Beyond MABEL: An Integrative Approach to First in Human Dose Selection of Immunomodulators by the Health and Environmental Sciences Institute (HESI) Immuno-Safety Technical Committee (ITC).

Administration of a new drug candidate in a first-in-human (FIH) clinical trial is a particularly challenging phase in drug development and is especially true for immunomodulators, which are a diverse and complex class of drugs with a broad range of mechanisms of action and associated safety risks. Risk is generally greater for immunostimulators, in which safety concerns are associated with acute toxicity, compared to immunosuppressors, where the risks are related to chronic effects. Current methodologies for FIH dose selection for immunostimulators are focused primarily on identifying the minimum anticipated biological effect level (MABEL), which has often resulted in sub-therapeutic doses, leading to long and costly escalation phases. The Health and Environmental Sciences Institute (HESI) - Immuno-Safety Technical Committee (ITC) organized a project to address this issue through two complementary approaches: (i) an industry survey on FIH dose selection strategies and (ii) detailed case studies for immunomodulators in oncology and non-oncology indications. Key messages from the industry survey responses highlighted a preference toward more dynamic PK/PD approaches as in vitro assays are seemingly not representative of true physiological conditions for immunomodulators. These principles are highlighted in case studies. To address the above themes, we have proposed a revised decision tree, which expands on the guidance by the IQ MABEL Working Group (Leach et al. 2021). This approach facilitates a more refined recommendation of FIH dose selection for immunomodulators, allowing for a nuanced consideration of their mechanisms of action (MOAs) and the associated risk-to-benefit ratio, among other factors.

'All In': a pragmatic framework for COVID-19 testing and action on a global scale.

Current demand for SARS-CoV-2 testing is straining material resource and labor capacity around the globe. As a result, the public health and clinical community are hindered in their ability to monitor and contain the spread of COVID-19. Despite broad consensus that more testing is needed, pragmatic guidance toward realizing this objective has been limited. This paper addresses this limitation by proposing a novel and geographically agnostic framework (the 4Ps framework) to guide multidisciplinary, scalable, resource-efficient, and achievable efforts toward enhanced testing capacity. The 4Ps (Prioritize, Propagate, Partition, and Provide) are described in terms of specific opportunities to enhance the volume, diversity, characterization, and implementation of SARS-CoV-2 testing to benefit public health. Coordinated deployment of the strategic and tactical recommendations described in this framework has the potential to rapidly expand available testing capacity, improve public health decision-making in response to the COVID-19 pandemic, and/or to be applied in future emergent disease outbreaks.

Investigating toxicity specific to adjuvanted vaccines.

In an attempt to understand the unique toxicity of adjuvanted vaccines, we studied how toxicity develops over time following vaccine administration. In addition to on- and off-target toxicity typically observed with general pharmaceuticals, we observed toxicity associated with both the generation and the broad action of effectors (antibodies and/or cytotoxic T lymphocytes, CTLs). The impact on effector generation appears to be related to local tolerance specific to the adjuvant. The vaccine immune response by effectors serves to demonstrate species relevance as outlined in the recent WHO guideline on the nonclinical evaluation of adjuvanted vaccines. When regarded as pharmaceuticals that function at sites of local administration, adjuvants have inherent on- and off-target toxicity. On-target toxicity of the adjuvant is typically associated with effector generation, and could vary depending on animal species. Therefore, the use of species with sensitivity to adjuvants described in the WHO guidelines is required to evaluate the toxicity of the vaccine associated with effector generation. Changes in safety pharmacology endpoints would be considered off-target and further studies are conducted only if changes in these endpoints are observed in nonclinical or clinical studies. Thus our decision tree does not recommend the routine conduct of stand-alone safety pharmacology studies.

Considerations for non-clinical safety studies of therapeutic peptide vaccines.

Guidelines for non-clinical studies of prophylactic vaccines against infectious diseases have been published widely, but similar guidelines for therapeutic vaccines, and especially therapeutic peptide vaccines, have yet to be established. The approach to non-clinical safety studies required for therapeutic vaccines differs from that for prophylactic vaccines due to differences in the risk-benefit balance and the mechanisms of action. We propose the following guidelines for non-clinical safety studies for therapeutic peptide vaccines. (i) Since the main safety concern is related to the immune response that might occur at normal sites that express a target antigen, identification of these possible target sites using in silico human expression data is important. (ii) Due to the strong dependence on HLA, it is not feasible to replicate immune responses in animals. Thus, the required non-clinical safety studies are characterized as those detecting off-target toxicity rather than on-target toxicity.

Overview of global regulatory toxicology requirements for vaccines and adjuvants.

This paper provides an overview of the legislations and regulatory approaches currently applied to the nonclinical safety assessment of human preventive vaccine products in three ICH regions, i.e., the EU, USA, and Japan. Perspectives of the three regions with regard to the various types of toxicity studies currently considered to assess the nonclinical safety of preventive vaccines are compared and described in more detail than in published guidelines. In addition, the common issues and current challenges in nonclinical safety assessment of preventive vaccines are discussed.

