A randomised, double-blind, placebo-controlled study of the LAG-3-depleting monoclonal antibody GSK2831781 in patients with active ulcerative colitis

BACKGROUND

Selective depletion of T cells expressing LAG-3, an immune checkpoint receptor that is upregulated on activated T cells, has been investigated in pre-clinical models as a potential therapeutic approach in inflammatory and autoimmune diseases where activated T cells are implicated.

AIMS

GSK2831781, a depleting monoclonal antibody that specifically binds LAG-3 proteins, may deplete activated LAG-3⁺ cells in ulcerative colitis (UC).

METHODS

Patients with moderate to severe UC were randomised to GSK2831781 or placebo. Safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of GSK2831781 were evaluated.

RESULTS

One hundred four participants across all dose levels were randomised prior to an interim analysis indicating efficacy futility criteria had been met. Efficacy results focus on the double-blind induction phase of the study (GSK2831781 450 mg intravenously [IV], N = 48; placebo, N = 27). Median change from baseline (95% credible interval [CrI]) in complete Mayo score was similar between groups (GSK2831781 450 mg IV: -1.4 [-2.2, -0.7]; placebo: -1.4 [-2.4, -0.5]). Response rates for endoscopic improvement favoured placebo. Clinical remission rates were similar between groups. In the 450-mg IV group, 14 (29%) participants had an adverse event of UC versus 1 (4%) with placebo. LAG-3⁺ cells were depleted to 51% of baseline in blood; however, there was no reduction in LAG-3⁺ cells in the colonic mucosa. Transcriptomic analysis of colon biopsies showed no difference between groups.

CONCLUSION

Despite evidence of target cell depletion in blood, GSK2831781 failed to reduce inflammation in the colonic mucosa suggesting no pharmacological effect. The study was terminated early (NCT03893565).

Randomized Trial of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of GSK2831781 in Healthy Japanese and White Participants

This study investigated ethnic differences in the safety, tolerability, pharmacokinetics, and pharmacodynamics of GSK2831781, an anti-lymphocyte activation gene 3 (LAG3) monoclonal antibody, in healthy participants, and determined local tolerability and bioavailability following subcutaneous (SC) administration. A double-blind, randomized study of (A) single intravenous (IV) doses of GSK2831781 450 mg or placebo in Japanese and White participants; and (B) single SC doses of GSK2831781 150 or 450 mg, or placebo in White participants, was conducted. Blood samples for analyses were collected before dosing and over 112 days after dosing. GSK2831781 was well tolerated in Japanese and White participants after both IV and SC doses, with the adverse event profile in Japanese being consistent with other populations. There were no injection site adverse events. There was no evidence of differences in systemic exposure among Japanese and White participants. Systemic exposure did not vary with body weight. SC bioavailability was 76.5%, as estimated using population pharmacokinetic modeling. Full and sustained target engagement and evidence of LAG3⁺ cell depletion (≈53%-66%) were observed in both populations and after both administration routes. No evidence of reduced circulating regulatory T cells (CD4⁺ CD25⁺ CD127^low FoxP3⁺ ) was observed. Following IV and SC administration, GSK2831781 depleted circulating LAG3⁺ T cells with no interethnic difference observed. There were no major impacts on circulating regulatory T cells.

Advanced imaging for quantification of abnormalities in the salivary glands of patients with primary Sjögren's syndrome

Objectives

To assess non-invasive imaging for detection and quantification of gland structure, inflammation and function in patients with primary Sjogren's syndrome (pSS) using PET-CT with ¹¹C-Methionine (¹¹C-MET; radiolabelled amino acid), and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG; glucose uptake marker), to assess protein synthesis and inflammation, respectively; multiparametric MRI evaluated salivary gland structural and physiological changes.

Methods

In this imaging/clinical/histology comparative study (GSK study 203818; NCT02899377) patients with pSS and age- and sex-matched healthy volunteers underwent MRI of the salivary glands and ¹¹C-MET PET-CT. Patients also underwent ¹⁸F-FDG PET-CT and labial salivary gland biopsies. Clinical and biomarker assessments were performed. Primary endpoints were semi-quantitative parameters of ¹¹C-MET and ¹⁸F-FDG uptake in submandibular and parotid salivary glands and quantitative MRI measures of structure and inflammation. Clinical and minor salivary gland histological parameter correlations were explored.

