cells from the lower noncartilaginous airway. We conclude that SCGB3A2/SFTPB/CFTR cells are enriched in the lower airways of the developing human lung and contribute to the epithelial diversity and heterogeneity in this region.

The performance of 68Ga-FAPI-04 PET/CT in head and neck squamous cell carcinoma: a prospective comparison with 18F-FDG PET/CT

PURPOSE

This study was designed to compare the performance of 68Ga-FAPI-04 and 18F-FDG PET/CT for initial staging and recurrence detection of head and neck squamous cell carcinoma (HNSCC).

METHODS

Prospectively, 77 patients with histologically proven or highly suspected HNSCC underwent paired 18F-FDG and 68Ga-FAPI-04 PET/CT in a week for either initial staging (n = 67) or restaging (n = 10). The diagnostic performance was compared for the two imaging approaches, especially for N staging. SUVmax, SUVmean, and target-to-background ratio (TBR) were assessed for paired positive lesions. Furthermore, change in management by 68Ga-FAPI-04 PET/CT and histopathologic FAP expression of some lesions were explored.

RESULTS

18F-FDG and 68Ga-FAPI-04 PET/CT exhibited a comparable detection efficiency for primary tumor (100%) and recurrence (62.5%). In the twenty-nine patients receiving neck dissection, 68Ga-FAPI-04 PET/CT showed greater specificity and accuracy in evaluating preoperative N staging than 18F-FDG based on patient (p = 0.031 and p = 0.070), neck side (p = 0.002 and p = 0.006), and neck level (p < 0.001 and p < 0.001). As for distant metastasis, 68Ga-FAPI-04 PET/CT detected more positive lesions than 18F-FDG (25 vs 23) and with higher SUVmax (7.99 ± 9.04 vs 3.62 ± 2.68, p = 0.002) by lesion-based analysis. The type of neck dissection in 9 cases (9/33) was altered by 68Ga-FAPI-04. Overall, clinical management was significantly changed in 10 patients (10/61). Three patients had a follow-up 68Ga-FAPI-04 PET/CT post neoadjuvant therapy: One showed complete remission, and the others showed progression. The 68Ga-FAPI-04 uptake intensity was confirmed to be consistent with FAP expression.

CONCLUSION

68Ga-FAPI-04 outperforms 18F-FDG PET/CT in evaluating preoperative N staging in patients with HNSCC. Furthermore, 68Ga-FAPI-04 PET/CT also shows the potential in clinical management and monitoring response to treatment.

Deoxygenation of ClSO2CF2COOMe with Triphenylphosphine for the Metal-Free Direct Electrophilic Difluoroalkylthiolation of Various Heterocycles

A direct electrophilic difluoroalkylthiolation reaction of indole derivatives and other electron-rich heterocycles using methyl 2,2-difluoro-2-(chlorsulfonyl)acetate (ClSO₂CF₂COOMe) derived from Chen's reagent (FSO₂CF₂COOMe) is described. The ester group in the product can be further utilized in subsequent versatile transformations. The reactions provide good yields of the corresponding difluoroalkylthiolation products and exhibit high functional group compatibility. It is expected to serve as an alternative and practical protocol for difluoroalkylthiolation of various heterocycles.

Evaluation of [18F]Favipiravir in Rodents and Nonhuman Primates (NHP) with Positron Emission Tomography

The COVID-19 pandemic has posed a significant challenge to global public health. In response, the search for specific antiviral drugs that can effectively treat the disease caused by the SARS-CoV-2 virus has become a priority. While significant progress has been made in this regard, much work remains to address this ongoing crisis effectively. Favipiravir is an antiviral drug initially developed for the treatment of influenza and has received approval for emergency use for COVID-19 in many countries. A better understanding of the biodistribution and pharmacokinetics of Favipiravir in vivo would facilitate the development and translation of clinical antiviral drugs for COVID-19. Herein, we report the evaluation of [18F]Favipiravir in naive mice, transgenic mice models of Alzheimer’s disease, and nonhuman primates (NHP) with positron emission tomography (PET). The [18F]Favipiravir was obtained in an overall decay-corrected radiochemical yield of 29% with a molar activity of 25 GBq/µmol at the end of synthesis (EOS). PET imaging in naive mice, transgenic mice models of Alzheimer’s disease, and nonhuman primates revealed a low initial brain uptake, followed by a slow washout of [18F]Favipiravir in vivo. The [18F]Favipiravir was eliminated by a combination of hepatobiliary and urinary excretion. The low brain uptake was probably attributed to the low lipophilicity and low passive permeability of the drug. We hope this proof-of-concept study will provide a unique feature to study antiviral drugs using their corresponding isotopologues by PET.

CAXII inhibitors: Potential sensitizers for immune checkpoint inhibitors in HCC treatment

Hepatocellular carcinoma (HCC) is a lethal malignancy with a lack of effective treatments particularly for the disease at an advanced stage. Even though immune checkpoint inhibitors (ICIs) have made great progress in the treatment of HCC, durable and ideal clinical benefits still cannot be achieved in plenty of patients with HCC. Therefore, novel and refined ICI-based combination therapies are still needed to enhance the therapeutic effect. The latest study has reported that the carbonic anhydrase XII inhibitor (CAXIIi), a novel type of anticancer drug, can modify the tumor immunosuppression microenvironment by affecting hypoxic/acidic metabolism and alter the functions of monocytes and macrophages by regulating the expression of C-C motif chemokine ligand 8 (CCL8). These observations shine a light on improving programmed cell death protein 1 (PD-1)/programmed cell death ligand-1 (PD-L1) immunotherapy in combination with CAXIIis. This mini-review aims to ignite enthusiasm to explore the potential application of CAXIIis in combination with immunotherapy for HCC.

