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157 Fecal Loss of Infliximab As a Cause of Lack of Response in Severe Inflammatory Bowel Disease
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score of 0. Patients (n=124) were randomized in a 1:1:1 ratio to either 2 dose levels of etrolizumab (100mg monthly SC or 300mg monthly SC + loading dose [LD] of 420mg SC between Wk 0 & 2) or placebo for 3 doses. Concomitant therapy for UC remained stable through to the primary endpoint at Wk 10. MCS was evaluated at Wks 0, 6 & 10. Five patients were excluded from the primary efficacy analysis due to a screening endoscopy subscore of , 2 by central read. Results: Patient demographics and baseline characteristics are outlined in Table 1. Primary and secondary efficacy endpoints are summarized in Table 2. Etrolizumab showed significantly higher rates of clinical remission vs Pbo at Wk 10: 100mg dose 20.5% and 300mg + LD dose 10.3% versus Pbo 0% (p=0.004 and 0.049 respectively). In the anti-TNF Naïve subgroup, the rates of clinical remission at Wk 10 were significantly higher in the 100mg dose group compared with Pbo (43.8% vs 0%, p=0.007). Etrolizumab achieved endoscopic remission in the 100mg dose of 10.3% and in the 300mg + LD dose of 7.7% vs Pbo of 0%. In the anti-TNF Naïve subgroup, endoscopic remission was 25% and 16.7% vs 0% respectively (p=0.058 vs Pbo for the 100mg dose group). Etrolizumab demonstrated apparent full occupancy of beta7 receptors on CD4 and CD8 T cells in both colonic tissue (α4β7 and αEβ7) and peripheral blood (α4β7), and of the α4β7 receptor on B cells in peripheral blood, in both etrolizumab dose groups. Rates of AEs were comparable for the 3 groups. One etrolizumab treated patient suffered a rash & headache after the first dose and was admitted to hospital for observation. This patient was negative for ATAs. There were a total of 4 actively treated patients with mild (Grade 1) injection site reactions all of whom were in the 300mg + LD dose group. Conclusion: Etrolizumab administered SC is well tolerated and has shown clinically meaningful efficacy compared with Pbo in patients with moderate-to-severely active UC. These promising results warrant further Phase III studies. Table 1: Patient demographics and baseline characteristics
AGA Abstracts
Fecal Loss of Infliximab As a Cause of Lack of Response in Severe Inflammatory Bowel Disease Johannan F. Brandse, Manon Wildenberg, Jessica R. de Bruyn, Gert-Jan Wolbink, M. Lowenberg, Cyriel Ponsioen, Gijs R. van den Brink, Geert R. D'Haens BACKGROUND Although Infliximab (IFX) has proven its efficacy both in Crohn's disease (CD) and Ulcerative Colitis (UC), still a considerable group of patients fails to respond to induction therapy. One of the hypotheses behind this phenomenon is increased clearance or loss of the drug. In severe CD and UC, the mucosa is diffusely denuded and ulcerated, leading to massive loss of proteins, electrolytes and other nutrients. We hypothesized that, even after intravenous administration, IFX may be lost through this ‘leaky gut'. Fecal loss of IFX in this context has not been investigated up to date and this was the focus of the current study METHODS In this pilot study we prospectively collected repeated fecal samples of IBD patients within the first 14 days after starting IFX therapy. Fecal samples were weighed and homogenized in PBS containing bovine serum albumin. Supernatant was collected after centrifugation and tested with a well established ELISA by Sanquin Laboratories to detect the presence of Infliximab. Clinical response in these patients was assessed 3 months after the initiation of IFX therapy. RESULTS 9 IBD patients (3 CD, 6 UC) with different disease localizations (5 Ulcerative Pancolitis, 1 Proctitis, 2 Ileocecal CD, 1 Crohn's Colitis) starting on IFX 5 mg/kg at week 0-2-6 were included. One patient (Crohn's colitis) received an extra infusion (5mg/kg) at day 4 because of initial non response. IFX could be detected in the feces of all patients. The highest concentrations were measured in the first days after initiation of therapy, meaning in the most acute phase of the disease. In non responders (3/9) the amount of drug detected in stool at the first day after infusion was significantly (p: 0.024) higher than in patients who had clinical response. CONCLUSION IFX can be detected in the feces of patients with severe IBD, especially short after infusion. This phenomenon may contribute to rapid disappearance of the drug out of the gut and the circulation leading to insufficient response. 