Matthew A. Brown's research while affiliated with Institute of Genetics and Molecular Medicine and other places

Background/Aims Acute anterior uveitis (‘uveitis’) is a common extra musculoskeletal manifestation of axial spondyloarthritis (axSpA). Interleukin (IL)-17 has been implicated in uveitis pathogenesis; however, inhibition of IL-17A alone may not be optimal for uveitis management. We report the incidence of uveitis following IL-17A and IL17F inhibition with bimekizumab (BKZ) in patients with axSpA. Methods Data were pooled for patients randomised to placebo (PBO) or BKZ 160mg every 4 weeks (Q4W) in the double-blind treatment period (DBTP) of the phase (ph)3 studies BE MOBILE 1 (NCT03928704; non-radiographic axSpA) and 2 (NCT03928743; radiographic axSpA [i.e. ankylosing spondylitis]). Data were also pooled for all patients treated with BKZ in BE MOBILE 1, BE MOBILE 2, BE MOVING (NCT04436640; open-label extension [OLE] of BE MOBILE 1 and 2), the ph2b study BE AGILE (NCT02963506; r-axSpA) and its OLE BE AGILE 2 (NCT03355573; data cut-off 4 July 2022). Uveitis events were identified using the preferred terms “autoimmune uveitis,” “iridocyclitis,” “iritis” and “uveitis,” and are reported as exposure adjusted incidence rates (EAIRs) per 100 patient-years (PY) for all patients who received ≥1 BKZ dose. Results Baseline characteristics of the axSpA study populations are shown in the Table. In the DBTP of BE MOBILE 1 and 2, uveitis events occurred in 11/237 (4.6%; EAIR/100 PY [95% CI]: 15.4 [7.7, 27.5]) and 2/349 (0.6%; 1.8 [0.2, 6.7]) patients randomised to PBO and BKZ (percentage difference [95% CI]: 4.1 [1.7, 7.6]), respectively. In 45 PBO-randomised (19.0%) and 52 BKZ-randomised (14.9%) patients with history of uveitis, uveitis occurred in 20.0% (EAIR/100 PY [95% CI]: 70.4 [32.2, 133.7]) and 1.9% (6.2 [0.2, 34.8]) of patients, respectively. In the ph2b/3 pool (N = 848) total BKZ exposure was 2,034.4 PY and 130 (15.3%) patients had history of uveitis. Uveitis occurred in 25 (2.9%; EAIR/100 PY [95% CI]: 1.2 [0.8, 1.8]) and 14 (10.8%; 4.6 [2.5, 7.7]) patients overall and with history of uveitis, respectively. All uveitis events were mild/moderate; one led to discontinuation. Conclusion Incidence of uveitis was lower to Week 16 in patients with axSpA randomised to BKZ 160mg Q4W versus PBO and remained low at 1.2/100 PY in the largest ph2b/3 pool. Disclosure M. Rudwaleit: Consultancies; AbbVie, Eli Lilly, Novartis and UCB Pharma. Member of speakers’ bureau; AbbVie, Boehringer Ingelheim, Chugai, Eli Lilly, Janssen, Novartis, Pfizer and UCB Pharma. M.A. Brown: Consultancies; Clementia, Grey Wolf Therapeutics, Incyte, Ipsen, Pfizer, Regeneron and Xinthera. Member of speakers’ bureau; Novartis and Pfizer. Grants/research support; UCB Pharma. F. van Gaalen: Grants/research support; Jacobus Stichting, Novartis, Stichting ASAS, Stichting Vrienden van Sole Mio and UCB Pharma. Other; fees from Novartis; personal fees from AbbVie, BMS, Eli Lilly and MSD. N. Haroon: Consultancies; AbbVie, Eli Lilly, Janssen, Novartis and UCB Pharma. L.S. Gensler: Consultancies; AbbVie, Acelyrin, Eli Lilly, Fresenius Kabi, Janssen, Novartis, Pfizer and UCB Pharma. Grants/research support; Novartis and UCB Pharma paid to institution. C. Fleurinck: Other; Employee of UCB Pharma. A. Marten: Other; Employee of UCB Pharma. U. Massow: Other; Employee of UCB Pharma. N. de Peyrecave: Other; Employee of UCB Pharma. T. Vaux: Other; Employee of UCB Pharma. K. White: Shareholder/stock ownership; UCB Pharma. Other; Employee of UCB Pharma. A. Deodhar: Consultancies; AbbVie, BMS, Eli Lilly, Janssen, MoonLake, Novartis, Pfizer and UCB Pharma. Member of speakers’ bureau; Janssen, Novartis and Pfizer. Grants/research support; AbbVie, BMS, Celgene, Eli Lilly, MoonLake, Novartis, Pfizer and UCB Pharma. D. McGonagle: Consultancies; AbbVie, Celgene, Janssen, Merck, Novartis, Pfizer and UCB Pharma. Honoraria; AbbVie, Celgene, Janssen, Merck, Novartis, Pfizer and UCB Pharma. Member of speakers’ bureau; AbbVie, Celgene, Janssen, Merck, Novartis, Pfizer and UCB Pharma. Grants/research support; AbbVie, Celgene, Janssen, Merck and Pfizer. I. van der Horst-Bruinsma: Consultancies; Abbvie, Eli Lilly, MSD, Novartis and UCB Pharma. Other; unrestricted grants received for investigator-initiated studies from AbbVie, MSD, Pfizer and UCB Pharma; fees received for lectures from AbbVie, BMS, MSD and Pfizer.

