Vancouver-based XPhyto Therapeutics announces progress in efforts to create an easy-to-use saliva test for COVID-19

A Vancouver-based biotech company says that its exclusive German partner has validated a rapid prototype that could lead to an easy-to-use oral screening test for COVID-19.

XPhyto Therapeutics Corp. is aiming to develop a pipeline of potential biosensor screening products.

Today, it announced that its German partner, 3a-Diagnostic GmbH, "has confirmed successful function of its novel and proprietary COVID-19 (SARS-CoV-2) RNA probes and its universal coronavirus RNA probes in prototype lateral flow assay (the 'LFA') testing".

Visual confirmation occurred within five to seven minutes from tests of saliva. The research took place in 3a's laboratory in Baden-Württemberg.

"We believe that a low-cost, portable and easy to use screening tool that provides rapid on-the-spot results would be a disruptive tool in the fight against pandemic threats," XPhyto CEO Hugh Rogers said in a news release. "We see an enormous global market opportunity that includes individual households, schools, hospitals, public transportation, airports and border services as well as many private employers."

RNA is an acronym for ribonucleic acid, which exists in all living cells. In coronaviruses, RNA carries genetic information.

According to XPhyto, 3a's LFA screening tests run a liquid sample "across a matrix that contains one or more reactive compounds that provide a visual indication of a positive or negative result".

"3a refers to their approach as 'anywhere' (no power or additional equipment required), 'anytime' (decentralized and rapidly deployable), and 'anyone' (no specialized training required)," XPhyto stated.

The next step will be to design and manufacture tests for use in clinical evaluation.

XPhyto stated that within 30 to 60 days, 3a plans a pilot study using human saliva from health and COVID-19-infected humans.

Nature magazine describes RNA probes as "stretches of single-stranded RNA used to detect the presence of complementary nucleic acid sequences (target sequences) by hybridization".

"RNA probes are usually labelled, for example, with radioisotopes, epitopes, biotin or fluorophores to enable their detection," Nature stated. 

A paper published in the peer-reviewed journal Diseases in 2016 pointed out that RNA serves as a "template for replication and transcription" in human coronaviruses.

"Under the electron microscope, the CoV virions appear to be roughly spherical or moderately pleomorphic, with distinct 'club-like' projections formed by the spike (S) protein," the researchers wrote. "Within the virion interior lies a helically symmetrical nucleocapsid that encloses a single-stranded and positive sense RNA viral genome of an extraordinarily large size of about 26 to 32 kilobases."

XPhyto stated that 3a has designed, engineered, and tested two RNA probes: one that's COVID-19 specific and the other that detects a universal coronavirus RNA sequence shared by all known members of this family.

"As per the screening test design and the positive prototype test results, patients infected with COVID-19 are expected to activate the COVID-19 probes and the universal coronavirus probes," XPhyto stated. "Patients infected with an alternate coronavirus strain or a highly mutated form of COVID-19 are expected to activate only the universal coronavirus probes. These patients could be selected for further investigation."

On July 3, XPhyto Therapeutics Corp.'s shares closed at $3.00 on the Canadian Securities Exchange. The company's market capitalization is $166.74 million.

One of its subsidiaries, XPhyto Laboratories Inc., provides third-party testing for Canadian licensed cannabis producers.