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What it is

- Enter here to get some general information about the Act.In.Sarc study -


The study is a clinical study that evaluates the effect of the compound NBTXR3 in patients with a certain type of soft tissue sarcoma. Patients with this certain subtype of the tumor may receive radiotherapy before surgery to remove the tumor.

The goal of the study is to evaluate whether the combination of NBTXR3 plus radiotherapy before surgery to remove the tumor is better than radiotherapy alone.

The results of this study – if successful – may serve to register the product across Europe and certain other countries which would be the basis to make the product available for the treatment of the disease.


NBTXR3 is a product that is based on the NanoXray technology. NanoXray particles are so called nanoparticles, these are particles that are smaller than 100 nm. NBTXR3, specifically, is a nanoparticle with an average size of 50 nm. This nanoparticle is composed of an inorganic center containing a coating on its surface. As a comparison, around 2,000 of these nanoparticles are need to cover the diameter of a human hair.

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Before the study has been started NBTXR3 has been tested in a smaller study with patients having soft tissue sarcoma. In this so called pilot study 22 patients participated. All of these patients received a single injection of NBTXR3 into the tumor followed by standard radiotherapy.

The results of this pilot study showed promising signs of antitumor activity in different sarcomas. Tumor shrinkage and pathological response (how much tumor cells die as a result of the therapy) were observed in tumors which are known to be refractory (difficult to treat or cure) to radiotherapy. Importantly, all patients in this pilot study underwent a wide surgical resection of their tumor.

This optimal surgery impacts the local recurrence rate (when does the tumor return locally) and improves the prognosis of the patient as the local disease control prolongs the duration of the so called progression free survival and overall survival in patients with specific types of sarcomas.


Soft tissue sarcoma is a type of cancer that begins in the soft tissues of the body. Soft tissues connect, support and surround other body structures. Soft tissue sarcomas are cancers arising from different types of soft tissues such as fat cells, muscles, joint structures and small vessels etc.

Many different types of soft tissue sarcoma (more than 50) exist.

Soft tissue sarcoma can occur anywhere in your body, but the most common types occur in the abdomen and in the arms and legs.

Wide surgical removal of the tumor (along with a minimum of healthy tissue) is the main treatment for soft tissue sarcoma of the limbs and the trunk wall. This resection is necessary for an optimal treatment of the disease and constitutes the basis to achieve prolonged survival.

Nevertheless, a considerable proportion of patients present with locally advanced primary or relapsed tumors and cannot be resected with clean margins which means that tumor mass remains within the body despite the surgery.

Radiotherapy is a treatment that has demonstrated good efficacy. It is conducted before the surgery in order to decrease the tumor volume. This aims at making the surgery easier and to allow whole removal of the tumor in one piece.

Although better surgical techniques and the use of pre-operative radiotherapy have improved the disease outcome so called local and distant failures are frequently observed. This means that after some time, the tumor starts to grow again either locally or in another place of the body.

There is strong evidence in the scientific literature that supports the importance to control the tumor in patients with locally advanced soft tissue sarcomas. Indeed, controlling the tumor in these patients is a determinant factor to improve disease free survival (how long the patient stays without the tumor) and overall survival (how long the patient is living after diagnosis). This is not surprising as similar relationships are observed for other type of cancers.

Patients with high risk soft tissue sarcoma unfortunately only have few therapeutic options. Innovative treatments aiming to increase the cancer cell killing or to make the surgery easier are therefore urgently needed. (weblinks)

I am a patient, can I participate?

Patients can enroll the study at participating study centers only. The decision whether you can participate the study or not will be taken by your doctor. If you wish, please contact your doctor to discuss participation of the study, please do not contact Nanobiotix (the sponsor of the study).

Please also note that this website only provides a general description about NBTXR3 and the study. A doctor will provide you with a more comprehensive and thorough information about the study, including all potential risks.