Assessment of the right ventricular-pulmonary circulation unit during stress in ankylosing spondylitis and psoriatic arthritis patients

Background

Cardiopulmonary complications are common in ankylosing spondylitis (AS) and arthritis psoriatica (APs), which have an unfavourable impact on mortality and quality of life. APs may be connected with pulmonary hypertension, while AS is linked to interstitial lung disease and chest wall restriction.

We aimed to assess the response of the pulmonary circulation unit during stress in AS and APs patients.

Methods

A total of 71 patients were enrolled in the study: 28 of them had AS (age 50.8±11.8 years), 17 APs (age 52.1±13.5 years), and 26 were healthy individuals (age 54.23±9.9 years). To the maximally tolerated workload, all subjects underwent resting and exercise stress echocardiography on a supine bicycle ergometer. Echocardiographic measurements were taken at rest, at 50 watts workload, and at maximal exercise.

Results

AS patients had significantly higher pulmonary artery systolic pressure (PASP; AS: 32.6±16.8 mmHg, APs: 21.6±12.7 mmHg, p<0.05) and pulmonary vascular resistance (PVR; AS: 1.3±0.4 WU, PsA: 1.1±0.3 WU, p<0.05) at maximal workload, while the right ventricular-pulmonary arterial (RV-PA) coupling at peak stress was higher in APs patients (AS: 1.2±0.6 mm/mmHg, PsA: 1.8±1.1 mm/mmHg, p<0.05). Comparing to the control group, AS and PsA patients had significantly higher resting PASP (control: 12.6±6.4 mmHg; AS: 22.8±7.6 mmHg, p<0.001; PsA: 21.4±7.0 mmHg, p<0.001), lower resting RV-PA coupling (control: 2.7±1.4 mm/mmHg; AS: 1.3±0.4, p<0.001; PsA 1.3±0.4 mm/mmHg, p<0.001), and higher peak PVR (control: 0.6±0.4 WU; AS: 1.3±0.4, p<0.001; PsA: 1.1±0.3 WU, p<0.005). One-way analysis of variance of the three groups also showed significant differencies in the resting PASP (p<0.001), peak PASP (p<0.05), resting RV-PA coupling (p<0.001), peak PVR (p<0.001).

Conclusion

Stress echocardiography is a promising, radiation-free method for assessing the subclinical cardiopulmonary changes among AS and PsA patients. The changes of PVR during stress may highlight the pulmonary complications in the subclinical stage.

Funding Acknowledgement

Type of funding sources: None.

The Discovery of BMS-737 as a Potent, CYP17 Lyase-Selective Inhibitor for the Treatment of Castration-Resistant Prostate Cancer

We report herein, the discovery of BMS-737 (compound 33) as a potent, non-steroidal, reversible small molecule inhibitor demonstrating 11-fold selectivity for CYP17 lyase over CYP17 hydroxylase, as well as a clean xenobiotic CYP profile for the treatment of castration-resistant prostate cancer (CRPC). Extensive SAR studies on the initial lead 1 at three different regions of the molecule resulted in the identification of BMS-737, which demonstrated a robust 83% lowering of testosterone without any significant perturbation of the mineralocorticoid and glucocorticoid levels in cynomologous monkeys in a 1-day PK/PD study.

Trends in Opioid Utilisation in Hungary, 2006-2020: A Nationwide Retrospective Study with Multiple Metrics

BACKGROUND

Opioid use is well-documented in several countries: some countries struggle with overuse while others have almost no access to opioids. For Europe, limited data are available. This study analysed Hungarian opioid utilisation in ambulatory care between 2006 and 2020.

METHODS

We obtained national drug utilization data on reimbursed opioid analgesics (ATC code: N02A) from a national health insurance database for a 15-year period. We investigated utilisation trends, using three volume-based metrics (defined daily dose per 1000 inhabitants per day (DID), oral morphine equivalent per 1000 inhabitants per day, packages dispensed per 1000 inhabitants per year). We stratified data based on administration routes, analgesic potency and reimbursement categories.