158 Innate IL-10 Receptor Signaling Regulates Intestinal Mucosal Homeostasis Dror S. Shouval, Jeremy A. Goettel, Marc-Andre Wurbel, Aleixo M. Muise, Scott B. Snapper Background: IL-10 receptor (IL-10R) mutations cause severe very early onset IBD in humans, and similarly, IL-10Rβ KO mice develop spontaneous colitis. While recent data show that IL-10R signaling is important on T cell populations to prevent IBD, there is no data on the role of IL-10R signaling on innate immune cells in maintaining mucosal homeostasis. We hypothesized that innate IL-10R signaling is a key regulator in the intestine of immune responses and prevention of colitis. Methods: IL-10R β KO and RAG KO mice were crossed to generate double KO mice (DKO), which lack an adaptive immune system and possess IL-10R deficient innate immune cells. For adoptive transfer experiments, RAG KO and DKO mice were injected with wild-type (WT) CD4+ T cells, either unfractionated, or fractionated as CD45RBhigh, CD45RBlow alone or in combination. Since IL-10R β is expressed on both hematopoietic and non-hematopoietic cells, bone marrow chimeras of DKO into RAG KO mice were generated. Colitis was assessed based on clinical, endoscopic and histological scores. FACS analysis to assess immune cell populations was performed, as well as RT-PCR for various transcripts. To assess whether IL-10R signaling in dendritic cells (DCs) affects proliferation and suppression in-vitro, WT CFSE-labeled T Naïve cells were cultured with WT or IL-10Rβ KO DCs and different concentrations of WT Tregs. In-vitro Treg generation was assessed by defining the frequency of CD4+CD25+FoxP3+ T cells, following culture of WT T Naïve cells with TGF-β, αCD3 and either WT or IL-10Rβ KO DCs. Results: DKO mice were viable, occasionally developed abscesses, but importantly, did not develop spontaneous colitis. However, transfer of total WT CD4+ T cells into DKO mice caused severe intestinal inflammation after 4-5 weeks, associated with Th1-Th17 immune responses. Similarly, when CD4+ T cells were transferred into RAG KO mice reconstituted with DKO bone marrow, severe colitis resulted, indicating that the loss of IL-10R signaling on innate immune cells was responsible for the phenotype. CD4+CD45RBhigh transfer also elicited severe colitis in DKO mice, was not ameliorated by co-transfer of CD45RBlow cells, and was associated with a significant decrease in generation of inducible Tregs. Decreased Treg generation was also observed in-vitro in the presence of IL-10R β KO DCs. Moreover, IL-10Rβ KO DCs increased the proliferation of WT T effector cells, and decreased the suppressive function of WT Tregs. Conclusions: IL-10R signaling on innate immune cells is a key regulator of intestinal mucosal homeostasis. Aberrant signaling in innate immune cells enables WT T cells to become colitogenic, and impairs the suppressive functions of Tregs. Ongoing work will elucidate the relevant downstream signaling pathways mediated by IL-10R activation in innate immune cells and how it modulates the cross talk with T cells.
Table 2: Summary of Primary and Secondary Efficacy Results at Week 10 in Eucalyptus
159 Differentiation Between Etrolizumab (Rhumab Beta7) and Placebo in the Eucalyptus Phase II Randomized Double-Blind Placebo-Controlled Induction Study to Evaluate Efficacy and Safety in Patients With Refractory Moderate-toSeverely Active Ulcerative Colitis Severine Vermeire, Sharon O'Byrne, Marna Williams, John C. Mansfield, Brian G. Feagan, Julian Panes, Daniel C. Baumgart, Stefan Schreiber, Iris Dotan, William Sandborn, Mary E. Keir, Diana Luca, Paul J. Rutgeerts Introduction: Selective inhibition of leucocyte trafficking is a promising treatment for IBD. We evaluated a humanized monoclonal antibody to the β7 subunit of the heterodimeric integrins α4β7 and αEβ7 in patients with moderate-to-severely active UC. Methods: This parallel, randomized, double-blind, placebo-controlled study enrolled outpatients with a total Mayo Clinic Score (MCS) ≥ 5, an endoscopy subscore ≥ 2 by central reading and a rectal bleeding subscore ≥ 1. The primary efficacy endpoint was the proportion of patients in clinical remission at Wk 10 (defined as a total MCS of ≤ 2 with no individual subscore . 1). The secondary endpoint at Wk 10 of endoscopic remission was defined as an endoscopy
AGA Abstracts
a 4 patients distributed across the treatment groups are anti-TNF exposed but are not antiTNF-inadequate responders (IR) * p,0.05, ** p,0.01, *** p,0.005 vs placebo
