Cancer Pharmacogenetics: Lessons Learned Geoffrey Liu, MD FRCPC Scientist, OCI Currently Approved Oncology Drugs Cost of Colorectal Cancer Treatment Per 6 Months ($) Meropol NJ, Schulman KA. Cost of Cancer Care: Issues and Implications. J Clin Oncol 2007 25:180-186. NY Times, September 2, 2009 Personalized Medicine Tailoring medical prevention and treatment therapies to the characteristics of each patient improving their quality of life and health outcome. "The right medicine to the right person at the right dosage at the right time" • Pharmacoepidemiology • Pharmacogenomics "Here's my sequence...” New Yorker Personalized or Predictive Medicine Patients with same diagnosis Respond to treatment No response to treatment Experience adverse events What Disciplines are Involved? Pharmacology Genomics Molecular biology Pharmacoepidemiology Personalized/ Stratified/ Predictive Medicine Bioinformatics BioStatistics Bioethics Cancer Pharmacogenomics (PGx) The study of how variation in an individual’s germline and/or tumor genome are related to their metabolism and physiological response to drugs used in cancer treatment • • • • • • Single Nucleotide Polymorphisms (substitutions) Insertions and deletions Copy number Variations Methylation patterns Molecular biomarkers Gene expression Cancer Pharmacogenetics Cancer Pharmacogenomics Biomarkers Predictive for Drug Outcomes Biomarkers Predictive for Treatment Outcomes Cancer Pharmacogenetics GERMLINE Cancer Pharmacogenomics SOMATIC or TUMOUR Biomarkers Predictive for PROTEINS, IMAGING Drug Outcomes RADIATION THERAPY Biomarkers Predictive for Treatment Outcomes Gene Mutations — Inherited or Acquired Hereditary (germline) mutations • alterations in DNA inherited from a parent and are found in the DNA of virtually all of your cells. Acquired (somatic) mutations • alterations in DNA that develop throughout a person’s life Somatic Examples Her2neu and Herceptin in breast ca KRAS and EGFR MoAbs in colorectal ca EGFR activating mutations and EGFR TKIs in NSCLC ?ALK-EML4 translocation and ALK-targeting ?BRAF mutations and BRAF inhibitor in melanoma (inherited) Genetic Variations? Substitutions (or SNPs) Insertions Deletions Duplications Short repeats Gene deletions Copy Number Variation Gene and Protein Expression Levels/Function /Regulation Polymorphisms can alter function through multiple mechanisms Promoter Exon Intron Conformational change Binding site change Early termination UTRs Polymorphisms can alter function through multiple mechanisms mRNA Transport guidance UTRs Promoter Exon Intron Regions that are spliced into non-coding RNAs UTRs “junk areas” microRNAs Meta-regulators Pharmacology Pharmacokinetics (PK): the study of the time course of substances and their relationship with an organism or system (Journey of drugs) • • • • Every aspect may affect the final drug effect Absorption Distribution Metabolism Excretion Pharmacodynamics (PD): the study of the biochemical and physiological effects of drugs and the mechanisms of drug action and the relationship between drug concentration and effect (Drug effect on the body) Pharmacogenetics The Study of the genetics of factors related to PD and PK Genes involved in PK Drug Absorption/Transport Activation/Metabolism/Excretion Genes involved in PD Drug mechanism of action. targets/downstream effectors Genetic Variation Mech’m Outcome 5FU/analogue DPD PK Toxicity 6MP and AZA TPMT PK Toxicity Irinotecan UGT1A1 PK Toxicity Aromatase Inhibitors TCL1 PD? Toxicity Warfarin CYP2C9 & VKORC1 PK & PD Toxicity Cisplatin TPMT and COMT Unclear Toxicity Tamoxifen CYP2D6 PK Efficacy 5FU/analogue TS PK Toxicity 5FU/analogue MTHFR PK Toxicity Cyclophosphamide CYPs PK Eff & Tox MoAbs Fc-gamma-RII & III PD Efficacy EGFR TKIs EGFR, ABCG2 PD Eff & Tox Cisplatin