The novel cytotoxic polybisphosphonate osteodex decreases bone resorption by enhancing cell death of mature osteoclasts without affecting osteoclastogenesis of RANKL-stimulated mouse bone marrow macrophages.

It has previously been demonstrated that the polybisphosphonate osteodex (ODX) inhibits bone resorption in organ-cultured mouse calvarial bone. In this study, we further investigate the effects by ODX on osteoclast differentiation, formation, and function in several different bone organ and cell cultures. Zoledronic acid (ZOL) was used for comparison. In retinoid-stimulated mouse calvarial organ cultures, ODX and ZOL significantly reduced the numbers of periosteal osteoclasts without affecting Tnfsf11 or Tnfrsf11b mRNA expression. ODX and ZOL also drastically reduced the numbers of osteoclasts in cell cultures isolated from the calvarial bone and in vitamin D3-stimulated mouse crude bone marrow cell cultures. These data suggest that ODX can inhibit osteoclast formation by inhibiting the differentiation of osteoclast progenitor cells or by directly targeting mature osteoclasts. We therefore assessed if osteoclast formation in purified bone marrow macrophage cultures stimulated by RANKL was inhibited by ODX and ZOL and found that the initial formation of mature osteoclasts was not affected, but that the bisphosphonates enhanced cell death of mature osteoclasts. In agreement with these findings, ODX and ZOL did not affect the mRNA expression of the osteoclastic genes Acp5 and Ctsk and the osteoclastogenic transcription factor Nfatc1. When bone marrow macrophages were incubated on bone slices, ODX and ZOL inhibited RANKL-stimulated bone resorption. In conclusion, ODX does not inhibit osteoclast formation but inhibits osteoclastic bone resorption by decreasing osteoclast numbers through enhanced cell death of mature osteoclasts.

The long-term safety and tolerability of anifrolumab for patients with systemic lupus erythematosus in Japan: TULIP-LTE subgroup analysis.

OBJECTIVES: Evaluate the long-term safety and tolerability of anifrolumab 300 mg, alongside standard therapy, in patients from Japan with systemic lupus erythematosus (SLE) in the TULIP-LTE trial (NCT02794285). METHODS: TULIP-LTE was a 3-year, randomized, double-blind, placebo-controlled long-term extension (LTE) of the TULIP trials. The primary safety outcome included serious adverse events (SAEs) and AEs of special interest (AESIs) during the LTE period. Exploratory efficacy outcomes included SLE Disease Activity Index 2000 (SLEDAI-2K) scores and glucocorticoid use. We performed a post hoc subgroup analysis of patients who enrolled in Japan. RESULTS: Exposure-adjusted incidence rates of SAEs during the LTE and follow-up for patients receiving anifrolumab 300 mg (n=21) were 8.7 per 100 patient-years; AESIs included influenza (6.9) and herpes zoster (3.5). One of three patients receiving placebo had an SAE (13.9). One patient per group discontinued due to an AE. There were no deaths. During the TULIP+LTE period, patients receiving anifrolumab 300 mg (n=24) had sustained reduction from baseline in mean SLEDAI-2K scores and cumulative glucocorticoid dosage. CONCLUSIONS: Anifrolumab 300 mg showed a favourable benefit-risk profile for the long-term treatment of adult patients with moderate to severe SLE from Japan, with safety, tolerability, and efficacy profiles consistent with the overall population.

Phase II randomised trial of type I interferon inhibitor anifrolumab in patients with active lupus nephritis.

OBJECTIVE: To assess the efficacy and safety of the type I interferon receptor antibody, anifrolumab, in patients with active, biopsy-proven, Class III/IV lupus nephritis. METHODS: This phase II double-blinded study randomised 147 patients (1:1:1) to receive monthly intravenous anifrolumab basic regimen (BR, 300 mg), intensified regimen (IR, 900 mg ×3, 300 mg thereafter) or placebo, alongside standard therapy (oral glucocorticoids, mycophenolate mofetil). The primary endpoint was change in baseline 24-hour urine protein-creatinine ratio (UPCR) at week (W) 52 for combined anifrolumab versus placebo groups. The secondary endpoint was complete renal response (CRR) at W52. Exploratory endpoints included more stringent CRR definitions and sustained glucocorticoid reductions (≤7.5 mg/day, W24-52). Safety was analysed descriptively. RESULTS: Patients received anifrolumab BR (n=45), IR (n=51), or placebo (n=49). At W52, 24-hour UPCR improved by 69% and 70% for combined anifrolumab and placebo groups, respectively (geometric mean ratio=1.03; 95% CI 0.62 to 1.71; p=0.905). Serum concentrations were higher with anifrolumab IR versus anifrolumab BR, which provided suboptimal exposure. Numerically more patients treated with anifrolumab IR vs placebo attained CRR (45.5% vs 31.1%), CRR with UPCR ≤0.5 mg/mg (40.9% vs 26.7%), CRR with inactive urinary sediment (40.9% vs 13.3%) and sustained glucocorticoid reductions (55.6% vs 33.3%). Incidence of herpes zoster was higher with combined anifrolumab vs placebo (16.7% vs 8.2%). Incidence of serious adverse events was similar across groups. CONCLUSION: Although the primary endpoint was not met, anifrolumab IR was associated with numerical improvements over placebo across endpoints, including CRR, in patients with active lupus nephritis. TRIAL REGISTRATION NUMBER: NCT02547922.

