Risankizumab as maintenance therapy for moderately to severely active Crohn's disease: results from the multicentre, randomised, double-blind, placebo-controlled, withdrawal phase 3 FORTIFY maintenance trial.

BACKGROUND: There is a great unmet need for new therapeutics with novel mechanisms of action for patients with Crohn's disease. The ADVANCE and MOTIVATE studies showed that intravenous risankizumab, a selective p19 anti-interleukin (IL)-23 antibody, was efficacious and well tolerated as induction therapy. Here, we report the efficacy and safety of subcutaneous risankizumab as maintenance therapy. METHODS: FORTIFY is a phase 3, multicentre, randomised, double-blind, placebo-controlled, maintenance withdrawal study across 273 clinical centres in 44 countries across North and South America, Europe, Oceania, Africa, and the Asia-Pacific region that enrolled participants with clinical response to risankizumab in the ADVANCE or MOTIVATE induction studies. Patients in ADVANCE or MOTIVATE were aged 16-80 years with moderately to severely active Crohn's disease. Patients in the FORTIFY substudy 1 were randomly assigned again (1:1:1) to receive either subcutaneous risankizumab 180 mg, subcutaneous risankizumab 360 mg, or withdrawal from risankizumab to receive subcutaneous placebo (herein referred to as withdrawal [subcutaneous placebo]). Treatment was given every 8 weeks. Patients were stratified by induction dose, post-induction endoscopic response, and clinical remission status. Patients, investigators, and study personnel were masked to treatment assignments. Week 52 co-primary endpoints were clinical remission (Crohn's disease activity index [CDAI] in the US protocol, or stool frequency and abdominal pain score in the non-US protocol) and endoscopic response in patients who received at least one dose of study drug during the 52-week maintenance period. Safety was assessed in patients receiving at least one dose of study medication. This study is registered with ClinicalTrials.gov, NCT03105102. FINDINGS: 712 patients were initially assessed and, between April 9, 2018, and April 24, 2020, 542 patients were randomly assigned to either the risankizumab 180 mg group (n=179), the risankizumab 360 mg group (n=179), or the placebo group (n=184). Greater clinical remission and endoscopic response rates were reached with 360 mg risankizumab versus placebo (CDAI clinical remission was reached in 74 (52%) of 141 patients vs 67 (41%) of 164 patients, adjusted difference 15% [95% CI 5-24]; stool frequency and abdominal pain score clinical remission was reached in 73 (52%) of 141 vs 65 (40%) of 164, adjusted difference 15% [5-25]; endoscopic response 66 (47%) of 141 patients vs 36 (22%) of 164 patients, adjusted difference 28% [19-37]). Higher rates of CDAI clinical remission and endoscopic response (but not stool frequency and abdominal pain score clinical remission [p=0·124]) were also reached with risankizumab 180 mg versus withdrawal (subcutaneous placebo; CDAI clinical remission reached in 87 [55%] of 157 patients, adjusted difference 15% [95% CI 5-24]; endoscopic response 74 [47%] of 157, adjusted difference 26% [17-35]). Results for more stringent endoscopic and composite endpoints and inflammatory biomarkers were consistent with a dose-response relationship. Maintenance treatment was well tolerated. Adverse event rates were similar among groups, and the most frequently reported adverse events in all treatment groups were worsening Crohn's disease, arthralgia, and headache. INTERPRETATION: Subcutaneous risankizumab is a safe and efficacious treatment for maintenance of remission in patients with moderately to severely active Crohn's disease and offers a new therapeutic option for a broad range of patients by meeting endpoints that might change the future course of disease. FUNDING: AbbVie.

Risankizumab as induction therapy for Crohn's disease: results from the phase 3 ADVANCE and MOTIVATE induction trials.

