Design of rigid protein-protein interaction inhibitors enables targeting of undruggable Mcl-1.

The structure-based design of small-molecule inhibitors targeting protein-protein interactions (PPIs) remains a huge challenge as the drug must bind typically wide and shallow protein sites. A PPI target of high interest for hematological cancer therapy is myeloid cell leukemia 1 (Mcl-1), a prosurvival guardian protein from the Bcl-2 family. Despite being previously considered undruggable, seven small-molecule Mcl-1 inhibitors have recently entered clinical trials. Here, we report the crystal structure of the clinical-stage inhibitor AMG-176 bound to Mcl-1 and analyze its interaction along with clinical inhibitors AZD5991 and S64315. Our X-ray data reveal high plasticity of Mcl-1 and a remarkable ligand-induced pocket deepening. Nuclear Magnetic Resonance (NMR)-based free ligand conformer analysis demonstrates that such unprecedented induced fit is uniquely achieved by designing highly rigid inhibitors, preorganized in their bioactive conformation. By elucidating key chemistry design principles, this work provides a roadmap for targeting the largely untapped PPI class more successfully.

AMG232 inhibits angiogenesis in glioma through the p53-RBM4-VEGFR2 pathway.

AMG232 effectively inhibits cancers with wild-type p53 (also known as TP53) by reactivating p53, but whether it inhibits glioma angiogenesis remains unclear. This study confirms that AMG232 inhibits the proliferation of glioma endothelial cells (GECs) in a dose-dependent manner and inhibits the angiogenesis of GECs. p53 and RNA-binding motif protein 4 (RBM4) were expressed at low levels in GECs, while MDM2 and vascular endothelial growth factor receptor 2 (VEGFR2, also known as KDR) were highly expressed. In vitro and in vivo experiments confirmed that AMG232 upregulated p53 and RBM4, and downregulated MDM2 and VEGFR2 by blocking the MDM2-p53 interaction. Both p53 silencing and RBM4 silencing significantly upregulated the expression of VEGFR2, promoted the proliferation, migration and tube formation of GECs, and reversed the effects of AMG232 on downregulating VEGFR2 and inhibiting the angiogenesis of GECs. AMG232 increased RBM4 expression by upregulating p53, and p53 bound to RBM4 and promoted its transcription. RBM4 bound to and shortened the half-life of VEGFR2, promoting its degradation. Finally, AMG232 produced a significant decrease in new vessels and hemoglobin content in vivo. This study proves that AMG232 inhibits glioma angiogenesis by blocking the MDM2-p53 interaction, in which the p53-RBM4-VEGFR2 pathway plays an important role.

Bioinformatics and Experimental Validation for Identifying Biomarkers Associated with AMG510 (Sotorasib) Resistance in KRASG12C-Mutated Lung Adenocarcinoma.

The Kirsten rat sarcoma viral oncogene homolog (KRAS)G12C mutation is prevalent in lung adenocarcinoma (LUAD), driving tumor progression and indicating a poor prognosis. While the FDA-approved AMG510 (Sotorasib) initially demonstrated efficacy in treating KRASG12C-mutated LUAD, resistance emerged within months. Data from AMG510 treatment-resistant LUAD (GSE204753) and single-cell datasets (GSE149655) were analyzed. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were used to explore enriched signaling pathways, nomogram models were constructed, and transcription factors predicting resistance biomarkers were predicted. CIBERSORT identified immune cell subpopulations, and their association with resistance biomarkers was assessed through single-cell analysis. AMG510-resistant LUAD cells (H358-AR) were constructed, and proliferative changes were evaluated using a CCK-8 assay. Key molecules for AMG510 resistance, including SLC2A1, TLE1, FAM83A, HMGA2, FBXO44, and MTRNR2L12, were recognized. These molecules impacted multiple signaling pathways and the tumor microenvironment and were co-regulated by various transcription factors. Single-cell analysis revealed a dampening effect on immune cell function, with associations with programmed cell death ligand 1 (PDL1) expression, cytokine factors, and failure factors. The findings indicate that these newly identified biomarkers are linked to the abnormal expression of PDL1 and have the potential to induce resistance through immunosuppression. These results highlight the need for further research and therapeutic intervention to address this issue effectively.