In situ proteomics with imaging mass spectrometry and principal component analysis in the Scrapper-knockout mouse brain.

Imaging MS is emerging as a useful tool for proteomic analysis. We utilized this technique to analyze gene knockout (KO) mice in addition to traditional 2-DE analysis. The Scrapper-knockout (SCR-KO) mouse brain showed two types of neurodegenerative pathologies, the spongiform neurodegeneration and shrinkage of neuronal cells. 2-DE analysis of the whole brain lysates of SCR-KO mice indicated slight changes in annexin A6, Rap1 GTPase, and glyoxalase domain containing four spots while most of the main components did not show significant changes. By imaging MS analysis based on principal component analysis (PCA), we could find numerous alterations in the KO mouse brain. Furthermore, we could also know the information on the position of altered substances all together. PCA provides information about which molecules in tissue microdomains have altered and is helpful in analyzing large dataset of imaging MS, while exact identification of each molecule from peaks in MALDI imaging MS may require additional analyses such as MS/MS. Direct imaging with PCA is a powerful tool to perform in situ proteomics and will lead to novel findings. Our study shows that imaging MS yields information complementary to conventional 2-DE analysis.

High-sensitivity analysis of glycosphingolipids by matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight imaging mass spectrometry on transfer membranes.

Glycosphingolipids are ubiquitous constituents of cells. Yet there is still room for improvement in the techniques for analyzing glycosphingolipids. Here we report our highly sensitive and convenient analytical technology with imaging mass spectrometry for detailed structural analysis of glycosphingolipids. We were able to determine detailed ceramide structures; i.e., both the sphingosine base and fatty acid, by MS/MS/MS analysis on a PVDF membrane with 10 pmol of GM1, with which only faint bands were visible by primuline staining. The limit of detection was approximately 1 pmol of GM1, which is lower than the value in the conventional reports (10 pmol).

Mass imaging and identification of biomolecules with MALDI-QIT-TOF-based system.

Imaging mass spectrometry is becoming a popular visualization technique in the medical and biological sciences. For its continued development, the ability to both visualize and identify molecules directly on the tissue surface using tandem mass spectrometry (MSn) is essential. We established an imaging system based on a matrix-assisted laser/desorption ionization quadrupole ion trap time-of-flight type instrument (AXIMA-QIT, Shimadzu, Kyoto, Japan), which was compatible with both imaging and highly sensitive MSn. In this paper, we present the operating conditions of the AXIMA-QIT as an imaging instrument and introduce the data converter we developed that is available free of charge. The converted data can be applied to Biomap, the commonly used visualization software. For the feasibility experiments, we demonstrated the visualization of phospholipids, glycolipid, and tryptic-digested proteins in the mouse cerebellum. The visualized lipids were successfully identified by MSn directly on the tissue surface, with a strong ability to isolate precursor ions. In the analysis of tryptic-digested proteins, we compared the product ion spectra between AXIMA-QIT and a tandem TOF-type instrument. The results confirmed that AXIMA-QIT can provide a high quality of product ion spectra even on the tissue surface.

Transcriptome analysis reveals the population of dendritic RNAs and their redistribution by neural activity.

Subcellular localization of RNA is an efficient way to localize proteins to a specific region of a cell. The dendritic localization of RNAs underlies the establishment and maintenance of the synaptic functions of neuronal cells. A requirement for dendritic RNA localization and subsequent local translation has been demonstrated in several forms of experience-dependent synaptic plasticity. In spite of several attempts to identify these RNAs, the population of RNA species present in dendrites as a whole has not been well described. Here we show the results of microarray analyses with RNAs isolated from heavy portion of polysome (HP) fraction where RNA granules are enriched in and synaptosome fraction, prepared from the rat brain. These analyses revealed the complex nature of the dendritic RNA population, which included RNAs that were not expected to be in the dendrites. Neural activity caused by an electroconvulsive shock triggered a redistribution of the population of dendritic transcriptome towards the area of overlap between the HP and the synaptosome, which is assumed to be neck of spine. This redistribution may accompany some changes in the translatability of those transcriptome, which suggests complex mechanisms of local translation in response to synaptic inputs.

In vivo imaging of the dendritic arbors of layer V pyramidal cells in the cerebral cortex using a laser scanning microscope with a stick-type objective lens.

In the field of neuroscience, low-invasive in vivo imaging would be a very useful method of monitoring the morphological dynamics of intact neurons in living animals. At present, there are two widely used in vivo imaging methods; one is the two-photon microscope method, and the other is the fiber optics method. However, these methods are not suitable for the in vivo imaging of deeper subcortical structures. In our study, we have developed a novel method for the in vivo imaging of pyramidal neurons in layer V of the cerebral cortex, utilizing a MicroLSM system and a stick-type objective lens that can be directly inserted into the target tissue. By using this method, we succeeded in obtaining clear images of pyramidal neurons in layer V of the cerebral cortex under a low-invasive condition. The MicroLSM system is a useful and versatile in vivo imaging system that will be applicable not only to the brain but also to other organs.