BACKGROUND: Risankizumab, an interleukin (IL)-23 p19 inhibitor, was evaluated for safety and efficacy as induction therapy in patients with moderately to severely active Crohn's disease. METHODS: ADVANCE and MOTIVATE were randomised, double-masked, placebo-controlled, phase 3 induction studies. Eligible patients aged 16-80 years with moderately to severely active Crohn's disease, previously showing intolerance or inadequate response to one or more approved biologics or conventional therapy (ADVANCE) or to biologics (MOTIVATE), were randomly assigned to receive a single dose of intravenous risankizumab (600 mg or 1200 mg) or placebo (2:2:1 in ADVANCE, 1:1:1 in MOTIVATE) at weeks 0, 4, and 8. We used interactive response technology for random assignment, with stratification by number of previous failed biologics, corticosteroid use at baseline, and Simple Endoscopic Score for Crohn's disease (SES-CD). All patients and study personnel (excluding pharmacists who prepared intravenous solutions) were masked to treatment allocation throughout the study. Coprimary endpoints were clinical remission (defined by Crohn's disease activity index [CDAI] or patient-reported outcome criteria [average daily stool frequency and abdominal pain score]) and endoscopic response at week 12. The intention-to-treat population (all eligible patients who received at least one dose of study drug in the 12-week induction period) was analysed for efficacy outcomes. Safety was assessed in all patients who received at least one dose of study drug. Both trials were registered on ClinicalTrials.gov, NCT03105128 (ADVANCE) and NCT03104413 (MOTIVATE), and are now complete. FINDINGS: Participants were enrolled between May 10, 2017, and Aug 24, 2020 (ADVANCE trial), and Dec 18, 2017 and Sept 9, 2020 (MOTIVATE trial). In ADVANCE, 931 patients were assigned to either risankizumab 600 mg (n=373), risankizumab 1200 mg (n=372), or placebo (n=186). In MOTIVATE, 618 patients were assigned to risankizumab 600 mg (n=206), risankizumab 1200 mg (n=205), or placebo (n=207). The primary analysis population comprised 850 participants in ADVANCE and 569 participants in MOTIVATE. All coprimary endpoints at week 12 were met in both trials with both doses of risankizumab (p values ≤0·0001). In ADVANCE, CDAI clinical remission rate was 45% (adjusted difference 21%, 95% CI 12-29; 152/336) with risankizumab 600 mg and 42% (17%, 8-25; 141/339) with risankizumab 1200 mg versus 25% (43/175) with placebo; stool frequency and abdominal pain score clinical remission rate was 43% (22%, 14-30; 146/336) with risankizumab 600 mg and 41% (19%, 11-27; 139/339) with risankizumab 1200 mg versus 22% (38/175) with placebo; and endoscopic response rate was 40% (28%, 21-35; 135/336) with risankizumab 600 mg and 32% (20%, 14-27; 109/339) with risankizumab 1200 mg versus 12% (21/175) with placebo. In MOTIVATE, CDAI clinical remission rate was 42% (22%, 13-31; 80/191) with risankizumab 600 mg and 40% (21%, 12-29; 77/191) with risankizumab 1200 mg versus 20% (37/187) with placebo; stool frequency and abdominal pain score clinical remission rate was 35% (15%, 6-24; 66/191) with risankizumab 600 mg and 40% (20%, 12-29; 76/191) with risankizumab 1200 mg versus 19% (36/187) with placebo; and endoscopic response rate was 29% (18%, 10-25; 55/191) with risankizumab 600 mg and 34% (23%, 15-31; 65/191) with risankizumab 1200 mg versus 11% (21/187) with placebo. The overall incidence of treatment-emergent adverse events was similar among the treatment groups in both trials. Three deaths occurred during induction (two in the placebo group [ADVANCE] and one in the risankizumab 1200 mg group [MOTIVATE]). The death in the risankizumab-treated patient was deemed unrelated to the study drug. INTERPRETATION: Risankizumab was effective and well tolerated as induction therapy in patients with moderately to severely active Crohn's disease. FUNDING: AbbVie.

Higher vs Standard Adalimumab Induction Dosing Regimens and Two Maintenance Strategies: Randomized SERENE CD Trial Results.

BACKGROUND & AIMS: Dose-optimization strategies for biologic therapies in Crohn's disease (CD) are not well established. The SERENE CD (Study of a Novel Approach to Induction and Maintenance Dosing With Adalimumab in Patients With Moderate to Severe Crohn's Disease) trial evaluated higher vs standard adalimumab induction dosing and clinically adjusted (CA) vs therapeutic drug monitoring (TDM) maintenance strategies in patients with moderately to severely active CD. METHODS: In this phase 3, randomized, double-blind, multicenter trial, eligible adults (Crohn's Disease Activity Index score of 220-450, endoscopic evidence of mucosal inflammation, and previous failure of standard therapies) were randomized to higher induction regimen (adalimumab 160 mg at weeks 0, 1, 2, and 3; n = 308) or standard induction regimen (adalimumab 160 mg at week 0 and 80 mg at week 2; n = 206) followed by 40 mg every other week from week 4 onward. Co-primary end points included clinical remission at week 4 and endoscopic response at week 12. At week 12, patients were re-randomized to maintenance therapy optimized by Crohn's Disease Activity Index and C-reactive protein (CA; n = 92) or serum adalimumab concentrations and/or clinical criteria (TDM; n = 92); exploratory end points were evaluated at week 56. RESULTS: Similar proportions of patients receiving higher induction regimen and standard induction regimen achieved clinical remission at week 4 (44% in both; P = .939) and endoscopic response at week 12 (43% vs 39%, respectively, P = .462). Week 56 efficacy was similar between CA and TDM. Safety profiles were comparable between dosing regimens. CONCLUSIONS: Higher induction regimen was not superior to standard induction regimen, and CA and TDM maintenance strategies were similarly efficacious. Adalimumab therapy was well tolerated, and no new safety concerns were identified. (ClinicalTrials.gov, Number: NCT02065570).