Therapeutics Targeting Mutant KRAS.

Aberrations in rat sarcoma (RAS) viral oncogene are the most prevalent and best-known genetic alterations identified in human cancers. Indeed, RAS drives tumorigenesis as one of the downstream effectors of EGFR activation, regulating cellular switches and functions and triggering intracellular signaling cascades such as the MAPK and PI3K pathways. Of the three RAS isoforms expressed in human cells, all of which were linked to tumorigenesis more than three decades ago, KRAS is the most frequently mutated. In particular, point mutations in KRAS codon 12 are present in up to 80% of KRAS-mutant malignancies. Unfortunately, there are no approved KRAS-targeted agents, despite decades of research and development. Recently, a revolutionary strategy to use covalent allosteric inhibitors that target a shallow pocket on the KRAS surface has provided new impetus for renewed drug development efforts, specifically against KRASG12C. These inhibitors, such as AMG 510 and MRTX849, show promise in early-phase studies. Nevertheless, combination strategies that target resistance mechanisms have become vital in the war against KRAS-mutant tumors.

Results of TRIO-15, a multicenter, open-label, phase II study of the efficacy and safety of ganitumab in patients with recurrent platinum-sensitive ovarian cancer.

BACKGROUND: IGF signaling has been implicated in the pathogenesis and progression of ovarian carcinoma (OC). Single agent activity and safety of ganitumab (AMG 479), a fully human monoclonal antibody against IGF1R that blocks binding of IGF1 and IGF2, were evaluated in patients with platinum-sensitive recurrent OC. METHODS: Patients with CA125 progression (GCIG criteria) or measurable disease per RECIST following primary platinum-based therapy received 18 mg/kg of ganitumab q3w. The primary endpoint was objective response rate (ORR) assessed per RECIST 1.1 by an independent radiology review committee (IRC) and/or GCIG CA125 criteria. Secondary endpoints included clinical benefit rate (CBR), progression free survival (PFS) and overall survival (OS). RESULTS: 61 pts. were accrued. Objective responses were seen in 5/61 patients (ORR 8.2%, 95% CI, 3.1-18.8) with 1 partial response (PR) by RECIST and 2 complete responses (CR) as well as 2 PR by CA125 criteria. CBR was 80.3% (95% CI, 67.8-89.0%). The median PFS according to RECIST by IRC was 2.1 months (95% CI, 2.0-3.1). The median PFS per RECIST IRC and/or CA125 was 2.0 months (95% CI, 1.8-2.2). The median OS was 21 months (95% CI, 19.5-NA). The most common overall adverse events were fatigue (36.1%) and hypertension (34.4%). Grade 1/2 hyperglycemia occurred in 30.4% of patients. Hypertension (11.5%) and hypersensitivity (8.2%) were the most frequent grade 3 adverse events. CONCLUSIONS: IGF1R inhibition with ganitumab was well-tolerated, however, our results do not support further study of ganitumab as a single agent in unselected OC patients.

A First-in-Human Study of AMG 986, a Novel Apelin Receptor Agonist, in Healthy Subjects and Heart Failure Patients.