RESULTS

Total opioid utilisation increased during the study period according to all three metrics (74% in DID) and reached 5.31 DID by 2020. Upward trends were driven by an increase both in weak and strong opioid use (79% vs. 53%). The most commonly used opioids were fentanyl (in the strong category; 0.76 DID in 2020) and tramadol (in the weak category; 2.62 DID in 2020). Overall, tramadol was also the most commonly used opioid throughout the study period. Oral administration of opioid medications was dominant. Based on reimbursement categories, musculoskeletal pain was becoming a more frequent indication for opioid use (1552% increase in DID), while opioid use for cancer pain declined significantly during the study period (-33% in DID).

CONCLUSIONS

Our low utilisation numbers might indicate underuse of opioid analgesia, especially for cancer pain.

Quantification of Linrodostat and its metabolites: Overcoming bioanalytical challenges in support of a discovery Indoleamine 2,3 dioxygenase program

BMS-986205 (Linrodostat) is a small molecule inhibitor of Indoleamine 2, 3 dioxygenase (IDO) that is currently being evaluated in clinical trials for the oral treatment of advanced cancer. Initially, there were concerns regarding possible toxicity following administration, since BMS-986205 undergoes metabolism to form 4-chloroaniline. However, it was later determined that the downstream metabolites of 4-chloroaniline might be a greater concern. To evaluate the potential toxicity of these metabolites, a sensitive LC-MS/MS analytical method was needed to quantify both the parent compound and multiple metabolites. This presented a challenge since the method required the analysis of multiple analytes while still retaining the analytical sensitivity required to support studies. By utilizing a multi-function analytical method, we were able to quantify the necessary analytes using a complex LC-MS/MS-based method including the application of both negative and positive electrospray ionization.

Assessment of pulmonary circulation unit during exercise in patients with ankylosing spondilitis and sporiatic arthritis

Funding Acknowledgements

Type of funding sources: None.

Background  Ankylosing spondylitis (AS) and psoriatic arthritis (PsA) are chronic multisystem inflammatory disorders that present with articular and extra-articular features. Cardiac dysfunction and pulmonary disease are well-known and commonly reported extra-articular manifestations of AS and PsA.  The inflammatory process can induce respiratory complications, including chest wall restriction, significantly impacting patients" cardiorespiratory status.

We aimed to assess pulmonary circulation and right ventricle behaviour during exercise in patients with AS and PsA and to detect the possible effect of chest wall restriction on right heart function.

Methods  A total of 45 spondylarthritis patients were enrolled in the study (age 51.5 ± 12.3 years, 82.2% men): 27 of them were diagnosed with AS (20 of them had ankylosis at the time of the study), while 18 had PsA (2 of them in ankylosis). According to a standardized protocol, all subjects underwent resting and exercise stress echocardiography on a semi-recumbent cycle ergometer with an incremental workload up to the maximal tolerated workload. Basic echocardiographic measurements were taken, focusing on the right and left ventricular functions and the systolic pulmonary artery pressure (PASP) at rest, at 50 watts workload, and maximal exercise. During the examination, non-invasive blood pressure measurements, transcutaneous capillary oxygen saturation and continuous ECG recording were performed. 

Results PASP did not differ between the AS and PsA patients at rest (15.6 ± 6.7 mmHg vs 13.7 ± 8.3 mmHg; p = ns); however, PASP measured at the maximal workload was significantly higher among AS patients  (31.4 ± 15.9mmHg vs 21.6 ± 12.7mmHg; p < 0.05; Figure 1). PASP did not correlate with the age or the time that passed since the diagnosis. Parameters describing the left and right ventricular systolic and diastolic function did not differ significantly between AS and PsA patients at rest and peak stress. Comparing the LV diastolic parameters of ankylosing patients with non-ankylosing patients irrespective of the underlying disease showed significantly different values in peak E/e"ratio (8.9 ± 3 vs 7.4 ± 1.6; p < 0,05; Figure 2).

