Leadership

Josh Silvertown, PhD, MBA, MSM

Founder & Chief Cancer Navigator

    • 25+ years across oncology spanning cancer research, precision medicine, drug development, and real-world clinical translation

    • Global oncology leadership with senior roles at Bayer, including Head of Medical Affairs (Oncology) and Global Medical Affairs Lead

    • Precision oncology pioneer, including leadership in the launch of Vitrakvi (larotrectinib), the first tumor-agnostic, biomarker-guided cancer therapy

    • Rare integration of science, systems, and strategy, enabling end-to-end insight from molecular diagnostics to treatment access and clinical trials

    • Independent cancer navigation authority, combining deep technical expertise with advanced certification in Cancer Patient Navigation

  • Josh Silvertown has spent more than 25 years in oncology, with a career uniquely spanning cancer research, precision oncology, drug development, global medical affairs leadership, and patient-facing cancer navigation. What distinguishes Josh is the integration of deep scientific training, global oncology leadership, and real-world system knowledge, allowing him to translate innovation into practical, actionable guidance across diagnostics, treatment strategy, drug access, and clinical trials.

    Before founding Navexio, Josh held multiple senior leadership roles at Bayer, including Head of Medical Affairs for Oncology and Global Medical Affairs Lead for Oncology. He worked closely with oncologists, pathologists, researchers, and regulatory agencies worldwide and supported the launch of several cancer therapies. Most notably, he played a leadership role in the global launch of Vitrakvi (larotrectinib) - the world’s first biomarker-guided cancer therapy approved across all tumor types and all ages, a landmark in precision oncology. His earlier roles as Director of Precision Oncology, Medical Affairs Strategist, and Medical Scientific Advisor provided broad expertise across many cancer types. Josh is a co-author in over 60 scientific peer-reviewed journal articles and abstracts, including publications in the International Journal of Cancer, Cancer Genetics, and Molecular Diagnosis and Therapy.

    As Founder and Chief Cancer Navigator at Navexio, Josh applies this integrated experience to help clients understand advanced molecular and genomic testing, evaluate precision treatment and clinical trial options, and navigate complex care pathways with clarity and confidence.

  • Josh earned a PhD in Molecular Biology and completed a Post-Doctorate in oncology as a Canadian Institutes of Health Research (CIHR) Fellow at the Ontario Cancer Institute, part of Princess Margaret Hospital in Toronto. He earned an MBA with a specialization in healthcare from the Ivey School of Business, equipping him with deep fluency in both the science of oncology and the systems that govern cancer care delivery. He also holds advanced certification in Cancer Patient Navigation.

  • Josh’s work is grounded in the belief that access to high-quality cancer care should not depend on geography, system limitations, or the ability to navigate complexity alone. His commitment to access and empowerment extends beyond oncology. He was awarded the Meritorious Service Medal by the Governor General of Canada for founding and scaling a national e-mentorship program connecting youth in northern Canadian communities with mentors worldwide. He is also a previous Top 40 Under 40 recipient recognized by the Medical Device and Diagnostic Industry (MDDI).

    Through Navexio, Josh brings together a uniquely integrated body of expertise, experience, and purpose ensuring that individuals and loved ones facing cancer are supported with urgency, integrity, and clarity, and that no stone is left unturned in the pursuit of the best possible care.

Rhonda Nichol, RN, CON(c)

Lead, Oncology Nurse Navigator

    • 36+ years in nursing, 25+ in oncology across public and private healthcare settings, supporting patients from diagnosis through treatment and palliative care

    • Certified Oncology Nurse (CON(c)), recertified in 2023, reflecting advanced training and nationally recognized oncology standards

    • Clinical trials expertise in Phase II–III academic studies, including patient screening, education, symptom management, and protocol-based care coordination

    • Advanced clinical oncology care focused on treatment navigation, therapy education, side-effect management, and multidisciplinary coordination

    • Broad disease-site experience across solid tumors and hematologic malignancies, enabling tailored, diagnosis-specific guidance

  • Rhonda Nichol is an experienced Oncology Nurse Navigator with more than 36 years of nursing practice, including over 25 years dedicated to oncology care. She brings deep clinical expertise, steady leadership, and compassionate guidance to patients and families navigating complex cancer decisions.

    She most recently served as a Research Nurse in the Clinical Trials Unit at CancerCare Manitoba, supporting Phase II and III open-label, double-blind, and multi-arm studies. Her role included patient screening and enrollment, education, symptom management, data collection, and care coordination in compliance with study protocols, ethics requirements, and regulatory standards—providing a strong foundation in clinical trial navigation and research-informed care.

