S. Paul

Development of an algorithm incorporating pharmacokinetics of adalimumab in inflammatory bowel diseases.

OBJECTIVES:Several decision algorithms based on the measurement of infliximab (IFX) trough levels and antibodies to IFX have been proposed. Whether such algorithms can be extrapolated to the pharmacokinetics of adalimumab (ADA) has yet to be determined.METHODS:A prospective study included all consecutive patients with inflammatory bowel disease (IBD) having a disease flare while being on ADA 40 mg every 2 weeks were included. All patients were primary responders to ADA therapy and were anti-tumor necrosis factor (TNF) naive. ADA trough levels and antibodies against ADA (AAA) were measured blinded to clinical data (Elisa LISA-Tracker, Theradiag). All patients were optimized with ADA 40 mg weekly. Four months later, in the absence of clinical remission (CR; Crohns disease activity index <150 for Crohns disease (CD), and Mayo score <2 for ulcerative colitis), patients were treated with IFX therapy. Patients were divided into three groups based on ADA trough levels and based on previous studies: group A, ADA>4.9 μg/ml; group B, ADA<4.9 μg/ml and undetectable levels of AAA (<10 ng/ml); and group C, ADA<4.9 μg/ml and AAA >10 ng/ml.RESULTS:A total of 82 patients were included (55% CD; mean age=43 years, disease duration=7.4 years, duration of ADA therapy=17 months). After optimization of ADA treatment, 29.2% of patients achieved CR in group A (N=41), 67% in group B (N=24), and 12% in group C (N=17; P<0.01 between groups A/B and B/C). C-reactive protein level at the time of relapse, disease duration, duration of ADA therapy, and IBD type was not predictive of CR after ADA optimization by univariate analysis. The response to ADA optimization was significantly more durable in group B (15 months) than in groups A and C (4 and 5 months, respectively). Fifty-two patients who failed following ADA optimization (63%) were treated with IFX, and 30.6% of them achieved CR. CR rates following IFX initiation were 6.9%, 25%, and 80% in groups A, B, and C, respectively (P<0.01 between groups C/A and between groups C/B). Duration of response to IFX was significantly higher in group C than in groups A and B (14 vs. 3 and 5 months, respectively, P<0.01).CONCLUSIONS:The presence of low ADA trough levels without AAA is strongly predictive of clinical response in 67% of cases after ADA optimization. Conversely, low ADA levels with detectable AAA are associated with ADA failure, and switching to IFX should be considered. ADA trough levels >4.9 μg/ml are associated with failure of two anti-TNF agents (ADA and IFX) in 90% of cases, and switching to another drug class should be considered.

Review article: biosimilars are the next generation of drugs for liver and gastrointestinal diseases

A biosimilar is a copy version of an approved original biological medicine whose data protection has expired.

Undetectable anti-TNF drug levels in patients with long-term remission predict successful drug withdrawal.

Low drug levels are associated with emerging loss of response to anti‐TNF. However, this may not be the case in patients with long‐term remission.

Encapsulation of Nod1 and Nod2 receptor ligands into poly(lactic acid) nanoparticles potentiates their immune properties

Most successful vaccines are able to induce persistent antibody responses that can last a lifetime. Emerging evidences indicate that activation of immune cells through pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) or Nod-like receptors (NLRs) may be critical mechanisms. Among PRRs, the use of TLR ligands as adjuvants is already largely described whereas the use of NLRs ligands remains largely unexplored. As activation of intracytoplasmic NLRs is able to induce proinflammatory molecules, the added value of encapsulation of Nod1 and Nod2 receptor ligands into Poly(Lactic Acid) (PLA) biodegradable nanocarriers to modulate their immune properties on human dendritic cells (DCs) maturation has been evaluated. Their ability to induce systemic immune responses in mice was also measured and compared to free ligands and the Alum adjuvant. Nod ligands encapsulated into PLA NPs were efficiently taken up by DCs and subsequently induced a strong up-regulation of maturation markers and the enhancement of proinflammatory cytokine secretion by DCs. Furthermore, co-injection of encapsulated Nod-ligands with PLA particles carrying Gag p24 HIV-1 antigen allowed a 100 fold increase in antibody responses in comparison to Alum. These results suggest that encapsulation of Nod ligands into PLA-NPs could be an effective way to improve vaccine efficiency.

Combination of C-reactive protein, infliximab trough levels and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease

BACKGROUND Antibodies to infliximab [ATI] and trough levels to infliximab [TRI] are associated with loss of response in inflammatory bowel diseases [IBD]. The best way to predict loss of response [LOR] to infliximab [IFX] is unknown. METHODS We conducted a prospective observational cohort study enrolling all IBD patients who were in clinical remission at Week 14 after IFX treatment initiation. TRI, ATI and C-reactive protein [CRP] level were measured at Week 22 [T1] and thereafter at every other IFX infusion. Loss of clinical response was defined by a flare requiring therapeutic change [IFX dose intensification, initiation of another drug class, and/or surgery]. RESULTS A total of 93 patients [59 Crohns disease, mean duration of follow-up 17.2 months] were included; 32 patients [34.4%] lost clinical response during follow-up. Cumulative probability of LOR was 50% at 20 months. Mean TRI at T1 was significantly lower in IBD patients with stable ATI as compared with those with transient ATI or without ATI [0.052, 3.34 ,and 4.29 µg/ml, respectively; p = 0.001 between no ATI vs stable ATI, and p = 0.005 between stable and transient ATI] [p = 0.0001]. Three independent factors were predictive of LOR after Cox proportional hazards modelling: TRI > 5.5 µg/ml (hazard ratio [HR]: 0.21; 95% confidence interval [CI]: 0.05-0.89;p = 0.034) at T1, CRP > 5mg/l [HR: 2.5; 95% CI: 1.16-5.26; p = 0.019] at T1, and stable ATI defined by two consecutive ATI > 20ng/ml [HR: 3.77; 95% CI: 1.45-10.0; p = 0.007]. Transient ATI did not influence LOR. CONCLUSIONS LOR can be predicted based on a combination of CRP, TRI and stable ATI with a high degree of accuracy.

