BIOACTIVE RENAL CELLS AUGMENT KIDNEY FUNCTION IN A RODENT MODEL OF CHRONIC KIDNEY DISEASE Rusty Kelley, PhD Regenerative Medicine & Biology Tengion Labs May 24, 2010 ISCT Annual Meeting, Philadelphia PA 1
2 Product Pipeline May 2010 Optimization Preclinical IND Phase I Phase II Phase III Neo-Bladder Augment Spina Bifida Spinal Cord Injured Urge Incontinence (laparascopic) Neo-Urinary Conduit Bladder Cancer Neo-Bladder Replacement Bladder Cancer Neo-Kidney Augment Advanced CKD Neo-GI Augment Esophagectomy Neo-Vessel Replacement Vascular Access Graft Peripheral Artery Bypass Coronary Artery Bypass
3 Chronic Renal Failure is a leading cause of death worldwide New treatment modalities are needed http://www.nationmaster.com/red/pie/mor_chr_ren_fai-mortality-chronic-renal-failure
Goal: Identify bioactive cellular components for Neo-Kidney Augment (NKA) prototypes Through in vitro characterization and in vivo testing Strategic Approach: 1) Generate testable array of kidney components based on native tissue composition 2) Design admixture experiments based on functional component characteristics 3) Test admixture arrays in vivo in small animal model of terminal, progressive CKD 2-step 5/6 Nx (Rodent) 4 *patent filed: 2009
Isolation and propagation of endocrine, tubular, and glomerular cells has been described from healthy rodent kidney tissue Work completed via Sponsored Research Agreement with Wake Forest Institute of Regenerative Medicine 5
6 Heterogeneous cultures of kidney cells (UNFX) Fractionated based on differences in buoyant density CKD or non-ckd Enzymatic Digestion Cell Culture/Expansion Gradient Separation FRACTIONS UNFX B1 B2 B3 B4 B5 a heterogeneous mixture of renal cells isolated cortical and medullary zones distal tubular and collecting duct cells with trace amounts of other cell types renal tubular epithelial cells with distal tubule and collecting duct cells present. Endocrine, glomerular and vascular cells are present in trace quantities proximal tubular cells, with fewer distal tubule, collecting duct, endocrine, vascular, glomerular, and progenitor-like cells vascular, endocrine, glomerular with fewer tubular and progenitor-like cells very small cells with low viability
7 In vitro characterization of subfractions Identified unique properties of B2 and B4 Subfraction B2 is enriched for tubular cells Subfraction B4 is enriched for vascular, glomerular, and oxygenregulated erythropoietin (EPO)-producing cells
Microarray gene expression analysis of Subfractions Validated rat expression and confirmed human translation by qrtpcr Validation of microarray by qrtpcr David* Annotated Functional Group: Blood Vessel Development -KDR Target Gene Sample Rat RQ Human CKD RQ Human Non-CKD RQ CDH5 B2 0.742 1.052 1.387 B4 8.065 6.205 2.340 KDR B2 0.708 0.607 0.233 B4 10.348 20.637 6.344 PLAT B2 1.008 1.224 0.430 B4 3.088 4.266 0.430 ANGPT2 B2 0.737 0.872 0.812 B4 6.697 14.115 13.446 B4-specific gene expression patterns were validated for the following David* Annotated Functional Groups: Blood vessel development Extracellular matrix Regeneration Localization of the cell Developmental processes *http://david.abcc.ncifcrf.gov 8
9 In vivo testing of subfractions & admixtures In a 2-step 5/6-nephrectomized (NX) rodent model Model Generation 2-step 5/6 Nephrectomy Day 0 Poles of Left Kidney removed (2/6 th ) 1 WEEK 4-7 WEEKS 12-24 WEEKS TREATMENT FOLLOW-UP Establishment Entry Criteria serum chemistry of Disease State Intrarenal delivery of cells in diluent urinalysis hematology survival Day 7 No Surgery & Sham Nx Right Kidney screat & BUN screat 200% weight gain Removed monitored weekly BUN 150% kidney weight (3/6 th ) 2 consecutive weeks egfr No treatment Blood Pressure histology RANDOMIZATION TEST CONTROLS Animals were treated after disease state established Series 1: B2 and B4 tested independently in comparison to UNFX Series 2: Subfraction admixtures tested in comparison to B2
10 Selected subpopulations enhanced systemic health Survival and weight gain B2 > B4 > UNFX for survival and weight gain Treatment with B2 100% survival at 6 month endpoint Series 1
11 Selected subpopulations enhanced renal function Filtration, functional renal mass, and erythropoiesis Series 1 B2 > B4 > UNFX Stabilized serum creatinine Enhanced functional renal mass Supported erythropoiesis
Summary of Results Series 1: Comparison of UNFX, B2, & B4 When data are considered across multiple parameters tested, the B2 cellular prototype provides significant and reproducible therapeutic benefits compared to UNFX and B4 Survival Filtration Erythropoiesis The B4 cellular prototype provides a mild survival benefit as well as supports erythropoiesis and facilitates glomerular repair. Thus, the B2 subpopulation served as comparison for Series 2 tests of subpopulation admixtures 12
13 Subpopulation admixture B2+B4 Provided superior therapeutic outcomes in vivo NS = No Survival Series 2 B2+B4 Improved egfr Stabilized serum Creatinine & BUN
14 Therapeutic effects of B2+B4 were confirmed histologically And compared to NX and an admixture of B1+B5 Remodeling and regeneration in tubular and glomerular compartments Modulation of glomerular and tubulo-interstitial fibrosis
15 Summary of Results Series 2: Testing of subpopulation admixtures The B2+B4 admixture outperformed other cell and cell-cell combinations tested on multiple systemic and histological parameters: Weight gain Survival (100%) Lowering serum creatinine and BUN Raising estimated Glomerular Filtration Rate (egfr) Lowering systemic blood pressure Reducing glomerular injury Reducing tubular injury Stimulating tubulogenesis
Conclusions Specific subpopulations of renal cells are more efficacious and reproducible in slowing the progression of CKD than unfractionated (UNFX) Tubular cell-enriched subpopulation B2 improves functional renal mass significantly and leads to organism-level benefits, including survival While B4 is less therapeutic on its own, an admixture of B2+B4 enhances the therapeutic outcome of B2, providing superior Renal filtration Tubular regeneration Glomerular repair B2-based admixtures (e.g., B2+B4) provide a regenerative stimulus for the treatment of renal insufficiency 16