Pre-treatment with IL2 gene therapy alleviates Staphylococcus aureus arthritis in mice.

BACKGROUND: Staphylococcus aureus (S. aureus) arthritis is one of the most detrimental joint diseases known and leads to severe joint destruction within days. We hypothesized that the provision of auxiliary immunoregulation via an expanded compartment of T regulatory cells (Tregs) could dampen detrimental aspects of the host immune response whilst preserving its protective nature. Administration of low-dose interleukin 2 (IL2) preferentially expands Tregs, and is being studied as a treatment choice in several autoimmune conditions. We aimed to evaluate the role of IL2 and Tregs in septic arthritis using a well-established mouse model of haematogenously spred S. aureus arthritis. METHODS: C57BL/6 or NMRI mice we intravenously (iv) injected with a defined dose of S. aureus LS-1 or Newman and the role of IL2 and Tregs were assessed by the following approaches: IL2 was endogenously delivered by intraperitoneal injection of a recombinant adeno-associated virus vector (rAAV) before iv S. aureus inoculation; Tregs were depleted before and during S. aureus arthritis using antiCD25 antibodies; Tregs were adoptively transferred before induction of S. aureus arthritis and finally, recombinant IL2 was used as a treatment starting day 3 after S. aureus injection. Studied outcomes included survival, weight change, bacterial clearance, and joint damage. RESULTS: Expansion of Tregs induced by IL2 gene therapy prior to disease onset does not compromise host resistance to S. aureus infection, as the increased proportions of Tregs reduced the arthritis severity as well as the systemic inflammatory response, while simultaneously preserving the host's ability to clear the infection. CONCLUSIONS: Pre-treatment with IL2 gene therapy dampens detrimental immune responses but preserves appropriate host defense, which alleviates S. aureus septic arthritis in a mouse model.

Antibiotics with Interleukin-15 Inhibition Reduce Joint Inflammation and Bone Erosions but Not Cartilage Destruction in Staphylococcus aureus-Induced Arthritis.

Staphylococcus aureus-induced arthritis causes rapid joint destruction, often leading to disabling joint damage despite antibiotics. We have previously shown that interleukin-15 (IL-15) inhibition without antibiotics is beneficial in S. aureus-induced arthritis. We therefore hypothesized that the inhibition of IL-15, in combination with antibiotics, might represent a useful therapy that would reduce inflammation and joint destruction but preserve the host's ability to clear the infection. Female wild-type C57BL/6 mice were intravenously inoculated with the toxic shock syndrome toxin 1 (TSST-1)-producing LS-1 strain of S. aureus with 0.8 × 108 CFU S. aureus LS-1/mouse. Three days later, treatment consisting of cloxacillin, followed by flucloxacillin, together with either anti-IL-15 antibodies (aIL-15ab) or control antibodies, was started. Studied outcomes included survival, weight change, bacterial clearance, and joint damage. The addition of aIL-15ab to antibiotics in S. aureus-induced arthritis reduced synovitis and bone erosions compared to controls. The number of bone-resorbing osteoclasts in the joints was reduced, whereas cartilage destruction was not significantly altered. Importantly, the combination therapy did not adversely affect the clinical outcome of S. aureus-induced arthritis, such as survival or weight change, or compromise the host's ability to clear the infection. Since the clinical outcome of S. aureus-induced arthritis was not affected, the addition of aIL-15ab to antibiotics ought to be safe. Taken together, the combination of aIL-15ab and antibiotics is a beneficial, but not optimal, treatment of S. aureus-induced arthritis since it reduces synovitis and bone erosions but has a limited effect on cartilage destruction.

Porphyromonas gingivalis Stimulates Bone Resorption by Enhancing RANKL (Receptor Activator of NF-κB Ligand) through Activation of Toll-like Receptor 2 in Osteoblasts.

