Tocilizumab Robert A. Montgomery, M.D., D.Phil. Professor of Surgery Director of the NYU Langone Transplant Institute

Scope of the Problem Sensitization to HLA molecules limits access to transplantation for about 30,000 patients on the kidney waiting list The post-transplant presence of DSA is perhaps the most significant contributor to premature graft loss Acute AMR further accelerates the the rate and speed of graft loss Strategies to prevent or treat chronic microcirculation injury and transplant glomerulopathy from DSA remains an important unmet need

Need for Efficacious Therapies Standard of care therapy (plasmapheresis and IVIg) can effectively ameliorate antibody mediated injury especially when the AMR is early and associated with acute renal dysfunction Many drugs with autoimmune and oncologic indications have been repurposed to treat or prevent AMR because of attractive mechanisms of action These add-on therapies may enhance the efficacy of SOC treatments and the search for more effective therapeutic agents continues

Therapies and Intervention For HLA DSA The Tackle Box Standard of Care (SOC) Add-ons to SOC Plasmapheresis Immunoabsorption IVIg (high or low dose) Steroids, ATG, Bela [Rituximab] Splenectomy Anti-CD20 Complement Inhibitors (eculizumab and C1INH) Proteosomal Inhibitors Anti-BAFF/BLyS IdeS Anti-IL-6R

IL-6 IL-6 : B-cell stimulatory factor-2 Is a Pleiotropic Cytokine IL-6 Levels increase in Major Depressive Disorder (MDD) , Alzheimer’s Disease and schizophrenia. Neuron IL-6 Stimulate B- cells to Increase antibody production Increase plasmablast Decrease Treg differentiation Enhances Th17 and Tfh cells Immune cells Skin IL-6 Increase Keratinocytes Increase dermal fibroblast collagen Liver Increase CRP, decrease albumin & transferrin Increase Serum Amyloid A Increase Fibrinogen Increase Hepcidin IL-6 Cardiac Increase VEGF to increase angiogenesis Increase cardiovascular disease Increases mesangial cell proliferation, critical to ANCA vasculitis. Proximal tubular cells express IL-6 with injury. Kidney IL-6 Increase osteoclast differentiation Increase angiogenesis Increase platelet Bone Marrow Synovial Fibroblast Dysregulation of IL-6-type cytokine signaling contributes to the onset and maintenance of multiple diseases and cancers

Tocilizumab Humanized monoclonal antibody against the Interleukin-6 receptor (IL-6R) Its delivered by monthly infusion or subcutaneous injection Used for rheumatoid arthritis, systemic juvenile arthritis, and Castleman’s disease. In Phase II/III trials for GVHD. Very limited experience in solid organ transplantation For naïve B-cells, IL-6 promotes activation and differentiation into plasmablasts and plasma cells IL-6 may also be important for the maintenance of: survival milieu in the long-lived plasma cell niche Germinal center and Tfh/B-cell interactions

IL-6 Producing Plasmablast Figure 3a IL-6 Drives B-cell Activation & Differentiation to Antibody Producing Plasma Cells CD4+ Tfh CXCR5+ Bcl-6+ Naïve B-cell Donor Specific Antibodies Plasma Cell IL-6 IL-21 + IL-6 Producing Plasmablast Germinal Center

Pathogenesis of the Humoral Immune Response1 HLA antibody Plasmablasts Plasma cells Clonal expansion Complement Activation Tocilizumab Tfh cell AMR: Pathogenesis of the Immune Response Regina, do we need all of the little y-looking images? We are going to need to condense this down. Do you know where this comes from? I added the title. I’ll have studio redraw if we determine we are keeping this. Do we need a reference at all? I can’t find a definition for LLPC. I removed some of the Ys at the top. Please look at the original and let me know if this works. Naïve and Memory B cells Tocilizumab LLPC Bone marrow Coagulative necrosis 1. Modified Montgomery et al. Seminars in Immunology. 2011. 23:224-234.

Figure 5

Kim et al Transplantation 2014 Anti-IL-6R Inhibits Plasma Cell IgG Production and Anti-HLA-A2 Antibody Anti-HLA-A2 Anti-HLA-A2 Kim et al Transplantation 2014

Vo et al. Transplantation. 2015; 99:2356.

Tocilizumab Protocol for Patients Unresponsive to IVIg/Rituxumab

Fate of Patients Enrolled The mean time to transplant from first DES was 25 ± 10.5 months but after TCZ was 8.1 ± 5.4 months. No ABMR was seen on protocol biopsies performed at 6 months from all transplanted patients. Vo et al. Transplantation. 2015; 99:2356.

Serum IL-6 and IL-6R Levels Increase On Tocilizumab Vo et al. Transplantation. 2015; 99:2356.

Fate of Immuno-dominant DSAs Vo et al. Transplantation. 2015; 99:2356.

Tocilizumab Treatment of Chronic ABMR & TG: Treatment Protocol 75 Patients with Chronic Active ABMR +/- Transplant Glomerulopathy (TG) 39 Patients Treated with IVIG + Rituximab +/- PLEX (SOC) 37 Patients who failed IVIG + Rituximab + PLEX Rx with Tocilizumab 8mg/kg monthly 6-18M Patients followed for up to 5 years post-treatment with assessments Shin & Toyoda, ATC, Abstract C9 2016

Allograft Survival Since Initial Biopsy: TCZ v. SOC

Allograft Survival Since Biopsy in Patients with TG

Patient Survival Since Biopsy: TCZ v. SOC

GFR Values for TCZ Treated Patients GFR ml/min Tocilizumab 4-8mg/kg monthly x 6M or more

Effect of 6M Tocilizumab Therapy on IgG Subclasses in Patients with ABMR & TG IgG Levels (mg/dl) Shin & Toyoda, ATC, Abstract C9 2016

Mean Immunodominant DSA Values for TCZ Treated Patients RIS* p = 0.0001 Tocilizumab 4-8mg/kg monthly x 6M or more *Relative Intensity Scale (RIS) [0 points = No DSA; 2 points = <5000MFI {weak}; 5 points = 5000-10,000 MFI {moderate}; 10 points = >10,000MFI {strong}].

Conclusions Tocilizumab (anti-IL-6R mAB) has an attractive mechanism of action for desensitization and treatment of AMR In two small uncontrolled clinical trials appears to have a good safety profile in patients pre and post-transplant The drug may show promise as an add-on therapy to SOC for patients recalcitrant to desensitization with the Cedars protocol It may also be one of the first drugs to extend the half-life of grafts chronically injured by persistent DSA