Background The design of clinical trials in rare diseases is often complicated by a lack of real-world translational knowledge. Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disorder characterized by skeletal malformations and progressive heterotopic ossification (HO). Palovarotene is a selective retinoic acid receptor gamma agonist. Here, we describe the methodology of three studies in the palovarotene clinical development program in FOP and discuss insights that could inform future research, including endpoint suitability and the impact of trial design. Methods PVO-1A-001 (NCT02322255) was a prospective, protocol-specified, longitudinal FOP natural history study (NHS). PVO-1A-201 (NCT02190747) was a randomized, double-blind, placebo-controlled phase II trial; PVO-1A-202 (NCT02279095) was its open-label extension. Trial designs, including treatment regimens and imaging assessments, were refined between PVO-1A-201 and PVO-‍1A-202, and within PVO-1A-202, based on emerging data as the studies progressed. Palovarotene doses were administered using a flare-up treatment regimen (higher dose for 2/4 weeks, followed by lower dose for 4/≥8 weeks; from flare-up onset), with or without accompanying chronic (daily) treatment. Flare-up and disease progression outcomes were assessed, including incidence and volume of new HO during flare-ups and/or annually, as well as other clinical, patient-reported, and exploratory outcomes. Safety was monitored throughout all studies. Results Overall, 114 and 58 individuals with FOP were enrolled in the NHS and phase II trials, respectively. Results of the NHS and PVO-1A-201 were published in 2022; complete results of PVO-1A-202 will be publicly available in due course. Together the studies yielded important information on endpoint suitability, including that low-dose whole-body computed tomography was the optimum imaging modality for assessing HO progression annually and that long study durations are needed to detect substantial changes in functional and patient-reported outcomes. Conclusions A flexible clinical development program is necessary for underexplored rare diseases to overcome the many challenges faced. Here, the NHS provided a longitudinal evaluation of FOP progression and interventional trials were based on emerging data. The studies described informed the design and endpoints implemented in the phase III MOVE trial (NCT03312634) and provide a foundation for future clinical trial development. Trial registration NCT02322255 (registered 23/12/2014); NCT02190747 (registered 15/07/2014); NCT02279095 (registered 30/10/2014).

Psoriasis is a common, debilitating immune-mediated skin disease. Genetic studies have identified biological mechanisms of psoriasis risk, including those targeted by effective therapies. However, the genetic liability to psoriasis is not fully explained by variation at robustly identified risk loci. To move towards a saturation map of psoriasis susceptibility we meta-analysed 18 GWAS comprising 36,466 cases and 458,078 controls and identified 109 distinct psoriasis susceptibility loci, including 45 that have not been previously reported. These include susceptibility variants at loci in which the therapeutic targets IL17RA and AHR are encoded, and deleterious coding variants supporting potential new drug targets (including in STAP2, CPVL and POU2F3). We conducted a transcriptome-wide association study to identify regulatory effects of psoriasis susceptibility variants and cross-referenced these against single cell expression profiles in psoriasis-affected skin, highlighting roles for the transcriptional regulation of haematopoietic cell development and epigenetic modulation of interferon signalling in psoriasis pathobiology.

