Nanotechnology Made Clear

Nanoparticles for enhanced x-ray treatment of cancer tumors.

Nanobiotix, an emerging nanomedicine company, announced today that preclinical follow-up data regarding long-term toxicity evaluation suggests that its patented NBTXR3 nanoparticles are designed to be a safe and effective treatment for radiosensitive and radioresistant tumors. The preclinical studies were performed at NAMSA Biomatech. NAMSA is registered with the CDER and CBER divisions of the FDA.

Nanobiotix is using technology that it calls 'nanoXray therapeutics' to resolve radiation therapy's biggest drawback: destruction of healthy tissue and its subsequent deleterious side effects when a high dose of xray is necessary. The Company believes that nanoXray therapeutics offer a dramatic innovation in cancer therapy, based on a technology that is designed to allow destruction of cancer cells only-a new treatment weapon that could be used alone, or in concert with existing anticancer protocols: chemotherapy, surgery, and immunotherapy. Because NBTXR3 is comprised of crystalline nanoparticles, it does not have deleterious effects on healthy cells, unlike chemotherapy or other systemic anticancer agents.

"Our nanotechnology is designed to allow for the precise destruction of cancer cells via the controlled application of an outside-the-body energy source-in this case, an xray. We have aggressively worked to achieve our goal of completing this preclinical program in order for Nanobiotix to be able to start the first-in-man clinical trial by the end of this year. We are highly encouraged by these latest results, with confirmation of good tolerance and negligible toxicity observed in animals," said Laurent Lévy, Ph.D., President and CEOof Nanobiotix and Co-President of the French Technology Platform on Nanotechnology (FTPN).

"These preclinical results strongly suggest that NBTXR3 activated by ionizing radiation may represent a safe, solid-tumor treatment option capable of enhancing existing therapeutic options. These data also suggest that NBTXR3-based treatment can be used for patients with kidney or liver dysfunctions, resulting in potentially better clinical benefit in specific populations where pharmaceuticals and biologicals cannot be used," added Elsa Borghi, M.D., Chief Medical Officer for Nanobiotix.

One in four deaths in the United States is from cancer, making it the second-leading cause of death after heart attack. Radiation therapy-also called radiotherapy, xray, or irradiation-is typically used to kill cancer cells and shrink tumors. Radiation therapy injures or destroys cells in the area being treated by damaging their genetic material, making it impossible for these cells to continue to grow and divide. The goal of radiation therapy is to damage as many cancer cells as possible, while limiting harm to nearby healthy tissue. About half of all cancer patients receive some type of radiation therapy, which may be used alone or in combination with other cancer treatments, such as chemotherapy or surgery. Radiation therapy may be used to treat almost every type of solid tumor.

NBTXR3 is a suspension of inert crystalline nanoparticles of hafnium oxide with a simple coating that is formulated in water for injection. These nanoparticles have a simple composition: the hafnium oxide core represent the therapeutic source, but only when its electrons are excited by the application of an external beam of xray. Of note: the crystalline structure of the nanoparticles prevents metabolization by living organisms. NBTXR3 works according to an "on-off" activity status: When the nanoparticles are not activated, they do not have any effect because they are inert. Under standard external beam xray activation, xrays are absorbed by NBTXR3 nanoparticles exactly as ionizing radiations are absorbed by water molecules, leading to emission of electrons losing energy and the subsequent creation of free radicals. In both cases, xray energy will generate electrons with kinetic energy that will be released into the medium and will generate free radicals. The nanoparticles do not react directly with any biological recipient cell and tissue.

About the NBTXR3 Toxicology Evaluation Follow-Up Data

Two years ago, Nanobiotix commenced a large safety assessment program in animals to acquire knowledge about NBTXR3's biodistribution, excretion and potential toxicology effects in healthy and tumor-bearing animals. Despite the intended use of NBTXR3 as a local injection directly into a tumor, NBTXR3 was tested in animals as a systemic injection in the vein in order to mimic a clinical situation of accidental and massive passage of NBTXR3 nanoparticles into the bloodstream during the procedure of intratumor injection. Preclinical tolerance studies in terms of animal survival, behavior and pathological assessment indicated capture by the reticulo-endothelial system and negligible toxicity, even for dose-maximization situations in which NBTXR3 was injected by intravenous route on five consecutive days. Results suggested absence of any indolent disease characteristics in male and female animals. Excretion studies following intravenous administration showed identical data for male and female animals, with NBTXR3 very slowly eliminated by feces per plan and no presence of NBTXR3 in urine. Regarding local injection tolerance, there was no evidence of irritant potential at the intramuscular site. For the systemic administrations, NBTXR3 nanoparticles underwent phagocytosis mainly in the mononuclear phagocyte system. Therefore, they were observed in liver, spleen, small intestine and lymph nodes. There was no evidence of blood/brain barrier rupture. Also, no presence of inflammation or degenerative change was found in any of the 39 evaluated tissues at any time point. Hematology and biochemistry were exactly equivalent to those values observed in animal controls.

About Nanobiotix

Nanobiotix is an emerging nanomedicine company combining dramatic advances in nanotechnology and molecular biology to develop nanoXray™- a technology platform that is expected to be turned 'on' and 'off' outside the body to selectively treat a variety of cancers safely and noninvasively. Use of nanoXray is intended to resolve radiation therapy's biggest drawback: destruction of healthy tissue and its subsequent deleterious side effects when a high dose of xray is necessary. The core of a nanoXray nanoparticle is an inactive and inert substance-not drugs-that can be activated to locally (intratumor) increase the dose of xray, which is then expected to lead to higher efficiency. After nanoXray nanoparticles accumulate in the target tissues, a standard xray is applied that is intended to generate a local therapeutic effect, designed to destroy only the targeted tumor cells. This mechanism suggests total control of the intended therapeutic effect.

Source: Nanobiotix Press Release; July 2009

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