Aryl Radical Enabled, Copper-Catalyzed Sonogashira-Type Cross-Coupling of Alkynes with Alkyl Iodides

Despite the success of Sonogashira coupling for the synthesis of arylalkynes and conjugated enynes, the engagement of unactivated alkyl halides in such reactions remains historically challenging. We report herein a strategy that merges Cu-catalyzed alkyne transfer with the aryl radical activation of carbon-halide bonds to enable a general approach for the coupling of alkyl iodides with terminal alkynes. This unprecedented Sonogashira-type cross-coupling reaction tolerates a broad range of functional groups and has been applied to the late-stage cross-coupling of densely functionalized pharmaceutical agents as well as the synthesis of positron emission tomography tracers.

Yifei Sanjie Formula or Placebo With Anlotinib as Second-Line or Above Treatment for Metastatic Non-Small-Cell Lung Cancer: Study Protocol for a Double-Blind, Placebo-Controlled Randomized Pilot Study

BACKGROUND

Anlotinib is used as a third-line treatment for advanced non-small-cell lung cancer (NSCLC), but has limited clinical benefits and several side effects, such as diarrhea and acneiform skin rash. Traditional Chinese Medicine (TCM) is commonly used to treat cancers in China. Chinese herbal medicines may have the potential as adjuvant therapies to reduce toxicity and improve the efficacy of treatments for NSCLC. Given the positive outcomes of basic research, we plan to evaluate whether the addition of the Chinese herbal medicine Yifei Sanjie formula (YFSJF) to anlotinib can improve the progression-free survival (PFS) of advanced NSCLC patients.

METHODS

A multicenter, randomized, double-blind, placebo-controlled parallel-group controlled pilot trial will be performed. Forty eligible patients will be randomized in a ratio of 1:1 to the intervention (YFSJF + anlotinib) and control (placebo + anlotinib) groups. Participants will be advised to take 12 mg/day of anlotinib on days 1 to 14 of each 21-day cycle. YFSJF or placebo will be administered (15 g twice daily) during each cycle until progression of disease (PD). The primary outcome will be progression-free survival (PFS), and the secondary outcomes will be overall survival (OS), the objective response rate (ORR), and patient-reported outcomes (PRO). Tumors will be assessed based on RECIST v. 1.1 after every 2 cycles of treatment. The M. D. Anderson Symptom Inventory-Lung Cancer (MDASI-LC) will be used to evaluate PRO at baseline and weekly thereafter until PD.

DISCUSSION

This will be the first trial to evaluate the effectiveness and safety of TCM combined with anlotinib for the treatment of NSCLC. The results of this randomized controlled trial will fill a gap in the research by showing whether YFSJF combined with anlotinib can improve PFS in NSCLC patients.

TRIAL REGISTRATION

The study was registered on June 8th, 2021 on Chinese Clinical Registry; registration number ChiCTR2100047143. (https://www.chictr.org.cn/index.aspx).

ETHICS AND DISSEMINATION

The Ethics Committee of the First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine approved the study protocol (approval no.: K2020151, 2021/08/19). The study will also be supervised and managed by the Ethics Committee.

Synthesis and Biological Evaluation of Enantiomerically Pure (R)- and (S)-[18F]OF-NB1 for Imaging the GluN2B Subunit-Containing NMDA receptors

GluN2B subunit-containing N-methyl-d-aspartate (NMDA) receptors have been implicated in various neurological disorders. Nonetheless, a validated fluorine-18 labeled positron emission tomography (PET) ligand for GluN2B imaging in the living human brain is currently lacking. As part of our PET ligand development program, we have recently reported on the preclinical evaluation of [18F]OF-NB1 - a GluN2B PET ligand with promising attributes for potential clinical translation. However, the further development of [18F]OF-NB1 is currently precluded by major limitations in the radiolabeling procedure. These limitations include the use of highly corrosive reactants and racemization during the radiosynthesis. As such, the aim of this study was to develop a synthetic approach that allows an enantiomerically pure radiosynthesis of (R)-[18F]OF-NB1 and (S)-[18F]OF-NB1, as well as to assess their in vitro and in vivo performance characteristics for imaging the GluN2B subunit-containing NMDA receptor in rodents. A two-step radiosynthesis involving radiofluorination of the boronic acid pinacol ester, followed by coupling to the 3-benzazepine core structure via reductive amination was employed. The new synthetic approach yielded enantiomerically pure (R)-[18F]OF-NB1 and (S)-[18F]OF-NB1, while concurrently circumventing the use of corrosive reactants. In vitro autoradiograms with mouse and rat brain sections revealed a higher selectivity of (R)-[18F]OF-NB1 over (S)-[18F]OFNB1 for GluN2B-rich brain regions. In concert with these observations, blockade studies with commercially available GluN2B antagonist, CP101606, showed a significant signal reduction, which was more pronounced for (R)-[18F]OF-NB1 than for (S)-[18F]OF-NB1. Conversely, blockade experiments with sigma2 ligand, FA10, did not result in a significant reduction of tracer binding for both enantiomers. PET imaging experiments with CD1 mice revealed a higher brain uptake and retention for (R)-[18F]OF-NB1, as assessed by visual inspection and volumes of distribution from Logan graphical analyses. In vivo blocking experiments with sigma2 ligand, FA10, did not result in a significant reduction of the brain signal for both enantiomers, thus corroborating the selectivity over sigma2 receptors. In conclusion, we have developed a novel synthetic approach that is suitable for upscale to human use and allows the enantiomerically pure radiosynthesis of (R)-[18F]OF-NB1 and (S)-[18F]OF-NB1. While both enantiomers were selective over sigma2 receptors in vitro and in vivo, (R)-[18F]OF-NB1 showed superior GluN2B subunit specificity by in vitro autoradiography and higher volumes of distribution in small animal PET studies.