PURPOSE: AMG 986 is a novel apelin receptor (APJ) agonist that improves cardiac contractility in animal models without adversely impacting hemodynamics. This phase 1b study evaluated the safety/tolerability, pharmacokinetics, and pharmacodynamics of AMG 986 in healthy subjects and patients with heart failure (HF). METHODS: Healthy adults (Parts A/B) and HF patients (Part C) aged 18-85 years were randomized 3:1 to single-dose oral/IV AMG 986 or placebo (Part A); multiple-dose oral/IV AMG 986 or placebo (Part B); or escalating-dose oral AMG 986 or placebo (Part C). PRIMARY ENDPOINT: treatment-emergent adverse events, laboratory values/vital signs/ECGs; others included AMG 986 pharmacokinetics, left ventricular (LV) function. RESULTS: Overall, 182 subjects were randomized (AMG 986/healthy: n = 116, placebo, n = 38; AMG 986/HF: n = 20, placebo, n = 8). AMG 986 had acceptable safety profile; no clinically significant dose-related impact on safety parameters up to 650 mg/day was observed. AMG 986 exposures increased nonlinearly with increasing doses; minimal accumulation was observed. In HF with reduced ejection fraction patients, there were numerical increases in percent changes from baseline in LV ejection fraction and stroke volume by volumetric assessment with AMG 986 vs placebo (stroke volume increase not recapitulated by Doppler). CONCLUSIONS: In healthy subjects and HF patients, short-term AMG 986 treatment was well tolerated. Consistent with this observation, clinically meaningful pharmacodynamic effects in HF patients were not observed. Changes in ejection fraction and stroke volume in HF patients suggest additional studies may be needed to better define the clinical utility and optimal dosing for this molecule. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT03276728. DATE OF REGISTRATION: September 8, 2017.

Targeting PI3Kα overcomes resistance to KRasG12C inhibitors mediated by activation of EGFR and/or IGF1R.

Although several KRasG12C inhibitors have displayed promising efficacy in clinical settings, acquired resistance developed rapidly and circumvented the activity of KRasG12C inhibitors. To explore the mechanism rendering acquired resistance to KRasG12C inhibitors, we established a series of KRASG12C-mutant cells with acquired resistance to AMG510. We found that differential activation of receptor tyrosine kinases (RTKs) especially EGFR or IGF1R rendered resistance to AMG510 in different cellular contexts by maintaining the activation of MAPK and PI3K signaling. Simultaneous inhibition of EGFR and IGF1R restored sensitivity to AMG510 in resistant cells. PI3K integrates signals from multiple RTKs and the level of phosphorylated AKT was revealed to negatively correlate with the anti-proliferative activity of AMG510 in KRASG12C-mutant cells. Concurrently treatment of a novel PI3Kα inhibitor CYH33 with AMG510 exhibited a synergistic effect against parental and resistant KRASG12C-mutant cells in vitro and in vivo, which was accompanied with concomitant inhibition of AKT and MAPK signaling. Taken together, these findings revealed the potential mechanism rendering acquired resistance to KRasG12C inhibitors and provided a mechanistic rationale to combine PI3Kα inhibitors with KRasG12C inhibitors for therapy of KRASG12C-mutant cancers in future clinical trials.

The effects of environmental taxes, renewable energy consumption and environmental technology on the ecological footprint: Evidence from advanced panel data analysis.

The world faces various challenges in terms of environmental sustainability. An increasing world population, the rigidity of traditional production and consumption patterns, the complexity of economic activities, globalization, and harmful emissions intensify environmental pressures. In this context, the evaluation of various environmental policy instruments is important to alleviate environmental pressures and, thus, combat climate change. This study aims to investigate the impact of environmental taxes, renewable energy consumption, and environmental technology on the ecological footprint in OECD countries by using data from 1994 to 2018 and modern panel data techniques. The results of the AMG estimator indicate that environmental taxation and renewable energy consumption play a role in reducing the ecological footprint; however, results imply that environmental technology does not have a statistically significant effect on the ecological footprint. In addition, we applied DCCE and CS-ARDL estimators to obtain robustness results and observed that the findings remained valid. Therefore, the results of the study suggest that regulations to increase the effectiveness of environmental taxes, renewable energy consumption, and environmental technology should be promoted to ensure environmental sustainability.

[The new approval procedure for clinical trials of medicinal products in the European Union-challenges for the pharmaceutical industry in Germany]. / Das neue Genehmigungsverfahren für klinische Arzneimittelprüfungen in der Europäischen Union ­ Herausforderungen für die pharmazeutische Industrie in Deutschland.