DNA repair SNPs PD Eff & Tox Dasatinib CYP3A4/3A5 PK Eff & Tox Adapted from Coate et al, JCO, 2010) High Level of Evidence Drug Candidate Genetic Factors Determining Drug Response Polymorphisms in • Drug Receptors/Targets Beta-2AR • Drug Transporters MDR1 • Drug Metabolizing Enzymes CYP2D6 Goal of Pharmacogenetics Optimize Therapy So Benefits Outweigh the Risks Methodological Approaches Biological Pathway-defined Epidemiological Association Studies In vitro and In vivo Human tissue and Clinical Information Issues to consider with Epidemiological Association Studies Tumour vs Blood = which is your target tissue? When do you believe an association study biomarker result? • Multiple comparisons? • Heterogeneity (of disease, of patients, of clinical scenario) = humans are not mice; how are these things controlled? • Biological Grounding/Functional Data? • Study Design and Study Population issues = if I choose the “right” controls, I will always be able to find a statistically significant result Three Common Genetic and Epidemiological Approaches Germline • Candidate-Gene • Genome-Wide Association (GWAS) • Candidate-Pathway Candidate-Gene Approach Typically genetic variants are selected based on their known physiologic or pharmacologic effect on disease or drug response Three Cancer Examples of candidate polymorphism approaches Irinotecan and UGT1A1 polymorphisms Tamoxifen and CYP2D6 polymorphisms EGFR tyrosine kinase inhibitors and EGFR polymorphisms Three Cancer Examples of candidate polymorphism approaches Irinotecan and UGT1A1 polymorphisms Tamoxifen and CYP2D6 polymorphisms EGFR tyrosine kinase inhibitors and EGFR polymorphisms Irinotecan metabolism and its toxicity ATP-binding cassette transporters (ABC gene family) Help drug transfer into hepatic cell membrane carboxylesterase 1, 2 Cytochrome P450 3A family SN-38+Glucuronide Bone Marrow Intestine Leukopenia Thrombocytopenia Anemia (UGT1A)-- uridine diphospho-glucuronosyltransferase 1A subfamily Diarrhea Irinotecan metabolism and its toxicity ATP-binding cassette transporters (ABC gene family) Help drug transfer into hepatic cell membrane carboxylesterase 1, 2 Cytochrome P450 3A family SN-38+Glucuronide Bone Marrow Intestine Leukopenia Thrombocytopenia Anemia (UGT1A)-- uridine diphospho-glucuronosyltransferase 1A subfamily Diarrhea Irinotecan metabolism and its toxicity ATP-binding cassette transporters (ABC gene family) Help drug transfer into hepatic cell membrane carboxylesterase 1, 2 Cytochrome P450 3A family SN-38+Glucuronide Bone Marrow Intestine Leukopenia Thrombocytopenia Anemia (UGT1A)-- uridine diphospho-glucuronosyltransferase 1A subfamily Diarrhea Irinotecan metabolism and its toxicity ATP-binding cassette transporters (ABC gene family) Help drug transfer into hepatic cell membrane carboxylesterase 1, 2 Cytochrome P450 3A family SN-38+Glucuronide Bone Marrow Intestine Leukopenia Thrombocytopenia Anemia (UGT1A)-- uridine diphospho-glucuronosyltransferase 1A subfamily Diarrhea Irinotecan metabolism and its toxicity ATP-binding cassette transporters (ABC gene family) Help drug transfer into hepatic cell membrane carboxylesterase 1, 2 Cytochrome P450 3A family SN-38+Glucuronide Bone Marrow Intestine Leukopenia Thrombocytopenia Anemia (UGT1A)-- uridine diphospho-glucuronosyltransferase 1A subfamily Diarrhea UGT1A1 Genotype Innocenti et al, JCO, 2004 UGT1A1 Genotype Less functional allele UGT1A1 Genotype Less functional allele Protein structure of UGT1A family 540 AA, 28 signal AA, ~243 common AA in different isoforms N Signal peptide Functional part 28AA ~243 AA ~269AA C Protein structure of UGT1A family 540 AA, 28 signal AA, ~243 common AA in different isoforms 28AA ~243 AA ~269AA Signal peptide Functional part TM Protein structure of UGT1A family 540 AA, 28 