Results

Twelve patients with pSS and 13 healthy volunteers were included. Lower ¹¹C-MET uptake in parotid, submandibular and lacrimal glands, lower submandibular gland volume, higher MRI fat fraction, and lower pure diffusion in parotid and submandibular glands were observed in patients vs healthy volunteer, consistent with reduced synthetic function. Disease duration correlated positively with fat fraction and negatively with ¹¹C-MET and ¹⁸F-FDG uptake, consistent with impaired function, inflammation and fatty replacement over time. Lacrimal gland ¹¹C-MET uptake positively correlated with tear flow in patients, and parotid gland ¹⁸F-FDG uptake positively correlated with salivary gland CD20+ B-cell infiltration.

Conclusion

Molecular imaging and MRI may be useful tools to non-invasively assess loss of glandular function, increased glandular inflammation and fat accumulation in pSS.

Fibroblastic Subtype has a Favourable Prognosis in Appendicular Osteosarcoma of Dogs

Osteosarcoma (OS) is an aggressive malignant bone neoplasm that occurs mostly in the appendicular skeleton of dogs and people. OS is classified based on the presence of malignant stroma and the formation of extracellular matrix into osteoblastic, chondroblastic and fibroblastic forms. This study investigated the correlation between the three histological subtypes of canine OS and clinical outcome. Additionally, we examined whether there was any difference in the immunolabelling of desmin, S100 and neuron-specific enolase (NSE) between the three histological subtypes. Formalin-fixed and paraffin wax-embedded tissues from 87 dogs with primary OS were available for this study. The survival times were correlated with appendicular OS subtypes in dogs that were treated surgically, received adjuvant chemotherapy and had no pulmonary metastasis at the time of diagnosis. Dogs with an appendicular fibroblastic OS had significantly prolonged mean average survival times (546 ± 105 days) in comparison with dogs having appendicular osteoblastic (257 ± 48 days) or appendicular chondroblastic (170 ± 28 days) OS (P = 0.003, Log Rank). The results also revealed that the appendicular chondroblastic subtype is a significant indicator for poor prognosis in dogs compared with the fibroblastic or osteoblastic subtypes (P = 0.006, Cox regression). Moreover, the findings indicated that there was no significant correlation between the localization of desmin, NSE or S100 and histological subtypes. Importantly, dogs with appendicular fibroblastic OS were found to have a better prognosis when compared with dogs with other subtypes. This may suggest that histological subtypes of appendicular OS have diverse behaviour and could be used to categorize patients for risk-based assessment.

Lymphocyte Activation Gene (LAG)-3 Is Associated With Mucosal Inflammation and Disease Activity in Ulcerative Colitis

BACKGROUND AND AIMS

Lymphocyte activation gene [LAG]-3 is an immune checkpoint and its expression identifies recently activated lymphocytes that may contribute to inflammation. We investigated the role of LAG-3 by analysing its expression and function in immune cells from blood and tissue of patients with ulcerative colitis [UC].

METHODS

The phenotypic properties of LAG-3+ T cells were determined by flow cytometry, qRT-PCR and single-cell RNA-sequencing. LAG-3+ cells were quantified and correlated with disease activity. The functional effects of LAG-3+ cells were tested using a depleting anti-LAG-3 monoclonal antibody [mAb] in a mixed lymphocyte reaction [MLR].

RESULTS

LAG-3+ cells in the blood were negligible. LAG-3+ lymphocytes were markedly increased in inflamed mucosal tissue and both frequencies of LAG-3+ T cells and transcript levels of LAG3 correlated with endoscopic severity. LAG-3 expression was predominantly on effector memory T cells, and single-cell RNA-sequencing revealed LAG3 expression in activated and cytokine-producing T cell subsets. Foxp3+CD25hi Tregs also expressed LAG-3, although most mucosal Tregs were LAG-3-. Mucosal LAG-3+ cells produced mainly interferon γ [IFNγ] and interleukin-17A. LAG-3+ cell numbers decreased in patients who responded to biologics, and remained elevated in non-responders. Treatment with a depleting anti-LAG-3 mAb led to a reduction in proliferation and IFNγ production in an MLR.