Erratum: HMEJ-mediated site-specific integration of a myostatin inhibitor increases skeletal muscle mass in porcine

[This corrects the article DOI: 10.1016/j.omtn.2021.06.011.].

Nanomedicine for renal cell carcinoma: imaging, treatment and beyond

The kidney is a vital organ responsible for maintaining homeostasis in the human body. However, renal cell carcinoma (RCC) is a common malignancy of the urinary system and represents a serious threat to human health. Although the overall survival of RCC has improved substantially with the development of cancer diagnosis and management, there are various reasons for treatment failure. Firstly, without any readily available biomarkers, timely diagnosis has been greatly hampered. Secondly, the imaging appearance also varies greatly, and its early detection often remains difficult. Thirdly, chemotherapy has been validated as unavailable for treating renal cancer in the clinic due to its intrinsic drug resistance. Concomitant with the progress of nanotechnological methods in pharmaceuticals, the management of kidney cancer has undergone a transformation in the recent decade. Nanotechnology has shown many advantages over widely used traditional methods, leading to broad biomedical applications ranging from drug delivery, prevention, diagnosis to treatment. This review focuses on nanotechnologies in RCC management and further discusses their biomedical translation with the aim of identifying the most promising nanomedicines for clinical needs. As our understanding of nanotechnologies continues to grow, more opportunities to improve the management of renal cancer are expected to emerge.

The Joint Effect of Body Mass Index and Serum Lipid Levels on Incident Dementia among Community-Dwelling Older Adults

OBJECTIVES

This study aimed to explore the joint effect of body mass index (BMI) and serum lipids levels on incident dementia.

METHODS

We prospectively followed up with 1,627 dementia-free community residents aged ≥60 for 5.7 years on average. At baseline, weight, and height were measured, and total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were detected in serum. Demographic characteristics were collected through questionnaires. Dementia was based on consensus diagnosis of neurologists and neuropsychologists using DSM-IV criteria. Additive Cox proportional model was used to assess the exposure-response relationship between BMI and serum lipid levels and dementia risk. Interactions and further classifications of BMI and serum lipid levels were further presented by bivariate surface models and decision-tree models.

RESULTS

The joint effects of TC with BMI, TG with BMI, and LDL-C with BMI on the risk of incident dementia shared a similar pattern, different from their independent exposure-response curves. The joint effect of HDL-C with BMI showed an S-surface but without statistical significance. Participants with TC<5.4 mmol/L and BMI<21 kg/m2 (Hazard Ratio(HR) 1.93, 95% Confidence Interval (CI) 1.05-3.53), TC<5.4 mmol/L and BMI≥21 kg/m2 (HR 1.73, 95% CI 1.09-2.72), and TC≥5.4 mmol/L and BMI<21 kg/m2 (HR 4.02, 95% CI 2.10-7.71) were identified to have the increased risk of incident dementia compared to those with TC≥5.4 mmol/L and BMI≥21 kg/m2. Participants with TG<1.7 mmol/L and BMI<21 kg/m2 had an increased risk of incident dementia compared to those with TG≥1.7 mmol/L and BMI≥21 kg/m2 (HR 1.98, 95%CI 1.17-3.3). Participants with LDL-C≥3.3 mmol/L and BMI<21 kg/m2 were identified to have an increased risk of incident dementia compared to those with LDL-C≥3.3 mmol/L and BMI≥21 kg/m2 (HR 3.33, 95%CI 1.64-6.78).

CONCLUSIONS

Our study showed that low BMI combined with low or high levels of serum lipids may increase the risk of dementia among older adults. This finding suggests the potential impacts of these two metabolic indexes on the risk of dementia.

DNA damage repair gene mutations predict the efficacy of platinum-based chemotherapy and immunotherapy plus platinum-based chemotherapy in advanced non-small cell lung cancer: a retrospective Chinese cohort study

Background

Platinum-based chemotherapy (PC) and immunotherapy plus platinum-based chemotherapy (IPC) remain the first-line treatment for advanced NSCLC. But only a minority patients benefit from PC, and existing biomarkers, such as PD-L1, have been shown to be defective in predicting the efficacy of IPC. Highlighting the need to identify novel biomarkers for the efficacy of PC and IPC. DNA damage repair (DDR) mutations are known to predict response to PC in solid tumors. However, the predictive value of DDR in PC and IPC of NSCLC remains unclear.

