Radiation therapy, also called radiotherapy, is one of the most common methods of treatment for cancer. More than 60 percent of cancer patients undergo radiotherapy at some point during their treatment. With surgery, radiotherapy is the standard of care for local cancer treatment.
Surgery plus radiotherapy improves the prognosis for many patients. However, while radiotherapy can be an effective treatment, the efficacy of treatment may be limited for some patients because the dose required to destroy the tumor may cause too much damage to surrounding healthy tissues.
To meet this unmet need, Nanobiotix is developing NBTXR3, a first-in-class radiohancer composed of hafnium oxide nanoparticles that is designed to destroy tumors when activated by radiotherapy. Clinical data have suggested that when NBTXR3 is activated, it increases the energy absorbed from radiotherapy up to nine times and enhances the dose delivered, inducing significant tumor cell death without increasing the damage to surrounding healthy tissue.
The mechanism of action of NBTXR3 is physical, rather than biological or chemical. In theory, thanks to its physical mechanism of action, this means that its effects should be scalable across solid tumor types.
We believe that NBTXR3 activated by radiotherapy may become a new standard of care in the treat-ment of cancer, potentially helping millions of patients. Under the brand name Hensify®, NBTXR3 obtained its first European CE marking for the treatment of locally advanced soft tissue sarcoma in 27 European countries in 2019. NBTXR3 is currently evaluated in 14 clinical trials including 7 active in 6 different indications. In 2019, The FDA are designated as a Fast Track development program the investigation of NBTXR3, in combination with radiation therapy with or without cetuximab, for the treatment of patients with locally advanced head and neck squamous cell cancer who are not eligible for platinum-based chemotherapy.
NBTXR3 mode of actionOur novel radioenhancer, NBTXR3, is composed of hafnium oxide nanoparticles. These nanoparticles are spherical in shape, have an average size of approximately 50 nanometers, and are coated with negatively charged surface ligands (molecules that bind to other molecules). NBTXR3 is injected one time directly into a malignant tumor prior to standard radiotherapy. Its physical mechanism of action, size, shape, and surface charge is designed for efficient tumor cell uptake; once injected into the tumor, the nanoparticles accumulate in cancer cells in clusters thanks to their unique properties while remaining inert (inactive).
NBTXR3’s physical mechanism of action is based on its interaction with ionizing radiation (the kind of radiation used in the radiotherapy that activates NBTXR3). Clinical data suggests that once activated, NBTXR3 increases the energy absorbed from radiotherapy and enhances the dose delivered. By enhancing the dose of radiotherapy to a solid tumor, NBTXR3 induces significant tumor cell death without increasing the damage to surrounding healthy tissue.
Ionizing radiation can be applied to NBTXR3 nanoparticles repeatedly because they return to their inactive state after each exposure to radiation. Multiple courses of radiotherapy can be administered to a tumor that has received a single injection of NBTXR3.
In our preclinical studies, radiation-activated NBTXR3 has also been observed to trigger metastatic cell destruction due to immunogenic cell death, which is any type of cell death that leads to activation of the immune system. Based on these observations, we believe that NBTXR3 may prime the body’s immune response to render tumors more prone to recognition by a patient’s immune system.