In the European Union (EU), 27 May 2014 was a significant date for clinical trials. Since that day, the EU Clinical Trials Regulation 536/2014 (EU-CTR) officially came into force. The new EU-CTR replaces EU Directive 2001/20/EC and fundamentally reforms the way clinical trials are applied for and conducted in Europe. For clinical trial sponsors, the responsible regulatory authorities, ethics committees, and all EU member states, the new EU-CTR brings profound changes. However, it has taken a long time for the new regulation to be applied, as the establishment of the new Clinical Trials Information System (CTIS) of the European Medicines Agency (EMA) has taken some time. Contrary to expectations, the establishment of this system could not be completed in 2016, but only with a notification from the EMA on 31 July 2021.Overall, Germany is well prepared for the new regulation. The German Medicinal Products Act (AMG) was adjusted at an early stage. Authorities and ethics committees have tested the cooperation in a pilot phase from 2015 to 2021 and have shown that the cooperation in Germany works well in the evaluation of applications.However, initial experience from the application process shows that there are some fundamental problems with CTIS and that there is also a need for further adaptation at the national level in Germany. This includes, for example, the integration of the Federal Office for Radiation Protection (BfS) approval or the harmonization of ethics committee requirements. It is important that Germany addresses these points at the national level to remain competitive.

SMILE lenticule versus amniotic membrane graft (AMG) augmented with platelet-rich plasma (PRP) for the treatment of perforated corneal ulcer.

PURPOSE: To evaluate the safety and efficacy of stromal lenticule obtained from small-incision lenticule extraction (SMILE) surgery versus amniotic membrane graft (AMG) augmented with platelet-rich plasma (PRP) for the treatment of perforated corneal ulcers and compare the results between the two groups. PATIENTS AND METHODS: This is a comparative retrospective study that included 40 eyes with medium-sized corneal perforations, which were classified into two equal groups of 20 eyes each; group (A) was treated with SMILE lenticule graft and group (B) was treated with AMG augmented with PRP. Pre- and postoperative evaluations were carried out using both slit-lamp (SL) examination and anterior segment optical coherence tomography (AS-OCT), including closure of perforation, complete healing, and best corrected visual acuity (BCVA). RESULTS: Complete closure of the perforation was achieved in both groups. However, healing was faster in the SMILE lenticule group than in the AMG with PRP group (P < 0.05). Complete healing was achieved in both groups: 100% in SMILE lenticule group and 95% in AMG with PRP group (P > 0.05). Both groups had few insignificant complications (30% in each), which were managed. CONCLUSION: Both methods achieved adequate healing of corneal perforations within few weeks without significant complications. However, the stromal lenticule obtained from small-incision lenticule extraction (SMILE) surgery tended to be safer with faster healing than AMG with PRP.

CXCR3 antagonist AMG487 ameliorates experimental autoimmune prostatitis by diminishing Th1 cell differentiation and inhibiting macrophage M1 phenotypic activation.