Methods

Patients diagnosed with advanced or metastatic NSCLC were retrospectively included if they underwent next generation sequencing prior to starting treatment. Primary endpoints were to explore whether DDR mutations (DDRmut) are associated with clinical outcomes of PC and IPC. Secondary end point were to explore the association between DDRmut and the choice to add immunotherapy to chemotherapy, and the impact of different DDR pathways on efficacy in PC and IPC.

Results

DDRmut showed a strong association with tumor mutation burden-high (TMB-H) versus DDR wild-type (DDRwt) and higher rates of PD-L1 TPS ≥50% positivity. In 63 patients treated with PC, ORRs were 15.38% and 2.86% for DDRmut and DDRwt subgroup (P=0.1536), and DCRs were 88.46% and 45.72% (P=0.00097) at 6 months after PC. The DDRmut patients had significantly improved median PFS (mPFS) and median overall survival (mOS) than DDRwt group (mPFS: 7.6 vs. 3.9 months, HR =1.93, 95% CI: 1.09 to 3.14, P=0.0220. mOS: 29.9 vs. 20.7 months, HR =2.31, 95% CI: 1.09 to 4.9, P=0.0250). Moreover, among 37 patients treated with IPC, ORRs were 45% and 11.76% for DDRmut and DDRwt patients (P=0.0365), and the DCRs were 95% and 70.58% (P=0.0752), respectively at 6 months after IPC. The DDRmut patients had significantly improved mPFS compared to the DDRwt group (19.5 vs. 4.5 months, HR =3.28, 95% CI: 1.53 to 9.56, P=0.0022). In DDRmut group, mPFS of IPC recipients was significantly better than that of PC recipients (19.5 vs. 7.6 months, HR =2.09, 95% CI: 0.98 to 4.42, P=0.050).

Conclusions

There is potential for DDR to serve as a positive predictor of PC and IPC in advanced NSCLC patients.

Stable iPSC-derived NKX2-1+ lung bud tip progenitor organoids give rise to airway and alveolar cell types

Bud tip progenitors (BTPs) in the developing lung give rise to all epithelial cell types found in the airways and alveoli. This work aimed to develop an iPSC organoid model enriched with NKX2-1+ BTP-like cells. Building on previous studies, we optimized a directed differentiation paradigm to generate spheroids with more robust NKX2-1 expression. Spheroids were expanded into organoids that possessed NKX2-1+/CPM+ BTP-like cells, which increased in number over time. Single cell RNA-sequencing analysis revealed a high degree of transcriptional similarity between induced BTPs (iBTPs) and in vivo BTPs. Using FACS, iBTPs were purified and expanded as induced bud tip progenitor organoids (iBTOs), which maintained an enriched population of bud tip progenitors. When iBTOs were directed to differentiate into airway or alveolar cell types using well-established methods, they gave rise to organoids composed of organized airway or alveolar epithelium, respectively. Collectively, iBTOs are transcriptionally and functionally similar to in vivo BTPs, providing an important model for studying human lung development and differentiation.

Assessment of cholesterol homeostasis in the living human brain

Alterations in brain cholesterol homeostasis have been broadly implicated in neurological disorders. Notwithstanding the complexity by which cholesterol biology is governed in the mammalian brain, excess neuronal cholesterol is primarily eliminated by metabolic clearance via cytochrome P450 46A1 (CYP46A1). No methods are currently available for visualizing cholesterol metabolism in the living human brain; therefore, a noninvasive technology that quantitatively measures the extent of brain cholesterol metabolism via CYP46A1 could broadly affect disease diagnosis and treatment options using targeted therapies. Here, we describe the development and testing of a CYP46A1-targeted positron emission tomography (PET) tracer, 18F-CHL-2205 (18F-Cholestify). Our data show that PET imaging readouts correlate with CYP46A1 protein expression and with the extent to which cholesterol is metabolized in the brain, as assessed by cross-species postmortem analyses of specimens from rodents, nonhuman primates, and humans. Proof of concept of in vivo efficacy is provided in the well-established 3xTg-AD murine model of Alzheimer's disease (AD), where we show that the probe is sensitive to differences in brain cholesterol metabolism between 3xTg-AD mice and control animals. Furthermore, our clinical observations point toward a considerably higher baseline brain cholesterol clearance via CYP46A1 in women, as compared to age-matched men. These findings illustrate the vast potential of assessing brain cholesterol metabolism using PET and establish PET as a sensitive tool for noninvasive assessment of brain cholesterol homeostasis in the clinic.

Correction: Wang et al. TERT Promoter Revertant Mutation Inhibits Melanoma Growth through Intrinsic Apoptosis. Biology 2022, 11, 141

The authors would like to make the following correction to the published paper [...].

