Prion protein monoclonal antibody (PRN100) therapy for Creutzfeldt–Jakob disease: evaluation of a first-in-human treatment programme

Background: Human prion diseases, including Creutzfeldt–Jakob disease (CJD), are rapidly progressive, invariably fatal neurodegenerative conditions with no effective therapies. Their pathogenesis involves the obligate recruitment of cellular prion protein (PrPC) into self-propagating multimeric assemblies or prions. Preclinical studies have firmly validated the targeting of PrPC as a therapeutic strategy. We aimed to evaluate a first-in-human treatment programme using an anti-PrPC monoclonal antibody under a Specials Licence. Methods: We generated a fully humanised anti-PrPC monoclonal antibody (an IgG4κ isotype; PRN100) for human use. We offered treatment with PRN100 to six patients with a clinical diagnosis of probable CJD who were not in the terminal disease stages at the point of first assessment and who were able to readily travel to the University College London Hospital (UCLH) Clinical Research Facility, London, UK, for treatment. After titration (1 mg/kg and 10 mg/kg at 48-h intervals), patients were treated with 80–120 mg/kg of intravenous PRN100 every 2 weeks until death or withdrawal from the programme, or until the supply of PRN100 was exhausted, and closely monitored for evidence of adverse effects. Disease progression was assessed by use of the Medical Research Council (MRC) Prion Disease Rating Scale, Motor Scale, and Cognitive Scale, and compared with that of untreated natural history controls (matched for disease severity, subtype, and PRNP codon 129 genotype) recruited between Oct 1, 2008, and July 31, 2018, from the National Prion Monitoring Cohort study. Autopsies were done in two patients and findings were compared with those from untreated natural history controls. Findings: We treated six patients (two men; four women) with CJD for 7–260 days at UCLH between Oct 9, 2018, and July 31, 2019. Repeated intravenous dosing of PRN100 was well tolerated and reached the target CSF drug concentration (50 nM) in four patients after 22–70 days; no clinically significant adverse reactions were seen. All patients showed progressive neurological decline on serial assessments with the MRC Scales. Neuropathological examination was done in two patients (patients 2 and 3) and showed no evidence of cytotoxicity. Patient 2, who was treated for 140 days, had the longest clinical duration we have yet documented for iatrogenic CJD and showed patterns of disease-associated PrP that differed from untreated patients with CJD, consistent with drug effects. Patient 3, who had sporadic CJD and only received one therapeutic dose of 80 mg/kg, had weak PrP synaptic labelling in the periventricular regions, which was not a feature of untreated patients with sporadic CJD. Brain tissue-bound drug concentrations across multiple regions in patient 2 ranged from 9·9 μg per g of tissue (SD 0·3) in the thalamus to 27·4 μg per g of tissue (1·5) in the basal ganglia (equivalent to 66–182 nM). Interpretation: Our academic-led programme delivered what is, to our knowledge, the first rationally designed experimental treatment for human prion disease to a small number of patients with CJD. The treatment appeared to be safe and reached encouraging CSF and brain tissue concentrations. These findings justify the need for formal efficacy trials in patients with CJD at the earliest possible clinical stages and as prophylaxis in those at risk of prion disease due to PRNP mutations or prion exposure. Funding: The Cure CJD Campaign, the National Institute for Health Research UCLH Biomedical Research Centre, the Jon Moulton Charitable Trust, and the UK MRC

Fractures are common within 18 months following first-line R-CHOP in older patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) and osteoporotic fracture are both more common in older patients. Exposure to R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) is likely to increase the risk of fracture, but evidence is lacking to define fracture incidence in this group. Data on consecutive patients with DLBCL aged ≥70 years treated with 1 to 8 cycles of full or attenuated R-CHOP were retrospectively collected across 10 UK centers (2009-2019). Patients were followed up from starting R-CHOP for a minimum of 6 months and censored at 18 months; at last follow-up if <18 months; or at progression or death. Of 877 patients identified, 148 were excluded: 121 had progression or died before 6 months; 23 had follow-up <6 months. Across 729 remaining patients, the median age was 77 years, and 68% had an Eastern Cooperative Oncology Group performance status of 0 to 1. Eighty-one fractures occurred within 18 months of follow-up; 42 were symptomatic, including 30 requiring hospital attendance or admission. The cumulative fracture incidence was 6.2% (95% confidence interval [CI], 4.7-8.2) at 6 months; 9.7% (95% CI, 7.8-12.1) at 12 months; and 11.4% (95% CI, 9.3-14.0) at 18 months. Multivariate analysis identified a predisposing history (osteoporosis, osteopenia, prior fracture, and rheumatoid arthritis [RhA]), DLBCL bone involvement at baseline, and receipt of prephase steroids as independent risk factors for fracture. There is a clinically relevant fracture risk and significant associated morbidity in older patients receiving R-CHOP. Careful attention to bone health is warranted in older patients receiving R-CHOP. Randomized studies are required to better define the most effective strategies to reduce fracture risk

The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis

<p>Abstract</p> <p>Background</p> <p>The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed.</p> <p>Results</p> <p>Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented.</p> <p>Conclusions</p> <p>This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.</p

Anopheles kochi in Irian Jaya detected by size polymorphism of polymerase chain reaction-amplified internal transcribed spacer unit 2

Anopheles kochi is reported for the Ist time from New Guinea, probably introduced by aircraft. This Oriental species was originally detected by analysis of polymerase chain reaction-amplified rDNA internal transcribed spacer unit 2 (ITS-2). identification was confirmed by morphologic examination. Size of ITS-2 is presented for 32 species of Australasian and Oriental anophelines to assist morphologic identifications for distribution and vector studies

CCR9 inhibition does not interfere with the development of immune tolerance to oral antigens

AbstractRecent literature indicates that mice deficient in the chemokine receptor CCR9 (CCR9−/− mice) are unable to generate oral tolerance. The present report describes how such inability can be overcome by increasing the dose of oral antigen. Pharmacological inhibition of CCR9 did not affect the generation of oral tolerance, regardless of antigen dose. These results highlight the inadequacy of genetic deletion of CCR9 when predicting the effects of pharmacological CCR9 inhibition on intestinal biology