Cancer Therapy After Diagnosis and How Argeon Fits Your Plan
After a diagnosis, see how cancer therapy with Argeon can run alongside your oncologist's plan, and what the first steps look like.
If your cancer has spread, or your chemotherapy has stopped doing its job, you may be looking for stage 4 cancer treatment options that you have not yet heard about. One of them is Argeon, an enzyme that removes arginine from your blood so that tumour cells lose a nutrient they depend on. It is given over 24 weeks, usually alongside your standard therapy, and your own oncologist stays in charge. This article explains how it works, what the weeks look like and what it costs.
Stage 4 cancer treatment options when standard therapy is running out
When cancer has spread, metastatic cancer treatment becomes a long plan rather than a single step. Surgery, chemotherapy, immunotherapy, targeted therapy and radiation each have a place in it. Over time a drug can lose its effect, side effects can become hard to carry, or the list of standard options can grow short. This is usually the moment when patients start asking about cancer treatment when chemo stops working.
Argeon can be used in three ways.
- Alongside chemotherapy, immunotherapy, targeted therapy or radiation.
- After you have completed standard therapy.
- On its own, where standard options are exhausted or you have declined them.
Which of these fits you is decided together with your oncologist. We do not ask you to stop or delay any treatment you are receiving.
Argeon is used at every stage, for solid tumours and some leukaemias. Response is particularly strong in sarcoma, pancreatic, liver and prostate cancer, mesothelioma and melanoma. If you are reading about new treatments for pancreatic cancer or about mesothelioma treatment, these are among the cancers where our physicians see the strongest response. It is also used in breast, lung, gastric, colorectal, bladder, ovarian and brain tumours.
Argeon is not an approved medicine. It is given as physician-led individual treatment, in countries where the law allows a physician to treat one patient with a medicine that is not yet licensed, and at our licensed partner clinics.
How arginine deprivation works next to your current treatment
Arginine is an amino acid, one of the building blocks of protein. Healthy cells make their own arginine through a chain of reactions called the urea cycle. Many cancers switch off two enzymes in that chain, known as ASS1 and OTC. Without them, a tumour cannot make the arginine it needs and has to take it from your blood.
Argeon is an arginase, an enzyme that breaks down arginine in the blood. As the level falls, the tumour starves. Your healthy cells keep making their own arginine and are not affected. A starved tumour cell is also more vulnerable to chemotherapy, immunotherapy, targeted therapy and radiation, which is why Argeon is designed to run alongside them. You can read a fuller account of how arginine deprivation works on our site.
Earlier enzymes came from bacteria. The body sees them as foreign and builds antibodies within a few weeks, and the enzyme then loses its effect. Argeon is a human-type arginase bound to albumin, a protein your blood already carries. It is built for months of treatment, and in most cases one injection lasts 14 days. That figure comes from our own laboratory. The earlier enzyme ADI-PEG 20 works only on tumours lacking ASS1. Argeon acts on tumours lacking ASS1 or OTC, a wider range. How well your tumour is likely to respond is assessed individually when you enquire.
The principle has been tested in controlled trials with ADI-PEG 20. In ATOMIC-Meso, published in JAMA Oncology in 2024, 249 patients with non-epithelioid pleural mesothelioma received chemotherapy with or without the enzyme. Median survival was 9.3 months with it and 7.7 months without. At three years about 12 % were alive, compared with about 3 %. In liver cancer, a Phase III trial of 635 patients showed no survival benefit overall. Those patients were not selected by tumour markers, and the ones with sustained arginine depletion did better.
Argeon itself has not yet been tested in controlled studies. More than 100 patients have been treated. Five cases are documented in full with laboratory values. Tumour markers fell in four of them, and in one they returned to the normal range within 37 days. No adverse events were reported. The studies and results are set out in detail on our evidence page.
The 24 weeks, step by step
Before the first injection you receive a written answer to your enquiry, an individual assessment of how your tumour is likely to respond, and a binding written quote. You give consent only after you have seen the quote.
The standard protocol is twelve injections, one every 14 days, over 24 weeks. Some cancers need injections every 7 days, particularly advanced or fast-growing ones. Your physician will tell you which schedule suits your tumour.
At every visit we measure your arginine level, so we can see whether the enzyme is doing its work. Liver and kidney values are checked at every visit as well, and tumour markers are checked regularly. Every result goes to you and to your oncologist. Three reviews include imaging.
- Week 8, the first review.
- Week 16, the second review.
- Week 24, the end of the course.
If your tumour does not respond, treatment ends at the next review. You do not continue for the sake of finishing the course.
Side effects are usually mild. Tiredness in the first weeks is the most common. Some patients have a reaction at the injection site, and occasionally nausea or a rash. The enzyme does not cause hair loss.
Treatment takes place at licensed partner clinics in Georgia, Dubai and Hong Kong. In countries where the law allows it, Argeon is shipped to your own oncologist, who is guided through the protocol and the monitoring. We select the treating physician for you by tumour type, language and location.
Timeline and cost
You receive a written answer to every enquiry within five working days. From enquiry to first injection usually takes four to six weeks. It can be faster when your records are complete and your situation is urgent.
The full 24-week course costs USD 150,000 to 250,000, depending on tumour type and the number of injections. The price includes the enzyme, the visits, the administration and the scheduled laboratory and imaging monitoring. Travel, accommodation and any standard therapies you combine with Argeon are separate. Insurers do not cover the enzyme. We discuss payment terms with you personally. Families who want to take part in these conversations will find more on our page for patients and families.
Common questions
Can I use Argeon if my chemotherapy has stopped working?
In many cases, yes. Argeon can follow completed standard therapy, or be used on its own where standard options are exhausted or declined. Your oncologist decides on any combination and stays in charge of your care.
Is Argeon an approved treatment for stage 4 cancer?
No. It is used as physician-led individual treatment and has not yet been tested in controlled studies. The principle of arginine deprivation has been studied in controlled trials with an earlier enzyme.
Who cannot be treated with Argeon?
We do not treat people who are pregnant or breastfeeding, or who have a urea-cycle disorder, severe liver, kidney or heart failure, or an uncontrolled infection. Your physician will go through this with you at the start.
If you would like to know whether Argeon could fit your situation, the eligibility check takes about three minutes, and a physician will answer you in writing within five working days.