Conclusion  Exercise stress echocardiography is a promising diagnostic modality in autoimmune diseases. In AS patients, the chest wall restriction may results in elevation of PASP during the exercise. The noninvasive indice of left ventricular filling pressure increases significantly in patients with ankylosis in both groups, explaining the effect of the rigid chest wall on the left ventricular filling. Abstract Figure.  Abstract Figure.

Conformational-Analysis-Guided Discovery of 2,3-Disubstituted Pyridine IDO1 Inhibitors

IDO1 inhibitors have shown promise as immunotherapies for the treatment of a variety of cancers, including metastatic melanoma and renal cell carcinoma. We recently reported the identification of several novel heme-displacing IDO1 inhibitors, including the clinical molecules linrodostat (BMS-986205) and BMS-986242. Both molecules contain quinolines that, while being present in successful medicines, are known to be potentially susceptible to oxidative metabolism. Efforts to swap this quinoline with an alternative aromatic system led to the discovery of 2,3-disubstituted pyridines as suitable replacements. Further optimization, which included lowering ClogP in combination with strategic fluorine incorporation, led to the discovery of compound 29, a potent, selective IDO1 inhibitor with robust pharmacodynamic activity in a mouse xenograft model.

Discovery of Imidazopyridines as Potent Inhibitors of Indoleamine 2,3-Dioxygenase 1 for Cancer Immunotherapy

Indoleamine 2,3-dioxygenase 1 (IDO1) has been identified as a target for small-molecule immunotherapy for the treatment of a variety of cancers including renal cell carcinoma and metastatic melanoma. This work focuses on the identification of IDO1 inhibitors containing replacements or isosteres for the amide found in BMS-986205, an amide-containing, IDO1-selective inhibitor currently in phase III clinical trials. Detailed subsequently are efforts to identify a structurally differentiated IDO1 inhibitor via the pursuit of a variety of heterocyclic isosteres, leading to the discovery of highly potent, imidazopyridine-containing IDO1 inhibitors.

Discovery and Preclinical Evaluation of BMS-986242, a Potent, Selective Inhibitor of Indoleamine-2,3-dioxygenase 1

Indoleamine 2,3-dioxygenase 1 (IDO1) is a heme-containing dioxygenase enzyme implicated in cancer immune response. This account details the discovery of BMS-986242, a novel IDO1 inhibitor designed for the treatment of a variety of cancers including metastatic melanoma and renal cell carcinoma. Given the substantial interest around this target for cancer immunotherapy, we sought to identify a structurally differentiated clinical candidate that performs comparably to linrodostat (BMS-986205) in terms of both in vitro potency and in vivo pharmacodynamic effect in a mouse xenograft model. On the basis of its preclinical profile, BMS-986242 was selected as a candidate for clinical development.

Preclinical Characterization of Linrodostat Mesylate, a Novel, Potent, and Selective Oral Indoleamine 2,3-Dioxygenase 1 Inhibitor

Tumors can exploit the indoleamine 2,3-dioxygenase 1 (IDO1) pathway to create an immunosuppressive microenvironment. Activated IDO1 metabolizes tryptophan into immunosuppressive kynurenine, leading to suppressed effector T-cell (Teff) proliferation, allowing for tumor escape from host immune surveillance. IDO1 inhibition counteracts this immunosuppressive tumor microenvironment and may improve cancer outcomes, particularly when combined with other immunotherapies. Linrodostat mesylate (linrodostat) is a potent, selective oral IDO1 inhibitor that occupies the heme cofactor-binding site to prevent further IDO1 activation and is currently in multiple clinical trials for treatment of patients with advanced cancers. Here, we assess the in vitro potency, in vivo pharmacodynamic (PD) activity, and preclinical pharmacokinetics (PKs) of linrodostat. Linrodostat exhibited potent cellular activity, suppressing kynurenine production in HEK293 cells overexpressing human IDO1 and HeLa cells stimulated with IFNγ, with no activity against tryptophan 2,3-dioxygenase or murine indoleamine 2,3-dioxygenase 2 detected. Linrodostat restored T-cell proliferation in a mixed-lymphocyte reaction of T cells and allogeneic IDO1-expressing dendritic cells. In vivo, linrodostat reduced kynurenine levels in human tumor xenograft models, exhibiting significant PD activity. Linrodostat demonstrated a PK/PD relationship in the xenograft model, preclinical species, and samples from patients with advanced cancers, with high oral bioavailability in preclinical species and low to moderate systemic clearance. Our data demonstrate that linrodostat potently and specifically inhibits IDO1 to block an immunosuppressive mechanism that could be responsible for tumor escape from host immune surveillance with favorable PK/PD characteristics that support clinical development.