Imaging of Transmembrane AMPA Receptor Regulatory Proteins by Positron Emission Tomography

The transmembrane α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (AMPA) receptor regulatory protein γ-8 (TARP γ-8) constitutes an auxiliary subunit of AMPA receptors, which mediates various brain functions including learning and memory. TARP γ-8 has emerged as a promising therapeutic target for central nervous system disorders. Despite considerable efforts, previously reported TARP γ-8 PET radioligands, such as [11C]TARP-1903 and [11C]TARP-1811 series, were plagued by limited brain uptake and/or high nonspecific binding in vivo. Herein, we developed two novel 11C-labeled probes, [11C]8 and [11C]15 (also named as [11C]TARP-2105), of which the latter exhibited a reasonable brain uptake as well as specific binding toward TARP γ-8 both in vitro and in vivo, as confirmed by blocking experiments with the commercially available TARP γ-8 inhibitor, JNJ-55511118 in the TARP γ-8-rich hippocampus. Overall, [11C]15 exhibited promising tracer characteristics and proved to be a lead positron-emission tomography ligand for the non-invasive quantification of TARP γ-8 in the mammalian brain.

Comparisons of Forecasting for Survival Outcome for Head and Neck Squamous Cell Carcinoma by using Machine Learning Models based on Multi-omics

Background: Machine learning methods showed excellent predictive ability in a wide range of fields. For the survival of head and neck squamous cell carcinoma (HNSC), its multi-omics influence is crucial. This study attempts to establish a variety of machine learning multi-omics models to predict the survival of HNSC and find the most suitable machine learning prediction method. Methods: The HNSC clinical data and multi-omics data were downloaded from the TCGA database. The important variables were screened by the LASSO algorithm. We used a total of 12 supervised machine learning models to predict the outcome of HNSC survival and compared the results. In vitro qPCR was performed to verify core genes predicted by the random forest algorithm. Results: For omics of HNSC, the results of the twelve models showed that the performance of multi-omics was better than each single-omic alone. Results were presented, which showed that the Bayesian network(BN) model (area under the curve [AUC] 0.8250, F1 score=0.7917) and random forest(RF) model (area under the curve [AUC] 0.8002,F1 score=0.7839) played good prediction performance in HNSC multi-omics data. The results of in vitro qPCR were consistent with the RF algorithm. Conclusion: Machine learning methods could better forecast the survival outcome of HNSC. Meanwhile, this study found that the BN model and the RF model were the most superior. Moreover, the forecast result of multi-omics was better than single-omic alone in HNSC.

AB0392 EFFICACY AND SAFETY OF UPADACITINIB IN A CHINESE SUBGROUP OF PATIENTS WITH RHEUMATOID ARTHRITIS AND INADEQUATE RESPONSE TO CONVENTIONAL SYNTHETIC DISEASE-MODIFYING ANTI-RHEUMATIC DRUGS

Background

Upadacitinib (UPA) was effective in global Phase 3 trials in rheumatoid arthritis (RA) patients (pts) with inadequate response (IR) to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs).

Objectives

To assess the efficacy and safety of UPA in csDMARD-IR pts with RA in Chinese subgroup from a Phase 3, randomized, double-blind, placebo (PBO)-controlled study (NCT02955212) 1.

Methods

Pts were randomized to 12 weeks of blinded treatment with UPA 15 mg once daily (QD) or PBO, in combination with csDMARDs. Primary and secondary endpoints were analyzed in a Chinese subgroup, including American College of Rheumatology criteria (ACR) responses, remission and low disease activity measures. Safety was analyzed for pts who received ≥1 dose of study drug.

Results

228 Chinese pts (67.5% of overall trial population) were randomized and took at least one dose of study drug. Baseline characteristics were generally balanced between UPA and PBO. 46% and 35.1% used methotrexate (MTX) alone as concomitant csDMARD in UPA and PBO group, respectively. 38.9% in UPA and 43.0% in PBO group used concomitant csDMARDs other than MTX and 15.0% and 21.9% respectively used a combination. At week 12, more Chinese pts receiving UPA achieved the primary endpoint of ACR20 compared with PBO (71.9% vs 31.6%, nominal p<0.001). UPA also showed greater improvements in all secondary endpoints vs PBO at Week 12 (Table 1), including ACR50 and ACR70, mean change in Disease Activity Score in 28 joints using C-reactive protein (DAS28-CRP), Health Assessment Questionnaire-Disability Index (HAQ-DI), Short-Form 36-item Health Survey-Physical Component Summary (SF-36 PCS), as well as proportion of pts achieving low disease activity based on DAS28-CRP ≤3.2 and Clinical Disease Activity Index (CDAI) ≤10, and clinical remission based on DAS28-CRP <2.6. Onset of response was rapid with more pts receiving UPA achieving ACR20 by Week 1 versus PBO (25.4% vs 5.3%, nominal p<0.001). Through Week 12 treatment-emergent adverse events (TEAEs) occurred in 57.9% of pts on UPA and 49.1% on PBO. The rate of pts with serious AEs (SAEs) was numerically higher with UPA than with PBO (6.1% vs 4.4%). TEAEs reported in ≥ 3% of subjects and with a higher rate on UPA vs. PBO were: upper respiratory tract infection, alanine aminotransferase increased, aspartate aminotransferase increased, hypertension, diarrhea, and leukopenia. Overall safety was consistent with the trial population1 and similar with the reported safety profile of the global clinical program2.

Table 1.