Higher vs Standard Adalimumab Induction and Maintenance Dosing Regimens for Treatment of Ulcerative Colitis: SERENE UC Trial Results.

BACKGROUND & AIMS: SERENE UC (Study of a Novel Approach to Induction and Maintenance Dosing With Adalimumab in Patients With Moderate to Severe Ulcerative Colitis) evaluated the efficacy of higher adalimumab induction and maintenance dose regimens in patients with ulcerative colitis. METHODS: This phase 3, double-blind, randomized trial included induction and maintenance studies, with a main study (ex-Japan) and Japan substudy. Eligible patients (18-75 years, full Mayo score 6-12, centrally read endoscopy subscore 2-3) were randomized 3:2 to higher induction regimen (adalimumab 160 mg at weeks 0, 1, 2, and 3) or standard induction regimen (160 mg at week 0 and 80 mg at week 2); all received 40 mg at weeks 4 and 6. At week 8, all patients were rerandomized 2:2:1 (main study) to 40 mg every week (ew), 40 mg every other week (eow), or exploratory therapeutic drug monitoring; or 1:1 (Japan substudy) to 40 mg ew or 40 mg eow maintenance regimens. RESULTS: In the main study, 13.3% vs 10.9% of patients receiving the higher induction regimen vs standard induction regimen achieved clinical remission (full Mayo score ≤2 with no subscore >1) at week 8 (induction primary end point; P = .265); among week-8 responders, 39.5% vs 29.0% receiving 40 mg ew vs 40 mg eow achieved clinical remission at week 52 (maintenance primary end point; P = .069). In the integrated (main + Japan) population, 41.1% vs 30.1% of week-8 responders receiving 40 mg ew vs 40 mg eow achieved clinical remission at week 52 (nominal P = .045). Safety profiles were comparable between dosing regimens. CONCLUSION: Although primary end points were not met, a >10% absolute difference in clinical remission was demonstrated with higher adalimumab maintenance dosing. Higher dosing regimens were generally well tolerated and consistent with the known safety profile of adalimumab in ulcerative colitis. CLINICALTRIALS: gov, Number: NCT002209456.

The Interplay between GSK3ß and Tau Ser262 Phosphorylation during the Progression of Tau Pathology.

Tau hyperphosphorylation has been linked directly to the formation of toxic neurofibrillary tangles (NFTs) in tauopathies, however, prior to NFT formation, the sequence of pathological events involving tau phosphorylation remains unclear. Here, the effect of glycogen synthase kinase 3ß (GSK3ß) on tau pathology was examined independently for each step of transcellular propagation; namely, tau intracellular aggregation, release, cellular uptake and seeding activity. We find that overexpression of GSK3ß-induced phosphorylated 0N4R tau led to a higher level of tau oligomerization in SH-SY5Y neuroblastoma cells than wild type 0N4R, as determined by several orthogonal assays. Interestingly, the presence of GSK3ß also enhanced tau release. Further, we demonstrated that cells endocytosed more monomeric tau protein when pre-phosphorylated by GSK3ß. Using an extracellular vesicle (EVs)-assisted tau neuronal delivery system, we show that exosomal GSK3ß-phosphorylated tau, when added to differentiated SH-SY5Y cells, induced more efficient tau transfer, showing much higher total tau levels and increased tau aggregate formation as compared to wild type exosomal tau. The role of a primary tau phosphorylation site targeted by microtubule-affinity regulating kinases (MARKs), Ser262, was tested by pseudo-phosphorylation using site-directed mutagenesis to aspartate (S262D). S262D tau overexpression significantly enhanced tau release and intracellular tau accumulation, which were concurrent with the increase of pathological states of tau, as determined by immunodetection. Importantly, phosphorylation-induced tau accumulation was augmented by co-transfecting S262D tau with GSK3ß, suggesting a possible interplay between Ser262 phosphorylation and GSK3ß activity in tau pathology. Lastly, we found that pre-treatment of cells with amyloid-ß (Aß) further tau phosphorylation and accumulation when Ser262 pre-phosphorylation was present, suggesting that S262 may be a primary mediator of Aß-induced tau toxicity. These findings provide a potential therapeutic target for treating tau-related disorders by targeting specific phospho-tau isoforms and further elucidate the GSK3ß-mediated pathological seeding mechanisms.

