Lot-to-lot immunogenicity consistency of the respiratory syncytial virus prefusion F protein vaccine in older adults.

Background: Previous phase 3 studies showed that the AS01E-adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine for older adults (RSVPreF3 OA) is well tolerated and efficacious in preventing RSV-associated lower respiratory tract disease in adults ≥ 60 years of age. This study evaluated lot-to-lot immunogenicity consistency, reactogenicity, and safety of three RSVPreF3 OA lots. Methods: This phase 3, multicenter, double-blind study randomized (1:1:1) participants ≥ 60 years of age to receive one of three RSVPreF3 OA lots. Serum RSVPreF3-binding immunoglobulin G (IgG) concentration was assessed at baseline and 30 days post-vaccination. Lot-to-lot consistency was demonstrated if the two-sided 95 % confidence intervals (CIs) of the RSVPreF3-binding IgG geometric mean concentration (GMC) ratios between each lot pair at 30 days post-vaccination were within 0.67 and 1.50. Solicited adverse events (AEs) within four days, unsolicited AEs within 30 days, and serious AEs (SAEs) and potential immune-mediated diseases within six months post-vaccination were recorded. Results: A total of 757 participants received RSVPreF3 OA, of whom 708 were included in the per-protocol set (234, 237, and 237 participants for each lot). Lot-to-lot consistency was demonstrated: GMC ratios were 1.06 (95 % CI: 0.94-1.21), 0.92 (0.81-1.04), and 0.87 (0.77-0.99) between the lot pairs (lot 1/2; 1/3; 2/3). For the three lots, the RSVPreF3-binding IgG concentration increased 11.84-, 11.29-, and 12.46-fold post-vaccination compared to baseline. The reporting rates of solicited and unsolicited AEs, SAEs, and potential immune-mediated diseases were balanced between lots. Twenty-one participants reported SAEs; one of these-a case of atrial fibrillation-was considered by the investigator as vaccine-related. SAEs with a fatal outcome were reported for four participants, none of which were considered by the investigator as vaccine-related. Conclusion: This study demonstrated lot-to-lot immunogenicity consistency of three RSVPreF3 OA vaccine lots and indicated that the vaccine had an acceptable safety profile.ClinicalTrials.gov: NCT05059301.

Safety and Immunogenicity of a Revaccination With a Respiratory Syncytial Virus Prefusion F Vaccine in Older Adults: A Phase 2b Study.

BACKGROUND: In the previous (parent) study, 2 doses of different formulations of an investigational vaccine against respiratory syncytial virus (RSVPreF3 OA) were well tolerated and immunogenic in older adults. This multicenter phase 2b extension study assessed safety and immunogenicity of a revaccination (third) dose of the 120 µg RSVPreF3-AS01E formulation. METHODS: In total, 122 older adults (60-80 years), previously vaccinated with 2 doses of RSVPreF3-AS01E formulations (containing 30, 60, or 120 µg RSVPreF3 antigen), received an additional 120 µg RSVPreF3-AS01E dose 18 months after dose 2. Vaccine safety was evaluated in all participants up to 6 months and immunogenicity in participants who received 120 µg RSVPreF3-AS01E doses until 1 month after dose 3. RESULTS: Similar to the parent study, mostly mild-to-moderate solicited adverse events and no vaccine-related serious adverse events or potential immune-mediated disorders were reported. Neutralizing titers and cell-mediated immune responses persisted for 18 months after 2-dose vaccination. Dose 3 increased RSV-specific neutralizing titers against RSV-A and RSV-B and median CD4+ T-cell frequencies. After dose 3, RSV-specific neutralizing titers but not CD4+ T-cell frequencies were below levels detected 1 month after dose 1. CONCLUSIONS: Revaccination with 120 µg RSVPreF3-AS01E 18 months after dose 2 is well tolerated and immunogenic in older adults. CLINICAL TRIALS REGISTRATION: NCT04657198; EudraCT, 2020-000692-21.