BACKGROUND: Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS) is an inflammatory immune disease that is characterized by infiltrating inflammatory cells in the prostate and pelvic or by perineal pain. Receptor CXCR3modulates immune and inflammatory responses; however, the effects of CXCR3 antagonist AMG487 in the context of CP/CPPS are unknown. Therefore, we investigated the effect of AMG487 in experimental autoimmune prostatitis (EAP) mice and explored the potential functional mechanisms. METHODS: The EAP model was induced by intradermally injecting a mixture of prostate antigens and complete Freund's adjuvant on Days 0 and 28. To evaluate the effect of AMG487 on EAP mice, treatment with AMG487 and vehicle solution was conducted for the indicated period. Then, procedures were performed, including behavioral test, to evaluate the pain response to stimulation before the mice were killed and a histological assessment to evaluate the inflammation after the mice were killed. Immunofluorescence, flow cytometry, and Western blot assay were used to analyze the functional phenotype and regulation mechanism of AMG487 on T helper type 1 (Th1) cells and macrophages. RESULTS: We found high expression of CXCR3 in human benign prostate tissues with inflammation and EAP mice. The elevated CXCR3 in prostate tissues correlates with the severity of inflammation. CXCR3 antagonist AMG487 treatment ameliorated the inflammatory changes and the pelvic pain of EAP mice. AMG487 inhibits Th1 cell differentiation through the IL-12/STAT4pathway and inhibits pro-inflammatory M1 macrophages through the lipopolysaccharide/NF-κB p65signaling. AMG487 could inhibit the secretion of inflammatory mediators in EAP mice. CONCLUSION: CXCR3 antagonist AMG487 could ameliorate the inflammatory changes and the pelvic pain of EAP mice by diminishing Th1 cell differentiation and inhibiting macrophage M1 phenotypic activation. Thus, the results imply that AMG487 has the potential as an effective therapeutic agent in the prevention and treatment of EAP.

Characterization of false positive, contaminant-driven mutagenicity in impurities associated with the sotorasib drug substance.

Sotorasib (Lumakras™) is a first-in-class, non-genotoxic, small molecule inhibitor of KRAS G12C developed as an anticancer therapeutic for treatment of patients that have a high unmet medical need. Anticancer therapeutics are considered out of scope of ICH M7 guidance for control of mutagenic impurities; however, based on ICH S9 Q&A, mutagenicity assessments are needed for impurities that exceed the qualification threshold, consistent with ICH Q3A/B, and non-mutagenic drugs. Here, we carried out hybrid-based mutagenicity assessment of sotorasib drug substance (DS) impurities using in silico quantitative structure-activity relationship (QSAR) modelling and Ames tests (for in silico positive mutagens). We encountered contradictive mutagenicity results for 2 impurities (Beta-Chloride and PAC). PAC was negative initially by QSAR but positive in a GLP full plate Ames test and Beta-Chloride was positive by QSAR, negative in a non-GLP micro-Ames but positive in a GLP full plate Ames assay. Root cause analyses identified and characterized mutagenic contaminants, 3-chloropropionic acid in batches of Beta-Chloride and 3-chloropropionic acid and Chloro-PAC in batches of PAC, used in initial GLP full-plate Ames tests. Significant reduction of these contaminants in re-purified batches resulted in no induction of mutagenicity in follow-up GLP micro-Ames tests. In summary, root-cause analyses led to accurate mutagenicity assessment for sotorasib DS-associated impurities.

Local delivery of a CXCR3 antagonist decreases the progression of bone resorption induced by LPS injection in a murine model.

OBJECTIVES: This experimental study was carried out to investigate the effects of locally delivered nanoparticles (AMG-487 NP) containing a CXCR3 antagonist in inhibiting the progression of LPS-induced inflammation, osteoclastic activity, and bone resorption on a murine model. MATERIALS AND METHODS: Thirty, 7-week-old C57BL/6 J male mice were used. Inflammatory bone loss was induced by Porphyromonas gingivalis-lipopolysaccharide (P.g.-LPS) injections between the first and second maxillary molars, bilaterally, twice a week for 6 weeks (n = 20). AMG-487 NP were incorporated into a liposome carrier and locally delivered on sites where P.g.-LPS was injected. Control mice (n = 10) were injected with vehicle only. Experimental groups included (1) control, (2) LPS, and (3) LPS + NP. At the end of 1 and 6 weeks, mice were euthanized, maxillae harvested, fixed, and stored for further analysis. RESULTS: Volumetric bone loss analysis revealed, at 1 week, an increase in bone loss in the LPS group (47.9%) compared to control (27.4%) and LPS + NP (27.8%) groups. H&E staining demonstrated reduced inflammatory infiltrate in the LPS + NP group compared to LPS group. At 6 weeks, volumetric bone loss increased in all groups; however, treatment with the CXCR3 antagonist (LPS + NP) significantly reduced bone loss compared to the LPS group. CXCR3 antagonist treatment significantly reduced osteoclast numbers when compared to LPS group at 1 and 6 weeks. CONCLUSIONS: This study showed that local delivery of a CXCR antagonist, via nanoparticles, in a bone resorption model, induced by LPS injection, was effective in reducing inflammation, osteoclast numbers, and bone loss. CLINICAL RELEVANCE: CXCR3 blockade can be regarded as a novel target for therapeutic intervention of bone loss. It can be a safe and convenient method for periodontitis treatment or prevention applicable in clinical practice.