Cholesterol Dependent Activity of the Adenosine A2A Receptor Is Modulated via the Cholesterol Consensus Motif.

BACKGROUND: Membrane cholesterol dysregulation has been shown to alter the activity of the adenosine A2A receptor (A2AR), a G protein-coupled receptor, thereby implicating cholesterol levels in diseases such as Alzheimer's and Parkinson's. A limited number of A2AR crystal structures show the receptor interacting with cholesterol, as such molecular simulations are often used to predict cholesterol interaction sites. METHODS: Here, we use experimental methods to determine whether a specific interaction between amino acid side chains in the cholesterol consensus motif (CCM) of full length, wild-type human A2AR, and cholesterol modulates activity of the receptor by testing the effects of mutational changes on functional consequences, including ligand binding, G protein coupling, and downstream activation of cyclic AMP. RESULTS AND CONCLUSIONS: Our data, taken with previously published studies, support a model of receptor state-dependent binding between cholesterol and the CCM, whereby cholesterol facilitates both G protein coupling and downstream signaling of A2AR.

Characterization of binding kinetics of A2AR to Gαs protein by surface plasmon resonance.

Because of their surface localization, G protein-coupled receptors (GPCRs) are often pharmaceutical targets as they respond to a variety of extracellular stimuli (e.g., light, hormones, small molecules) that may activate or inhibit a downstream signaling response. The adenosine A2A receptor (A2AR) is a well-characterized GPCR that is expressed widely throughout the human body, with over 10 crystal structures determined. Truncation of the A2AR C-terminus is necessary for crystallization as this portion of the receptor is long and unstructured; however, previous work suggests shortening of the A2AR C-terminus from 412 to 316 amino acids (A2AΔ316R) ablates downstream signaling, as measured by cAMP production, to below that of constitutive full-length A2AR levels. As cAMP production is downstream of the first activation event-coupling of G protein to its receptor-investigating that first step in activation is important in understanding how the truncation effects native GPCR function. Here, using purified receptor and Gαs proteins, we characterize the association of A2AR and A2AΔ316R to Gαs with and without GDP or GTPγs using surface plasmon resonance (SPR). Gαs affinity for A2AR was greatest for apo-Gαs, moderately affected in the presence of GDP and nearly completely ablated by the addition of GTPγs. Truncation of the A2AR C-terminus (A2AΔ316R) decreased the affinity of the unliganded receptor for Gαs by ∼20%, suggesting small changes to binding can greatly impact downstream signaling.

Media supplementation for targeted manipulation of monoclonal antibody galactosylation and fucosylation.

Monoclonal antibodies are critically important biologics as the largest class of molecules used to treat cancers, rheumatoid arthritis, and other chronic diseases. Antibody glycosylation is a critical quality attribute that has ramifications for patient safety and physiological efficacy-one that can be modified by such factors as media formulation and process conditions during production. Using a design-of-experiments approach, we examined the effect of 2-F-peracetyl fucose (2FP), uridine, and galactose on cell growth and metabolism, titer, and gene expression of key glycosylation-related proteins, and report how the glycoform distribution changed from Days 4 to 7 in a batch process used for IgG1 production from Chinese hamster ovary cells. We observed major glycosylation changes upon supplement addition, where the addition of 2FP decreased antibody fucosylation by up to 48%, galactose addition increased galactosylation by up to 21%, and uridine addition decreased fucosylation and increased galactosylation by 6% and 2%, respectively. Despite having major effects on glycosylation, neither galactose nor 2FP significantly affected cell culture growth, metabolism, or titer. Uridine improved peak cell densities by 23% but also reduced titer by ∼30%. The supplements caused significant changes in gene expression by Day 4 of the cultures where 2FP addition significantly reduced fucosyltransferase 8 and nucleotide sugar transporter gene expression (by ∼2-fold), and uridine addition significantly increased expression of UDP-GlcNAcT (SLC35A3) and B4GALT1-6 genes (by 1.5-3-fold). These gene expression data alongside glycosylation, metabolic, and growth data improve our understanding of the cellular mechanisms affected by media supplementation and suggest approaches for modifying antibody glycosylation in antibody production processes.

New free-exchange model of EmrE transport.