Respiratory syncytial virus (RSV) is a common, contagious seasonal virus causing respiratory tract infections. In older adults, RSV can cause serious respiratory illnesses or worsen underlying medical conditions such as chronic diseases of the lungs or heart failure. Severe disease may lead to hospitalization, increased need for oxygen, and ventilatory support. However, several vaccines against RSV in older adults have recently been licensed in the United States and European Union. This study evaluated safety and immune responses after revaccination (third dose) with an adjuvanted vaccine against RSV in older adults aged 60­80 years, who had received 2 doses of the vaccine with a similar adjuvanted formulation in a previous (parent) study. Revaccination was done with the licensed vaccine formulation, which was also selected for further investigation in several phase 3 clinical trials. This study found that immune responses against RSV persisted above prevaccination levels for at least 18 months after the second vaccination in the parent study. The third vaccine dose was well tolerated and recalled the immune responses in older adults. Together with the ongoing confirmatory clinical trials, these results help better characterize this RSV vaccine, in terms of safety and RSV-specific immune responses elicited in older adults.

Safety and immunogenicity of a respiratory syncytial virus prefusion F protein (RSVPreF3) candidate vaccine in older Japanese adults: A phase I, randomized, observer-blind clinical trial.

BACKGROUND: Respiratory syncytial virus (RSV) causes lower respiratory tract infection, with a high burden of disease among adults ≥60 years. This study assessed the safety, reactogenicity, and immunogenicity of an investigational adjuvanted RSV vaccine (RSVPreF3/AS01B) in Japanese adults aged 60-80 years. METHODS: Forty participants were randomized to receive two doses of RSVPreF3/AS01B or the placebo, in a 1:1 ratio, two months apart, in this placebo-controlled study. Solicited administration-site and systemic adverse events (AEs) were collected within 7 days and unsolicited AEs within 30 days post-vaccination. Serious AEs (SAEs) and potential immune-mediated diseases (pIMDs) were collected throughout the study (12 months post-dose 2). RSVPreF3-specific immunoglobulin G (IgG) antibody concentrations and neutralizing antibody (nAb) titers against RSV-A were evaluated on day (D)1, D31, D61, D91 and those against RSV-B on D1, D31, D91. RESULTS: Solicited AEs were reported more frequently in RSVPreF3/AS01B recipients (80.0%-90.0%) than in placebo recipients (10.0%-20.0%). Two RSVPreF3/AS01B recipients experienced grade 3 solicited AEs. Rate of unsolicited AEs were similar (30.0%-35.0%) in both groups. No RSVPreF3/AS01B recipient reported SAEs/pIMDs, while one placebo recipient reported two SAEs that were unrelated to vaccination. Baseline RSVPreF3-specific IgG and RSV-A/-B nAb levels were above the assay cut-off values. In the RSVPreF3/AS01B group, RSVPreF3-specific IgG concentrations increased 12.8-fold on D31 and 9.2-fold on D91 versus baseline while nAb titers increased 7.3-fold (RSV-A) and 8.4-fold (RSV-B) on D31 and 6.3-fold (RSV-A) and 9.9-fold (RSV-B) on D91. CONCLUSIONS: The RSVPreF3/AS01B vaccine was well tolerated and immunogenic in older Japanese adults. CLINICAL TRIAL REGISTRATION NUMBER: NCT04090658.

Author Correction: Selective Priming of Tumor Blood Vessels by Radiation Therapy Enhances Nanodrug Delivery.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Selective Priming of Tumor Blood Vessels by Radiation Therapy Enhances Nanodrug Delivery.

Effective drug delivery is restricted by pathophysiological barriers in solid tumors. In human pancreatic adenocarcinoma, poorly-permeable blood vessels limit the intratumoral permeation and penetration of chemo or nanotherapeutic drugs. New and clinically viable strategies are urgently sought to breach the neoplastic barriers that prevent effective drug delivery. Here, we present an original idea to boost drug delivery by selectively knocking down the tumor vascular barrier in a human pancreatic cancer model. Clinical radiation activates the tumor endothelial-targeted gold nanoparticles to induce a physical vascular damage due to the high photoelectric interactions. Active modulation of these tumor neovessels lead to distinct changes in tumor vascular permeability. Noninvasive MRI and fluorescence studies, using a short-circulating nanocarrier with MR-sensitive gadolinium and a long-circulating nanocarrier with fluorescence-sensitive nearinfrared dye, demonstrate more than two-fold increase in nanodrug delivery, post tumor vascular modulation. Functional changes in altered tumor blood vessels and its downstream parameters, particularly, changes in Ktrans (permeability), Kep (flux rate), and Ve (extracellular interstitial volume), reflect changes that relate to augmented drug delivery. The proposed dual-targeted therapy effectively invades the tumor vascular barrier and improve nanodrug delivery in a human pancreatic tumor model and it may also be applied to other nonresectable, intransigent tumors that barely respond to standard drug therapies.