Summary of Efficacy Endpoint Results at Week 12 in Chinese Subgroup

Endpoint aUPA 15mg (N=114)PBO (N=114)Primary endpointACR20, %71.9***31.6Secondary endpointsΔ DAS28-CRP-2.42***-0.75Δ HAQ-DI-0.55***-0.11Δ SF-36 PCS7.63 b***2.94 cDAS28-CRP ≤3.2, %46.5***9.6DAS28-CRP <2.6, %28.1***1.8CDAI ≤10, %33.3***7.0ACR50, %39.5***7.0ACR70, %16.7***2.6ACR20 at Week 1, %25.4***5.3

***Nominal p<0.001 vs PBO

aNon-responder imputation for binary endpoints; ANCOVA with multiple imputation for DAS28(CRP) and HAQ-DI; mixed model repeated measures for other continuous endpoints. Δ: mean change from baseline

bN=106

cN=104

Conclusion

UPA demonstrated clinical and functional improvement in Chinese csDMARD-IR RA pts. The safety of UPA was comparable with the overall study population and with the safety seen in the global Phase 3 program.

References

[1]Zeng X, Zhao D, Radominski SC, et al. Int J Rheum Dis. 2021;24:1530–1539.

[2]Cohen SB, van Vollenhoven RF, Winthrop KL, et al. Ann Rheum Dis 2021;80:304–311.

Acknowledgements

AbbVie funded this study; contributed to its design; participated in data collection, analysis, and interpretation of the data; and in the writing, review, and approval of the abstract. No honoraria or payments were made for authorship.

Disclosure of Interests

Xiaofeng Zeng: None declared, Yi Liu: None declared, Jiankang Hu: None declared, Jingyang Li: None declared, Yongfu Wang: None declared, Dongbao Zhao: None declared, Lijun Wu: None declared, Zhengyu Xiao: None declared, ZHIJUN LI: None declared, Jian Xu: None declared, Sebastian Meerwein Shareholder of: may own AbbVie stock or options, Employee of: AbbVie employee, Yunxia Xie Shareholder of: may own AbbVie stock or options, Employee of: AbbVie employee, Peiwen Liang Employee of: AbbVie

Discovery of a highly specific 18F-labeled PET ligand for phosphodiesterase 10A enabled by novel spirocyclic iodonium ylide radiofluorination

As a member of cyclic nucleotide phosphodiesterase (PDE) enzyme family, PDE10A is in charge of the degradation of cyclic adenosine (cAMP) and guanosine monophosphates (cGMP). While PDE10A is primarily expressed in the medium spiny neurons of the striatum, it has been implicated in a variety of neurological disorders. Indeed, inhibition of PDE10A has proven to be of potential use for the treatment of central nervous system (CNS) pathologies caused by dysfunction of the basal ganglia–of which the striatum constitutes the largest component. A PDE10A-targeted positron emission tomography (PET) radioligand would enable a better assessment of the pathophysiologic role of PDE10A, as well as confirm the relationship between target occupancy and administrated dose of a given drug candidate, thus accelerating the development of effective PDE10A inhibitors. In this study, we designed and synthesized a novel ¹⁸F-aryl PDE10A PET radioligand, codenamed [¹⁸F]P10A-1910 ([¹⁸F]9), in high radiochemical yield and molar activity via spirocyclic iodonium ylide-mediated radiofluorination. [¹⁸F]9 possessed good in vitro binding affinity (IC₅₀ = 2.1 nmol/L) and selectivity towards PDE10A. Further, [¹⁸F]9 exhibited reasonable lipophilicity (logD = 3.50) and brain permeability (P_app > 10 × 10⁻⁶ cm/s in MDCK-MDR1 cells). PET imaging studies of [¹⁸F]9 revealed high striatal uptake and excellent in vivo specificity with reversible tracer kinetics. Preclinical studies in rodents revealed an improved plasma and brain stability of [¹⁸F]9 when compared to the current reference standard for PDE10A-targeted PET, [¹⁸F]MNI659. Further, dose–response experiments with a series of escalating doses of PDE10A inhibitor 1 in rhesus monkey brains confirmed the utility of [¹⁸F]9 for evaluating target occupancy in vivo in higher species. In conclusion, our results indicated that [¹⁸F]9 is a promising PDE10A PET radioligand for clinical translation.

A Real-World Comparative Effectiveness Analysis of Thromboprophylactic Use of Enoxaparin Versus Unfractionated Heparin in Abdominal Surgery Patients in a Large U.S. Hospital Database

Introduction: Little is known about outcomes associated with enoxaparin versus unfractionated heparin (UFH) for venous thromboembolism (VTE) prophylaxis in abdominal surgery patients in U.S. clinical practice. The purpose of this study was to compare VTE, all-cause mortality, PE-related in-hospital mortality, and hospital costs during abdominal surgery hospitalization and the 90 days post-discharge between patients who received enoxaparin versus UFH prophylaxis. Materials and Methods: Using the Premier Healthcare Database, abdominal surgery patients who received at least 1 day of VTE prophylaxis with enoxaparin or UFH were identified between January 1, 2010 and September 30, 2016. Clinical outcomes were assessed using multivariable logistic regression models and cost outcomes were assessed using generalized linear models. Results: Of 363,669 patients identified, 59% received enoxaparin and 41% UFH. In adjusted analyses, there were statistically significant lower odds of VTE (OR 0.80; 95% CI 0.65-0.97), all-cause mortality (OR 0.67; 95% CI 0.60-0.75), and major bleeding (OR 0.88; 95% CI 0.82-0.94) during the hospitalization for enoxaparin versus UFH, but no differences during the 90-days post-discharge or for PE-related mortality. There was a statistically significant lower total hospital cost with enoxaparin versus UFH during index hospitalization ($8,913 vs $9,017, P < .0001), but not post-discharge ($3,342 vs $3,368, P = .42). Unadjusted rates of heparin-induced thrombocytopenia (index:0.1% vs 0.3%; post-discharge: 0.02% vs 0.06%) were reported for enoxaparin and UFH, respectively. Conclusion: In contemporary U.S. hospital practice, statistically significant lower odds of VTE, all-cause mortality and major bleeding with enoxaparin versus UFH prophylaxis were found during abdominal surgery hospitalizations.

