Discover Biotrial’s Scientific publications & posters

Treating patients affected by schizophrenia (SZ) remains highly challenging for drug developers. While available antipsychotics mostly reduce positive symptoms, their effects on cognitive and social deficits as well as their underlying pathophysiology remain insufficient. Disinhibition in SZ patients’ cortex is considered a key player in the genesis of these symptoms and would result from N-methyl-D-aspartate receptor (NMDAr) hypofunction on interneurons. Besides, electroencephalography-based biomarkers of these mechanisms including spontaneous and evoked gamma oscillations have been highlighted. These strongly depend on NMDAr function, associate with symptoms and therefore represent translational tools for drug development. However, reversing these circuit abnormalities is challenging for the field and finding drugs engaging them would constitute a major milestone. Here, we tested three different drugs whose features attract scientists for restoration of excitation/ inhibition balance: cariprazine (D2/D3 receptor partial agonist and 5-HT2A receptor antagonist), LY379268 (mGlur2/3 receptor agonist) and donepezil (acetylcholinesterase inhibitor). We investigated their effects on spontaneous oscillations and auditory steady-state responses (ASSR, measuring evoked gamma oscillations) in a rat model of SZ induced by MK-801, a selective NMDAr blocker. MK-801 increased locomotor activity, impaired spontaneous and evoked gamma oscillations and altered spontaneous oscillations in delta, alpha and beta frequencies of male Sprague Dawley rats. Remarkably, both cariprazine and LY379268 normalized spontaneous gamma oscillations. Moreover, cariprazine normalized alpha and beta waves and LY379268 selectively corrected delta activity. Interestingly, only cariprazine mitigated the ASSR deficit. These differential normalization profiles, including cariprazine’s unique broad-spectrum signature, reveal distinct patterns of circuit engagement and provide a translational pharmaco-EEG framework for circuit-level target engagement in SZ drug development.

We are engaged in the setup of cancer preclinical models in order to test new therapies or new combinations of current therapies. Recently our work has focused on two highly lethal cancer
pathologies, Glioblastoma Multiforme (GBM) and Triple Negative Breast Cancer (TNBC).

Treating people with schizophrenia still represents a major challenge for neuropsychiatric drug development companies. While available atypical antipsychotics are mainly effective on positive symptoms of schizophrenia, their effects on cognitive and social-cognitive deficits remain insufficient and poorly characterized. For instance, a modest improvement of cognitive functions has been described following clozapine treatment. Nevertheless, it remains unclear whether this outcome is due to a direct effect on the neural circuits underlying cognition or to an indirect effect mediated by an overall reduction in positive symptoms. To address this question, we sought to measure mismatch negativity (MMN) responses in telemetered rats. MMN constitutes an electroencephalography-based biomarker of sensory, pre-attentional and predictive coding processes, functions whose disruptions highly influence certain aspects of patients’ cognitive symptoms. MMN was measured under N-methyl-D-aspartate receptor (NMDAr) pharmacological inhibition by MK-801 (dizocilpine), a model based on the glutamatergic hypothesis of schizophrenia, and we tested whether clozapine could improve MMN under this condition or not. We found that MK-801 dose-dependently reduced the MMN peak amplitude in rats, aligning with the MMN response deficit seen in schizophrenia patients. Strikingly, clozapine was able to mitigate this electrophysiological deficit, an unprecedented observation that has the potential to inspire new treatment strategies aimed towards unaddressed schizophrenia symptoms.

Genetic characterization of cell lines is essential for understanding and predicting sensitivity to anti-tumoral targeted therapies. A panel of genetically characterized cell lines from rare tumors (mucosal melanomas, histiocytic sarcomas, osteosarcomas, gliomas…) has been developed to test novel and repositioned anti-tumor therapies, focusing on mucosal melanoma (MM) models.

Ketamir-2 is a new molecular entity, and a novel ketamine analog designed to improve oral bioavailability, and offer a superior safety profile compared to existing ketamine treatments. It was found that Ketamir-2 is a low affinity NMDA receptor antagonist, that selectively binds to the PCP site. Its IC₅₀ on this receptor site is ∼100 µM. Ketamine acts as an NMDA receptor antagonist (0.5–1 µM affinity) and influences opioid receptors, monoaminergic systems (such as serotonin and dopamine). The selectivity of Ketamir-2 was evaluated across a broad range of receptors, transporters, and binding sites, but no activity was detected. Ketamir-2 is a lower affinity and selective PCP-site NMDA antagonist, compared with ketamine. Upon oral administration, Ketamir-2 does not induce hyperlocomotion in mice. Thus, it is different from Ketamine, which induces marked hyperlocomotion, a behavior which is thought to mimic the psychomotor agitation and disorganized behavior seen in schizophrenia, often linked to disruptions in brain neurotransmitter systems. Ketamir-2 was also evaluated via several pharmacological tests in mice to evaluate its anti-depressive and anxiolytic effects. These tests included the Open Field test (OFT), Elevated Plus Maze (EPM), and Forced Swimming Test (FST); all of which are commonly employed behavioral assays used to evaluate the efficacy of anxiety and depression medications. While showing significant effects in these tests at variable doses, ketamine, which was used as a positive control, did not differ from vehicle treatment or showed an opposite response to Ketamir in the majority of the tests studied.