Periodontitis has been associated with rheumatoid arthritis. In experimental arthritis, concomitant periodontitis caused by oral infection with Porphyromonas gingivalis enhances articular bone loss. The aim of this study was to investigate how lipopolysaccharide (LPS) from P. gingivalis stimulates bone resorption. The effects by LPS P. gingivalis and four other TLR2 ligands on bone resorption, osteoclast formation, and gene expression in wild type and Tlr2-deficient mice were assessed in ex vivo cultures of mouse parietal bones and in an in vivo model in which TLR2 agonists were injected subcutaneously over the skull bones. LPS P. gingivalis stimulated mineral release and matrix degradation in the parietal bone organ cultures by increasing differentiation and formation of mature osteoclasts, a response dependent on increased RANKL (receptor activator of NF-κB ligand). LPS P. gingivalis stimulated RANKL in parietal osteoblasts dependent on the presence of TLR2 and through a MyD88 and NF-κB-mediated mechanism. Similarly, the TLR2 agonists HKLM, FSL1, Pam2, and Pam3 stimulated RANKL in osteoblasts and parietal bone resorption. LPS P. gingivalis and Pam2 robustly enhanced osteoclast formation in periosteal/endosteal cell cultures by increasing RANKL. LPS P. gingivalis and Pam2 also up-regulated RANKL and osteoclastic genes in vivo, resulting in an increased number of periosteal osteoclasts and immense bone loss in wild type mice but not in Tlr2-deficient mice. These data demonstrate that LPS P. gingivalis stimulates periosteal osteoclast formation and bone resorption by stimulating RANKL in osteoblasts via TLR2. This effect might be important for periodontal bone loss and for the enhanced bone loss seen in rheumatoid arthritis patients with concomitant periodontal disease.

TLR5, a novel mediator of innate immunity-induced osteoclastogenesis and bone loss.

Accumulating evidence points to the importance of the innate immune system in inflammation-induced bone loss in infectious and autoimmune diseases. TLRs are well known for being activated by ligands expressed by bacteria, viruses, and fungi. Recent findings indicate that also endogenous ligands in inflammatory processes are important, one being a TLR5 agonist present in synovial fluid from patients with rheumatoid arthritis (RA). We found that activation of TLR5 by its specific ligand, flagellin, caused robust osteoclast formation and bone loss in cultured mouse neonatal parietal bones dependent on increased receptor activator of NF-κB ligand (RANKL):osteoprotegerin ratio, with half-maximal stimulation at 0.01 µg/ml. Flagellin enhanced Rankl mRNA in isolated osteoblasts by a myeloid differentiation primary response gene 88 and NF-κB-dependent mechanism. Injection of flagellin locally over skull bones in 5-wk-old mice resulted in increased mRNA expression of Rankl and osteoclastic genes, robust osteoclast formation, and bone loss. The effects in vitro and in vivo were absent in Tlr5(-/-) mice. These data show that TLR5 is a novel activator of RANKL and osteoclast formation and, therefore, a potential key factor in inflammation-induced bone erosions in diseases like RA, reactive arthritis, and periodontitis. TLR5 might be a promising novel treatment target for prevention of inflammatory bone loss.

Cytokine expression in patients with bladder pain syndrome/interstitial cystitis ESSIC type 3C.

PURPOSE: Bladder wall nitric oxide production in patients with bladder pain syndrome type 3C is increased compared to undetectable nitric oxide in patients with nonHunner bladder pain syndrome and healthy controls. However, the underlying mechanism/s of the increased nitric oxide production is largely unknown. We compared mRNA expression of a select group of cytokines in patients with bladder pain syndrome/interstitial cystitis type 3C and in pain-free controls. MATERIALS AND METHODS: Cold cup biopsies from 7 patients with bladder pain syndrome type 3C and 6 healthy subjects were analyzed. mRNA expression of IL-4, 6, 10 and 17A, iNOS, TNF-α, TGF-ß and IFN-γ was estimated by real-time polymerase chain reaction. IL-17 protein expression was determined by immunohistochemistry. Mast cells were labeled with tryptase to evaluate cell appearance and count. RESULTS: IL-6, 10 and 17A, and iNOS mRNA levels as well as the number of mast cells infiltrating the bladder mucosa were significantly increased in patients with bladder pain syndrome type 3C compared to healthy controls. TNF-α, TGF-ß and IFN-γ mRNA levels were similar in patients and controls. IL-17A expression at the protein level was up-regulated and localized to inflammatory cells and urothelium in patients with bladder pain syndrome type 3C. CONCLUSIONS: Patients with bladder pain syndrome/interstitial cystitis had increased mRNA levels of IL-17A, 10 and 6, and iNOS. IL-17A might be important in the inflammatory process. To our knowledge the increase in IL-17A is a novel finding that may have new treatment implications.

Periarticular bone loss in antigen-induced arthritis.