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score of 0. Patients (n=124) were randomized in a 1:1:1 ratio to either 2 dose levels of etrolizumab (100mg monthly SC or 300mg monthly SC + loading dose [LD] of 420mg SC between Wk 0 & 2) or placebo for 3 doses. Concomitant therapy for UC remained stable through to the primary endpoint at Wk 10. MCS was evaluated at Wks 0, 6 & 10. Five patients were excluded from the primary efficacy analysis due to a screening endoscopy subscore of , 2 by central read. Results: Patient demographics and baseline characteristics are outlined in Table 1. Primary and secondary efficacy endpoints are summarized in Table 2. Etrolizumab showed significantly higher rates of clinical remission vs Pbo at Wk 10: 100mg dose 20.5% and 300mg + LD dose 10.3% versus Pbo 0% (p=0.004 and 0.049 respectively). In the anti-TNF Naïve subgroup, the rates of clinical remission at Wk 10 were significantly higher in the 100mg dose group compared with Pbo (43.8% vs 0%, p=0.007). Etrolizumab achieved endoscopic remission in the 100mg dose of 10.3% and in the 300mg + LD dose of 7.7% vs Pbo of 0%. In the anti-TNF Naïve subgroup, endoscopic remission was 25% and 16.7% vs 0% respectively (p=0.058 vs Pbo for the 100mg dose group). Etrolizumab demonstrated apparent full occupancy of beta7 receptors on CD4 and CD8 T cells in both colonic tissue (α4β7 and αEβ7) and peripheral blood (α4β7), and of the α4β7 receptor on B cells in peripheral blood, in both etrolizumab dose groups. Rates of AEs were comparable for the 3 groups. One etrolizumab treated patient suffered a rash & headache after the first dose and was admitted to hospital for observation. This patient was negative for ATAs. There were a total of 4 actively treated patients with mild (Grade 1) injection site reactions all of whom were in the 300mg + LD dose group. Conclusion: Etrolizumab administered SC is well tolerated and has shown clinically meaningful efficacy compared with Pbo in patients with moderate-to-severely active UC. These promising results warrant further Phase III studies. Table 1: Patient demographics and baseline characteristics
AGA Abstracts
Fecal Loss of Infliximab As a Cause of Lack of Response in Severe Inflammatory Bowel Disease Johannan F. Brandse, Manon Wildenberg, Jessica R. de Bruyn, Gert-Jan Wolbink, M. Lowenberg, Cyriel Ponsioen, Gijs R. van den Brink, Geert R. D'Haens BACKGROUND Although Infliximab (IFX) has proven its efficacy both in Crohn's disease (CD) and Ulcerative Colitis (UC), still a considerable group of patients fails to respond to induction therapy. One of the hypotheses behind this phenomenon is increased clearance or loss of the drug. In severe CD and UC, the mucosa is diffusely denuded and ulcerated, leading to massive loss of proteins, electrolytes and other nutrients. We hypothesized that, even after intravenous administration, IFX may be lost through this ‘leaky gut'. Fecal loss of IFX in this context has not been investigated up to date and this was the focus of the current study METHODS In this pilot study we prospectively collected repeated fecal samples of IBD patients within the first 14 days after starting IFX therapy. Fecal samples were weighed and homogenized in PBS containing bovine serum albumin. Supernatant was collected after centrifugation and tested with a well established ELISA by Sanquin Laboratories to detect the presence of Infliximab. Clinical response in these patients was assessed 3 months after the initiation of IFX therapy. RESULTS 9 IBD patients (3 CD, 6 UC) with different disease localizations (5 Ulcerative Pancolitis, 1 Proctitis, 2 Ileocecal CD, 1 Crohn's Colitis) starting on IFX 5 mg/kg at week 0-2-6 were included. One patient (Crohn's colitis) received an extra infusion (5mg/kg) at day 4 because of initial non response. IFX could be detected in the feces of all patients. The highest concentrations were measured in the first days after initiation of therapy, meaning in the most acute phase of the disease. In non responders (3/9) the amount of drug detected in stool at the first day after infusion was significantly (p: 0.024) higher than in patients who had clinical response. CONCLUSION IFX can be detected in the feces of patients with severe IBD, especially short after infusion. This phenomenon may contribute to rapid disappearance of the drug out of the gut and the circulation leading to insufficient response. 