signal AA, ~243 common AA in different isoforms 28AA Signal peptide Functional part ~243 AA ~269AA UGT1A gene family: Alternative Splicing Variants Important Genetic Variations for UGT1A1 UGT1A7 allele nomenclature and important SNPs Promoter Nucleotide change Allele name Protein Coding nucleotide change Amino acid change UGT1A7*1a UGT1A7.1 UGT1A7*1b UGT1A7.1 UGT1A7*2 UGT1A7.2 387(T>G)/391(C>A)/392(G>A) ( K129, k131) N129K/R131K UGT1A7*3 UGT1A7.3 387(T>G)/391(C>A)/392(G>A)/ 622(T>C); (k129, K131,R208) N129K/R131K/W208R UGT1A7*4 UGT1A7.4 622(T>C) (R208) W208R UGT1A7*5 UGT1A7.5 343(G>A) G115S UGT1A7*6 UGT1A7.6 417(G>C) E139D UGT1A7*7 UGT1A7.7 387(T>G)/391(C>A)/392(G>A)/417(G>C) N129K/R131K/E139D UGT1A7*8 UGT1A7.8 387(T>G)/391(C>A)/392(G>A)/417(G>C)/622(T>C) N129K/R131K/E139D/W208 R UGT1A7*9 UGT1A7.9 343(G>A)/387(T>G)/391(C>A)/392(G>A) G115S/N129K/R131K UGT1A7*10 UGT1A7.10 386(A>G)/387(T>G)/391(C>A)/392(G>A)/622(T>C) N129R/R131K/W208R UGT1A7*11 UGT1A7.11 392(G>A) R131Q UGT1A7*12 UGT1A7.12 622(T>C)/760(C>T) W208R/R254X UGT1A7*13 UGT1A7.13 828(C>A) N276K UGT1A7*14 UGT1A7.14 422(G>C) C141S G115, N129, R131, W208 -70(G>A) -57(T>G) UGT1A9 allele nomenclature and important SNPs Variations across UGT1A polymorphisms Chr2:234330521-Chr2:234330398 =123bp Chr2, 234245202 Chr234255266-Chr234255944 =678bp Chr234333883-Chr23433633 =250bp UGT1A7 UGT1A9 UGT1A1 -57 T>G 2 3 4 5A 5B 622T>C W208R rs7586110 rs176832 UGT1A1*6 rs4148323 391C>A(rs17863778), 392G>A(rs17868324) R131K 342 G>A G115S() UGT1A1*28 rs8175347 387T>G N129K UGT1A1*93 rs176832 UGT1A9*22 -118T9/T10 rs3832043 -3156G>A rs10929302 UGT1A7 *1*2*3*4*5*6*7*8*9*10 *11*12*14 UGT1A1*60 -3279T>G rs4124874 Current Situation UGT1As much more complex than initially thought Additional polymorphisms involved in determining metabolism of irinotecan Despite FDA labeling change, UGT testing is currently not being used widespread. Current Situation UGT1As much more complex than initially thought Additional polymorphisms involved in determining metabolism of irinotecan Despite FDA labeling change, UGT testing is currently not being used widespread. Take-Home Message: Heterogeneity and Complexity of Associations affect Results That is why you get difference association studies that state that red meat is good, neutral or bad for you…. …but don’t throw the baby out with the bathwater Training-Test Paradigm in Human Samples Training Set (correct for multiple comparisons) Multiple Validation Sets From Bench to Bedside: Complexity of the Human Being Causal Prognostic Factors Biomarkers related to the host Environmental Modifying Factors Psychosocial Cultural, Economic Biomarkers of tumor Treatment Factors Clinical Outcomes Non-causal Prognostic Factors -Hard outcomes (OS/DFS) -Soft outcomes (toxicity/QOL) Adapted from Liu et al, 2006 From Bench to Bedside: Complexity of the Human Being Causal Prognostic Factors Biomarkers related to the host Environmental Modifying Factors Psychosocial Cultural, Economic Biomarkers of tumor Treatment Factors Clinical Outcomes -Hard outcomes (OS/DFS) -Soft outcomes (toxicity/QOL) Non-causal Prognostic Factors Pharmacogenetics Adapted from Liu et al, 2006 Tamoxifen Metabolism Clinical Cancer Research January 2009 15; 15 Tamoxifen Metabolism Clinical Cancer Research January 2009 15; 15 Tamoxifen Metabolism Clinical Cancer Research January 2009 15; 15 Tamoxifen Metabolism Clinical Cancer Research January 2009 15; 15 CYP2D6 Meyer. Nature Review 2004 CYP2D6 Meyer. Nature Review 2004 CYP2D6 Genotype and Endoxifen P<0.001, r2=0.24 180 160 140 120 Plasma 100 Endoxifen 80 (nM) 60 40 20 0 Wt/Wt Wt/*4 *4/*4 CYP2D6*4 (most common genetic variant associated with the CYP2D6 poor metabolizer state) Jin Y et al. JNCI;97:30, 2005 Relapse-Free Survival 100 80 EM n=115 60 2-year RFS EM 98% IM 92% PM 68% % 40 IM n=40 PM n=16 20 Log Rank P=0.009 0 0 2 4 6 8 10 12 Years after randomization Goetz et al. Breast Cancer Res Treat. 