We investigated the temporal course of microglia activation in different brain regions after permanent middle cerebral artery (MCA) occlusion in mice and compared this microglia response with the appearance of apoptotic cells, Microglia activation and morphological changes of microglial cells were visualized using an immunohistochemical method with a polyclonal antibody recognizing the mouse CR3 complement receptor. Cells showing morphological and biochemical features of apoptosis were identified using the terminal deoxynucleotidyl transferase nick end-labeling (TUNEL) method and light microscopy. As early as 30 min after onset of MCA occlusion activated microglia with hypertrophic cell bodies and stout processes were detected in the periphery of the ischemic lesion as identified by diffusion-weighted magnetic resonance imaging. A wider distribution and a progressive increase in the number of activated microglia was found with increasing time. Only few TUNEL-positive cells with apoptotic features were observed within the lesion area at 6 h after onset of cerebral ischemia. From 12 h after MCA occlusion onward a tremendous increase in the number of TUNEL-positive cells was found. Within the thalamus from 24 h onward microglia cells with few processes, irregular morphology and fragmented appearance were detected. Microglia activation in the thalamus progressed up to 4 weeks after MCA occlusion, but had declined after 90 days. Neuronal degeneration in the thalamus as determined by anti-neuronal nuclei immunohistochemistry progressed from 6 days after MCA occlusion onward. Only a few TUNEL-positive cells were found in the thalamus. In summary, microglia activation both in the primary cortical lesion area and in the secondarily affected thalamus preceded the manifestation of tissue injury. These observations encourage further studies on the role of microglia in focal cerebral ischemia.

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Cancer is a growing public health problem in China. Despite the high unmet medical need of patients with cancer in China, oncology drug approvals have historically lagged behind those in the West, mainly the United States and Europe. China is currently undertaking regulatory reforms at a fast pace in order to mitigate this lag.

BackgroundCancer remains one of the most common causes of morbidity and mortality worldwide. Multiregional (MRCTs) and single-country clinical trials are two common approaches to support new oncology drug approvals internationally. However, systematic reviews comparing MRCTs with single-country trials for international oncology drug approval are lacking.MethodsWe searched health agency websites to retrieve all approved oncology drugs from 2010 to 2022. ClinicalTrials.gov was used to retrieve all pivotal study information. We used an adapted version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB 2) and Risk Of Bias In Non-randomized Studies - of Interventions (ROBINS-I) checklist to assess the risk-of-bias in randomized and non-randomized trials, respectively.ResultsA total of 48 new drugs and biologics (comprising 215 pivotal clinical trials) with initial marketing approval in the United States, European Union, Japan, and China were included. The reporting quality of MRCTs vs. single-country studies was similar. The median time interval for approval was significantly longer for MRCTs than for single-country bridging studies (1,399 vs. 975 days, P < 0.0001), whereas the median time interval for approval was shorter for MRCTs than for single-country standalone studies. The time gap for oncology drugs approved before 2015 was significantly longer than for those approved after 2015. The median timeline for approval in MRCTs involving 3 regions showed the shortest time-to-approval compared with MRCTs involving 4–5 and 1–2 regions. There was no significant difference in the time-to-approval among different tumor types and product types.ConclusionThe median time-to-approval of MRCTs was significantly longer than that of single-country bridging studies but shorter than that of single-country standalone studies, primarily involving 3 regions as the most frequent pattern and the shortest time-to-approval to operate MRCTs as a pivotal trial. Single-country bridging studies still provide essential supplements for international oncology drug approvals if MRCTs do not apply. Future studies should explore how to shorten the time-to-approval for MRCTs.Systematic review registration[https://www.researchregistry.com/browsethe-registry#registryofsystematicreviewsmeta-analyses/], identifier [1390].

Scientific advice constitutes an important part of the development strategy as it can increase the likelihood of regulatory success. For this reason, its timing has to be carefully planned.There are essentially two routes which can be followed to get scientific advice in the EU:-a "national advice", which is a decentralised procedure and involves meeting with one national authority; -a "scientific advice" at the CHMP level, which is centralised, called protocol assistance for designated orphan drugs. This is a pan-European advice, which is adopted by the CHMP based on the recommedations of the SAWP.

Background Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) and 5 (CEACAM5, CEA) are members of the carcinoembryonic antigen (CEA) family. CEA-CAM1 is expressed on a variety of immune cells and acts as a cell-cell communication molecule. The signal transduction process is associated with immune cell activation, apoptosis, proliferation and differentiation. In the pathophysiological stage, CEACAM1 and 5 are dysregulated in various malignancies including, for instance, breast, lung, and gastrointestinal cancer. This seems associated with poor prognosis linked to a novel checkpoint blockade mechanism mediated by homophilic CEACAM1⇔1 and heterophilic CEACAM1⇔5 interaction between immune and tumor cells, respectively. YB-200 is a novel IgG1 antibody targeting CEACAM 1/5, which has shown to preserve the immune agonistic function of CEA-CAM1 on leukocytes in addition to potentially inhibiting both the homophilic and heterophilic checkpoint blockade of CEA-CAM1 and 5 on tumor cells. The present study was designed to test the in vivo anti-tumor activity of YB-200 and its effect on immune cells. Methods Anti-tumor activity of YB-200 was assessed using the validated ReactionBiology's SubQperior ® experimental syngeneic liver Hepa-1-6 tumor model. The tumor cells were injected into the mammary fat pad of C57BL/6 mice. On Day 5 after tumor cell injection, animals were randomized (median tumor size ~50 mm 3 ) in two groups and treatment started. Mice were treated i.p. BIWx3 with either isotype control or YB-200 at 10 mg/kg/administration. Animals were euthanized on Day 20, and tumors harvested for flow cytometry analysis. Flow cytometry for immune-cell profiling was performed using the ReactionBiology All-in-one ® staining panel. Results Treatment with YB-200 induced statistically significant tumor growth inhibition by ~80% compared to isotype control, at well-tolerated dose. Flow cytometry analysis revealed that YB-200 led to a 10-fold increase in B-cells in the tumor micro-environment compared to the isotype control. In addition, a statistically significant increase in CD3+ and CD4+ Tcells was observed while granulocytes decreased. Conclusions This study demonstrates that treatment with YB-200 induced statistically significant tumor growth inhibition compared to isotype control in a validated hepatocellular carcinoma model. Consistent with the role of CEACAM1 as cellcell communication molecule the anti-tumor activity of YB-200 was correlated with a strong modulation of the immune cell compartment in the tumor micro environment. Ethics Approval This animal study has been approved by the Ethics Committee for Animal Experimentation and is registered by the regional board Freiburg, Germany. Mice were handled according to the German animal welfare law and the GV-SOLAS guidelines.