Managing Metastatic Cancer: A Matter of Degree

Managing Metastatic Cancer: A Matter of Degree

By Deborah Borfitz

April 7, 2026 | Cancer recurrence is a significant health issue and a major concern for survivors but could potentially be transformed into a manageable chronic condition with the advent of a magnetic nanoparticle hyperthermia system developed by the Israeli startup New Phase and newly installed at the Mayo Clinic last December. The novel technology uses iron oxide-containing nanoparticles that amass in tumors, which are then heated by an electromagnetic field to destroy them, according to co-founder and CEO Ofer Shalev.

The approach uses the company’s Sarah Nanotechnology System to heat tumor cells to 50 degrees Celsius (122 degrees Fahrenheit) to selectively kill them while sparing healthy tissue, he explains. In addition, the nanoparticles take advantage of the leaky blood vessels in tumors and poor lymphatic drainage to accumulate specifically at the site of cancerous tissue.

Since biology mechanisms in the body are being leveraged, the method should be applicable to all solid tumors sharing the “enhanced permeability and retention” (EPR) phenomenon, says Shalev. “We’re using this to navigate our nanoparticles to reach to those cancers.” But since the tumor-associated blood vessels are leakier in some cancers (e.g., breast, liver, and ovarian) than others, “probably those cancers will have a better result.”

The promise of the magnetic hyperthermia technology was most recently suggested by a first-in-human safety study in 30 Israeli patients in whom no toxicities or serious side effects were observed, he says. Only transient heat sensation in the lower back in some of the patients was reported.

This enabled the initial clinical step in the U.S. at the end of 2025 with the launch of an early feasibility trial at Mayo Clinic to determine the safety profile of the Sarah Nanotechnology System and initial signs of efficacy to optimize the dosing. Mayo Clinic’s researchers have been administering the investigational therapy to metastatic solid tumors in any body area except the brain, and the focus is on patients whose cancers are resistant to multiple lines of systemic therapies and advanced treatments such as radiotherapy.

“As of today, we have treated about nine indications,” reports Shalev, including breast, lung, ovarian, liver, cervical, colon, pancreatic, small intestine, and adrenal. Of the original 30 trial participants who had exhausted all other treatment options, 18 have signals of stable disease, meaning their tumors are not significantly growing, and no new tumors have formed.

A higher number of patients will be required to learn more about the relevant indications for the treatment approach, but as imagined the regimen would involve getting an intravenous injection of the proprietary Sarah Nanoparticles (SaNP) every few months, he says. The timing would depend on the aggressiveness of the cancer.

Another planned feasibility study launching this fall will include several hyperthermia treatments over five or six months to see if the approach can keep stage 4 cancer patients in the same stable disease condition over that longer period, says Shalev. The Sarah Nanotechnology System, which uses alternating magnetic field irradiation to induce magnetic hyperthermia, has not yet been tested in combination with other treatment modalities such as immunotherapy.

Those conversations are ongoing, Shalev says. Mayo researchers have already expressed interest in studying hyperthermia together with immunotherapy treatments, which might allow for lower radiation doses with the same effectiveness or improve outcomes in tumors.

‘Straightforward Vision’

Metastatic cancer is a highly aggressive disease but also has vulnerabilities that can be exploited therapeutically, says Shalev. He and his colleagues discovered those weak points and then founded New Phase to build the electromagnetic induction system and nanoparticles to target them and thereby prolong the life of patients.

While other companies are developing drug therapies based on findings in the lab, the treatments typically don’t work for everyone and come with toxicities since they target rapidly dividing healthy cells along with cancer cells. The aim of New Phase is to find a way to treat returning solid cancers broadly while minimizing the severe side effects associated with conventional chemotherapy and radiation.

Its Sarah Nanotechnology System is designed to transform stage 4 cancer from a terminal illness into a manageable chronic disease, like how HIV is treated, Shalev says. “It’s a straightforward vision.”

It has been known for many years that cancer cells are highly sensitive to heat—specifically, that the membrane of cancer cells collapse at temperatures between 41 C and 45 C, says Shalev. New Phase set out to develop nanoparticles that could be heated to 50 C in a controlled manner to ensure the complete and rapid destruction of tumor cells even with low-dose systemic administration.