OBJECTIVE: Bone loss in arthritis is a complex process characterized by bone erosions and periarticular and generalized bone loss. The antigen-induced arthritis (AIA) model is mainly used to study synovitis and joint destruction, including bone erosions; however, periarticular bone loss has been less extensively investigated. The objectives of this study were to characterize and establish AIA as a model for periarticular bone loss, and to determine the importance of NADPH oxidase 2 (NOX-2)-derived reactive oxygen species (ROS) in periarticular bone loss. METHODS: Arthritis was induced in mice by local injection of antigen in one knee; the other knee was used as a nonarthritis control. At study termination, the knees were collected for histologic assessment. Periarticular bone mineral density (BMD) was investigated by peripheral quantitative computed tomography. Flow cytometric analyses were performed using synovial and bone marrow cells. RESULTS: AIA resulted in decreased periarticular trabecular BMD and increased frequencies of preosteoclasts, neutrophils, and monocytes in the arthritic synovial tissue. Arthritis induction resulted in an increased capability to produce ROS. However, induction of arthritis in Ncf1 / mice, which lack NOX-2-derived ROS, and control mice resulted in similar reductions in periarticular trabecular BMD. CONCLUSION: The initiation of AIA resulted in periarticular bone loss associated with local effects on inflammatory cells and osteoclasts. Furthermore, based on our observations using this model, we conclude that NOX-2-derived ROS production is not essential for inflammation-mediated periarticular bone loss. Thus, AIA can be used as a model to investigate the pathogenesis of local inflammation-mediated bone loss.

Inflammation characteristics in bladder pain syndrome ESSIC type 3C/classic interstitial cystitis.

OBJECTIVES: Interstitial cystitis is regarded as a heterogenous syndrome with two distinguishable forms: the non-ulcer and the classic form of interstitial cystitis, the latter with Hunner's lesions; or bladder pain syndrome type 3C and non-Hunner bladder pain syndrome, respectively. METHODS: A cohort of 379 patients diagnosed with interstitial cystitis was studied. Nitric oxide release from the bladder was measured using a chemiluminescence nitric oxide analyzer. Bladder biopsies from the patients and healthy controls were analyzed by routine histopathological examination. Biopsies from a subset of patients and controls were also analyzed by immunohistochemistry and cytokine gene expression by real-time polymerase chain reaction. RESULTS: Patients with bladder pain syndrome type 3C/classic interstitial cystitis had considerably higher levels of nitric oxide as compared with non-Hunner bladder pain syndrome/non-ulcer interstitial cystitis patients and healthy individuals, and showed histologically a chronic inflammation in the bladder mucosa, with abundant mast cell infiltration in all layers of the bladder wall. No inflammation was noted in non-Hunner bladder pain syndrome/non-ulcer interstitial cystitis patients. The isoenzymes inducible nitric oxide synthase, the catalyst in the nitric oxide production, was strongly expressed in the inflammatory cells in the bladder mucosa of bladder pain syndrome type 3C/classic interstitial cystitis patients. In addition, the expression of the pro-inflammatory cytokines interleukin-6 and interleukin-17A messenger ribonucleic acid, and of anti-inflammatory interleukin-10 messenger ribonucleic acid showed significantly increased levels in bladder pain syndrome type 3C/classic interstitial cystitis compared with healthy controls. CONCLUSION: Bladder pain syndrome type 3C/classic interstitial cystitis is a distinct inflammatory disease and in many aspects shares features of inflammatory autoimmune diseases. These findings could open up novel research avenues with expectations for new targets for pharmacological treatment.

Toll-like receptor-2 induced inflammation causes local bone formation and activates canonical Wnt signaling.

It is well established that inflammatory processes in the vicinity of bone often induce osteoclast formation and bone resorption. Effects of inflammatory processes on bone formation are less studied. Therefore, we investigated the effect of locally induced inflammation on bone formation. Toll-like receptor (TLR) 2 agonists LPS from Porphyromonas gingivalis and PAM2 were injected once subcutaneously above mouse calvarial bones. After five days, both agonists induced bone formation mainly at endocranial surfaces. The injection resulted in progressively increased calvarial thickness during 21 days. Excessive new bone formation was mainly observed separated from bone resorption cavities. Anti-RANKL did not affect the increase of bone formation. Inflammation caused increased bone formation rate due to increased mineralizing surfaces as assessed by dynamic histomorphometry. In areas close to new bone formation, an abundance of proliferating cells was observed as well as cells robustly stained for Runx2 and alkaline phosphatase. PAM2 increased the mRNA expression of Lrp5, Lrp6 and Wnt7b, and decreased the expression of Sost and Dkk1. In situ hybridization demonstrated decreased Sost mRNA expression in osteocytes present in old bone. An abundance of cells expressed Wnt7b in Runx2-positive osteoblasts and ß-catenin in areas with new bone formation. These data demonstrate that inflammation, not only induces osteoclastogenesis, but also locally activates canonical WNT signaling and stimulates new bone formation independent on bone resorption.