2007 CP1229323-16 Relapse-Free Survival 100 Extensive n=115 80 60 % 40 Decreased n=65 20 P=0.007 0 0 2 4 6 8 10 12 Years after randomization Goetz et al. Breast Cancer Res Treat. 2007 CP1234316-3 Validation? Follow-up studies have had variable results • Not as clear cut CYP2D6 is inducible and inhibited by many drugs • including anti-depressants and SSRIs Many of these drugs have been used to ameliorate peri-menopausal symptoms induced by Tamoxifen Tamoxifen and CYP2D6 CYP2D6 associated with BC outcome • Goetz et al. 2005, 2007 (USA) • Schroth et al. 2007 (Germany) • Kiyotani et al. 2008 (Japan) • Newman et al. 2008 (UK) • Xu et al. 2008 (China) • Okishiro et al. 2009 (Japan) • Ramon et al. 2009 (Spain) • Bijl et al. 2009 (Netherlands) CYP2D6 not associated with BC outcome • Wegman et al. 2005, 2007 (Sweden) • Nowell et al. 2005 (USA) • Goetz et al. 2009 (international consortia, n=2800) Tamoxifen complexities Tamoxifen CYP2D6 CYP3A Tamoxifen active metabolites SULT1A1 Inactive Metabolites Tamoxifen complexities Tamoxifen CYP2D6 CYP3A Tamoxifen active metabolites Side Effects SULT1A1 compliance Inactive Metabolites Tamoxifen complexities Tamoxifen CYP inhibitory agents = Treatment of Side Effects CYP2D6 CYP3A Tamoxifen active metabolites Side Effects SULT1A1 compliance Inactive Metabolites Tamoxifen complexities Tamoxifen CYP inhibitory agents = Treatment of Side Effects CYP2D6 CYP3A Tamoxifen active metabolites Side Effects SULT1A1 compliance Inactive Metabolites Take-Home Messages: Confounders Play Key Roles in Association Studies Proper Phenotyping Critical Importance of accounting for variables and of choosing reliable and accurate clinical endpoints Pharmacogenetic Example: EGFR polymorphisms and EGFR TKIs (2004-) Review of existing PK/PD/PG data In silico and bioinformatic determination of best targets SNP - HapMap Haploview/Tagger I2D/PPI Networks Proprietary PK data PGRN and public source PK/PG/PD data SIFT/PolyPhen/Coddle Pharmacogenetic Example: EGFR polymorphisms and EGFR TKIs (2004-) Functional Assays Identification of key targets to test in patient samples Promoter Analysis AMPL Gene Expression/Binding Assays Collaboration with A. Adjei (Mayo/RPCI) Luciferase Promoter Assays Haplotype Constructs and functional Binding and Expression assays Liu et al, CR 2005 CADR and-216G/T combined: PFS BLUE S/S+T/- L/-+G/G N (%) 64 (70%) 28 (30%) Med PFS 3.9 mos 2.0 mos Adj. HR 0.60 reference 95%CI (0.36-0.98) 100% Logrank p=0.0006 80% Probability RED 60% 40% 20% 0% Phase II Study of Gefitinib In NSCLC 0 12 24 36 48 Progression-free Survival (months) Liu et al, TPJ 2007 CADR and-216G/T combined: OS L/-+G/G N (%) 64 (70%) Med OS 12.0 mos 7.6 mos Adj. HR 0.60 95%CI (0.36-1.00) 100% 28 (30%) reference Logrank p=0.02 80% Probability S/S+T/- 60% 40% 20% 0% 0 12 24 36 48 Overall Survival (months) Liu et al, TPJ 2007 Prospective Validation? *21 day cycles P R E Stratification R E G I S T R A T I O N FISH+ EGFR FISH status FISH- R A N D O M I Z A T I O N Stratification factors: ECOG PS: 0/1/2 Cooperative Group Stage: IIIB/IV Gender: M/F Smoking Status: Never/≤15py/> 15py Erlotinib 150 mg PO daily Pemetrexed 500mg IV D1 Erlotinib 150 mg PO daily Pemetrexed 500mg IV D1 C L I N I C A L O U T C O M E RECIST with re-staging q2 cycles Until PD or toxicity or withdrawal Schema P R E *21 day cycles Closed due to poor accrual Stratification R E G I S T R A T I O N FISH+ EGFR FISH status FISH- R A N D O M I Z A T I O N Erlotinib 150 mg PO daily Pemetrexed 500mg IV D1 Erlotinib 150 mg PO daily Mutation Testing First Line Stratification factors: ECOG PS: 0/1/2 Cooperative Group Stage: IIIB/IV Gender: M/F