EmrE is a small multidrug resistance transporter found in Escherichia coli that confers resistance to toxic polyaromatic cations due to its proton-coupled antiport of these substrates. Here we show that EmrE breaks the rules generally deemed essential for coupled antiport. NMR spectra reveal that EmrE can simultaneously bind and cotransport proton and drug. The functional consequence of this finding is an exceptionally promiscuous transporter: not only can EmrE export diverse drug substrates, it can couple antiport of a drug to either one or two protons, performing both electrogenic and electroneutral transport of a single substrate. We present a free-exchange model for EmrE antiport that is consistent with these results and recapitulates ∆pH-driven concentrative drug uptake. Kinetic modeling suggests that free exchange by EmrE sacrifices coupling efficiency but boosts initial transport speed and drug release rate, which may facilitate efficient multidrug efflux.

Functional Expression of Adenosine A3 Receptor in Yeast Utilizing a Chimera with the A2AR C-Terminus.

The adenosine A3 receptor (A3R) is the only adenosine receptor subtype to be overexpressed in inflammatory and cancer cells and therefore is considered a novel and promising therapeutic target for inflammatory diseases and cancer. Heterologous expression of A3R at levels to allow biophysical characterization is a major bottleneck in structure-guided drug discovery efforts. Here, we apply protein engineering using chimeric receptors to improve expression and activity in yeast. Previously we had reported improved expression and trafficking of the chimeric A1R variant using a similar approach. In this report, we constructed chimeric A3/A2AR comprising the N-terminus and transmembrane domains from A3R (residues 1-284) and the cytoplasmic C-terminus of the A2AR (residues 291-412). The chimeric receptor showed approximately 2-fold improved expression with a 2-fold decreased unfolded protein response when compared to wild type A3R. Moreover, by varying culture conditions such as initial cell density and induction temperature a further 1.7-fold increase in total receptor yields was obtained. We observed native-like coupling of the chimeric receptor to Gai-Gpa1 in engineered yeast strains, activating the downstream, modified MAPK pathway. This strategy of utilizing chimeric receptor variants in yeast thus provides an exciting opportunity to improve expression and activity of "difficult-to-express" receptors, expanding the opportunity for utilizing yeast in drug discovery.

Uropathogenic enterobacteria use the yersiniabactin metallophore system to acquire nickel.

Invasive Gram-negative bacteria often express multiple virulence-associated metal ion chelators to combat host-mediated metal deficiencies. Escherichia coli, Klebsiella, and Yersinia pestis isolates encoding the Yersinia high pathogenicity island (HPI) secrete yersiniabactin (Ybt), a metallophore originally shown to chelate iron ions during infection. However, our recent demonstration that Ybt also scavenges copper ions during infection led us to question whether it might be capable of retrieving other metals as well. Here, we find that uropathogenic E. coli also use Ybt to bind extracellular nickel ions. Using quantitative MS, we show that the canonical metal-Ybt import pathway internalizes the resulting Ni-Ybt complexes, extracts the nickel, and releases metal-free Ybt back to the extracellular space. We find that E. coli and Klebsiella direct the nickel liberated from this pathway to intracellular nickel enzymes. Thus, Ybt may provide access to nickel that is inaccessible to the conserved NikABCDE permease system. Nickel should be considered alongside iron and copper as a plausible substrate for Ybt-mediated metal import by enterobacteria during human infections.

The C terminus of the bacterial multidrug transporter EmrE couples drug binding to proton release.

Ion-coupled transporters must regulate access of ions and substrates into and out of the binding site to actively transport substrates and minimize dissipative leak of ions. Within the single-site alternating access model, competitive substrate binding forms the foundation of ion-coupled antiport. Strict competition between substrates leads to stoichiometric antiport without slippage. However, recent NMR studies of the bacterial multidrug transporter EmrE have demonstrated that this multidrug transporter can simultaneously bind drug and proton, which will affect the transport stoichiometry and efficiency of coupled antiport. Here, we investigated the nature of substrate competition in EmrE using multiple methods to measure proton release upon the addition of saturating concentrations of drug as a function of pH. The resulting proton-release profile confirmed simultaneous binding of drug and proton, but suggested that a residue outside EmrE's Glu-14 binding site may release protons upon drug binding. Using NMR-monitored pH titrations, we trace this drug-induced deprotonation event to His-110, EmrE's C-terminal residue. Further NMR experiments disclosed that the C-terminal tail is strongly coupled to EmrE's drug-binding domain. Consideration of our results alongside those from previous studies of EmrE suggests that this conserved tail participates in secondary gating of EmrE-mediated proton/drug transport, occluding the binding pocket of fully protonated EmrE in the absence of drug to prevent dissipative proton transport.

Copper import in Escherichia coli by the yersiniabactin metallophore system.

