Singapore's National Cancer Centre Singapore (NCCS) and National University Cancer Institute, Singapore (NCIS) are set to begin clinical trials of a revolutionary cancer treatment called histotripsy in the second half of 2025. This groundbreaking technology uses precisely targeted ultrasound waves to generate microbubbles that destroy tumor cells without incisions, radiation, or damage to surrounding tissues.
The S$12 million initiative is funded by the Li Ka Shing Foundation and Temasek Trust, which will provide two histotripsy machines—the first such devices in Southeast Asia. One machine will be placed at NCCS and the other at NCIS.
How Histotripsy Works
Derived from Greek words meaning "soft tissue" and "mechanical breakdown," histotripsy represents a significant departure from conventional cancer treatments. Co-inventor Professor Zhen Xu, a biomedical engineer from the University of Michigan, explained that the procedure uses ultrasound waves to create microbubbles that rapidly expand and collapse, generating forces that liquify tumors at the cellular level.
The single-session treatment takes approximately four minutes to complete, with patients typically able to return home the same day. Unlike thermal ablation techniques that use radiofrequency or microwaves, histotripsy employs mechanical energy, potentially reducing side effects. Patients undergo general anesthesia during the procedure primarily to ensure they remain still.
"Patients often wonder if they've been treated at all because there's no pain," noted Professor Xu during the launch event on April 3, where a demonstration of the technology was provided.
Clinical Trial Plans
Professor Brian Goh, head of the department of hepatopancreatobiliary and transplant surgery at Singapore General Hospital and NCCS, will serve as the principal investigator for the trial. The research team is currently preparing the application for a combined trial that will initially involve 40 liver cancer patients deemed unsuitable for current treatments.
"Many of these patients would have late-stage liver cancer. The rest could include some who are undergoing therapy for other cancers but have one or two lesions in the liver that are not shrinking," explained Professor Goh.
The initial phase will focus on patients with tumors measuring 3cm or smaller, mirroring the parameters of the 2021 Hope4Liver trial in the United States that led to FDA approval in October 2023. Following the liver cancer trials, researchers plan to extend the study to include patients with kidney and pancreatic cancers.
Global Progress and Potential
Histotripsy received FDA approval for liver tumors in October 2023 following successful clinical trials. The technology has already been used to treat approximately 50 cancer patients in Hong Kong and over 1,000 patients in the United States.
Mike Blue, president and chief executive of HistoSonics, the company behind the technology, joined Professor Xu at the Singapore launch event. They highlighted that clinical trials for kidney cancer (Hope4Kidney) are already underway in the US and Europe, with pancreatic cancer trials having begun in December 2024.
An intriguing development noted by researchers is histotripsy's potential to stimulate immune responses against non-targeted tumors. Associate Professor David Tan Shao Peng, a senior consultant at NCIS, indicated that this immune-stimulating effect will be a focus of the Singapore trials, along with evaluating how local patients respond to the treatment.
Limitations and Future Outlook
Despite its promise, experts caution that histotripsy will not immediately replace current cancer treatments. The US Hope4Liver study reported a low complication rate of 6.8 percent, but this was based on a small sample of 44 patients of Caucasian descent.
"The treatment is not for patients with widespread cancer or systemic cancer," noted Professor Tan, adding that longer-term data on safety and effectiveness is still needed.
Ms. Ho Ching, chairman of Temasek Trust, emphasized at the April 3 event that the funding will help extend the treatment beyond liver cancer to kidney and pancreatic cancers. In a video address, billionaire Li Ka Shing expressed being "deeply impressed by the treatment's ground-breaking potential" when he first learned about histotripsy.
To drive long-term impact in the region, funding will be disbursed through a Donor-Advised Fund managed by Temasek Trust's philanthropy advisory services arm, which aims to attract additional capital from other donors to sustainably support the next phase of cancer research.