Formylated peptides are important virulence factors in Staphylococcus aureus arthritis in mice.

BACKGROUND: Staphylococcus aureus is the most common pathogen causing septic arthritis in humans. The affected joints are often rapidly and permanently damaged despite antibiotic treatment, indicating that the elicited host immune response contributes substantially to joint destruction. Bacterial formylated peptides are important chemotactic molecules mediating neutrophil recruitment into infected tissues as an important first step of host defense against invading bacteria. The role of formylated peptides in S. aureus infections has been unknown. METHODS: Mice were intravenously inoculated with wild-type S. aureus strain RN4220 or its isogenic mutant strain (Δfmt) lacking the ability to produce formylated peptides. The development of arthritis was followed clinically and histopathologically. RESULTS: Mice inoculated with the formyl peptide-producing wild-type strain showed a significantly increased frequency and severity of arthritis and subsequent joint destruction as compared with Δfmt mutant strain-inoculated mice. The wild-type S. aureus strain also induced significantly more weight loss than the Δfmt mutant strain. The recruitment of neutrophils into infected kidneys and synovial tissue was significantly higher in mice inoculated with the wild-type strain. CONCLUSIONS: Our data show that formylated peptides function as important virulence factors in S. aureus arthritis, partly by mediating neutrophil recruitment, which contributes substantially to the joint damage.

Interleukin 15 mediates joint destruction in Staphylococcus aureus arthritis.

BACKGROUND: Staphylococcus aureus arthritis causes severe and rapid joint damage despite antibiotics. Thus, there is a need to identify new treatment targets in addition to antibiotics. Lately, interleukin 15 (IL-15) has been implicated both in osteoclastogenesis and in bacterial clearance-2 important issues in S. aureus-induced joint destruction. This has prompted us to investigate the importance of IL-15 in S. aureus-induced arthritis. METHODS: Toxic shock syndrome toxin-1 producing S. aureus was intravenously inoculated in IL-15 knockout and wildtype mice and in wildtype mice treated with anti-IL-15 antibodies (aIL-15ab) or isotype control antibody. RESULTS: Absence of IL-15, either in knockout mice or after treatment with aIL-15ab, significantly reduced weight loss compared with controls during the infection. The severity of synovitis and joint destruction was significantly decreased in IL-15 knockout and aIL-15ab treated mice compared with controls. In IL-15 knockout mice there was a reduced number of osteoclasts in the joints. The host's ability to clear bacteria was not influenced in the IL-15 knockout mice, but significantly increased after treatment with aIL-15ab. CONCLUSIONS: IL-15 is a mediator of joint destruction in S. aureus-induced arthritis and contributes to general morbidity, which makes this cytokine an interesting treatment target in addition to conventional antibiotics.

Time to onset of clinical response to anifrolumab in patients with SLE: pooled data from the phase III TULIP-1 and TULIP-2 trials.

OBJECTIVES: To evaluate the time course of clinical response following anifrolumab treatment in patients with SLE. METHODS: A post hoc analysis was conducted using pooled data from phase III, randomised, 52-week, placebo-controlled, Treatment of Uncontrolled Lupus via the Interferon Pathway (TULIP)-1 and TULIP-2 trials of intravenous anifrolumab (every 4 weeks, 48 weeks) in patients with moderate-to-severe SLE receiving standard therapy. Anifrolumab 300 mg and placebo groups were compared for British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) response over time, time to sustained BICLA response, SLE Responder Index ≥4 (SRI(4)) response over time, time to sustained Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity (CLASI-A) response and change in glucocorticoid dosage over time. All p values for comparisons were nominal. RESULTS: Of the 726 evaluated patients (anifrolumab 300 mg, n=360; placebo, n=366), a greater proportion attained a BICLA response in the anifrolumab versus the placebo group from Week 8 (p<0.001); treatment group differentiation was maintained at all subsequent visits to Week 52. Consistently, more patients achieved a BICLA response sustained to Week 52 in the anifrolumab versus placebo group (HR=1.73, 95% CI 1.37 to 2.20). More patients attained SRI(4) response with anifrolumab than placebo from Week 12 (p=0.005). As early as Week 8, more patients achieved CLASI-A skin response sustained to Week 52 with anifrolumab versus placebo (HR=1.72, 95% CI 1.17 to 2.55). Glucocorticoid dosage reductions from baseline were greater in anifrolumab-treated versus placebo-treated patients from Week 20 (p=0.010) through Week 52. CONCLUSIONS: Anifrolumab treatment was associated with sustained improvements in overall SLE disease activity and skin responses versus placebo from Week 8, which likely led to greater glucocorticoid reductions in the anifrolumab versus placebo groups from Week 20. These findings provide insights to physicians and patients on when to expect potential clinical responses following anifrolumab treatment.