Copper plays a dual role as a nutrient and a toxin during bacterial infections. While uropathogenic Escherichia coli (UPEC) strains can use the copper-binding metallophore yersiniabactin (Ybt) to resist copper toxicity, Ybt also converts bioavailable copper to Cu(II)-Ybt in low-copper conditions. Although E. coli have long been considered to lack a copper import pathway, we observed Ybt-mediated copper import in UPEC using canonical Fe(III)-Ybt transport proteins. UPEC removed copper from Cu(II)-Ybt with subsequent re-export of metal-free Ybt to the extracellular space. Copper released through this process became available to an E. coli cuproenzyme (the amine oxidase TynA), linking this import pathway to a nutrient acquisition function. Ybt-expressing E. coli thus engage in nutritional passivation, a strategy of minimizing a metal ion's toxicity while preserving its nutritional availability. Copper acquisition through this process may contribute to the marked virulence defect of Ybt-transport-deficient UPEC.

Effect of tight control management on Crohn's disease (CALM): a multicentre, randomised, controlled phase 3 trial.

BACKGROUND: Biomarkers of intestinal inflammation, such as faecal calprotectin and C-reactive protein, have been recommended for monitoring patients with Crohn's disease, but whether their use in treatment decisions improves outcomes is unknown. We aimed to compare endoscopic and clinical outcomes in patients with moderate to severe Crohn's disease who were managed with a tight control algorithm, using clinical symptoms and biomarkers, versus patients managed with a clinical management algorithm. METHODS: CALM was an open-label, randomised, controlled phase 3 study, done in 22 countries at 74 hospitals and outpatient centres, which evaluated adult patients (aged 18-75 years) with active endoscopic Crohn's disease (Crohn's Disease Endoscopic Index of Severity [CDEIS] >6; sum of CDEIS subscores of >6 in one or more segments with ulcers), a Crohn's Disease Activity Index (CDAI) of 150-450 depending on dose of prednisone at baseline, and no previous use of immunomodulators or biologics. Patients were randomly assigned at a 1:1 ratio to tight control or clinical management groups, stratified by smoking status (yes or no), weight (<70 kg or ≥70 kg), and disease duration (≤2 years or >2 years) after 8 weeks of prednisone induction therapy, or earlier if they had active disease. In both groups, treatment was escalated in a stepwise manner, from no treatment, to adalimumab induction followed by adalimumab every other week, adalimumab every week, and lastly to both weekly adalimumab and daily azathioprine. This escalation was based on meeting treatment failure criteria, which differed between groups (tight control group before and after random assignment: faecal calprotectin ≥250 µg/g, C-reactive protein ≥5mg/L, CDAI ≥150, or prednisone use in the previous week; clinical management group before random assignment: CDAI decrease of <70 points compared with baseline or CDAI >200; clinical management group after random assignment: CDAI decrease of <100 points compared with baseline or CDAI ≥200, or prednisone use in the previous week). De-escalation was possible for patients receiving weekly adalimumab and azathioprine or weekly adalimumab alone if failure criteria were not met. The primary endpoint was mucosal healing (CDEIS <4) with absence of deep ulcers 48 weeks after randomisation. Primary and safety analyses were done in the intention-to-treat population. This trial has been completed, and is registered with ClinicalTrials.gov, number NCT01235689. FINDINGS: Between Feb 11, 2011, and Nov 3, 2016, 244 patients (mean disease duration: clinical management group, 0·9 years [SD 1·7]; tight control group, 1·0 year [2·3]) were randomly assigned to monitoring groups (n=122 per group). 29 (24%) patients in the clinical management group and 32 (26%) patients in the tight control group discontinued the study, mostly because of adverse events. A significantly higher proportion of patients in the tight control group achieved the primary endpoint at week 48 (56 [46%] of 122 patients) than in the clinical management group (37 [30%] of 122 patients), with a Cochran-Mantel-Haenszel test-adjusted risk difference of 16·1% (95% CI 3·9-28·3; p=0·010). 105 (86%) of 122 patients in the tight control group and 100 (82%) of 122 patients in the clinical management group reported treatment-emergent adverse events; no treatment-related deaths occurred. The most common adverse events were nausea (21 [17%] of 122 patients), nasopharyngitis (18 [15%]), and headache (18 [15%]) in the tight control group, and worsening Crohn's disease (35 [29%] of 122 patients), arthralgia (19 [16%]), and nasopharyngitis (18 [15%]) in the clinical management group. INTERPRETATION: CALM is the first study to show that timely escalation with an anti-tumour necrosis factor therapy on the basis of clinical symptoms combined with biomarkers in patients with early Crohn's disease results in better clinical and endoscopic outcomes than symptom-driven decisions alone. Future studies should assess the effects of such a strategy on long-term outcomes such as bowel damage, surgeries, hospital admissions, and disability. FUNDING: AbbVie.