Introduction Ankylosing spondylitis (AS), and carriage of HLA-B27 gene in otherwise healthy individuals, are reportedly associated with increased mortality. We evaluated this hypothesis, using data from both a 35-year AS follow-up study and UK Biobank data. Methods In 1985, 363 members of the Swiss AS Patient Society and 806 relatives were screened clinically and then radiographically for AS/axial spondyloarthritis (axSpA). Life expectancy was analysed in 377 axSpA patients having available pelvic radiographs and HLA-B27 status, comparing with matched Swiss population data. Survival in relation to HLA-B27 status in the general population was studied in UK Biobank European-ancestry participants (n=407 480, n=30 419 deaths). Results AS patients have increased standardised mortality rate (SMR) compared with the general population (1.37, 95% CI 1.11 to 1.62). This increase was significant for HLA-B27-positive AS (SMR 1.38, 95% CI 1.11 to 1.65). Shortened life expectancy was observed among both HLA-B27-positive AS women (SMR 1.77, 95% CI 1.09 to 2.70) and men (SMR 1.31, 95% CI 1.02 to 1.59). Patients with non-radiographic axSpA (nr-axSpA) had significantly lower SMR: 0.44 (95% CI 0.23 to 0.77), compared with the general population. In the UK Biobank European-ancestry population cohort, HLA-B27 carriage was not significantly associated with any change in mortality (HR 1, 95% CI 0.97 to 1.1, p=0.349, adjusted by sex), in either males (HR 1, 95% CI 0.98 to 1.1, p=0.281) or females (HR 0.96, 95% CI 0.9 to 1, p=0.232), and no increase in vascular disease mortality was observed. Discussion AS patients, but not nr-axSpA patients, have a significantly shortened life expectancy. Increased mortality is particularly significant among women with HLA-B27-positive AS. HLA-B27 carriage in the European-ancestry general population does not influence survival, or the risk of death due to vascular disease.

By converting physical forces into electrical signals or triggering intracellular cascades, stretch-activated ion channels allow the cell to respond to osmotic and mechanical stress. Knowledge of the pathophysiological mechanisms underlying associations of stretch-activated ion channels with human disease is limited. Here, we describe 17 unrelated individuals with severe early-onset developmental and epileptic encephalopathy (DEE), intellectual disability, and severe motor and cortical visual impairment associated with progressive neurodegenerative brain changes carrying ten distinct heterozygous variants of TMEM63B, encoding for a highly conserved stretch-activated ion channel. The variants occurred de novo in 16/17 individuals for whom parental DNA was available and either missense, including the recurrent p.Val44Met in 7/17 individuals, or in-frame, all affecting conserved residues located in transmembrane regions of the protein. In 12 individuals, hematological abnormalities co-occurred, such as macrocytosis and hemolysis, requiring blood transfusions in some. We modeled six variants (p.Val44Met, p.Arg433His, p.Thr481Asn, p.Gly580Ser, p.Arg660Thr, and p.Phe697Leu), each affecting a distinct transmembrane domain of the channel, in transfected Neuro2a cells and demonstrated inward leak cation currents across the mutated channel even in isotonic conditions, while the response to hypo-osmotic challenge was impaired, as were the Ca2+ transients generated under hypo-osmotic stimulation. Ectopic expression of the p.Val44Met and p.Gly580Cys variants in Drosophila resulted in early death. TMEM63B-associated DEE represents a recognizable clinicopathological entity in which altered cation conductivity results in a severe neurological phenotype with progressive brain damage and early-onset epilepsy associated with hematological abnormalities in most individuals.

The transcription factor STAT6 (Signal Transducer and Activator of Transcription 6) is a key regulator of Th2 (T-helper 2) mediated allergic inflammation via the IL-4 (interleukin-4) JAK (Janus kinase)/STAT signalling pathway. We identified a novel heterozygous germline mutation STAT6 c.1255G > C, p.D419H leading to overactivity of IL-4 JAK/STAT signalling pathway, in a kindred affected by early-onset atopic dermatitis, food allergy, eosinophilic asthma, anaphylaxis and follicular lymphoma. STAT6 D419H expression and functional activity were compared with wild type STAT6 in transduced HEK293T cells and to healthy control primary skin fibroblasts and peripheral blood mononuclear cells (PBMC). We observed consistently higher STAT6 levels at baseline and higher STAT6 and phosphorylated STAT6 following IL-4 stimulation in D419H cell lines and primary cells compared to wild type controls. The pSTAT6/STAT6 ratios were unchanged between D419H and control cells suggesting that elevated pSTAT6 levels resulted from higher total basal STAT6 expression. The selective JAK1/JAK2 inhibitor ruxolitinib reduced pSTAT6 levels in D419H HEK293T cells and patient PBMC. Nuclear staining demonstrated increased STAT6 in patient fibroblasts at baseline and both STAT6 and pSTAT6 after IL-4 stimulation. We also observed higher transcriptional upregulation of downstream genes ( XBP1 and EPAS1 ) in patient PBMC. Our study confirms STAT6 gain of function (GOF) as a novel monogenetic cause of early onset atopic disease. The clinical association of lymphoma in our kindred, along with previous data linking somatic STAT6 D419H mutations to follicular lymphoma suggest that patients with STAT6 GOF disease may be at higher risk of lymphomagenesis. 245 words.