Pre-clinical imaging for establishment and comparison of orthotopic non-small cell lung carcinoma: in search for models reflecting clinical scenarios.

OBJECTIVE:: Clinically relevant animal models of non-small cell lung carcinoma (NSCLC) are required for the validation of novel treatments. We compared two different orthotopic transplantation techniques as well as imaging modalities to identify suitable mouse models mimicking clinical scenarios. METHODS:: We used three genomically diverse NSCLC cell lines [National Cancer Institute (NCI)-H1703 adenosquamous cell carcinoma, NCI-H23 adenocarcinoma and A549 adenocarcinoma) for implanting tumour cells either as spheroids or cell suspension into lung parenchyma. Bioluminescence imaging (BLI) and contrast-enhanced cone beam CT (CBCT) were performed twice weekly to monitor tumour growth. Tumour histological data and microenvironmental parameters were determined. RESULTS:: Tumour development after spheroid-based transplantation differs probably due to the integrity of spheroids, as H1703 developed single localised nodules, whereas H23 showed diffuse metastatic spread starting early after transplantation. A549 transplantation as cell suspension with the help of a stereotactic system was associated with initial single localised tumour growth and eventual metastatic spread. Imaging techniques were successfully applied to monitor longitudinal tumour growth: BLI revealed highly sensitive qualitative data, whereas CBCT was associated with less sensitive quantitative data. Histology revealed significant model-dependent heterogeneity in proliferation, hypoxia, perfusion and necrosis. CONCLUSION:: Our developed orthotopic NSCLC tumours have similarity with biological growth behaviour comparable to that seen in the clinic and could therefore be used as attractive models to study tumour biology and evaluate new therapeutic strategies. The use of human cancer cell lines facilitates testing of different genomic tumour profiles that may affect treatment outcomes. ADVANCES IN KNOWLEDGE:: The combination of different imaging modalities to identify tumour growth with subsequent use in treatment planning and orthotopic transplantation techniques to develop initially single lesions to ultimate metastases pave the way towards representative pre-clinical NSCLC models for experimental testing of novel therapeutic options in future studies.

Safety Evaluation and Imaging Properties of Gadolinium-Based Nanoparticles in nonhuman primates.

In this article, we report the safety evaluation of gadolinium-based nanoparticles in nonhuman primates (NHP) in the context of magnetic resonance imaging (MRI) studies in atherosclerosis bearing animals and healthy controls. In healthy NHP, the pharmacokinetics and toxicity profiles demonstrated the absence of dose, time, and sex-effects, as well as a suitable tolerance of intravenous administration of the nanoparticles. We investigated their imaging properties for arterial plaque imaging in a standard diet or a high cholesterol diet NHP, and compared their characteristics with clinically applied Gd-chelate. This preliminary investigation reports the efficient and safe imaging of atherosclerotic plaques.

Key clinical beam parameters for nanoparticle-mediated radiation dose amplification.

As nanoparticle solutions move towards human clinical trials in radiation therapy, the influence of key clinical beam parameters on therapeutic efficacy must be considered. In this study, we have investigated the clinical radiation therapy delivery variables that may significantly affect nanoparticle-mediated radiation dose amplification. We found a benefit for situations which increased the proportion of low energy photons in the incident beam. Most notably, "unflattened" photon beams from a clinical linear accelerator results in improved outcomes relative to conventional "flat" beams. This is measured by significant DNA damage, tumor growth suppression, and overall improvement in survival in a pancreatic tumor model. These results, obtained in a clinical setting, clearly demonstrate the influence and importance of radiation therapy parameters that will impact clinical radiation dose amplification with nanoparticles.