TERT Promoter Revertant Mutation Inhibits Melanoma Growth through Intrinsic Apoptosis

Simple Summary

TERT -146 C>T frequently occurs in many cancer cells. Research targeting the telomerase reverse transcriptase (TERT) promoter contributes to a better understanding of cancer development and treatment. Many conventional cancer treatments aim to develop new drugs targeting TERT. Here, for TERT -146 we converted T to C. The proliferation, migration and invasion of melanoma cells in vitro, and the growth of the tumor in vivo were inhibited. Moreover, the downregulated protein expression of B-cell lymphoma 2 (Bcl-2) indicated that the TERT promoter revertant mutation abrogated the inhibitory effect of mutant TERT on apoptosis. These data elucidated the relationship between the TERT promoter revertant mutations and apoptosis for the first time, and also implied that TERT -146 may be a causal mutation of melanoma. This study provides a new insight into the TERT promoter revertant mutations and apoptosis. The TERT promoter provides preliminary validation of the potential tumor treatment.

Abstract

Human telomerase is a specialized DNA polymerase whose catalytic core includes both TERT and human telomerase RNA (hTR). Telomerase in humans, which is silent in most somatic cells, is activated to maintain the telomere length (TEL) in various types of cancer cells, including melanoma. In the vast majority of tumor cells, the TERT promoter is mutated to promote proliferation and inhibit apoptosis. Here, we exploited NG-ABEmax to revert TERT -146 T to -146 C in melanoma, and successfully obtained TERT promoter revertant mutant cells. These TERT revertant mutant cells exhibited significant growth inhibition both in vitro and in vivo. Moreover, A375^−146C/C cells exhibited telomere shortening and the downregulation of TERT at both the transcription and protein levels, and migration and invasion were inhibited. In addition, TERT promoter revertant mutation abrogated the inhibitory effect of mutant TERT on apoptosis via B-cell lymphoma 2 (Bcl-2), ultimately leading to cell death. Collectively, the results of our work demonstrate that reverting mutations in the TERT promoter is a potential therapeutic option for melanoma.

White Matter Alterations in Spastic Paraplegia Type 5: A Multiparametric Structural MRI Study and Correlations with Biochemical Measurements

BACKGROUND AND PURPOSE

In spastic paraplegia type 5, spinal cord atrophy and white matter signal abnormalities in the brain are the main MR imaging alterations. However, the specific mechanism remains unclear. We explored the microstructural changes occurring in spastic paraplegia type 5 and assessed the relation between MR imaging and clinical data.

MATERIALS AND METHODS

Seventeen patients with spastic paraplegia type 5 and 17 healthy controls were scanned with DTI and T1 mapping on a 3T MR imaging scanner. Fractional anisotropy, mean diffusivity, radial diffusivity, axial diffusivity, and T1 values were obtained using Tract-Based Spatial Statistics and the Spinal Cord Toolbox. Neurofilament light and myelin basic protein in the CSF were measured. The differences in MR imaging and biochemical data between patients with spastic paraplegia type 5 and healthy controls were compared using the Student t test.

RESULTS

A widespread reduction of fractional anisotropy values and an elevation of mean diffusivity, T1, and radial diffusivity values were found in most cervical, T4, and T5 spinal cords; corona radiata; optic radiations; and internal capsules in spastic paraplegia type 5. A variation in axial diffusivity values was shown only in C2, C6, and the corona radiata but not in the gray matter. The levels of neurofilament light and myelin basic protein were higher in those with spastic paraplegia type 5 than in healthy controls (myelin basic protein, 3507 [SD, 2291] versus 127 [SD, 219]  pg/mL; neurofilament light, 617 [SD, 207] versus 265 [SD, 187]  pg/mL; P < .001). No correlation was found between the clinical data and MR imaging-derived measures.

CONCLUSIONS

Multiparametric MR imaging and biochemical indicators demonstrated that demyelination (mainly) and axonal loss led to the white matter integrity loss without gray matter injury in spastic paraplegia type 5.

The Repertoire of Small-Molecule PET Probes for Neuroinflammation Imaging: Challenges and Opportunities beyond TSPO

Neuroinflammation is an adaptive response of the central nervous system to diverse potentially injurious stimuli, which is closely associated with neurodegeneration and typically characterized by activation of microglia and astrocytes. As a noninvasive and translational molecular imaging tool, positron emission tomography (PET) could provide a better understanding of neuroinflammation and its role in neurodegenerative diseases. Ligands to translator protein (TSPO), a putative marker of neuroinflammation, have been the most commonly studied in this context, but they suffer from serious limitations. Herein we present a repertoire of different structural chemotypes and novel PET ligand design for classical and emerging neuroinflammatory targets beyond TSPO. We believe that this Perspective will support multidisciplinary collaborations in academic and industrial institutions working on neuroinflammation and facilitate the progress of neuroinflammation PET probe development for clinical use.