Anifrolumab in lupus nephritis: results from second-year extension of a randomised phase II trial.

OBJECTIVE: To characterise the safety and efficacy of anifrolumab in active lupus nephritis (LN) through year 2 of the phase II randomised, double-blind Treatment of Uncontrolled Lupus via the Interferon Pathway (TULIP)-LN trial (NCT02547922) of 2 anifrolumab dosing regimens versus placebo. METHODS: Patients received intravenous anifrolumab 900 mg for the first 3 doses followed by 300 mg anifrolumab (intensified regimen (IR)), 300 mg anifrolumab (basic regimen (BR)) or placebo every 4 weeks throughout. To continue into Year 2, patients must have achieved at least partial renal response and a glucocorticoid tapering target. RESULTS: Of 147 randomised patients, 101 completed Year 1 study treatment; of these, 75 (74%) continued into Year 2 (anifrolumab IR: n=29, BR: n=23 and placebo: n=23). During Year 2, 72% of patients reported ≥1 adverse event (AE); serious AEs were reported in 6.9%, 8.7% and 8.7% of patients (anifrolumab IR, BR and placebo, respectively); 3 patients discontinued treatment due to an AE (anifrolumab IR: n=2 and placebo: n=1) and herpes zoster was reported in 2 patients (anifrolumab IR: n=1 and BR: n=1). The study was ongoing at the start of the pandemic, but no COVID-19 cases were reported. Of the 145 patients receiving treatment, more patients on the IR attained complete renal response at Week 104 compared with those on BR or placebo (27.3% vs 18.6% and 17.8%) and simultaneously achieved sustained glucocorticoid tapering (IR: 25.0%; BR: 18.6% and placebo: 17.8%). The improvements in estimated glomerular filtration rate were numerically larger in both anifrolumab groups versus placebo. CONCLUSIONS: The safety and tolerability profile through Year 2 of TULIP-LN was generally consistent with Year 1, with promising efficacy results for the anifrolumab IR regimen. Collectively, the results support further investigation of an anifrolumab intensified dosing regimen in larger populations of patients with active proliferative LN. TRIAL REGISTRATION NUMBER: NCT02547922.

A Randomized, Placebo-Controlled Phase III Extension Trial of the Long-Term Safety and Tolerability of Anifrolumab in Active Systemic Lupus Erythematosus.

OBJECTIVE: To explore long-term safety and tolerability of anifrolumab 300 mg compared with placebo in patients with systemic lupus erythematosus (SLE) who completed a Treatment of Uncontrolled Lupus via the Interferon Pathway (TULIP) trial and enrolled in the placebo-controlled 3-year long-term extension (LTE) study (ClinicalTrials.gov identifier: NCT02794285). METHODS: In the blinded LTE study, patients continued anifrolumab 300 mg, switched from anifrolumab 150 mg to 300 mg, or were re-randomized from placebo to receive either anifrolumab 300 mg or to continue placebo, administered every 4 weeks. Primary comparisons in the LTE study were between patients who received anifrolumab 300 mg or placebo throughout the TULIP and LTE studies. For rare safety events, comparisons included patients who received any anifrolumab dose during TULIP or LTE. When exposure differed, exposure-adjusted incidence rates (EAIRs) per 100 patient-years were calculated. RESULTS: In the LTE study, EAIRs of serious adverse events (SAEs) were 8.5 with anifrolumab compared with 11.2 with placebo; likewise, EAIRs of AEs leading to treatment discontinuation were 2.5 versus 3.2, respectively. EAIRs of non-opportunistic serious infections were comparable between groups (3.7 with anifrolumab versus 3.6 with placebo). Exposure-adjusted event rates of COVID-related AEs, including asymptomatic infections, were 15.5 with anifrolumab compared with 9.8 with placebo. No COVID-related AEs occurred in fully vaccinated individuals. EAIRs of malignancy and major acute cardiovascular events were low and comparable between groups. Anifrolumab was associated with lower cumulative glucocorticoid use and greater mean improvement in the SLE Disease Activity Index 2000, compared with placebo. CONCLUSION: This LTE study represents the longest placebo-controlled clinical trial performed in SLE to date. No new safety findings were identified in the LTE study, supporting the favorable benefit-risk profile of anifrolumab for patients with moderate-to-severe SLE receiving standard therapy.

Retinoids stimulate periosteal bone resorption by enhancing the protein RANKL, a response inhibited by monomeric glucocorticoid receptor.