    Across treatment and clinic settings, Rhonda has supported patients with diagnosis review and care planning; education on chemotherapy, immunotherapy, and biologic therapies; side-effect management; intravenous chemotherapy administration; bladder instillations; blood transfusions; phlebotomy; and interpretation of diagnostic results. She also facilitates enrollment into palliative care programs and coordinates referrals to home care and supportive oncology services.

    Rhonda brings over 25 years of experience in central venous access, with extensive expertise in PICC lines and port-a-caths, supporting patients with complex vascular access needs. Her disease-site experience includes breast, colorectal, lymphoma, CLL, gynecologic cancers, lung, sarcoma, multiple myeloma, melanoma, and bladder cancer, with additional exposure to renal, pancreatic, prostate, and esophageal cancers. Her practice is informed by current Canadian treatment protocols and nationally used patient education resources.

  • Rhonda is a Registered Nurse and a Certified Oncology Nurse (CON(c)) through the Canadian Nurses Association, first certified in 2018 and recertified in 2023. She holds a Leadership and Management Certificate from the University of Toronto Bloomberg Faculty of Nursing, is a Six Sigma Certified Healthcare Project Manager, and is an active member of the Canadian Association of Nurses in Oncology (CANO) and the Canadian Nurses Association (CNA).

    Rhonda currently practices in Manitoba and is registered with both the College of Registered Nurses of Manitoba, and the College of Nurses in Ontario.

  • At Navexio, Rhonda delivers personalized oncology nurse navigation focused on clarity, empathy, and practical support. She works closely with patients, caregivers, and the Navexio team to ensure individuals feel informed, supported, and empowered at every stage of their cancer journey.

    Rhonda is also active in serving her local community. She sits as a member on her local Palliative Care Board, and as a volunteer with NAV-Care. Her passion for helping others is clearly visible.

Clinical Advisory Board

The Navexio Clinical Advisory Board provides independent, high-level guidance to help ensure Navexio's services remain evidence-based, clinically relevant, and aligned with evolving standards of precision oncology-guided care.

Dr. Shivaani Kummar

  • ‍Dr. Shivaani Kummar is Director and Associate CEO, Knight Cancer Institute, Margaret and Lester DeArmond Chair of Molecular Oncology, Division Chief of Hematology and Medical Oncology, and co-Director of the Center of Experimental Therapeutics, Oregon Health & Science University (OHSU), Portland, Oregon, USA. Prior to joining OHSU, she was on faculty at Yale University Cancer Center, served as Head of Early Clinical Trials Development Office of the Director, National Cancer Institute, NIH, and was Professor of Medicine and Director of the Phase 1 Clinical Research Program and Translational Oncology Program at Stanford University, Palo Alto, California. She specializes in conducting pharmacokinetic and pharmacodynamic driven first-in-human trials tailored to make early, informed decisions regarding the suitability of novel molecular agents for further clinical investigation. She is a member of scientific planning committees of national and international professional organizations and has authored over 180 peer reviewed publications, 9 book chapters, and co-edited a book on ‘Novel Designs of Early Phase Trials for Cancer Therapies’. She has served as a member of the Scientific Planning Committee, American Society of Clinical Oncology (ASCO), American Association for Cancer Research (AACR) Exploratory IND/Phase 0 Clinical Trials Task Force, External Review Committee, Ontario Institute for Cancer Research, Ministry of Colleges and Universities, Ontario, Canada. She was on the US expert panel for the first U.S.-India Cancer Moonshot Dialogue hosted by the Department of Biotechnology, has served as Co-chair, AACR 2023 Clinical Trials Committee, Vice Chair AACR 2023 Program Committee, Member, Developmental Therapeutics Scientific Committee, Targeted Anticancer Therapies (TAT), European Society of Medical Oncology (ESMO) 2023, Member, Scientific Planning Committee, ESMO 2023. She is currently a member of the National Cancer Policy Forum, National Academies of Sciences, Engineering, and Medicine, and the Scientific Planning Committee for the American Society of Clinical Oncology 2025-26. She is also the PI for an NCI T32 grant to train MDs and PhDs in anticancer drug development. ‍

Dr. Brian Brown

  • Dr. Brian Brown is the Director of the Icahn Genomics Institute and Vice Chair of the Department of Immunology & Immunotherapy at the Mount Sinai Medical Center in New York City. He is also a Professor in the Department of Genetics and Genomic Sciences, a member of the Tisch Cancer Center, and the Endowed Chair of Genetic Engineering. He is an expert in immune oncology and a pioneer in gene therapy and functional genomics. He is inventor of a number of licensed patents, including a breakthrough technology for cell-specific targeting of gene and mRNA therapies, novel CAR T cell technology, and widely used technologies for functional genomics and RNA sequencing.