The assessment of drug-induced QT interval prolongation and associated proarrhythmic risks, such as Torsades de Pointes (TdP), has evolved significantly over the past decades. This review traces the development of nonclinical QT evaluation, highlighting key milestones and innovations that have shaped current practices in cardiac safety assessment. The emergence of regulatory guidelines, including International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) S7B, established a nonclinical framework for evaluating drug effects on cardiac repolarization, addressing concerns raised by drug withdrawals in the 1990s. Advances in in vitro, in vivo, and in silico models have enhanced the predictive accuracy of nonclinical studies, with the hERG assay and telemetry-based animal models becoming gold standards. Recent initiatives, such as the Comprehensive in vitro Proarrhythmia Assay (CiPA) and the Japan iPS Cardiac Safety Assessment (JiCSA), emphasize integrating mechanistic insights from human-derived cardiomyocyte models and computational approaches to refine risk predictions. The 2020s mark a shift toward integrated nonclinical-clinical risk assessments, as exemplified by the ICH E14/S7B Questions and Answers. These highlight the need of best practices for study design, data analysis, and interpretation to support regulatory decision-making. Further more, the adoption of New Approach Methodologies (NAMs) and reinforced adherence to 3Rs principles (Reduce, Refine, Replace) reflect a commitment to ethical and innovative safety science. This review underscores the importance of harmonized and translational approaches in cardiac safety evaluation, providing a foundation for advancing drug development while safeguarding patient safety. Future directions include further integration of advanced methodologies and regulatory harmonization to streamline nonclinical and clinical risk assessments.

The ICH E14/S7B Q&As highlighted the need for best practices concerning the design, execution, analysis, interpretation, and reporting of the in vivo non- rodent QT assay as a component of the integrated risk assessment to potentially support a TQT waiver or substitute. We conducted a dog telemetry study to assess the effects on QTc of six reference compounds (five positive and one negative) previously evaluated by Darpo et al. (2015) in humans. The sensitivity of the assay to detect QTc increases was determined, and exposure–response analysis was performed,
as done in clinical practice. By- timepoint analysis showed QTc prolongation induced by moxifloxacin, dofetilide, dolasetron, ondansetron, and quinine within human relevant plasma exposures ranges. Moreover, a hysteresis was observed for quinine. As expected, levocetirizine showed no statistically significant effect on QTc across a range of exposure, well exceeding the therapeutic Cmax. Power analyses confirmed the study ability to detect statistically significant QTc changes of less than 10 milliseconds with 80% probability, even with a sample size as low as n = 4 animals. Finally, concentration- QTc modeling enabled to predict the minimal plasma concentration needed to detect a 10 milliseconds QTc prolongation, including for quinine. The comparison with clinical available data supported the relevance of dogs under these experimental conditions as a robust translational predictor of drug- induced QTc prolongation in humans as a key pillar of the integrated risk assessment.

In cancer research, murine models play a crucial role as highly valuable preclinical tools. Here, we present a protocol to generate a murine model of glioblastoma through the direct intracranial
injection of tumor cells. We describe steps for cell culture, intracranial implantation, and standard-of-care treatments. We then detail procedures for monitoring tumor growth using  bioluminescent imaging.

Lung cancer is one of the most common and deadliest cancers. Preclinical models are essential to study new therapies and combinations taking tumor genetics into account. We
have established cell lines expressing the luciferase gene from lines with varied genetic backgrounds, commonly encountered in patients with pulmonary adenocarcinoma. We have
characterized these lines by testing their response to multiple drugs. Thus, we have developed orthotopic preclinical mouse models of NSCLC with very high engraftment efficiency.
These models allow the easy monitoring of tumor growth, particularly in response to treatment, and of tumor cells dissemination in the body. We show that concomitant treatment with
osimertinib (3rd generation tyrosine kinase inhibitor targeting mutated EGFR) and bevacizumab (anti-angiogenic targeting VEGF) can have a beneficial therapeutic effect on EGFRmutated
tumors. We also show that the addition of afatinib to osimertinib-treated tumors in escape leads to tumor growth inhibition. No such effect is observed with selumetinib or simvastatin.
These preclinical mouse models therefore make it possible to test innovative therapeutic combinations and are also a tool of choice for studying resistance mechanisms.