AB0107 INVESTIGATION OF THE EFFECTS OF KYNURENIC ACID ANALOGS IN RHEUMATOID ARTHRITIS

Background:

The investigation of anti-inflammatory and immunosuppressive functions of kynurenic acid (KYNA) is now in focus. Previously, we demonstrated the opposite effects of KYNA and different KYNA analogs on tumor necrosis factor-α (TNF-α) production and tumor necrosis factor-stimulated gene-6 (TSG-6) expression in U-937 monocytic cells. The potential effect of KYNA analogs on further immune mediators including alarmins (S100A12=EN-RAGE and S100A8/9=calprotectin), and on human neutrofil peptide 1-3(α-defensin) production has not been investigated.

Objectives:

Therefore, in the present study, we compared the effects of newly synthesized KYNA analog on the TNF-α, alarmins and α-defensin production, correlation with the effects on the TSG-6 expression in rheumatoid arthritis (RA).

Methods:

93 RA patients were involved and divided subgroups based on DAS28 activity score. Peripheral blood mononuclear cells (PBMC) was isolated from RA patients and healthy controls. As cytokine inducers heat inactivatedStaphylococcus aureus(SA1) were used. In parallel in vitro experiments, the SA1 induced PBMCs were pretreated with a newly synthesized KYNA analog (compound SZR-72 was synthesized by direct amidation of KYNA). The concentrations of the above mentioned inflammatory mediators in the supernatants were quantified by using ELISA kits and the TSG-6 expression was also determined by RTqPCR method.

Results:

The SA1 induced TNF-α, EN-RAGE, calprotectin and α-defensin production was significantly higher in RA patients’ group than in healthy controls. KYNA analog attenuated the SA1 induced TNF-α, EN-RAGE, calprotectin and α-defensin production, and increased TSG-6 production and TSG-6 mRNA expression in PBMC cells from RA patients. The SA1 induced TNF-α and TSG-6 production correlated with the DAS28 activity score. The TNF-α inhibitory effect of the KYNA analog correlated inversely with the TSG-6 stimulatory effect in all subgroups of RA patients based on DAS28 activity score.

Conclusion:

TSG-6 expression could participate in the suppression of inflammatory cytokines, such as TNF-α, EN-RAGE, calprotectin and α-defensin. We suppose that the elevation of the TSG-6 expression by KYNA and especially by new KYNA analogs might be one of the mechanisms that are responsible for their suppressive effect on TNF-α production as a feedback mechanism in RA. KYNA and KYNA analogs have an important role in influencing TSG-6 expression, and there is a possible benefit with potential therapeutic consequence of targeting TSG-6 expression by kynurenines in inflammatory conditions in RA.