Ankylosing spondylitis (AS) is an inflammatory disease leading to spine ankylosis; however, the mechanisms behind new bone formation are still not fully understood. Single Nucleotide Polymorphisms (SNPs) in PTGER4, encoding for the receptor EP4 of prostaglandin E2 (PGE2), are associated with AS. Since the PGE2-EP4 axis participates in inflammation and bone metabolism, this work aims at investigating the influence of the prostaglandin-E2 axis on radiographic progression in AS. In 185 AS (97 progressors), baseline serum PGE2 predicted progression, and PTGER4 SNP rs6896969 was more frequent in progressors. Increased EP4/PTGER4 expression was observed in AS circulating immune cells, synovial tissue, and bone marrow. CD14highEP4 + cells frequency correlated with disease activity, and when monocytes were cocultured with mesenchymal stem cells, the PGE2/EP4 axis induced bone formation. In conclusion, the Prostaglandin E2 axis is involved in bone remodelling and may contribute to the radiographic progression in AS due to genetic and environmental upregulation.

Anabolic treatment options for osteoporosis remain limited. One approach to discovering novel anabolic drug targets is to identify genetic causes of extreme high bone mass (HBM). We investigated a pedigree with unexplained HBM within the UK HBM study, a national cohort of probands with HBM and their relatives. Whole exome sequencing (WES) in a family with HBM identified a rare heterozygous missense variant (NM_004482.4:c.1657C>T, p.Arg553Trp) in GALNT3, segregating appropriately. Interrogation of data from the UK HBM study and the Anglo-Australasian Osteoporosis Genetics Consortium (AOGC) revealed an unrelated individual with HBM with another rare heterozygous variant (NM_004482.4:c.831T>A, p.Asp277Glu) within the same gene. In silico protein modelling predicted that p.Arg553Trp would disrupt salt-bridge interactions, causing instability of GALNT3; and that p.Asp277Glu would disrupt manganese binding and consequently GALNT3 catalytic function. Bi-allelic loss-of-function GALNT3 mutations alter FGF23 metabolism, resulting in hyperphosphatemia and causing familial tumoral calcinosis (FTC). However, bone mineral density (BMD) in FTC cases, when reported, has been either normal or low. Common variants in the GALNT3 locus show genome-wide significant associations with lumbar, femoral neck, and total body BMD. However, no significant associations with BMD are observed at loci coding for FGF23, its receptor FGFR1, or co-receptor klotho. Mendelian randomization analysis, using expression quantitative trait loci (eQTL) data from primary human osteoblasts and GWAS data from UK Biobank, suggested increased expression of GALNT3 reduces total body, lumbar spine and femoral neck BMD but has no effect on phosphate concentrations. In conclusion, rare heterozygous loss-of-function variants in GALNT3 may cause HBM without altering phosphate concentration. These findings suggest that GALNT3 may affect BMD through pathways other than FGF23 regulation, identification of which may yield novel anabolic drug targets for osteoporosis.

What is this summary about? This is a plain language summary of an article originally published in the Journal of Bone and Mineral Research. People with fibrodysplasia ossificans progressiva (FOP) become physically disabled over time as new bone forms in places where it is not usually found, such as in muscles and ligaments. Until recently, there were no treatments for FOP that had been proven through clinical trials; however, a drug called palovarotene has been tested in clinical trials and may be effective. Here, we describe the MOVE trial, which investigated how effectively palovarotene works, as well as its safety in treating patients with FOP. What were the results? Results from MOVE suggest that palovarotene may reduce extra bone formation outside the normal skeleton. Patients with FOP who took palovarotene formed less new bone than those who did not take palovarotene. The most common side effects involved the skin, and included dryness and irritation. Some children who were still growing when they took palovarotene had a side effect that resulted in the (normal) growth of their skeleton stopping too soon. What do the results of the trial mean? Palovarotene may be a useful treatment option for FOP. Patients, caregivers, and doctors would need to consider the benefits and risks of treatment with palovarotene, particularly with growing children. Clinical Trial Registration: NCT03312634 ( ClinicalTrials.gov )