CONCLUSIONS

LAG-3+ cells are increased in the inflamed mucosa, predominantly on effector memory T cells with an activated phenotype and their cell numbers positively correlate with disease activity. Depleting LAG-3 eliminates activated proliferating T cells, and hence LAG-3 could be a therapeutic target in UC.

CCL20 neutralization by a monoclonal antibody in healthy subjects selectively inhibits recruitment of CCR6+ cells in an experimental suction blister

AIMS

GSK3050002, a humanized IgG1κ antibody with high binding affinity to human CCL20, was administered in a first-in-human study to evaluate safety, pharmacokinetics (PK) and pharmacodynamics (PD). An experimental skin suction blister model was employed to assess target engagement and the ability of the compound to inhibit recruitment of inflammatory CCR6 expressing cells.

METHODS

This study was a randomized, double-blind (sponsor open), placebo-controlled, single-centre, single ascending intravenous dose escalation trial in 48 healthy male volunteers.

RESULTS

GSK3050002 (0.1-20 mg kg^-1 ) was well tolerated and no safety concerns were identified. The PK was linear over the dose range, with a half-life of approximately 2 weeks. Complex of GSK3050002/CCL20 increased in serum and blister fluid with increasing doses of GSK3050002. There were dose-dependent decreases in CCR6⁺ cell recruitment to skin blisters with maximal effects at doses of 5 mg kg^-1 and higher, doses at which GSK3050002/CCL20 complex in serum and blister fluid also appeared to reach maximum levels.

CONCLUSIONS

These results indicate a relationship between PK, target engagement and PD, suggesting a selective inhibition of recruitment of CCR6⁺ cells by GSK3050002 and support further development of GSK3050002 in autoimmune and inflammatory diseases.

Ofatumumab for B cell depletion therapy in ANCA-associated vasculitis: a single-centre case series

Objectives. B cell depletion is an effective treatment strategy in ANCA-associated vasculitis (AAV). Ofatumumab is a fully humanized anti-CD20 mAb that has shown efficacy in the treatment of haematological malignancy and RA. The use of ofatumumab in the treatment of AAV has not previously been reported.

Methods. This study was based on a case series of eight patients who received ofatumumab, in conjunction with low-dose CYC and oral steroids, in the treatment of AAV.

Results. Eight patients received ofatumumab: seven for remission induction in active disease (three relapsing; four with new disease) and one for remission maintenance. B cell depletion was achieved in all patients by 1 month, and was sustained for at least 6 months. All patients with active disease achieved clinical remission (BVAS of zero, or BVAS ⩽5 if all scores due to persistent urinary abnormalities in the presence of stable or improving renal function) by 3 months. This was associated with a rapid fall in ANCA titres, reduced inflammatory responses and improvements in renal function. At 12 months, three patients had repopulated B cells associated with the recurrence of circulating ANCAs, although no patients experienced major clinical relapse in the first 24 months. No unexpected side effects were observed.

Conclusion. Treatment with ofatumumab resulted in similar serological and clinical responses to those seen in previous cohorts treated at our centre with a comparable CS, CYC and rituximab-based regimen. Ofatumumab should be considered an alternative B cell depleting agent in patients who are intolerant of, or unresponsive to, rituximab.

Intravenous cyclophosphamide and plasmapheresis in dialysis-dependent ANCA-associated vasculitis

BACKGROUND AND OBJECTIVES

Induction therapy with oral cyclophosphamide (CYP) has been a mainstay of treatment in patients with severe renal failure secondary to ANCA-associated vasculitis (AAV). Recent evidence proposes using pulsed intravenous CYP in less severe disease to minimize adverse events. It is unclear if this can be translated to those with dialysis-dependent renal insufficiency.