Increased vitamin A (retinol) intake has been suggested to increase bone fragility. In the present study, we investigated effects of retinoids on bone resorption in cultured neonatal mouse calvarial bones and their interaction with glucocorticoids (GC). All-trans-retinoic acid (ATRA), retinol, retinalaldehyde, and 9-cis-retinoic acid stimulated release of (45)Ca from calvarial bones. The resorptive effect of ATRA was characterized by mRNA expression of genes associated with osteoclast differentiation, enhanced osteoclast number, and bone matrix degradation. In addition, the RANKL/OPG ratio was increased by ATRA, release of (45)Ca stimulated by ATRA was blocked by exogenous OPG, and mRNA expression of genes associated with bone formation was decreased by ATRA. All retinoid acid receptors (RARα/ß/γ) were expressed in calvarial bones. Agonists with affinity to all receptor subtypes or specifically to RARα enhanced the release of (45)Ca and mRNA expression of Rankl, whereas agonists with affinity to RARß/γ or RARγ had no effects. Stimulation of Rankl mRNA by ATRA was competitively inhibited by the RARα antagonist GR110. Exposure of calvarial bones to GC inhibited the stimulatory effects of ATRA on (45)Ca release and Rankl mRNA and protein expression. This inhibitory effect was reversed by the glucocorticoid receptor (GR) antagonist RU 486. Increased Rankl mRNA stimulated by ATRA was also blocked by GC in calvarial bones from mice with a GR mutation that blocks dimerization (GR(dim) mice). The data suggest that ATRA enhances periosteal bone resorption by increasing the RANKL/OPG ratio via RARα receptors, a response that can be inhibited by monomeric GR.

Intermediate monocytes correlate with CXCR3+ Th17 cells but not with bone characteristics in untreated early rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is associated with development of generalized osteoporosis. Bone-degrading osteoclasts are derived from circulating precursor cells of monocytic lineage, and the intermediate monocyte population is important as osteoclast precursors in inflammatory conditions. T cells of various subsets are critical in the pathogenesis of both RA and associated osteoporosis, but so far, no studies have examined associations between circulating intermediate monocytes, T cell subsets and bone characteristics in patients with RA. The aim of this study was to investigate the frequency of intermediate monocytes in patients with untreated early rheumatoid arthritis (ueRA) compared to healthy controls (HC), and to explore the correlation between intermediate monocytes and a comprehensive panel of T helper cell subsets, bone density and bone microarchitecture in ueRA patients. METHODS: 78 patients with ueRA fulfilling the ACR/EULAR 2010 criteria were included and compared to 29 age- and sex-matched HC. Peripheral blood samples were obtained before start of treatment and proportions of monocyte subsets and CD4+ helper and regulatory T cell subsets were analyzed by flow cytometry. Bone densitometry was performed on 46 of the ueRA patients at inclusion using DXA and HR-pQCT. RESULTS: Flow cytometric analyses showed that the majority of ueRA patients had frequencies of intermediate monocytes comparable to HC. The intermediate monocyte population correlated positively with CXCR3+ Th17 cells in ueRA patients but not in HC. However, neither the proportions of intermediate monocytes nor CXCR3+ Th17 cells were associated with bone density or bone microarchitecture measurements. CONCLUSIONS: Our findings suggest that in early RA, the intermediate monocytes do not correlate with bone characteristics, despite positive correlation with circulating CXCR3+ Th17 cells. Future longitudinal studies in patients with longer disease duration are required to fully explore the potential of intermediate monocytes to drive bone loss in RA.

Pharmacokinetics, pharmacodynamics, and safety of subcutaneous anifrolumab in patients with systemic lupus erythematosus, active skin disease, and high type I interferon gene signature: a multicentre, randomised, double-blind, placebo-controlled, phase 2 study.

