Stable isotope biomarker breath tests for human metabolic and infectious diseases: a review of recent patent literature

ABSTRACT

Introduction: Stable isotope breath tests can rapidly and quantitatively report metabolic phenotypes and disease in both humans and microbes in situ. The labelled compound is administered and acted upon by human or microbial metabolism, producing a labelled gas that is detected in exhaled breath.

Areas covered: This review details the unique advantages (and disadvantages) of phenotypic stable isotope based breath tests. A review of recent US patent applications and prosecutions since 2010 is conducted. Finally, current clinical trials, product pipelines and approved products are discussed.

Expert opinion: Stable isotope breath tests offer new approaches for rapid and minimally invasive detection and study of metabolic phenotypes, both human and microbial. The patent literature has developed considerably in the last 6 years, with over 30 patent applications made. Rates of issuance remain high, although rejections citing 35 U.S.C. §101(subject matter eligibility), §102 (novelty), §103 (obviousness) and §112 (description, enablement and best mode) have occurred. The prior art is significantly greater for human metabolism than microbial, and may drive differing rates of future issuance. These biomarker and diagnostic tools can enable optimization of drug doses, diagnosis of metabolic disease and its progression, and detection of infectious disease and optimize its treatment.

KEYWORDS:

• Stable Isotope
• breath test
• infection
• metabolic disorders

Article highlights

• Stable isotope breath tests can diagnose a range of metabolic disease, pathophysiology and infectious disease, and can act as biomarkers of treatment response.

• These tests directly measure phenotype, and provide information that can either complement, or is not available from, genotypic information.

• There is a significant and growing body of patent applications in this area, still with a relatively high rate of issuance.

• Several clinical trials of stable isotope breath tests are both ongoing and planned, and a new test for use in the diagnosis of gastroparesis has recently been approved .

• Significant commercial activity in this area bodes well for the development and approval of a wide range of diagnostic and biomarker tests to improve patient outcomes.

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Declaration of interest

G Timmins is cofounder and current Chief Science Advisor for Avisa Pharma, a clinical stage company that has licensed a number patents (of which Timmins is inventor or co-inventor) on ¹³CO₂ breath test detection of infectious diseases from the technology transfer arm of UNM, STC.UNM. Timmins has license revenue and stock interest managed through STC.UNM. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

G Timmins is currently funded by an NIH grant, AI117224.