References:

[1]Mándi Y, Endrész V, Mosolygó T, Burián K, Lantos I, Fülöp F, Szatmári I, Lőrinczi B, Balog A, Vécsei L, The Opposite Effects of Kynurenic Acid and Different Kynurenic Acid Analogs on Tumor Necrosis Factor-a (TNF-a) Production and Tumor Necrosis Factor-Stimulated Gene-6 (TSG-6) Expression. Frontiers in Immunology. doi: 10.3389/fimmu.2019.01406

Acknowledgments:

This work was supported by GINOP 2.3.2-2015-16-00034

Disclosure of Interests:

None declared

'Bottom-up' effects in a tritrophic plant-aphid-parasitoid system: Why being the perfect host can have its disadvantages

In this study the host plant genotype effect on cabbage aphid, Brevicoryne brassicae (L.)(Hemiptera: Aphididae) preference and performance, the effect of aphid genotype on parasitoids performance, as well as the indirect effects of plant genotypes on aphid parasitoid performance, were tested using different population samples of the aphid and its primary endoparasitoid wasp, Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae). Experiments were run as fully-factorial randomized block design in a greenhouse. Accordingly, host plant cultivar had significant effects on the total number of aphids and aphid-load whilst the fitness of the aphid genotypes were also influenced by plant cultivar. The effect of parasitism on cabbage aphids was significantly different between plant cultivars. Overall, the results revealed that cabbage aphid is under different selective pressures arising from both higher (parasitoid) and lower (host plant cultivar) trophic levels. The host plant cultivar had a significant effect on both aphid fitness and parasitism rate on particular aphid genotypes. This indicates that host-plant-adapted aphid species can create much context-dependency in the nature and strength of 'fitness benefits parasitism', which may in turn alter the costs and benefits of host specialization.

Characterization of the thrombin generation profile in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystemic inflammatory autoimmune disorder. Thrombotic events occur at a higher incidence among SLE patients. The investigation of thrombin generation (TG) with calibrated automated thrombogram (CAT) test as a global hemostasis assay is applicable for the overall functional assessment of the hemostasis. The aim of this study was to characterize the hemostatic alterations observed in SLE by CAT assay. In this study, CAT parameters and basic coagulation parameters of SLE patients (n = 22) and healthy control subjects (n = 34) were compared. CAT area under the curve (i.e., endogenous thrombin potential) was lower than normal in SLE (807 vs. 1,159 nM*min, respectively), whereas other CAT parameters (peak, lag time, time to peak, and velocity index) and the basic coagulation tests were within the normal range. The presence of anti-phospholipid antibodies and the applied therapy was not associated with hemostasis parameters in SLE. We concluded that the reported high risk of thrombosis is not related to TG potential.

[2.2.1]-Bicyclic sultams as potent androgen receptor antagonists

This letter describes the discovery, synthesis, SAR, and biological activity of [2.2.1]-bicyclic sultams as potent antagonists of the androgen receptor. Optimization of the series led to the identification of compound 25, which displayed robust pharmacodynamic effects in rats after oral dosing.

Discovery of the Selective CYP17A1 Lyase Inhibitor BMS-351 for the Treatment of Prostate Cancer

Efforts to identify a potent, reversible, nonsteroidal CYP17A1 lyase inhibitor with good selectivity over CYP17A1 hydroxylase and CYPs 11B1 and 21A2 for the treatment of castration-resistant prostate cancer (CRPC) culminated in the discovery of BMS-351 (compound 18), a pyridyl biaryl benzimidazole with an excellent in vivo profile. Biological evaluation of BMS-351 at a dose of 1.5 mg in castrated cynomolgus monkeys revealed a remarkable reduction in testosterone levels with minimal glucocorticoid and mineralcorticoid perturbation. Based on a favorable profile, BMS-351 was selected as a candidate for further preclinical evaluation.

Discovery of BMS-641988, a Novel Androgen Receptor Antagonist for the Treatment of Prostate Cancer

BMS-641988 (23) is a novel, nonsteroidal androgen receptor antagonist designed for the treatment of prostate cancer. The compound has high binding affinity for the AR and acts as a functional antagonist in vitro. BMS-641988 is efficacious in multiple human prostate cancer xenograft models, including CWR22-BMSLD1 where it displays superior efficacy relative to bicalutamide. Based on its promising preclinical profile, BMS-641988 was selected for clinical development.

