Sumanta K. Pal, MD; 1 Min Li, PhD; 2 Xiwei Wu, PhD; 3 Paul Frankel, PhD 2

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1 Bacteriomic profiling reveals potential etiology for vascular endothelial growth factor-tyrosine kinase inhibitor (VEGF-TKI)-related diarrhea in patients with metastatic renal cell carcinoma (mrcc) Sumanta K. Pal, MD; 1 Min Li, PhD; 2 Xiwei Wu, PhD; 3 Paul Frankel, PhD 2 1 Department of Medical Oncology, City of Hope Comprehensive Cancer Center, Duarte, CA; 2 Department of Biostatistics, City of Hope Comprehensive Cancer Center, Duarte, CA; 3 Department of Molecular & Cell Biology, City of Hope Comprehensive Cancer Center, Duarte, CA

2 Background VEGF-directed therapy remains a mainstay of treatment for mrcc Various molecular predictors of toxicity have been established Distinct SNPs may predict: Hypertension 1,2 Hypothyroidism 3 Diarrhea 4 Multiple toxicities have been associated with efficacy Hypertension 5 Fatigue 6 Hand-foot syndrome 7 Hypothyroidism 8 1 Kim et al Cancer 2012; 2 Eechoute et al Clin Pharmacol Ther 2012; 3 Rutkowski et al BMC Cancer 2012; 4 Bodou-Rouguette et al PLOS One 2012; 5 Ravaud et al Ann Oncol 2013; 6 Donskov et al Ann Oncol 2012; 7 Pusanov ECCO 2012; 8 Schmidinger et al Cancer 2011

3 Background The underlying biology of these toxicities has not been clearly demonstrated Few evidence-based strategies (e.g., ASIs for hypertension 1 ) have been proposed for managing toxicity Diarrhea is a pervasive problem across VEGF-TKIs, and the mechanism is poorly understood No evidence-based strategy exists to treat VEGF-TKI related diarrhea Agent N G 1/2 G 3/4 Overall Sorafenib % 2% 43% Sunitinib % 9% 61% Pazopanib % 4% 52% Cumulative % 5% 51% We hypothesize that bacteriomic profiling may identify protective species in the stool flora 1 McKay R et al ASCO GU 2014; 2 Escudier B et al NEJM 2007; 3 Motzer R et al NEJM 2007; 4 Sternberg C et al JCO 2009

4 Objectives Primary objective To determine if patients with mrcc with diarrhea in association with VEGF-TKI therapy have a decreased level of Bifidobacterium spp. as compared to patients treated with VEGF-TKI without diarrhea. Secondary: To compare the global stool bacteriomic profile of patients with and without diarrhea when treated with VEGF-TKI therapy To determine the feasibility of stool collection and bacteriomic assessment in patients with mrcc To compare levels of circulating Treg cells and levels of peripheral STAT3 in patients with and without diarrhea with VEGF-TKI therapy* 1 In progress

5 Eligibility Cytologically or pathologically verified diagnosis of RCC Metastatic by standard criteria (AJCC 7th edition, 2010) Current treatment with a VEGF-TKI Axitinib Pazopanib Sorafenib Sunitinib Age 18 or older

6 Methods Patients characterized on the presence or absence of diarrhea (all grade) at the time of study consent SOP document distributed to all patients to standardize stool collection Total genomic DNA isolated Purified DNA separated on a 1% agarose gel and quantified PCR protocol used to amplify bacterial 16S rrna genes from all samples 1 PCR primers including Illumina part of adapter sequences used to amplify V4 and V5 region 1 Stearns et al Sci Rep 2011

7 Statistical Analysis CD-HIT algorithm used to cluster 16S rrna sequences and identify OTUs Phylogeny constructed and diversity indexes calculated Weighted and unweighted UniFrac used to cluster patients and to explore patterns in bacteriomic profile associated with diarrhea Principle coordinate analysis (PCoA) used to examine possible correlation between phylum/genus and other phenotypic variables

8 Results Of 26 patients consented, 23 patients submitted stool specimens and 20 patients had sufficient data for the current analysis Total (%) Diarrhea Absent (%) Diarrhea Present (%) Sex Male Female N=20 12 (40) 8 (60) N=8 5 (63) 3 (36) N=12 7 (42) 5 (58) Age (Years) Mean (SD) Median Minimum Maximum Race White Asian Other 16 (80) 2 (10) 2 (10) 5 (63) 1 (13) 2 (24) 11 (92) 1 (8) 0 (0) IMDC Risk Group Intermediate Poor 15 (75) 5 (25) 6 (75) 2 (25) 9 (75) 3 (25)

9 Results Of 26 patients consented, 23 patients submitted stool specimens and 20 patients had sufficient data for the current analysis Total (%) Diarrhea Absent (%) Diarrhea Present (%) Metastatic Site Lung Liver Bone Brain 14 (70) 4 (20) 6 (30) 1 (5) 5 (63) 2 (25) 2 (25) 1 (13) 9 (75) 2 (17) 4 (33) 0 (0) Number of Prior Therapies (40) 0 (0) 6 (30) 6 (30) 3 (38) 0 (0) 2 (24) 3 (38) 5 (42) 0 (0) 4 (33) 3 (25) VEGF-TKI Therapy Sunitinib Pazopanib Axitinib Sorafenib 11 (55) 5 (25) 2 (10) 2 (10) 4 (49) 2 (25) 1 (13) 1 (13) 7 (59) 3 (25) 1 (8) 1 (8)

10 Results Total of 141 bacterial species identified Two species of Bifidobacterium spp. more abundant in patients without diarrhea (P<0.10): B. animalis B. bifidum No differences based on: 1 st -line v later line Type of VEGF-TKI

11 Conclusions Bacterial profiling feasible in patients with mrcc Two bacteria may be protective Bifidobacterium animalis Bifidobacterium bifidum Limitations: Small sample size No control for dietary intake, other factors that could impact fecal microbiota Unclear if fecal microbiota profile changed with VEGF-TKI therapy No correction for false discovery Future directions: Validation study including serial stool collection Interventional study using probiotic supplement

12 Acknowledgements Study team Min Li, PhD Xiwei Wu, PhD Paul Frankel, PhD Patients and families Kidney Cancer Association