DESIGN, SETTING, PARTICIPANTS, & METHODS

All AAV patients presenting between 2005 and 2010 requiring dialysis at presentation were retrospectively analyzed. Patients were treated with plasma exchange, corticosteroids, and intravenous CYP. Rate of dialysis independence at 3 and 12 months and adverse effects were assessed and compared with the outcome of the plasmapheresis, prednisolone, and oral CYP arm of the randomized MEPEX (methylprednisolone versus plasma exchange) trial.

RESULTS

Forty-one patients were included. At 3 months, 3 (7.3%) patients had died on dialysis, 12 (29.3%) remained dialysis dependent, and 26 (63.4%) were dialysis independent (creatinine, 2.5 mg/dl; GFR, 26 ml/min per 1.73 m(2)). Four patients subsequently reached ESRD at a median time of 83 days. Thirty-seven (90%) patients reached 1 year follow-up, 13 (35%) remained dialysis dependent, and 24 (65%) had independent renal function. Eleven patients (27%) had episodes of leukopenia (white cell count <4×10(9)/L) during CYP therapy and 17 (41%) experienced infectious complications. This compares favorably with the dialysis-dependent cohort treated with plasmapheresis in the MEPEX study in which 51% were alive with independent renal function at 1 year.

CONCLUSIONS

Intravenous CYP used with corticosteroids and plasmapheresis may be an effective alternative to oral CYP in patients with dialysis-dependent AAV.

AP-1 transcription factor JunD confers protection from accelerated nephrotoxic nephritis and control podocyte-specific Vegfa expression

Genetic investigation of crescentic glomerulonephritis (Crgn) susceptibility in the Wistar Kyoto rat, a strain uniquely susceptible to nephrotoxic nephritis (NTN), allowed us to positionally clone the activator protein-1 transcription factor Jund as a susceptibility gene associated with Crgn. To study the influence of Jund deficiency (Jund^-/-) on immune-mediated renal disease, susceptibility to accelerated NTN was examined in Jund^-/- mice and C57BL/6 wild-type (WT) controls. Jund^-/- mice showed exacerbated glomerular crescent formation and macrophage infiltration, 10 days after NTN induction. Serum urea levels were also significantly increased in the Jund^-/- mice compared with the WT controls. There was no evidence of immune response differences between Jund^-/- and WT animals because the quantitative immunofluorescence for sheep and mouse IgG deposition in glomeruli was similar. Because murine Jund was inactivated by replacement with a bacterial LacZ reporter gene, we then investigated its glomerular expression by IHC and found that the Jund promoter is mainly active in Jund^-/- podocytes. Furthermore, cultured glomeruli from Jund^-/- mice showed relatively increased expression of vascular endothelial growth factor A (Vegfa), Cxcr4, and Cxcl12, well-known HIF target genes. Accordingly, small-interfering RNA–mediated JUND knockdown in conditionally immortalized human podocyte cell lines led to increased VEGFA and HIF1A expression. Our findings suggest that deficiency of Jund may cause increased oxidative stress in podocytes, leading to altered VEGFA expression and subsequent glomerular injury in Crgn.

Prolonged disease-free remission following rituximab and low-dose cyclophosphamide therapy for renal ANCA-associated vasculitis

BACKGROUND

Rituximab (RTX) has been shown to be effective as an induction agent in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV), but studies have been limited by short-term follow-up. We decided to investigate the long-term efficacy and safety of an RTX-based cyclophosphamide (CYP)-sparing regimen (CycLowVas) for renal AAV.

METHODS

Consecutive patients with renal AAV presenting de novo or with a major relapse, except those with serum creatinine >500 μmol/L, previous treatment with RTX and pulmonary haemorrhage or cerebral vasculitis, were treated with two pulses of RTX 2 weeks apart and six fortnightly doses of CYP, as well as a reducing protocol of daily oral steroids. Maintenance was with low-dose steroids and azathioprine.