Discovery of Clinical Candidate BMS-906024: A Potent Pan-Notch Inhibitor for the Treatment of Leukemia and Solid Tumors

Structure-activity relationships in a series of (2-oxo-1,4-benzodiazepin-3-yl)-succinamides identified highly potent inhibitors of γ-secretase mediated signaling of Notch1/2/3/4 receptors. On the basis of its robust in vivo efficacy at tolerated doses in Notch driven leukemia and solid tumor xenograft models, 12 (BMS-906024) was selected as a candidate for clinical evaluation.

Chemically synthesized molecules with the targeting and effector functions of antibodies

This article reports the design, synthesis, and evaluation of a novel class of molecules of intermediate size (approximately 7000 Da), which possess both the targeting and effector functions of antibodies. These compounds—called synthetic antibody mimics targeting prostate cancer (SyAM-Ps)—bind simultaneously to prostate-specific membrane antigen and Fc gamma receptor I, thus eliciting highly selective cancer cell phagocytosis. SyAMs have the potential to combine the advantages of both small-molecule and biologic therapies, and may address many drawbacks associated with available treatments for cancer and other diseases.

Abstract 1643: BMS-983970, an oral pan-Notch inhibitor for the treatment of cancer

Deregulation of the Notch pathway has been shown to be oncogenic in numerous tissue types including T-cell acute lymphoblastic leukemia (T-ALL), breast cancer, non-small cell lung cancer, and colorectal carcinoma. Notch signal activation can cause uncontrolled proliferation, restrict differentiation leading to increased self-renewal capacity, evasion of apoptosis, and enhancement of angiogenesis and metastasis. There is increasing evidence that Notch plays a role in the maintenance and survival of cancer stem cells. γ-Secretase mediates the Notch signaling pathway by releasing the Notch intracellular domain (NICD) which translocates to the nucleus and binds to the transcription factor CSL to activate transcription of various target genes. BMS-906024 is a potent pan-Notch inhibitor that demonstrated robust anti-tumor activity at tolerated doses in multiple tumor xenograft models. It is being evaluated in Phase 1 clinical studies. BMS-906024 is being administered IV (once weekly) in the clinic and the projected human efficacious dose is 4 - 6 mg. Based on the preclinical data, the projected human half-life of BMS-906024 is in the 37 h - 124 h range.

This presentation will describe further structure-activity relationships in the 1,4-benzodiazepinone series that culminated in the identification of BMS-983970 as an oral-pan-Notch inhibitor. Pharmacokinetic properties and in vivo evaluation of BMS-983970 in T-ALL and solid tumor xenograft models will be presented.

Citation Format: Ashvinikumar V. Gavai, Yufen Zhao, Daniel O'Malley, Brian Fink, Claude Quesnelle, Derek Norris, Libing Chen, Soong-Hoon Kim, Wen-Ching Han, Patrice Gill, Weifang Shan, Aaron Balog, Andrew Tebben, Richard Rampulla, Dauh-Rurng Wu, Yingru Zhang, Arvind Mathur, Haiqing Wang, Zheng Yang, Qian Ruan, Robin Moore, David Rodrigues, Asoka Ranasinghe, Celia D'Arienzo, Ching Kim Tye, Ching Su, Gerry Everlof, Melissa Yarde, Mary Ellen Cvijic, Krista Menard, Mei-Li Wen, George Trainor, Bruce Fischer, John Hunt, Gregory Vite, Richard Westhouse, Francis Lee. BMS-983970, an oral pan-Notch inhibitor for the treatment of cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1643. doi:10.1158/1538-7445.AM2014-1643

Synthesis of [3α-(3) H] 17α-hydroxy pregnenolone and [3α-(3) H] pregnenolone

For the first time, [3α-(3) H] 17α-hydroxy pregnenolone (1) was synthesized through a multiple step sequence. The presence of [3β-(3) H] isomer in RP-HPLC purified product was identified by tritium NMR. The [3β-(3) H] isomer was then separated from [3α-(3) H] 17α-hydroxy pregnenolone with chiralPAK AD-H column. [3α-(3) H] pregnenolone (2) was synthesized from commercial available 5-pregnen-3,20-dione in one step with an improved procedure.

