Anil Modak - Diagnostic breath tests for unmet clinical needs with labeled and unlabeled probes
Anil Modak, PhD was till recently the Associate Director of Medical Products Research & Development at Cambridge Isotope Laboratories Inc.in Tewksbury, MA in the US. He has been involved in the design, research and development of novel non invasive breath tests for personalized medicine using stable isotope substrates for the monitoring of disease severity/toxicity and the evaluation of drug metabolizing enzyme activity. He is the author of several recent patents and publications and numerous presentations at medical conferences around the world. He has reviewed several papers for reputed journals and authored two book chapters. He serves on the Editorial board of the Journal of Breath Research, Journal of Pharmacogenomics & Pharmacoproteomics and International Journal of Clinical Pharmacology & Toxicology.
His previous experience includes working for Ribozyme Pharmaceuticals in Boulder, CO and Monsanto in St Louis, MO. His postdoctoral research was conducted at the University of Iowa and Kings College London.
In the modern era since Linus Pauling’s VOC microanalysis in 1971, breath tests have been extensively researched both with endogenous VOC’s as well as the more specific 13C-probe based breath tests using 13CO2 as a biomarker of physiological changes and genetic diversity in humans.
With the development of sensitive analytical techniques, we can now investigate for unique biomarkers in a person's breath to identify particular medical conditions. Breath analysis has the potential to become a non-invasive diagnostic tool in clinical practice.
Over the last two decades non invasive diagnostic phenotype [13C]-breath tests1 as well as tests using endogenous volatile organic compounds (VOCs) in breath2 have been researched extensively. However, only five breath tests have been approved by the regulatory boards in the US/Europe (FDA/EMA)
- NO breath test (endogenous VOC) by Aerocrine AB in 2003
- Heartsbreath test (endogenous VOC’s) by Menssana Research, Inc. in 2004
- Urea-13C breath test by Otsuka Pharm Inc and Exalenz Biosciences in 1998 and 2014
- Gastric emptying breath test using Spirulina-13C by Cairn Diagnostics in 2016
- LiMAx using Methacetin-13C by Humedics GmbH in 2017-8
Linking VOC’s to specific illnesses has been extremely challenging since oxidative processes in different organs of patients afflicted with various diseases could result in the generation of the exact same VOC’s lowering the ability to pinpoint one of more VOC’s to reliably detect a specific disease. The origins of the VOC’s due to physiological processes in the human body need to be identified for them to be useful as biomarkers of disease.
On the other hand using either stable isotope or unlabeled probes for evaluating various drug metabolizing enzyme deficiencies for personalizing medications have the potential of being the most promising breath tests that can make the transition from research to the clinic. The pros and cons of both breath test paradigms for medical applications will be discussed in great detail.
- Modak AS. An Update on 13C-BreathTests: The Transition to Acceptability into Clinical Practice in Volatile biomarkers: non-invasive diagnosis in physiology and medicine p 245-262. A Amann and D Smith (Eds), Elsevier 2013
- Lourenco C. & Turner C. Breath analysis in disease diagnosis: methodological considerations and applications. Metabolites, 4, 465–498