The nexus amid foreign direct investment, urbanization, and CO2 emissions: Evidence from energy grouping along the ECOWAS community.

The vision of every country or subregions is to achieve economic growth and sustainable economic growth. Thus, the Economic Community of West African States (ECOWAS) as an economic cooperation renders interaction among 16 relevant countries to increase economic development. However, CO2 emissions as a result of economic growth are of great concern. Thus, this study delves into the determinants of CO2 emissions along the ECOWAS community, taking into consideration if countries are energy exporters or energy importers. The analytical procedure applied indicated the presence of heterogeneity in the slope coefficient and cross-sectional dependencies across the various panels. Applying the Westerlund bootstrap co-integration unveiled, the employed variables have a long-run equilibrium association. The results from the augmented mean group (AMG) revealed that the contribution weight (order of importance) to CO2 emissions varies across panel clusters. Finally, the causality results unveil a bidirectional causation in all panels between urbanization and CO2 emissions, whereas foreign direct investment and CO2 emissions have a bidirectional effect in energy importers and the main panel. These results obtained indicate that foreign direct investment, urbanization, energy consumption, trade openness, and gross domestic product are the determinants of CO2 emissions along the community. Based on the outcome, the suggested policy implications indicate that (a) the need for a paradigm shift from fossil fuel sources to renewables be encouraged in the community and (b) again, the awareness of spillover of economic growth and energy transition on CO2 emissions from foreign companies to local businesses must be promoted.

Functional dissection of the KRAS G12C mutation by comparison among multiple oncogenic driver mutations in a lung cancer cell line model.

The development of molecular targeted therapy has improved clinical outcomes in patients with life-threatening advanced lung cancers with driver oncogenes. However, selective treatment for KRAS-mutant lung cancer remains underdeveloped. We have successfully characterised specific molecular and pathological features of KRAS-mutant lung cancer utilising newly developed cell line models that can elucidate the differences in driver oncogenes among tissues with identical genetic backgrounds. Among these KRAS-mutation-associated specific features, we focused on the IGF2-IGF1R pathway, which has been implicated in the drug resistance mechanisms to AMG 510, a recently developed selective inhibitor of KRAS G12C lung cancer. Experimental data derived from our cell line model can be used as a tool for clinical treatment strategy development through understanding of the biology of lung cancer. The model developed in this paper may help understand the mechanism of anticancer drug resistance in KRAS-mutated lung cancer and help develop new targeted therapies to treat patients with this disease.

Fluorine-18 Labeling of the MDM2 Inhibitor RG7388 for PET Imaging: Chemistry and Preliminary Evaluation.