SaNP leaves healthy cells unharmed through a combination of selective accumulation and targeted, non-toxic activation. They’re engineered to accumulate on cancer cells, which are then heated by an external magnetic field to destroy the malignant cells. The therapeutic approach uses a “sub-ablative” temperature of 50 C, he points out, meaning a thermal range to induce biological effects without causing damage to vital organs.

Cancer also isn’t apt to develop resistance to high-temperature hyperthermia as it does to drugs, adds Shalev. This is important, since the approach is intended to be a long-term disease management strategy.

It is additionally critical that there are no side effects. The biocompatible nanoparticles are engineered for enhanced stability in the body, and do not undergo degradation, avoiding traditional off-target accumulation in the liver, he continues. About 50% of an injected dose is cleared within one week, which allows for repeated treatment to progressively reduce the mass of metastases. The accumulation and clearance of the nanoparticles can be detected by MRI due to the superparamagnetic properties of the iron oxide-containing SaNP, enabling semi-quantitative analysis.

Leveraging Leakage

Solid metastatic tumors generally begin as micrometastases that have spread from the primary tumor and start to signal to the body that they need nutrition and oxygen, says Shalev. Capillaries consequently form to feed the beast through a process known as “neo-angiogenesis” which involves the formation of new blood vessels from pre-existing vasculature, crucial for tumor growth, metastasis, and chronic inflammation.

These tiny blood vessels are not fully developed and therefore leaky. “We are using this leakage in order to reach those metastases,” he notes. When SaNP are intravenously infused, they literally leak into those tumors because of their unique, enhanced permeability and retention features. “It is not relevant to any other organ or normal tissues in our body.”

The nanoparticles may concentrate elsewhere, but they don’t accumulate there, says Shalev. Unlike cancer tissue, organs such as the liver and spleen have a functional, organized lymphatic system to flush out foreign materials. Therefore, it takes only a few hours for enough SaNP to accumulate in the tumor to proceed with the electromagnetic treatment.

Preclinical research on the Sarah Nanotechnology System resulted in 14 granted patents and papers published in nine peer-reviewed journals, facilitating the collaboration with the Mayo Clinic, Shalev says. At that time in late 2024, Mayo looked to expand their therapeutic tools with hyperthermia. When New Phase approached Mayo, it immediately recognized the potential of collaboration and 12 months later the first patient was treated.

In the trial phase, the patient's experience is a day-long commitment whereby they arrive at the medical center in the morning for routine clinical tests before receiving an infused dose of the iron oxide-containing magnetic nanoparticles. After a four-hour wait, giving the nanoparticles time to accumulate in the cancer tissue, the patients go into the electromagnetic induction system, a machine somewhat like an MRI or CT equipped with a magnetic coil and a movable bed.

The machine has been likened to an induction cooktop, producing electromagnetic waves that heat tumors to destroy cancer cells. Iron oxide can be heated to extreme temperatures, but the patent technology of New Phase blocks it to 50 C, Shalev says.

Patients return home late in the afternoon and make a follow-up visit two weeks later, he adds. After one month, they return to the medical center for a CT scan to evaluate the results against a baseline reading of the tumor’s size.

Potential Impact

Unlike MRI and CT imaging, the magnetic nanoparticle hyperthermia system of New Phase doesn’t require a shielding room, Shalev says, which often costs hundreds of thousands of dollars. Any simple room will do, meaning oncology clinics as well as medical centers would easily be able to deploy the technology.

The machine itself will also cost far less than $1 million—while the cost of installing an MRI or CT scanner will be in a range of $2 million to $2.5 million, he notes. Immunotherapy in any case requires regular CT or MRI monitoring and is therefore already available at most cancer treatment centers.

Shalev says that if all goes well New Phase could get Premarket Approval from the U.S. Food and Drug Administration to commercialize its Sarah Nanotechnology System within the next three years. The impact could be substantial, as currently about 630,000 people in the country are dying from cancer each year, and the number is growing at the rate of between 2,000 and 3,000 deaths per annum.