Lymphoma Risk and Overall Safety Profile of Adalimumab in Patients With Crohn's Disease With up to 6 Years of Follow-Up in the Pyramid Registry.

OBJECTIVES: Real-world, prospective, long-term studies in Crohn's disease (CD) characterizing adalimumab safety data and lymphoma risk were lacking. We present the final results from the PYRAMID registry, which was designed to rule out a doubling of lymphoma risk in adalimumab-treated patients with CD. METHODS: Patients with moderately to severely active CD newly prescribed or currently receiving adalimumab according to local product labels were followed for up to 6 years and analyzed for adverse events (AEs). The registry exposure-adjusted observed rate of lymphoma was compared with the estimated background lymphoma rate from a sex-matched general population in the Surveillance, Epidemiology, and End Results 17 Registry database adjusted for anticipated prior or concurrent thiopurine use in a CD population. RESULTS: A total of 5025 patients were evaluated (16680.4 PY of adalimumab registry exposure, ≈3 years/patient mean follow-up). Registry treatment-emergent AEs included 4129 serious AEs (n = 1853 [36.9%]; 24.8 E/100 PY), 792 serious infections (n = 556 [11.1%]; 4.7 E/100 PY), and 134 malignancies (n = 116 [2.3%]; 0.8 E/100 PY), including ten lymphomas. The observed lymphoma rate (0.060 E/100 PY) was lower than the estimated background rate (0.084 E/100 PY), and the upper bound of the one-sided 95% CI of the observed rate (0.102 E/100 PY) was lower than double the estimated rate (0.168 E/100 PY). CONCLUSIONS: PYRAMID is the longest prospective adalimumab study in routine clinical practice, with up to 6 years of follow-up. No new safety signals were reported. The pre-specified registry objective of ruling out a doubling of lymphoma risk with adalimumab was met.

A mass spectrometry based transport assay for studying EmrE transport of unlabeled substrates.

Membrane transporters are an important class of proteins which remain challenging to study. Transport assays are crucial to developing our understanding of such proteins as they allow direct measurement of their transport activity. However, currently available methods for monitoring liposomal loading of organic substrates primarily rely on detection of radioactively or fluorescently labeled substrates. The requirement of a labeled substrate significantly restricts the systems and substrates that can be studied. Here we present a mass spectrometry based detection method for liposomal uptake assays that eliminates the need for labeled substrates. We demonstrate the efficacy of the assay with EmrE, a small multidrug resistance transporter found in E. coli that has become a model transport system for the study of secondary active transport. Furthermore, we develop a method for differentiation between bound and transported substrate, enhancing the information gained from the liposomal uptake assay. The transport assay presented here is readily applicable to other transport systems and substrates.

Responsiveness of Endoscopic Indices of Disease Activity for Crohn's Disease.

OBJECTIVES: The Crohn's Disease Endoscopic Index of Severity (CDEIS) and the Simple Endoscopic Score for Crohn's Disease (SES-CD) are commonly used to assess Crohn's disease (CD) activity; however neither instrument is fully validated. We evaluated the responsiveness to change of the SES-CD and CDEIS using data from a trial of adalimumab, a drug therapy of known efficacy. METHODS: Paired video recordings (N=112) of colonoscopies (baseline and week 8-12) obtained from patients with CD who participated in a trial of adalimumab therapy were reviewed in random order, in duplicate, by four central readers (56 pairs of videos by 2 groups of readers). Responsiveness of the SES-CD and the CDEIS was evaluated by comparing correlations between the observed and pre-specified predictions of change scores for these endoscopic indices with a global endoscopic evaluation of severity (GELS), a patient reported outcome (PRO2), and the Crohn's disease activity index (CDAI), and by calculation of the standardized effect size, and Guyatt's Responsiveness statistic (GRS) using 2 definitions of change; (1) treatment assignment and (2) an absolute change in total PRO2 of 50. The potential application of effect size estimates was demonstrated by calculating hypothetical sample sizes for comparing two independent groups. The impact of removing stenosis as an index item and adjusting for the number of segments observed was also assessed. RESULTS: Changes in both endoscopic instruments and the GELS were highly correlated. The SES-CD displayed numerically higher effect sizes for both definitions of change. The standardized effect size and GRS estimates (95% confidence interval) for the SES-CD based on treatment assignment were 0.84 (0.53, 1.15) and 0.79 (0.48, 1.09). Corresponding values for the CDEIS were 0.72 (0.42, 1.02) and 0.75 (0.45, 1.06). The standardized effect size and GRS estimates for the SES-CD based on an absolute change in total PRO2 of 50 points or greater were 0.76 (0.49, 1.02) and 0.93 (0.64, 1.21). Corresponding values for CDEIS were 0.70 (0.44, 0.97), 0.83 (0.55, 1.10). Removal of stenosis as an index item and adjusting for observed segments did not improve responsiveness estimates. CONCLUSIONS: Although both the SES-CD and CDEIS are valid measures of endoscopic disease activity that are moderately responsive to changes in endoscopic disease activity, the SES-CD displayed numerically greater responsiveness in this data set.