Spastic paraplegia as the only manifestation in neuropsychiatric lupus: a case report

Demyelination syndrome is one manifestation of neuropsychiatric lupus erythematosus (NPLE) and is rare in systemic lupus erythematosus (SLE). When SLE presents only neuropsychiatric symptoms without damage to other systems, its diagnosis becomes difficult. Herein, we report a 29-year-old male who suffered from lower limb stiffness with recessive onset and progressive aggravation in one year. He had paraplegia, spastic hypertonia, abnormal gait, and bilateral positive Babinski signs. His symptoms indicated spastic paraplegia. Brain MRI showed multiple small demyelinating lesions in the lateral ventricle, brainstem, and cerebellum. Anti-ds DNA, anti-Sm and anti-RNP antibodies were positive. He was diagnosed with NPLE and had a good treatment response to steroids. To the best of our knowledge, this is the first case of spastic paraplegia as the only manifestation in SLE.

Development of a triazolobenzodiazepine-based PET probe for subtype-selective vasopressin 1A receptor imaging

OBJECTIVES

To enable non-invasive real-time quantification of vasopressin 1A (V1A) receptors in peripheral organs, we sought to develop a suitable PET probe that would allow specific and selective V1A receptor imaging in vitro and in vivo.

METHODS

We synthesized a high-affinity and -selectivity ligand, designated compound 17. The target structure was labeled with carbon-11 and tested for its utility as a V1A-targeted PET tracer by cell uptake studies, autoradiography, in vivo PET imaging and ex vivo biodistribution experiments.

RESULTS

Compound 17 (PF-184563) and the respective precursor for radiolabeling were synthesized in an overall yield of 49% (over 7 steps) and 40% (over 8 steps), respectively. An inhibitory constant of 0.9 nM towards the V1A receptors was measured, while excellent selectivity over the related V1B, V2 and OT receptor (IC50 >10,000 nM) were obtained. Cell uptake studies revealed considerable V1A binding, which was significantly reduced in the presence of V1A antagonists. Conversely, there was no significant blockade in the presence of V1B and V2 antagonists. In vitro autoradiography and PET imaging studies in rodents indicated specific tracer binding mainly in the liver. Further, the pancreas, spleen and the heart exhibited specific binding of [11C]17 ([11C]PF-184563) by ex vivo biodistribution experiments.

CONCLUSION

We have developed the first V1A-targeted PET ligand that is suitable for subtype-selective receptor imaging in peripheral organs including the liver, heart, pancreas and spleen. Our findings suggest that [11C]PF-184563 can be a valuable tool to study the role of V1A receptors in liver diseases, as well as in cardiovascular pathologies.

Imaging Autotaxin In Vivo with 18F-Labeled Positron Emission Tomography Ligands

Autotaxin (ATX) is a secreted phosphodiesterase that has been implicated in a remarkably wide array of pathologies, especially in fibrosis and cancer. While ATX inhibitors have entered the clinical arena, a validated probe for positron emission tomography (PET) is currently lacking. With the aim to develop a suitable ATX-targeted PET radioligand, we have synthesized a focused library of fluorinated imidazo[1,2-a]pyridine derivatives, determined their inhibition constants, and confirmed their binding mode by crystallographic analysis. Based on their promising in vitro properties, compounds 9c, 9f, 9h, and 9j were radiofluorinated. Also, a deuterated analog of [¹⁸F]9j, designated as [¹⁸F]ATX-1905 ([¹⁸F]20), was designed and proved to be highly stable against in vivo radiodefluorination compared with [¹⁸F]9c, [¹⁸F]9f, [¹⁸F]9h, and [¹⁸F]9j. These results along with in vitro and in vivo studies toward ATX in a mouse model of LPS-induced liver injury suggest that [¹⁸F]ATX-1905 is a suitable PET probe for the non-invasive quantification of ATX.

Novel Reversible-Binding PET Ligands for Imaging Monoacylglycerol Lipase Based on the Piperazinyl Azetidine Scaffold

Monoacylglycerol lipase (MAGL) is a 33 kDa serine protease primarily responsible for hydrolyzing 2-arachidonoylglycerol into the proinflammatory eicosanoid precursor arachidonic acid in the central nervous system. Inhibition of MAGL constitutes an attractive therapeutic concept for treating psychiatric disorders and neurodegenerative diseases. Herein, we present the design and synthesis of multiple reversible MAGL inhibitor candidates based on a piperazinyl azetidine scaffold. Compounds 10 and 15 were identified as the best-performing reversible MAGL inhibitors by pharmacological evaluations, thus channeling their radiolabeling with fluorine-18 in high radiochemical yields and favorable molar activity. Furthermore, evaluation of [¹⁸F]10 and [¹⁸F]15 ([¹⁸F]MAGL-2102) by autoradiography and positron emission tomography (PET) imaging in rodents and nonhuman primates demonstrated favorable brain uptakes, heterogeneous radioactivity distribution, good specific binding, and adequate brain kinetics, and [¹⁸F]15 demonstrated a better performance. In conclusion, [¹⁸F]15 was found to be a suitable PET radioligand for the visualization of MAGL, harboring potential for the successful translation into humans.