158 Innate IL-10 Receptor Signaling Regulates Intestinal Mucosal Homeostasis Dror S. Shouval, Jeremy A. Goettel, Marc-Andre Wurbel, Aleixo M. Muise, Scott B. Snapper Background: IL-10 receptor (IL-10R) mutations cause severe very early onset IBD in humans, and similarly, IL-10Rβ KO mice develop spontaneous colitis. While recent data show that IL-10R signaling is important on T cell populations to prevent IBD, there is no data on the role of IL-10R signaling on innate immune cells in maintaining mucosal homeostasis. We hypothesized that innate IL-10R signaling is a key regulator in the intestine of immune responses and prevention of colitis. Methods: IL-10R β KO and RAG KO mice were crossed to generate double KO mice (DKO), which lack an adaptive immune system and possess IL-10R deficient innate immune cells. For adoptive transfer experiments, RAG KO and DKO mice were injected with wild-type (WT) CD4+ T cells, either unfractionated, or fractionated as CD45RBhigh, CD45RBlow alone or in combination. Since IL-10R β is expressed on both hematopoietic and non-hematopoietic cells, bone marrow chimeras of DKO into RAG KO mice were generated. Colitis was assessed based on clinical, endoscopic and histological scores. FACS analysis to assess immune cell populations was performed, as well as RT-PCR for various transcripts. To assess whether IL-10R signaling in dendritic cells (DCs) affects proliferation and suppression in-vitro, WT CFSE-labeled T Naïve cells were cultured with WT or IL-10Rβ KO DCs and different concentrations of WT Tregs. In-vitro Treg generation was assessed by defining the frequency of CD4+CD25+FoxP3+ T cells, following culture of WT T Naïve cells with TGF-β, αCD3 and either WT or IL-10Rβ KO DCs. Results: DKO mice were viable, occasionally developed abscesses, but importantly, did not develop spontaneous colitis. However, transfer of total WT CD4+ T cells into DKO mice caused severe intestinal inflammation after 4-5 weeks, associated with Th1-Th17 immune responses. Similarly, when CD4+ T cells were transferred into RAG KO mice reconstituted with DKO bone marrow, severe colitis resulted, indicating that the loss of IL-10R signaling on innate immune cells was responsible for the phenotype. CD4+CD45RBhigh transfer also elicited severe colitis in DKO mice, was not ameliorated by co-transfer of CD45RBlow cells, and was associated with a significant decrease in generation of inducible Tregs. Decreased Treg generation was also observed in-vitro in the presence of IL-10R β KO DCs. Moreover, IL-10Rβ KO DCs increased the proliferation of WT T effector cells, and decreased the suppressive function of WT Tregs. Conclusions: IL-10R signaling on innate immune cells is a key regulator of intestinal mucosal homeostasis. Aberrant signaling in innate immune cells enables WT T cells to become colitogenic, and impairs the suppressive functions of Tregs. Ongoing work will elucidate the relevant downstream signaling pathways mediated by IL-10R activation in innate immune cells and how it modulates the cross talk with T cells.
Table 2: Summary of Primary and Secondary Efficacy Results at Week 10 in Eucalyptus
159 Differentiation Between Etrolizumab (Rhumab Beta7) and Placebo in the Eucalyptus Phase II Randomized Double-Blind Placebo-Controlled Induction Study to Evaluate Efficacy and Safety in Patients With Refractory Moderate-toSeverely Active Ulcerative Colitis Severine Vermeire, Sharon O'Byrne, Marna Williams, John C. Mansfield, Brian G. Feagan, Julian Panes, Daniel C. Baumgart, Stefan Schreiber, Iris Dotan, William Sandborn, Mary E. Keir, Diana Luca, Paul J. Rutgeerts Introduction: Selective inhibition of leucocyte trafficking is a promising treatment for IBD. We evaluated a humanized monoclonal antibody to the β7 subunit of the heterodimeric integrins α4β7 and αEβ7 in patients with moderate-to-severely active UC. Methods: This parallel, randomized, double-blind, placebo-controlled study enrolled outpatients with a total Mayo Clinic Score (MCS) ≥ 5, an endoscopy subscore ≥ 2 by central reading and a rectal bleeding subscore ≥ 1. The primary efficacy endpoint was the proportion of patients in clinical remission at Wk 10 (defined as a total MCS of ≤ 2 with no individual subscore . 1). The secondary endpoint at Wk 10 of endoscopic remission was defined as an endoscopy
AGA Abstracts
a 4 patients distributed across the treatment groups are anti-TNF exposed but are not antiTNF-inadequate responders (IR) * p,0.05, ** p,0.01, *** p,0.005 vs placebo
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