Predation drives stable coexistence ratios between red and green pea aphid morphs

We conducted field surveys and experiments to evaluate the hypothesis that predation is an important driving factor determining the degree of coexistence between red and green morphs of the pea aphid Acyrthosiphon pisum. Theory suggests that the different colour morphs are differentially susceptible to natural enemies and selection by predation which in turn leads to variable relative abundances of red and green morphs among host plants across landscapes. Our field surveys on pea and alfalfa revealed, however, that the colour morphs tended to coexist closely in a ratio of one red to three green aphids across fields with different host plant monocultures. Experimentation involving manipulation of the relative abundances of the two colour morphs on host plants pea and alfalfa with and without predator presence revealed that red morphs had higher or same fitness (per capita reproduction) than green morphs on both pea and alfalfa only when in the proportion of one red/three green proportion. Moreover, experimentation evaluating predator efficiency revealed that red morphs are safest from predation when in a 1 : 3 ratio with green morphs. These results suggest that in addition to predation selection effects, red morphs may behaviourally choose to associate with green morphs in a narrow 1 : 3 ratio to maximize their fitness. This evidence, along with existing published data on red and green morph anti-predator behaviour indicates that a 1 : 3 red and green morph coexistence ratio is driven by a balance between predation pressure and behavioural assorting by red morphs across landscapes. In this way predators may have ecological-evolutionary consequences for traits that affect the colour morphs' proportion and tolerances to selective pressure.

Drug safety is a barrier to the discovery and development of new androgen receptor antagonists

BACKGROUND

Androgen receptor (AR) antagonists are part of the standard of care for prostate cancer. Despite the almost inevitable development of resistance in prostate tumors to AR antagonists, no new AR antagonists have been approved for over a decade. Treatment failure is due in part to mutations that increase activity of AR in response to lower ligand concentrations as well as to mutations that result in AR response to a broader range of ligands. The failure to discover new AR antagonists has occurred in the face of continued research; to enable progress, a clear understanding of the reasons for failure is required.

METHODS

Non-clinical drug safety studies and safety pharmacology assays were performed on previously approved AR antagonists (bicalutamide, flutamide, nilutamide), next generation antagonists in clinical testing (MDV3100, BMS-641988), and a pre-clinical drug candidate (BMS-501949). In addition, non-clinical studies with AR mutant mice, and EEG recordings in rats were performed. Non-clinical findings are compared to disclosures of clinical trial results.

RESULTS

As a drug class, AR antagonists cause seizure in animals by an off-target mechanism and are found in vitro to inhibit GABA-A currents. Clinical trials of candidate next generation AR antagonists identify seizure as a clinical safety risk.

CONCLUSIONS

Non-clinical drug safety profiles of the AR antagonist drug class create a significant barrier to the identification of next generation AR antagonists. GABA-A inhibition is a common off-target activity of approved and next generation AR antagonists potentially explaining some side effects and safety hazards of this class of drugs.

Effects of chitin and contact insecticide complexes on rove beetles in commercial orchards

A five-year research project was performed to explore the potential effects of contact insecticide applications on the change of abundance and species richness of predatory rove beetles (Coleoptera: Staphylinidae) in conventionally managed orchards. Twelve blocks of nine orchards were used for this study in Central Europe. High sensitivity atomic force microscopic examination was carried out for chitin structure analyses as well as computer simulation for steric energy calculation between insecticides and chitin. The species richness of rove beetles in orchards was relatively high after insecticide application. Comparing the mean abundance before and after insecticide application, a higher value was observed before spraying with alphacypermethrin and lambda-cyhalothrin, and a lower value was observed in the cases of diflubenzuron, malathion, lufenuron, and phosalone. The species richness was higher only before chlorpyrifos-methyl application. There was a negative correlation between abundance and stability value of chitin-insecticides, persistence time, and soil absorption coefficients. Positive correlation was observed with lipo- and water solubility.