Smoking Status: Never/≤15py/> 15py Pemetrexed 500mg IV D1 C L I N I C A L O U T C O M E RECIST with re-staging q2 cycles Until PD or toxicity or withdrawal Retrospective Validation? The NCIC CTG study, BR.21 double-blind randomized trial of erlotinib versus placebo as second/third line treatment in Stage IIIB/IV NSCLC. No blood collected = tiny small biopsies collected. Results Normal tissue (± tumor) DNA was extracted from 242/731 enrolled patients. Genotyping success rates exceeded 92%. In a 30 patient subset, genotyping concordance rates were >93% between normal and corresponding tumor tissue DNA. Results Individuals without tissue for genotyping: • were more likely to be Asian • had greater PR/CR rates • were more likely to have 2+ prior treatment regimens • and had longer time to randomization Subgroups of genotyped and nongenotyped patients had OS/PFS and benefited similarly from study treatment. Issues Too small a sample? Skewed non-representative population? Perhaps differences between erlotinib and gefitinib BR.19 analysis (also underpowered) RTOG 0436 – years away BIBW2772 – pending, but different drug Take-Home Message: Validation Key to Accepting Association Study Results; Validation not so easy… 1. Training Set Validation/Test Sets 2. Biological or Functional Validation Three Examples for Discussion Candidate Gene Example Genome-Wide Association Study (GWAS) Approach Examines common genetic variations for a role in drug response by genotyping large sets of genetic variations across genome • “Discovery-based” vs. “hypothesis-based” • Relate genetic variations to clinical outcome • Identify associations in genes not previously suspected Pathway-based Approach Examines biologically plausible associations between certain individual polymorphisms and clinical outcomes Usually combines 2+ related genetic variants to reveal otherwise undetectable effects of individual variants on clinical outcome. What have we learned? Training and Validation Sets important Control sample important (Prognostic vs Predictive) GWAS and Pathway analyses may improve chances of finding important and novel associations If Phenotype is carefully measured, chances improve in finding association (e.g. clinical trial data) Where do we go from here? Analytic Framework + Key Questions for Evaluating Genomic Tests in a Specific Clinical Scenario Overarching Question Clinical Validity Clinical Utility Prediction of Drug Efficacy Cancer Patients Germline / Somatic Genotype Incorrect Genotype Assignment Prediction of Metabolism Prediction of Adverse Drug Reactions • Improved Outcomes Treatment Decisions Harms of Subsequent Management Options • Enhanced Response • Minimize Toxicity Analytic Framework + Key Questions for Evaluating Genomic Tests in a Specific Clinical Scenario Overarching Question Clinical Validity Clinical Utility Prediction of Drug Efficacy Cancer Patients Germline / Somatic Genotype Incorrect Genotype Assignment Prediction of Metabolism Prediction of Adverse Drug Reactions • Improved Outcomes Treatment Decisions Harms of Subsequent Management Options • Enhanced Response • Minimize Toxicity Analytic Framework + Key Questions for Evaluating Genomic Tests in a Specific Clinical Scenario Overarching Question Clinical Validity Clinical Utility Prediction of Drug Efficacy Cancer Patients Germline / Somatic Genotype Incorrect Genotype Assignment Prediction of Metabolism Prediction of Adverse Drug Reactions • Improved Outcomes Treatment Decisions Harms of Subsequent Management Options • Enhanced Response • Minimize Toxicity Analytic Framework + Key Questions for Evaluating Genomic Tests in a Specific Clinical Scenario Overarching Question Clinical Validity √ Cancer Patients Clinical Utility Prediction of Drug Efficacy √ Germline / Somatic