The available antipsychotics for schizophrenia (SZ) only reduce positive symptoms and do not significantly modify SZ neurobiology. This has raised the question of the robustness and
translational value of methods employed during drug development. Electroencephalography (EEG)-based measures like evoked and spontaneous gamma oscillations are considered robust translational biomarkers as they can be recorded in both patients and animal models to probe a key mechanism underlying all SZ symptoms: the excitation/inhibition imbalance mediated by N-methyl-D-aspartate receptor (NMDAr) hypofunction. Understanding the effects of commercialized atypical antipsychotics on such measures could therefore contribute to developing better therapies for SZ. Yet, the effects of such drugs on these EEG readouts are unknown. Here, we studied the effect of the atypical antipsychotic aripiprazole on the gamma-band auditory steady-state response (ASSR), spontaneous gamma oscillations and behavioral features in a SZ rat model induced by the NMDAr antagonist MK-801. Interestingly, we found that aripiprazole could not normalize MK-801-induced abnormalities in ASSR, spontaneous gamma oscillations or social interaction while it still improved MK-801-induced hyperactivity. Suggesting that aripiprazole is unable to normalize electrophysiological features underlying SZ symptoms, our results might explain aripiprazole’s inefficacy towards the social interaction deficit in our model but also its limited efficacy against social symptoms in patients.

Fistulizing anoperineal lesions are severe complications of Crohn’s disease (CD) that affect quality of life with a long-term risk of anal sphincter destruction, incontinence, permanent stoma, and anal cancer. Despite several surgical procedures, they relapse in about two-thirds of patients, mandating innovative treatments. Ultrasmall particles of iron oxide (USPIO) have been described to achieve in vivo rapid healing of deep wounds in the skin and liver of rats thanks to their nanobridging capability that could be adapted to fistula treatment. Our main purpose was to highlight preclinical data with USPIO for the treatment of perianal fistulizing CD. Twenty male Sprague Dawley rats with severe 2,4,6 trinitrobenzenesulfonic acid solution (TNBS)-induced proctitis were operated to generate two perianal fistulas per rat. At day 35, two inflammatory fistulas were obtained per rat
and perineal magnetic resonance imaging (MRI) was performed. After a baseline MRI, a fistula
tract was randomly drawn and topically treated either with saline or with USPIO for 1 min (n = 17 for each). The rats underwent a perineal MRI on postoperative days (POD) 1, 4, and 7 and were sacrificed for pathological examination. The primary outcome was the filling or closure of the fistula tract, including the external or internal openings. USPIO treatment allowed the closure and/or
filling of all the treated fistulas from its application until POD 7 in comparison with the control fistulas (23%). The treatment with USPIO was safe, permanently closed the fistula along its entire length, including internal and external orifices, and paved new avenues for the treatment of perianal fistulizing Crohn’s disease.

Osimertinib is a third generation tyrosine kinase inhibitor (TKI) that targets the epidermal growth factor receptor (EGFR) in lung cancer. However, although this molecule is not subject to some of the resistance mechanisms observed in response to first generation TKIs, ultimately, patients relapse because of unknown resistance mechanisms. New relevant non-small cell lung cancer (NSCLC) mice models are therefore required to allow the analysis of these resistance mechanisms and to evaluate the efficacy of new therapeutic strategies.

Methods: Briefly, PC-9 cells, previously modified for luciferase expression, were injected into the tail vein of mice.

Tumor implantation and longitudinal growth, almost exclusively localized in the lung, were evaluated by bioluminescence. Once established, the tumor was treated with osimertinib until tumor escape and development of bone metastases.

Results: Micro-metastases were detected by bioluminescence and collected for further analysis.

Conclusion: We describe an orthotopic model of NSCLC protocol that led to lung primary tumor nesting and, after osimertinib treatment, by metastases dissemination, and that allow the isolation of these small osimertinib-resistant micro-metastases. This model provides new biological tools to study tumor progression from the establishment of a lung tumor to the generation of drug-resistant micro-metastases, mimicking the natural course of the disease in human NSCLC patients.