Azathioprine dose reduction in inflammatory bowel disease patients on combination therapy: an open-label, prospective and randomised clinical trial

Infliximab (IFX) combined with azathioprine (AZA) is more effective than IFX monotherapy in inflammatory bowel disease (IBD).

Triggering Intracellular Receptors for Vaccine Adjuvantation.

Immune adjuvants are components that stimulate, potentiate, or modulate the immune response to an antigen. They are key elements of vaccines in both the prophylactic and therapeutic domains. In the past decade substantial progress in our understanding of innate immunity has paved the way for the design of next-generation adjuvants that stimulate a wide range of receptors. Within the framework of vaccine adjuvant design, this review outlines the interest of targeting endosomal and intracellular receptors to enhance and guide the immune response. We present and compare the molecules as well as potential combinations which are currently in the spotlight. We emphasize how targeting the appropriate receptor can direct immunity towards the appropriate response, such as a cytotoxic or mucosal response.

Directing vaccine immune responses to mucosa by nanosized particulate carriers encapsulating NOD ligands

Mucosal surfaces are a major portal of entry for many pathogens that are the cause of infectious diseases. Therefore, effective vaccines that induce a protective immune response at these sites are much needed. However, despite early success with the live attenuated oral polio vaccine over 50 years ago, only a few new mucosal vaccines have been subsequently licensed. Development of new adjuvants, comprising antigen delivery platforms and immunostimulatory molecules, are critical for the successful development of new mucosal vaccines. Among them, biodegradable nanoparticle delivery systems are promising and NOD-like receptors are considered as potential new targets for immunostimulatory molecules. In this work, different NOD1 and NOD2 ligands were encapsulated in polylactic acid (PLA) nanoparticles, coated with HIV-1 gag p24 antigen. We showed that these new formulations are able to induce proliferation of HIV-specific T cells from HIV(+) individuals as well as autophagy. In vivo, these formulations highly enhanced p24-specific systemic and mucosal immune responses in mice not only after mucosal administration but also after immunization via the parenteral route. Our results provide a rational approach for combining nanosized particulate carriers and encapsulated NOD receptor ligands as potent synergistic tools for induction of specific mucosal immunity.

Letter: infliximab de-escalation based on trough levels in patients with inflammatory bowel disease.

*Laboratoire d’Immunologie et d’Immunomonitoring, CIC INSERM 1408 Vaccinologie, GIMAP EA3064, CHU de Saint-Etienne, SaintEtienne, France. Service de Gastrologie-Ent erologie-H epatologie, CHU de SaintEtienne, Saint-Etienne, France. Inserm U954 and Department of Gastroenterology, Nancy University Hospital, Henri Poincar e University, Vandoeuvre-l es-Nancy, France. E-mail: xavier.roblin@chu-st-etienne.fr

Association of Anti-glycan Antibodies and Inflammatory Bowel Disease Course

BACKGROUND AND AIMS The usefulness of anti-glycan antibodies alone or combined with anti-Saccharomyces cerevisiae [ASCA] or perinuclear antineutrophil cytoplasmic [pANCA] antibodies for diagnosis of inflammatory bowel disease [IBD], differentiation between Crohns disease [CD] and ulcerative colitis [UC], disease stratification including IBD phenotype, and also for determination of the course of the disease, remain unclear. METHODS A large panel of serological anti-glycan carbohydrate antibodies, including anti-mannobioside IgG antibodies [AMCA], anti-chitobioside IgA [ACCA], anti-laminaribioside IgG antibodies [ALCA], anti-laminarin [anti-L] and anti-chitine [anti-C] were measured in the serum from a cohort of 195 patients with IBD] [107 CD and 88 UC]. The respective accuracy of isolated or combined markers for diagnosis, disease differentiation, stratification disease phenotype, and severity of the disease course, defined by a wide panel of criteria obtained from the past medical history, was assessed. RESULTS The positivity of at least one anti-glycan antibody was detected in a significant higher proportion of CD and UC compared with healthy controls [p < 0.0001 and p < 0.0007, respectively]. Whereas ASCA and ANCA antibody status had the highest efficacy to be associated with CD in comparison with UC (area under receiver operating characteristic curve [AUROC] = 0.70 for each], the adjunction of anti-laminarin antibody substantially improved the differentiation between CD and UC [AUROC = 0.77]. Titres of ACCA [> 51U/ml] and anti-laminarin [> 31U/ml] were significantly linked with a higher association with steroid dependency (odds ratio [OR] =2.0 [1.0-4.0], p = 0.03 and OR = 2.4 [1.1-5.2], p = 0.02, respectively]. We further defined the respective performance of anti-glycan antibodies to discriminate between patients with severe or not severe CD and UC course and determined the associated optimal cut-off values: severe CD course was significantly more likely in case of AMCA > 77U/ml [OR = 4.3; p = 0.002], ASCA > 63U/ml [OR = 3.5; p < 0.009] and at a lesser degree ACCA > 50U/ml [OR = 2.8; p < 0.02] and severe UC course was significantly associated with AMCA > 52U/ml [OR = 3.4; p = 0.04] and ACCA > 25U/ml [OR = 3.0; p < 0.04]. CONCLUSIONS Anti-glycan antibodies are valuable serological markers, especially AMCA antibodies that may help clinicians to promptly classify patients into high risk for severe disease.