Gadolinium-Based Nanoparticles and Radiation Therapy for Multiple Brain Melanoma Metastases: Proof of Concept before Phase I Trial.

Nanoparticles containing high-Z elements are known to boost the efficacy of radiation therapy. Gadolinium (Gd) is particularly attractive because this element is also a positive contrast agent for MRI, which allows for the simultaneous use of imaging to guide the irradiation and to delineate the tumor. In this study, we used the Gd-based nanoparticles, AGuIX®. After intravenous injection into animals bearing B16F10 tumors, some nanoparticles remained inside the tumor cells for more than 24 hours, indicating that a single administration of nanoparticles might be sufficient for several irradiations. Combining AGuIX® with radiation therapy increases tumor cell death, and improves the life spans of animals bearing multiple brain melanoma metastases. These results provide preclinical proof-of-concept for a phase I clinical trial.

Ultrasmall Nanoplatforms as Calcium-Responsive Contrast Agents for Magnetic Resonance Imaging.

The preparation of ultrasmall and rigid platforms (USRPs) that are covalently coupled to macrocycle-based, calcium-responsive/smart contrast agents (SCAs), and the initial in vitro and in vivo validation of the resulting nanosized probes (SCA-USRPs) by means of magnetic resonance imaging (MRI) is reported. The synthetic procedure is robust, allowing preparation of the SCA-USRPs on a multigram scale. The resulting platforms display the desired MRI activity­i.e., longitudinal relaxivity increases almost twice at 7 T magnetic field strength upon saturation with Ca(2+). Cell viability is probed with the MTT assay using HEK-293 cells, which show good tolerance for lower contrast agent concentrations over longer periods of time. On intravenous administration of SCA-USRPs in living mice, MRI studies indicate their rapid accumulation in the renal pelvis and parenchyma. Importantly, the MRI signal increases in both kidney compartments when CaCl2 is also administrated. Laser-induced breakdown spectroscopy experiments confirm accumulation of SCA-USRPs in the renal cortex. To the best of our knowledge, these are the first studies which demonstrate calcium-sensitive MRI signal changes in vivo. Continuing contrast agent and MRI protocol optimizations should lead to wider application of these responsive probes and development of superior functional methods for monitoring calcium-dependent physiological and pathological processes in a dynamic manner.

Long-term in vivo clearance of gadolinium-based AGuIX nanoparticles and their biocompatibility after systemic injection.

We previously reported the synthesis of gadolinium-based nanoparticles (NPs) denoted AGuIX (activation and guiding of irradiation by X-ray) NPs and demonstrated their potential as an MRI contrast agent and their efficacy as radiosensitizing particles during X-ray cancer treatment. Here we focus on the elimination kinetics of AGuIX NPs from the subcellular to whole-organ scale using original and complementary methods such as laser-induced breakdown spectroscopy (LIBS), intravital two-photon microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), transmission electron microscopy (TEM), and electrospray ionization mass spectrometry (ESI-MS). This combination of techniques allows the exact mechanism of AGuIX NPs elimination to be elucidated, including their retention in proximal tubules and their excretion as degraded or native NPs. Finally, we demonstrated that systemic AGuIX NP administration induced moderate and transient effects on renal function. These results provide useful and promising preclinical information concerning the safety of theranostic AGuIX NPs.

Laser-induced breakdown spectroscopy: a new approach for nanoparticle's mapping and quantification in organ tissue.

Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) performed on thin sections of rodent tissues: kidneys and tumor, allows the detection of inorganic elements such as (i) Na, Ca, Cu, Mg, P, and Fe, naturally present in the body and (ii) Si and Gd, detected after the injection of gadolinium-based nanoparticles. The animals were euthanized 1 to 24 hr after intravenous injection of particles. A two-dimensional scan of the sample, performed using a motorized micrometric 3D-stage, allowed the infrared laser beam exploring the surface with a lateral resolution less than 100 µm. Quantitative chemical images of Gd element inside the organ were obtained with sub-mM sensitivity. LIBS offers a simple and robust method to study the distribution of inorganic materials without any specific labeling. Moreover, the compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of the same biological tissue with different types of response: elemental, molecular, or cellular.