Mesalazine granules promote disease clearance in patients with mild-to-moderate ulcerative colitis

BACKGROUND

Over the past decade, treatment targets for ulcerative colitis (UC) have become more stringent, incorporating multiple parameters. Recently, the concept of 'disease clearance'-defined as combined clinical, endoscopic, and histological remission-has been proposed as an ultimate endpoint in treating UC.

OBJECTIVE

To determine the rates of disease clearance in patients with mild-to-moderate UC treated with different doses of mesalazine granules as induction therapy.

METHODS

In a post hoc analysis, data were pooled from four randomised, active-controlled, phase 3 clinical trials in patients with mild-to-moderate UC receiving 8-week induction therapy with mesalazine granules at daily doses of 1.5, 3.0 or 4.5 g. Rates of clinical, endoscopic, and histological remission were determined using stringent criteria and used to calculate rates of the composite endpoints of clinical plus endoscopic remission, endoscopic plus histological remission, and disease clearance (clinical plus endoscopic plus histological remission).

RESULTS

A total of 860 patients were included in the analysis. Among the total population, 20.0% achieved disease clearance with mesalazine granules: 13.1% in patients receiving 1.5 g mesalazine granules/day, 21.8% in those receiving 3.0 g/day and 18.9% in those receiving 4.5 g/day. Among patients with moderate UC, 16.8% achieved disease clearance: 7.1% with 1.5 g/day, 18.8% with 3.0 g/day and 16.2% with 4.5 g/day.

CONCLUSION

Disease clearance, proposed to be predictive of improved long-term outcomes, can be achieved in a clinically meaningful proportion of mild-to-moderate UC patients treated with mesalazine granules. A daily dose of 3.0 g appears optimal to reach this target.

Membrane Fusion Mediated by Non-covalent Binding of Re-engineered Cholera Toxin Assemblies to Glycolipids

Membrane fusion is essential for the transport of macromolecules and viruses across membranes. While glycan-binding proteins (lectins) often initiate cellular adhesion, subsequent fusion events require additional protein machinery. No mechanism for membrane fusion arising from simply a protein binding to membrane glycolipids has been described thus far. Herein, we report that a biotinylated protein derived from cholera toxin becomes a fusogenic lectin upon cross-linking with streptavidin. This novel reengineered protein brings about hemifusion and fusion of vesicles as demonstrated by mixing of fluorescently labeled lipids between vesicles as well as content mixing of liposomes filled with fluorescently labeled dextran. Exclusion of the complex at vesicle-vesicle interfaces could also be observed, indicating the formation of hemifusion diaphragms. Discovery of this fusogenic lectin complex demonstrates that new emergent properties can arise from simple changes in protein architecture and provides insights into new mechanisms of lipid-driven fusion.

Bacterial lectin BambL acts as a B cell superantigen

B cell superantigens crosslink conserved domains of B cell receptors (BCRs) and cause dysregulated, polyclonal B cell activation irrespective of normal BCR-antigen complementarity. The cells typically succumb to activation-induced cell death, which can impede the adaptive immune response and favor infection. In the present study, we demonstrate that the fucose-binding lectin of Burkholderia ambifaria, BambL, bears functional resemblance to B cell superantigens. By engaging surface glycans, the bacterial lectin activated human peripheral blood B cells, which manifested in the surface expression of CD69, CD54 and CD86 but became increasingly cytotoxic at higher concentrations. The effects were sensitive to BCR pathway inhibitors and excess fucose, which corroborates a glycan-driven mode of action. Interactome analyses in a model cell line suggest BambL binds directly to glycans of the BCR and regulatory coreceptors. In vitro, BambL triggered BCR signaling and induced CD19 internalization and degradation. Owing to the lectin's six binding sites, we propose a BCR activation model in which BambL functions as a clustering hub for receptor glycans, modulates normal BCR regulation, and induces cell death through exhaustive activation.

Efficacy and safety of prolonged release budesonide granules in mesalazine-refractory ulcerative colitis: A multi-centre Phase IIa study (TOPICAL-1)

BACKGROUND

In patients with mesalazine-refractory ulcerative colitis, systemic corticosteroids are the treatment of choice.

OBJECTIVE

To evaluate the efficacy and safety of prolonged release budesonide granules for the induction of remission in patients with mesalazine-refractory ulcerative colitis.

METHODS

Patients with mesalazine-refractory ulcerative colitis discontinued mesalazine at baseline and received 9 mg prolonged release budesonide granules daily for 8 weeks in this open-label, phase IIa study, followed by a 2-week follow-up phase wherein patients continued treatment on alternate days (EudraCT number 2014-005635-14; ClinicalTrials.gov identifier NCT02550418). The primary endpoint was clinical remission (Clinical Activity Index ≤4; stool frequency <18 per week; absence of rectal bleeding) at Week 8. Secondary endpoints included clinical, endoscopic and histological measures of disease at Week 8. A post hoc analysis assessed histo-endoscopic mucosal healing. Treatment-emergent adverse events and morning cortisol levels were assessed throughout the treatment and follow-up phases.

RESULTS

A total of 61 patients were included in the intention-to-treat population; 50 were included in the follow-up analysis set. Clinical remission was achieved in 29 patients (47.5%; 95% confidence interval: 34.6-60.7%) by Week 8. Mean stool and bloody stool frequency decreased significantly from 32.5 to 22.9 per week (p<0.0001) and from 17.6 to 8.1 per week (p<0.0001), respectively. Rates of mucosal healing, endoscopic remission and histological remission were 58.0%, 54.0% and 36.0%, respectively. Histo-endoscopic mucosal healing was achieved by 34.0% of patients. Twenty-four patients (39.3%) experienced treatment-emergent adverse events, of which gastrointestinal disorders (16.4%) were the most common. Mean morning cortisol levels were not significantly suppressed by Week 8.

CONCLUSIONS

Treatment with prolonged release budesonide granules for 8 weeks was associated with clinical, endoscopic and histological remission and demonstrated a favourable safety profile in patients with mesalazine-refractory ulcerative colitis. These results warrant further investigation into the potential of prolonged release budesonide granules as an alternative treatment for this patient population.