Genotype Incorrect Genotype Assignment Prediction of Metabolism Prediction of Adverse Drug Reactions UGT1A1 and Irinotecan DPD and 5FU • Improved Outcomes X Treatment Decisions Harms of Subsequent Management Options • Enhanced Response • Minimize Toxicity Analytic Framework + Key Questions for Evaluating Genomic Tests in a Specific Clinical Scenario Overarching Question Clinical Validity √ Cancer Patients Clinical Utility Prediction of Drug Efficacy √ Germline / Somatic Genotype Incorrect Genotype Assignment Prediction of Metabolism Prediction of Adverse Drug Reactions • Improved Outcomes ? Treatment Decisions Harms of Subsequent Management Options • Enhanced Response • Minimize Toxicity Tamoxifen and CYP2D6 Cisplatin and ototoxicity; AIs and MSK toxicity Analytic Framework + Key Questions for Evaluating Genomic Tests in a Specific Clinical Scenario Overarching Question Clinical Validity √ Cancer Patients Clinical Utility Prediction of Drug Efficacy Germline / Somatic Genotype ? Incorrect Genotype Assignment Prediction of Metabolism Prediction of Adverse Drug Reactions FC-gamma-R VEGFR2 • Improved Outcomes Treatment Decisions Harms of Subsequent Management Options • Enhanced Response • Minimize Toxicity Summary Germline pharmacogenetic studies have changed patient management in several diseases • Cancer included In cancer, effects can be related to efficacy or toxicity, related to either PK or PD relationships Studies in patient populations require consideration of confounders (e.g. enzyme induction/inhibition) and interactions (drug-drug) Current research involves candidate gene, candidate pathway, or agnostic genome-wide evaluations • Next Gen Sequencing coming soon Validation, validation, validation Blatant Plug AMP-PEL (Liu lab) Applied Molecular ProfilingPharmacogenomic Laboratory DRY LAB Clinico-Epidemiological Research: Descriptive And Analytical Epidemiological Methods Research Health Outcomes and Knowledge Translation Research WET LAB Biomarker Research: Cancer Management Prevention Screening and Early Detection In vivo and In vitro Pharmacogenomic And Radiogenomic Research Companion Research For Clinical Trials Candidate-Based PG Validation Studies (Secondary Analyses of Clinical Trials) Study Name BR.10 (Lung) Tissue Sample 2011 FFPE Phase Drug/Tx III Cisplatin HN.6 (Head & Neck) Blood III Cisplatin and XRT Panitumumab BR.21 (Lung) FFPE/slides or blocks III Erlotinib √ BR.19 (Lung) 2012 FFPE III Gefitinib BR.24 (Lung) 2012 Blood III Cediranib TORCH (Lung) 2012 Blood III Erlotinib MA.31 (Breast) Blood III Her2neu/EGFR 2012 FFPE III Cetuximab FFPE III Gemcitabine 2013 Blood III Bevacizumab CO.17 (Colon) RTOG9704 (Panc) 2013 ICON7 Candidate-Based PG Validation Studies (Secondary Analyses of Observational Studies) Study Name Approach Sample Size Drug/Tx Harvard-Toronto Lung Cancer Pathway Candidate 3000+ Cisplatin Carboplatin Radiation Harvard-Toronto Pancreatic Cancer Pathway Candidate GWAS 1000+ Gemcitabine Harvard-Toronto Esophageal Cancer Pathway Candidate 1000+ Cisplatin 5FU Radiation Toronto-Quebec Head and Neck Cancer* Pathway Candidate GWAS 1400+ Radiation Cisplatin AMP-PEL Laboratory (Fall 2011) Dr. Zhuo Chen Dr. Dangxiao Cheng Dr. Azad Kalam Dr. Qi Wang Dr. Prakruthi Palepu Dr. Salma Momin Dr. Ehab Fadhel Qin Kuang Kangping Cui Mark MacPherson Anna Sergiou Devalben Patel Maryam Mirshams Kevin Boyd Alvina Tse Dr. Alex Chan Dr. Wei Xu Dr. Manal Nakhla Lawson Eng Anthony LaDelfa Melody Qiu Memori Otsuka Dr. Marjan Emami Nicole Perera Jennifer Teichman Bin Sun Andrew Fleet Lorin Dodbiba Vincent Pang Debbie Johnson Tammy Popper Sharon Fung Dr. Olusola Faluyi Steven Habbous Henrique Hon Jenny Wang Jenny Hui Crystal Gagnon Teresa Bianco Dr. Sinead Cuffe Andrea P-Cosio Dr. Gord Fehringer Yonathan Brhane Thank-you