Keywords: Orthotopic lung tumor model, Metastasis, Bioluminescence, EGFR TK inhibitor, Tumor escape, Osimertinib

Circulating tumor cells (CTC) have been studied in various solid tumors but clinical utility of CTC in small cell lung cancer (SCLC) remains unclear. The aim of the CTC-CPC study was to develop an EpCAM-independent CTC isolation method allowing isolation of a broader range of living CTC from SCLC and decipher their genomic and biological characteristics. CTC-CPC is a monocentric prospective non-interventional study including treatment-naïve newly diagnosed SCLC. CD56+ CTC were isolated from whole blood samples, at diagnosis and relapse after first-line treatment and submitted to whole- exome-sequencing (WES). Phenotypic study confirms tumor lineage and tumorigenic properties of isolated cells for the 4 patients analyzed with WES. WES of CD56+ CTC and matched tumor biopsy reveal genomic alteration frequently impaired in SCLC. At diagnosis CD56+ CTC were characterized by a high mutation load, a distinct mutational profile and a unique genomic signature, compared to match tumors biopsies. In addition to classical pathways altered in SCLC, we found new biological processes specifically affected in CD56+ CTC at diagnosis. High numeration of CD56+ CTC (> 7/ml) at diagnosis was associated with ES-SCLC. Comparing CD56+ CTC isolated at diagnosis and relapse, we identify differentially altered oncogenic pathways (e.g. DLL3 or MAPK pathway). We report a versatile method of CD56+ CTC detection in SCLC. Numeration of CD56+ CTC at diagnosis is correlated with disease extension. Isolated CD56+ CTC are tumorigenic and show a distinct mutational profile. We report a minimal gene set as a unique signature of CD56+ CTC and identify new affected biological pathways enriched in EpCAM-independent isolated CTC in SCLC.

Schizophrenia (SZ) is a devastating psychiatric disorder affecting about 1% of the world’s population. Social-cognitive impairments in SZ prevent positive social interactions and lead to progressive social withdrawal. The neurobiological underpinnings of social-cognitive symptoms remain poorly understood, which hinders the development of novel treatments. At the whole- brain level, an abnormal activation of social brain regions and interregional dysconnectivity within social-cognitive brain networks have been identified as major contributors to these symptoms. At the cellular and subcellular levels, an interplay between oxidative stress, neuroinflammation and N-methyl-D-aspartate receptor hypofunction is thought to underly SZ pathology. However, it is not clear how these molecular processes are linked with interregional dysconnectivity in the genesis of social-cognitive symptoms. Here, we aim to bridge the gap between macroscale (connectivity analyses) and microscale (molecular and cellular mechanistic) knowledge by proposing impaired myelination and the disinhibition of local microcircuits as possible causative biological pathways leading to dysconnectivity and abnormal activity of the social brain. Furthermore, we recommend electroencephalography as a promising translational technique that can foster pre-clinical drug development and discuss attractive drug targets for the treatment of social-cognitive symptoms in SZ.

Cancer treatments are frequently associated with nausea and vomiting despite greatly improved preventive medication. Administration of antinausea agents as eye drops might provide easy and rapid access to the systemic circulation for prevention of nausea and vomiting and for the treatment of breakthrough nausea, but the ocular administration route has rarely been evaluated. Palono- setron is a second-generation 5-hydroxytryptamine 3 receptor antagonist approved for prevention and treatment of chemotherapy induced nausea and vomiting. We compared ocular administration of palonosetron to non-active vehicle eye drops and to intravenous palonosetron in the prevention of cisplatin-induced nausea and vomiting in beagle dogs. Palonosetron ocular drops at the dose of 30 mg/kg reduced cumulative nausea over time as measured with the area under the visual analog scale curve by 98% compared with the vehicle and reduced nausea-associated dog behavior by 95%. Vomiting was completely prevented with repeated palonosetron ocular dosing. Hydroxypropyl-b-cyclodextrin (HP-b-CD) palonosetron formulation was well tolerated locally at the palonosetron concentration of 3 mg/ml. Absorption of palonosetron from eye drops was fast. Ten minutes after ocular administration, palonose- tron plasma concentrations were similar compared with intravenous administration, and remained similar for six hours. We conclude that palonosetron is rapidly absorbed into the systemic circulation from eye drops. Ocularly administered palonosetron was well tolerated in the HP-b-CD formulation and was highly effective in the prevention of cisplatin-induced nausea and vomiting. Evaluation of the safety and efficacy of ocular administration of palonosetron is warranted in the prevention and treatment of chemotherapy-induced nausea and vomiting in clinical trials.