RG7388 (Idasanutlin) is a potent inhibitor of oncoprotein murine double minute 2 (MDM2). Herein we investigated the feasibility of developing 18F-labeled RG7388 as a radiotracer for imaging MDM2 expression in tumors with positron emission tomography (PET). Two fluorinated analogues of RG7388, 6 and 7, were synthesized by attaching a fluoronicotinyl moiety to RG7388 via a polyethylene glycol (PEG3) or a propyl linker. The inhibitory potency (IC50) of 6 and 7 against MDM2 was determined by a fluorescence polarization (FP)-based assay. Next, compound 6 was labeled with 18F using a trimethylammonium triflate precursor to obtain [18F]FN-PEG3-RG7388 ([18F]6), and its properties were evaluated in MDM2 expressing wild-type p53 tumor cell lines (SJSA-1 and HepG2) in vitro and in tumor xenografts in vivo. The FP assays revealed an IC50 against MDM2 of 119 nM and 160 nM for 6 and 7, respectively. 18F-labeling of 6 was achieved in 50.3 ± 7.5% radiochemical yield. [18F]6 exhibited a high uptake (∼70% of input dose) and specificity in SJSA-1 and HepG2 cell lines. Saturation binding assays revealed a binding affinity (Kd) of 128 nM for [18F]6 on SJSA-1 cells. In mice, [18F]6 showed fast clearance from blood with a maximum tumor uptake of 3.80 ± 0.85% injected dose per gram (ID/g) in HepG2 xenografts at 30 min postinjection (p.i.) and 1.32 ± 0.32% ID/g in SJSA-1 xenografts at 1 h p.i. Specificity of [18F]6 uptake in tumors was demonstrated by pretreatment of mice with SJSA-xenografts with a blocking dose of RG7388 (35 mg/kg body weight, i.p.). In vivo stability studies in mice using HPLC showed ∼60% and ∼30% intact [18F]6 remaining in plasma at 30 min and 1 h p.i., respectively, with the remaining activity attributed to polar peaks. Our results suggest that RG7388 is a promising molecular scaffold for 18F-labeled probe development for MDM2. Additional labeling strategies and functionalizing locations on RG7388 are under development to improve binding affinity and in vivo stability of the 18F-labeled compound to make it more amenable for PET imaging of MDM2 in vivo.

A phase 2, randomized, double-blind, placebo-controlled trial of AMG 301, a pituitary adenylate cyclase-activating polypeptide PAC1 receptor monoclonal antibody for migraine prevention.

OBJECTIVE: To assess the safety and efficacy of AMG 301, an inhibitor of the pituitary adenylate cyclase-activating polypeptide (PACAP)-1 (PAC1) receptor, for prevention of migraine. METHODS: In a double-blind trial, patients were randomized 4:3:3 to placebo, AMG 301 210 mg every 4 weeks, or AMG 301 420 mg every 2 weeks for 12 weeks. Effect on monthly migraine days and other secondary measures were assessed over weeks 9-12. Safety and tolerability were assessed. RESULTS: Of 343 randomized patients (mean age, 41.8-42.5 years), the majority were women (85.4-90.4%), white (94.1-96.2%), and had episodic migraine (62.5-67.9%). A total of 305 patients completed treatment (placebo, n = 124; AMG 301 210 mg, n = 94; AMG 301 420 mg, n = 87). Least squares mean reduction at week 12 in monthly migraine days from baseline was -2.5 (0.4) days for placebo and -2.2 (0.5) days for both AMG 301 treatment groups. No difference between AMG 301 and placebo on any measure of efficacy was observed; mean (95% confidence interval) treatment difference versus placebo for monthly migraine days for AMG 301 210 mg, 0.3 (-0.9 to 1.4); AMG 301 420 mg, 0.3 (-0.9 to 1.4). The incidence of adverse events was similar across groups. CONCLUSION: AMG 301 offered no benefit over placebo for migraine prevention; further studies may be necessary to fully understand the role of PACAP isoforms and its receptors in migraine pathophysiology. STUDY REGISTRATION: ClinicalTrials.gov: NCT03238781.

Effect of etelcalcetide on parathyroid hormone secretion by primary hyperparathyroidism patient-derived primary parathyroid cells.