Design and synthesis of 4-[3,5-dioxo-11-oxa-4,9-diazatricyclo[5.3.1.0(2,6)]undec-4-yl]-2-trifluoromethyl-benzonitriles as androgen receptor antagonists

A novel series of 4-[3,5-dioxo-11-oxa-4,9-diazatricyclo[5.3.1.0(2,6)]undec-4-yl]-2-trifluoromethyl-benzonitriles has been synthesized. The ability of these compounds to act as antagonists of the androgen receptor was investigated and several were found to have potent activity in vitro and in vivo.

Abstract 5782: Androgen receptor antagonists: Lead optimization and preclinical pharmacology

The development and progression of prostate cancer is known to be dependent on androgens and their signaling mediated by the androgen receptor (AR). The primary therapeutic intervention involves using agents that lower serum testosterone (e.g., LHRH agonists), often in concert with an AR antagonist, such as bicalutamide. Despite a favorable initial anti-tumor response, most patients progress to the advanced hormone-refractory disease. The development of resistance to anti-androgen therapy has been shown to be associated with an increase in the levels of both AR mRNA and protein. This observation supports the concept that an AR antagonist with a significant improvement in potency as compared to bicalutamide and a broader spectrum of in vivo anti-tumor activity, including the bicalutamide-refractory human prostate tumor xenografts, may provide a significant clinical advantage in the treatment of advanced prostate cancer. This presentation will describe structure-activity relationships in a novel tetracyclic series of androgen receptor antagonists leading up to the identification of BMS-779333. It is a potent AR full antagonist, which exhibited broad spectrum efficacy in four human prostate tumor xenograft models. BMS-779333 did not exhibit agonist activity for AR mutant isoforms. Tumors that failed bicalutamide treatment were shown to retain their sensitivity to respond to BMS-779333. Transcriptomic changes in LuCaP-35 tumors treated with BMS-779333 were closer to castration than with other drug treatments. Based on its overall profile, BMS-779333 was selected for further preclinical evaluation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5782.

Dominance, activity density and prey preferences of rove beetles ( Coleoptera: Staphylinidae) in conventionally treated Hungarian agro-ecosystems

Field experiments were conducted to investigate the mechanism underlying patterns of the rove beetle populations in apple and pear orchards (1998-2002) and winter wheat (2006-2007) in Hungary following treatment with broad-spectrum insecticide. The capacity of predatory staphylinid species to feed on cereal pests was measured, with six species tested in petri dishes, in the laboratory at room temperature. Almost 23% of the Hungarian and 13% of the European staphylinid fauna are represented in the investigated agro-ecosystems. In orchards, 5236 individuals, belonging to 253 species, were collected. The most widely occurring were Omalium caesum Gravenhorst, Drusilla canaliculata (F.), Dinaraea angustula (Gyllenhal), Palporus nitidulus (F.), Xantholinus. longiventris (Olivier), X. linearis (Olivier) and Aleochara bipustulata (L.). In winter wheat, 798 individuals and 20 species were collected, the most frequent were Staphylinus caesareus Cederh, Tachyporus hypnorum (F.), Philonthus cognatus (Stephens), Aloconota gregaria (Erichson), Tachyporus chrysomelinus (L.) and T. obtusus (L.). Species composition differed by crop (apple, pear and wheat), soil composition and surrounding habitat. Species diversity was also influenced by these parameters. In wheat, one acute change in species composition was observed with the decline of Tachyporus spp., which occurred equally across all farms. The consumption rate of prey by the dominant species occurring in wheat ecosystems was relatively high; however, we did not offer any fungal food to compare with insects' prey.