RESULTS

Twenty-three patients were treated. Median follow-up was 39 months, with 17 patients reaching >2 years of follow-up. All patients achieved clinical remission within 6 weeks. Three major and two minor relapses occurred in five patients at a median of 30 months, which were treated by re-dosing with RTX for major relapses and steroid increase alone for minor relapses. Adverse events included one severe drug reaction, four non-serious and one serious infective episodes in the first 3 months, one skin malignancy at 21 months and one death at 19 months not related to treatment or disease.

CONCLUSIONS

A RTX-based low-dose CYP regimen is effective at inducing long-term disease-free remission and may be the platform on which to develop a steroid-minimizing regimen to further decrease adverse events in the future.

Screening for encapsulating peritoneal sclerosis in patients on peritoneal dialysis: role of CT scanning

BACKGROUND

We previously validated a scoring system for abdominal/pelvic CT scans in patients with symptomatic encapsulating peritoneal sclerosis (EPS). CT scans of patients with symptomatic EPS were significantly different from control peritoneal dialysis (PD) or haemodialysis patient scans; scans performed before EPS was clinically evident were near normal in 9 of 13 patients. We have now investigated CT scanning as a screening modality in a larger group of patients on long-term PD.

METHODS

Pre-diagnostic CT scans performed in 20 patients for routine screening or other indications at least 3 months before EPS developed, and later diagnostic scans when EPS was clinically evident, were scored by three radiologists. The control group included CT scans of 20 PD patients who had not developed EPS (median follow-up 2.25 years). Analysis was by non-parametric tests. CT scores ranged from 0 to 22; > 2.5 was considered abnormal.

RESULTS

Clinical EPS only developed after transplantation or transfer to HD. Diagnostic scans scored significantly higher than pre-diagnostic or control scans (median scores 9, 2 and 1; P < 0.001), confirming previous work. The pre-EPS diagnosis of 12 asymptomatic patients had a median CT score = 1.75, similar to the control group. Eight patients had had a limited episode of abdominal symptoms (seven required hospitalization), but did not have the clinical picture of EPS; their median CT score was 4.5 (P = 0.0016 cf control group). The time from pre-diagnostic scan to clinical EPS (median 0.82 years) and duration of PD at time of pre-diagnostic scan (median 7.1 years) did not differ significantly between the symptomatic and asymptomatic groups.

CONCLUSIONS

CT screening of asymptomatic PD patients is not indicated; EPS may occur within a year or less of a normal CT scan. Abdominal symptoms in long-term PD patients can be associated with CT scan abnormalities; these patients are at increased risk of EPS after stopping PD.

Evidence for both copy number and allelic (NA1/NA2) risk at the FCGR3B locus in systemic lupus erythematosus

The Fcgamma-receptor locus on chromosome 1q23 shows copy-number variation (CNV), and it has previously been shown that individuals with reduced numbers of copies of the Fcgamma-receptor-IIIB gene (FCGR3B) have an increased risk of developing systemic lupus erythematosus (SLE). It is not understood whether the association arises from FCGR3B (CD16b) itself, is observed because of linkage disequilibrium with actual causal alleles and/or is an effect of CNV on flanking FCGR genes. Thus, we extended this previous work by genotyping the FCGR3B alleles NA1/NA2 and re-assaying CNV using a paralogue ratio test assay in a family study (365 families). We have developed a novel case/pseudo-control approach to analyse family data, as the phase of copy number (CN) is not known in parents and cannot always be inferred in offspring. The results, obtained by fitting logistic regression models, confirm the association of low CN of FCGR3B with SLE (P=0.04). The risk conferred by low copies (<2) was contingent on FCGR3B allotype, being greater for deletion of NA1 than the for lower-affinity NA2. The simpler model with just CN was rejected in favour of the biallelic-CN model (P=0.03). We observed a correlation (R(2)=0.75, P<0.0001) between FCGR3B CNV and neutrophil expression in both healthy controls and patients with SLE. Our results suggest that one mechanism by which CNV at this locus confers disease risk is directly as a result of reduced FcgammaRIIIb function, either because of reduced expression (related to CNV) or because of reduced affinity for its ligand (NA1/NA2 allotype).