INTRODUCTION: Etelcalcetide (Parsabiv®, AMG 416/ONO-5163) is a novel allosteric modulator for the calcium-sensing receptor approved for hemodialysis patients with secondary hyperparathyroidism of uremia. Etelcalcetide reduced parathyroid hormone levels in hemodialysis patients with secondary hyperparathyroidism of uremia in clinical studies. However, its direct effect on parathyroid hormone secretion in human parathyroid cells remains unknown. This study aimed to determine if etelcalcetide suppresses parathyroid hormone secretion by human parathyroid cells in vitro. MATERIALS AND METHODS: We prepared primary cell cultures from human parathyroid tissue and determined calcium-sensing receptor expression levels by immunohistochemistry. Pathyroid tumors were removed from fourteen patients with primary hyperparathyrodism. Parathyroid tissue was dispersed with collagenase, resuspended in culture medium, incubated for 2 h with etelcalcetide and Ca2+, and the medium was then collected. Final etelcalcetide concentrations in the medium were 0.005-50 µmol/L. Levels of human parathyroid hormone in the medium were determined by enzyme-linked immunosorbent assay. RESULTS: In eight of the fourteen parathyroid cell cultures, extracellular Ca2+ reduced parathyroid hormone levels. In four of the eight parathyroid cell cultures which responded extracellular Ca2+, etelcalcetide reduced hormone secretion with the 50% effective concentrations of 0.57, 20.8, 0.42, and 0.57 µmol/L. Expression levels of the calcium-sensing receptor were significantly lower in primary hyperparathyroidism patient-derived parathyroid tissues compared with controls. CONCLUSION: This is the first report that etelcalcetide directly reduced parathyroid hormone secretion from the primary cultured human parathyroid cells from patients with primary hyperparathyroidism. To verify this conclusion, further studies are needed using secondary hyperparathyroidism patient-derived parathyroid cells.

Peripheral viral challenge increases c-fos level in cerebral neurons.

Peripheral viral infection can substantially alter brain function. We have previously shown that intraperitoneal (i.p.) injection of a viral mimetic, polyinosinic-polycytidylic acid (PIC), engenders hyperexcitability of cerebral neurons. Because neuronal activity is invariably associated with their expression of the Cfos gene, the present study was undertaken to determine whether PIC challenge also increases neuronal c-fos protein level. Female C57BL/6 mice were i.p. injected with PIC, and neuronal c-fos was analyzed in the motor cortex by immunohistochemistry. PIC challenge instigated a robust increase in the number of c-fos-positive neurons. This increase reached approximately tenfold over control at 24 h. Also, the c-fos staining intensity of individual neurons increased. AMG-487, a specific inhibitor of the chemokine receptor CXCR3, profoundly attenuated the accumulation of neuronal c-fos, indicating the activation of CXCL10/CXCR3 axis as the trigger of the process. Together, these results show that the accumulation of c-fos is a viable readout to assess the response of cerebral neurons to peripheral PIC challenge, and to elucidate the underlying molecular mechanisms.

Validated HPLC-MS/MS method for quantitation of AMG 510, a KRAS G12C inhibitor, in mouse plasma and its application to a pharmacokinetic study in mice.

AMG 510 is the first-in-class KRASG12C inhibitor, currently in phase 2 clinical trials as an orphan drug to treat non-small cell lung cancer patients. We developed and validated a sensitive, selective, and high-throughput HPLC-MS/MS method for the quantitation of AMG 510 in mouse plasma per the regulatory guideline of the US Food and Drug and Administration. AMG 510 and the IS (MRTX-1257) were extracted from mouse plasma using tert-butyl methyl ether and chromatographed using an isocratic mobile phase (0.2% formic acid:acetonitrile; 25:75, v/v) at a flow rate of 0.65 mL/min on an Atlantis dC18 column. AMG 510 and the IS eluted at ~0.95 and 0.73 min, respectively. AMG 510 and the IS were detected by positive electrospray ionization in multiple reaction monitoring using transition pair (Q1 → Q3) m/z 561.1 → 134.1 and m/z 566.5 → 98.2, respectively. Excellent linearity was achieved in the concentration range of 1.08-5040 ng/mL (r > 0.0996). No matrix effect and carryover were observed. Intra- and inter-day accuracies and precisions were within the acceptance range. AMG 510 was demonstrated to be stable under the tested storage conditions. This novel method has been applied to a pharmacokinetic study in mice.