ACTIPHAGE TB ENTERS THIRD CLINICAL TRIAL AIMED AT VALIDATING ITS UTILITY AS A TUBERCULOSIS DIAGNOSTIC

Phage-based diagnostic may play vital role in detecting TB progression

A new clinical trial of Actiphage TB®, a ground-breaking phage-based, molecular diagnostic, has been agreed between its developer PBD Biotech, the University of Leicester and the NIHR Respiratory Biomedical Research Centre, Leicester (UK) aimed at validating its diagnostic utility.

The challenge with tuberculosis is that it exists as a continuum of infection and can remain hidden within the individual for many years. It is estimated that a quarter of the world’s population is infected with latent tuberculosis and of these about 5-10 per cent will have progressive infection that will eventually develop into active TB disease; distinguishing these individuals is currently problematic. Furthermore, in the absence of sensitive diagnostics, those with early active TB frequently remain undiagnosed and contributes to the burden of transmitted infection. 

The targets of the WHO End-TB Strategy will not be achieved without developing new diagnostic tests to screen for early disease and provide increased predictive value for the development of active disease in those with latent infection (2017).

Dr Ben Swift, PBD Biotech’s Co-Founder and R&D Director, comments: “At PBD Biotech we are developing a novel bacteriophage-based method to detect Tuberculosis one of the biggest killers worldwide. It is acknowledged that there is a need for novel rapid diagnostics to tackle this problem.

“Our powerful technology, called ActiphageTB, enables the rapid detection of viable Mycobacterium tuberculosis (Mtb), the bacteria that causes TB. It uses a phage – the natural enemy of bacteria – to hunt down live bacterium and lyse them, to allow the DNA to be identified with qPCR.

“We can detect Mtb in a simple blood sample within a day. The current culture method takes up to eight weeks to grow Mtb from a sputum sample.

“In the fight to #EndTB, our test has the potential to be used to detect those with progressive disease, and to also monitor the efficacy of drug treatment – a test of cure – something that is not possible with current technology.”

It is currently difficult to identify those with asymptomatic TB infection that will progress to Pulmonary TB, a transmissible disease that causes significant damage to the lungs and can be fatal if undiagnosed and left untreated.

Dr Pranab Haldar, Clinical Senior Lecturer at the University of Leicester, UK, is based in a national TB hotspot. He has conducted several clinical trials with Actiphage and comments that it is a promising new type of biomarker as it can identify the organism itself in a blood sample and does not rely on the host immune response.

“The host immune biomarkers we currently use can tell us about the presence of current or previous TB infection but cannot discriminate between the two or tell us anything about the infecting pathogen.

“Pathogen-directed biomarkers may be complementary to the current host immune markers for the evaluation of different phenotypes of TB infection, allowing us to discriminate between people who do and potentially don’t require treatment for their TB infection. This would enable targeting of treatment – that’s very powerful.”

The simplicity of Actiphage and developments to reduce dependence on the cold chain, should enable it to be performed in those parts of the world that have the least resources yet suffer most from the burden of TB.

The trial is due to start in Q3.