Conserved disulfide bond is not essential for the adenosine A2A receptor: Extracellular cysteines influence receptor distribution within the cell and ligand-binding recognition.

G protein-coupled receptors (GPCRs) are integral membrane proteins involved in cellular signaling and constitute major drug targets. Despite their importance, the relationship between structure and function of these receptors is not well understood. In this study, the role of extracellular disulfide bonds on the trafficking and ligand-binding activity of the human A2A adenosine receptor was examined. To this end, cysteine-to-alanine mutations were conducted to replace individual and both cysteines in three disulfide bonds present in the first two extracellular loops. Although none of the disulfide bonds were essential for the formation of plasma membrane-localized active GPCR, loss of the disulfide bonds led to changes in the distribution of the receptor within the cell and changes in the ligand-binding affinity. These results indicate that in contrast to many class A GPCRs, the extracellular disulfide bonds of the A2A receptor are not essential, but can modulate the ligand-binding activity, by either changing the conformation of the extracellular loops or perturbing the interactions of the transmembrane domains.

Crohn's Disease Activity and Concomitant Immunosuppressants Affect the Risk of Serious and Opportunistic Infections in Patients Treated With Adalimumab.

OBJECTIVES: Anti-tumor necrosis factor (TNF) drugs are commonly used to treat moderate-to-severe Crohn's disease (CD). Both the activity of CD and the concomitant immunosuppressants (corticosteroids and immunomodulators) used with anti-TNF drugs could increase the risk of infection. We determined the relative risk of serious and opportunistic infections associated with increasing disease activity and concomitant immunomodulators and corticosteroids in patients with CD treated with adalimumab. METHODS: This pooled analysis identified incident treatment-emergent serious and opportunistic infections among patients with CD in clinical trials of adalimumab. Disease activity was assessed with the Crohn's Disease Activity Index (CDAI). RESULTS: The analysis included 2,266 patients treated with adalimumab with median age 35 years. Higher disease activity was associated with significantly increased risks of both serious and opportunistic infections at 1 year, with each 100-point increase in CDAI associated with a >30% increased risk of each type of infection. Concomitant use of immunomodulators was associated with a significant >3-fold decreased risk of serious infection (hazard ratio (HR) 0.29 (0.08-0.98), P=0.045) by 1 year. Concomitant use of corticosteroids was associated with a significantly increased risk of serious infection by day 120 (HR 2.40 (1.33-4.35), P=0.004). Concomitant use of either category of immmunosuppressant was associated with numerically higher rates of opportunistic infection, 40% of which were due to herpes zoster, compared with adalimumab monotherapy. CONCLUSIONS: Higher disease activity in CD is associated with significantly increased risks of both serious and opportunistic infections. In addition to corticosteroid-sparing strategies, consideration should be given to expanding herpes zoster vaccination guidelines to include younger patients.

Impact of purification conditions and history on A2A adenosine receptor activity: The role of CHAPS and lipids.

The adenosine A2A receptor (A2AR) is a much-studied class A G protein-coupled receptor (GPCR). For biophysical studies, A2AR is commonly purified in a detergent mixture of dodecylmaltoside (DDM), 3-(3-cholamidopropyl) dimethylammoniopropane sulfonate (CHAPS), and cholesteryl hemisuccinate (CHS). Here we studied the effects of CHAPS on the ligand binding activity and stability of wild type, full-length human A2AR. We also tested the cholesterol requirement for maintaining the active conformation of the receptor when solubilized in detergent micelles. To this end, the receptor was purified using DDM, DDM/CHAPS, or the short hydrocarbon chain lipid 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC, di-6:0PC). After solubilization in DDM, DDM/CHAPS, or DHPC micelles, although A2AR was found to retain its native-like fold, its binding ability was significantly compromised compared to DDM or DDM/CHAPS with CHS. It therefore appears that although cholesterol is not needed for A2AR to retain a native-like, α-helical conformation, it may be a critical component for high affinity ligand binding. Further, this result suggests that the conformational differences between the active and inactive protein may be so subtle that commonly used spectroscopic methods are unable to differentiate between the two forms, highlighting the need for activity measurements. The studies presented in this paper also underline the importance of the protein's purification history; i.e., detergents that interact with the protein during purification affect the ligand binding properties of the receptor in an irreversible manner.