BACKGROUND: 300 mg of intravenous anifrolumab every 4 weeks added to standard-of-care treatment for patients with systemic lupus erythematosus (SLE) reduced disease activity and glucocorticoid requirement in a previous phase 3 trial. Because patients might find subcutaneous administration more convenient than intravenous delivery, we aimed to evaluate the pharmacokinetics, pharmacodynamics, safety, and efficacy of subcutaneous anifrolumab in patients with SLE, active skin disease, and a high type I interferon gene signature. METHODS: This multicentre, randomised, double-blind, placebo-controlled, phase 2 study was done at 12 hospitals and outpatient clinics in Hungary, South Korea, Poland, and the USA. Eligible patients were aged 18-70 years, and had SLE with high type I interferon gene signature and an activity score on the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) of at least 10. Enrolled participants were randomly assigned (3:1:3:1) by use of a voice-web response system to receive either 150 mg of subcutaneous anifrolumab or corresponding placebo, or 300 mg of subcutaneous anifrolumab or corresponding placebo in addition to stable standard-of-care treatment. The study was double-blinded with respect to intervention but not dose, until 12 weeks. Doses of oral glucocorticoids were tapered after week 12. The primary pharmacokinetic endpoint was the serum concentration of anifrolumab based on the maximum concentration after the first dose and the minimum (trough) concentration before subsequent doses and was measured in all patients who received anifrolumab and had at least one quantifiable serum pharmacokinetics observation following the first dose. The primary pharmacodynamic endpoint was neutralisation of the type I interferon pharmacodynamic signature at week 12 and was assessed in all patients with a high type I interferon pharmacodynamics signature at baseline based on a 21-gene test. Safety was evaluated in the full analysis set, which included all patients who received at least one dose of anifrolumab. This trial is completed and is registered at ClinicalTrials.gov, NCT02962960. FINDINGS: Between March 14, 2017, and Oct 26, 2017, 36 patients were randomly assigned to receive 150 mg of anifrolumab (n=14), 300 mg of anifrolumab (n=13), or placebo (n=9). Two patients in the anifrolumab 150 mg group were excluded from the pharmacodynamic analysis set (n=34). Ten (71%) of 14 patients in the anifrolumab 150 mg group, ten (77%) of 13 patients in the anifrolumab 300 mg group, and nine (100%) of the nine patients in the placebo group completed 52 weeks of treatment. At week 12, pre-dose mean trough serum concentrations of anifrolumab were more than dose proportional between the anifrolumab 150 mg group (19·82 µg/mL [SD 15·01]) and the anifrolumab 300 mg group (60·28 µg/mL [43·66]), and the pharmacokinetics were non-linear. At week 12, the median percentage neutralisation of the type I interferon gene signature was higher with 150 mg (88·0% [median absolute deviation 7·4]) and 300 mg (90·7% [3·3]) of anifrolumab than with placebo (18·5% [8·1]), and more patients in the anifrolumab 150 mg group and the anifrolumab 300 mg group than in the placebo group had neutralisation of 75% or more (eight [67%] of 12 vs ten [77%] of 13 vs one [11%] of nine). At least one adverse event was reported by 23 (85%) of 27 patients in the anifrolumab groups and by seven (78%) of nine patients in the placebo group; most adverse events were of mild-to-moderate severity. Serious adverse events were reported in six (22%) of 27 patients in the anifrolumab groups (four patients in the 150 mg group and two in the 300 mg group). No serious adverse events were reported in the placebo group. Herpes zoster infection was reported by three (11%) of 27 patients in the anifrolumab groups and by one (11%) of nine patients in the placebo group. There were no treatment-related deaths. INTERPRETATION: Anifrolumab, administered subcutaneously every 2 weeks to patients with SLE and moderate-to-severe skin manifestations, had non-linear pharmacokinetics that were more than dose proportional, and neutralised the type I interferon gene signature in a dose-dependent manner. The safety profile was consistent with previous studies of intravenous anifrolumab, supporting the continued development of anifrolumab as a subcutaneously administered therapy for patients with SLE. FUNDING: AstraZeneca.

Interleukin-17A during local and systemic Staphylococcus aureus-induced arthritis in mice.

Staphylococcus aureus is one of the dominant pathogens that induce septic arthritis in immunocompromised hosts, e.g., patients suffering from rheumatoid arthritis treated with immunosuppressive drugs. S. aureus-induced arthritis leads to severe joint destruction and high mortality despite antibiotic treatment. Recently, interleukin-17A (IL-17A) has been discovered to be an important mediator of aseptic arthritis both in mice and humans, but its function in S. aureus-induced arthritis is largely unknown. Here, we investigated the role of IL-17A in host defense against arthritis following systemic and local S. aureus infection in vivo. IL-17A knockout mice and wild-type mice were inoculated systemically (intravenously) or locally (intra-articularly) with S. aureus. During systemic infection, IL-17A knockout mice lost significantly more weight than the wild-type mice did, but no differences were found in the mortality rate. The absence of IL-17A had no impact on clinical arthritis development but led to increased histopathological erosivity late during systemic S. aureus infection. Bacterial clearance in kidneys was increased in IL-17A knockout mice compared to the level in wild-type mice only 1 day after bacterial inoculation. During systemic S. aureus infection, serum IL-17F protein levels and mRNA levels in the lymph nodes were elevated in the IL-17A knockout mice compared to the level in wild-type mice. In contrast to systemic infection, the IL-17A knockout mice had increased synovitis and erosions and locally decreased clearance of bacteria 3 days after local bacterial inoculation. On the basis of these findings, we suggest that IL-17A is more important in local host defense than in systemic host defense against S. aureus-induced arthritis.