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Pictor Developing Point-of-Care Test to Detect Additional Stages of SARS-CoV-2 Infection

NEW YORK ─ Auckland, New Zealand-based Pictor is eyeing international expansion with a multiplexed microarray immunoassay to detect different stages of SARS-CoV-2 at the point of care.

The test, which is in development, may determine intermediate stages of COVID-19 that are not currently detectable and could give clinicians greater insight into how to better treat their patients, the firm's newly appointed CEO Thomas Schlumpberger said in an interview.

It may enable early diagnosis of infected patients, he said, including those who are asymptomatic, broadening the number of technological options available at the point of care.

Pictor has been marketing products for testing in low-resource settings for the past few years, and the SARS-CoV-2 test, if successful, will represent its first foray into diagnostic markets outside India.

The company recently received a NZ$500,000 (US$300,000) grant from New Zealand's Ministry of Business, Innovation, and Employment (MBIE) to adapt its microarray-based technology, the basis of its testing platform, to develop the SARS-CoV-2 test.

Pictor's platform leverages antigen-specific antibodies on a microarray. A reader captures images of signals generated during the detection of analytes, and the platform then uses software to conduct an analysis of the images and provide results for multiple target markers.

Paul Kinnon, a director on Pictor's board who recently served as CEO of UK-based diagnostics firm Predictimmune, noted that this type of multiplexed technology is broadly used on large test machines in diagnostic labs. "We've miniaturized ELISA testing and made it suitable for decentralized testing," he said. "An assay that has been developed for an ELISA platform could be run on our point-of-care multiplex platform, and that's what makes it compelling."

Hyungsoon Im, a researcher at Harvard Medical School and Massachusetts General Hospital Center for Systems Biology, said in an interview that "targeting multiple biomarkers sounds promising and may increase the test's detection accuracy compared to single-marker detection."

However, the choice of biomarkers for the SARS-CoV-2 test will be critical, he said, and it is not clear yet whether the new platform will seek to detect human IgG, IgM, interleukins, or viral antigens. Other factors "will also determine the technology's feasibility and competitiveness in the US and European markets," said Im, who is not associated with Pictor and is developing point-of-care tests, including for SARS-CoV-2, with colleagues at MGH. These factors include the performance of the Pictor assay, its requirements for preprocessing of blood samples and washing steps, and its level of automation.

Srikanth Singamaneni, a professor of mechanical engineering and materials science at Washington University in Saint Louis (WUSTL), noted that the Pictor platform's level of sensitivity and specificity will depend largely on the effectiveness of the biomarkers the firm selects. Though the company's platform uses blood samples, nasal swabs and saliva are proving ideal for SARS-CoV-2 antigen testing, while blood and plasma are better suited for antibody testing, he noted.

Singamaneni is also not involved in the development of Pictor's technology, but with colleagues at WUSTL he is developing a plasmonic sensor platform that he expects will provide greater sensitivity over current tests used to detect antibodies against SARS-CoV-2.

"We have 16 wells in the array that enable measurement of several fragments of the target, which increases sensitivity," Schlumpberger said of the Pictor platform. "Though we don't have data yet on the sensitivity, specificity, negative predictive value, and positive predictive value for our COVID-19 test, we have strong reason to believe that our technology will lead to higher sensitivity than the most sensitive current tests."

Pictor is considering different regulatory options to enable marketing and use of its future products, including US Food and Drug Administration Emergency Use Authorization and 510(k) clearance, as well as CE marking that would enable marketing in Europe and other countries that accept the designation. The firm believes that if it is successful, its test validation may be completed in six months or less and then the assay would be submitted for regulatory clearances or authorizations.

Schlumpberger said that the microarray platform lends itself to diagnosing complex diseases, "because you can put different antigen-specific antibodies in the different wells, and so you get a more complete picture of the disease complexity. You can also look at related diseases that have similar symptoms and use the test to stratify patients to the right care path."

The firm is further looking to expand its portfolio with additional analytes that could be used to manage patients recovering from SARS-CoV-2.

"The versatility of the platform attracted me to the company," said Schlumpberger, who was appointed CEO earlier this month. Schlumpberger previously held senior executive positions at Anixa, Invitae, Thermo Fisher Scientific's Affymetrix, Inivata, and Singulex. "The platform has the ability to make a significant difference to diseases beyond COVID-19. We are thinking about including new analytes such as IL-22 or IL-23 as diagnostic markers that could help clinicians manage patients after they have recovered from SARS-CoV-2 but still feel unwell," he said. 

Low-resource settings

Though the firm now anticipates targeting settings in the developed world for its SARS-CoV-2 test, it initially developed its platform for use in low-resource settings.

Pictor was founded in 2005 by New Zealand-based scientists Anand and Sarita Kumble on the back of $90,000 in seed financing. As they developed the testing platform, the scientists closed additional rounds of financing, including $1 million in a Series A financing in 2010; $1.4 million in a Series B financing in 2013; $750,000 in a Series C financing in 2014; $1.7 million in a Series D financing in 2017; and a $3.4 million Series D financing extension in 2019.

In its early years, Pictor's operations were in Auckland, but it opened an additional office in Maharashtra, India in 2016 and began distributing its first product, the PictArray Torch ELISA kit. The kit is used to diagnose a group of clinically similar congenital infections caused by Toxoplasma gondii ─ rubella, cytomegalovirus, herpes simplex virus 1, and herpes simplex virus 2.

The company also began distribution in India of its PictArray ENA ELISA kit, which simultaneously detects the most common clinically relevant autoantibodies associated with connective tissue disease, and it launched its PictArray HAE ELISA kit for hepatitis.

Though it will continue to sell products in India, Pictor is now prioritizing the development of the SARS-CoV-2 assay.

If the company is successful in validating the test, it will enter a burgeoning market for point-of-care testing products for SARS-CoV-2 detection, including high-sensitivity RT-PCR tests and fast-turnaround antigen tests for active infection as well as antibody-based tests for past infection.

Researchers have generally found that molecular SARS-CoV-2 tests have similar performance to each other and are highly accurate in detecting active infection. Point-of-care molecular tests, such as Abbott's ID Now, have reduced the time to a test result to within 15 minutes, though there have been concerns about its accuracy.

Rapid antigen tests are usually less sensitive than PCR tests, but their use is expected to grow as the number of coronavirus cases in the US remains alarmingly high and the country continues to struggle to meet testing demands.

Pictor expects the levels of sensitivity enabled by multiplexing will allow it to target its SARS-CoV-2 test for use in airports, long-term care facilities, sports stadiums, and doctors' clinics, among other settings. Its turnaround time, at around one hour, should be fast enough for most point-of-care applications, but potentially not fast enough for some doctors' clinics, Schlumpberger said.

Pictor hasn't set a price for its future SARS-CoV-2 test, but it plans to offer it at a cost that is competitive with current tests, Kinnon said. The firm expects to sell its low-cost reader or place it for free, he said and added that Pictor is looking to partner with a diagnostic company that can manufacturer its tests and collaborate on bringing them to market in the US and Europe.

Schlumpberger is currently planning the company's expansion from an office in San Francisco and is the firm's first US hire. "For me, this job is twofold," Schlumpberger said. "We need to go through the development of the SARS-CoV-2 assay as quickly as possible, and in parallel, we need to define two or three other analytes for the pipeline that could become the next killer app, like the test for COVID-19."