Phase Scientific International (PSI), the Hong Kong start-up that edged out established mainland Chinese peers to win US approval for a Covid-19 rapid antigen test (RAT) kit, owes its success to its US roots and experience in the field, according to its founder. The Bill and Melinda Gates Foundation-backed biotech company last July became the first in the mainland China, Hong Kong, Macau and Taiwan region to win approval from the US Food and Drugs Administration for emergency use for its Covid-19 kit. Ricky Chiu Yin-to, a Hongkonger who moved to the US to pursue a PhD in bioengineering at the University of California in Los Angeles, founded the company in 2015. He relocated its headquarters from California to Hong Kong in 2018. “This move, a gamble at the time, has fully paid off,” Chiu who is also the CEO told the South China Morning Post . “The technology I was working on was good but was mature and very competitive in the US … hence the thought of coming back to Hong Kong and tapping opportunities in China.” PSI initially focused on commercialising a patented methodology that improves the accuracy of liquid diagnostic tests by concentrating and purifying target molecules in blood or saliva. It started off by launching a US$10 tooth decay risk detection kit in late 2018. Its priorities shifted as soon as the Covid-19 virus started to spread outside mainland China in early 2020. “Our first thought at the time was to develop a rapid test kit for the virus because that was our business – we were developing test kits for tooth decay and sexually transmitted diseases based on the same technology platform,” he said. “Rapid tests is the fastest, simplest and cheapest way to identify the infected in a pandemic.” By mid 2020, its research teams in Hong Kong and the US had tested several hundred antibodies to find one that was most sensitive to the novel coronavirus. Indicaid’s rapid test kit production to rise fivefold as Phase Scientific goes into overdrive The US government, which in the summer of 2020 started to pursue RAT as its mainstay diagnostic strategy, invited companies including PSI to develop RAT kits and ramp up production. “Despite the US-China geopolitical rivalry, we were able to mobilise both our US and Hong Kong staff to develop our RAT round-the-clock and generate the data we needed for FDA approval,” he said. “We also had access to infectious diseases experts who collaborated with us both in Hong Kong and California.” In the US, its customers include the New York City government, search engine giant Google, and US schools. In Hong Kong, after partnering with ONCO Medical Laboratory to offer PCR tests, it started early last year to help the government and hospitals to roll out a “dual track” method to first screen high-risk groups of people with its RAT kit, followed by the PCR test with more accurate but delayed results. The work allowed PSI to collect samples from over 22,000 people in Hong Kong to compare accuracy of its RAT to the gold standard PCR. The results were published last August in Microbiology Spectrum, a peer-reviewed scientific journal. PSI’s Indicaid rapid test showed an accuracy rate of 84.2 per cent even when the viral load was low, with a 15.8 per cent chance of identifying an infected person as negative. Indicaid competes with products from established multinationals such as Switzerland-based Roche, which claims a 82.5 per cent rate in correctly identifying an infected person with a low viral load. “Covid gave a good lesson to the world on the importance of diagnostics,” Chiu said. “Good self-testing kits and self-monitoring of health data can empower telemedicine.” As the Hong Kong government turned to RAT to fight the more transmissive Omicron strain with a plan to distribute RAT kits to the entire population, PSI plans to quintuple its production capacity to 50 million units a month by June from 10 million in January. PSI is building a 10,000 square feet facility in California to focus on developing liquid diagnostic tests for various cancers, and plans to build a similar one in Shenzhen, he said. Having raised some US$23 million from investors, PSI has reached an impasse in fundraising. “Our potential investors believe the Covid test boom is a one-off phenomenon, so we were stuck in a deadlock over our valuation,” Chiu said. “As our brisk RAT sales in the US have generated cash similar to what we were trying to raise, we decided to halt talks for a while.”