Phase I Study Results Show First-in-class NBTXR3 Could Present as a Valuable Option for Patients With Hepatocellular Carcinoma or Liver Metastasis

Nanobiotix’s radioenhancer NBTXR3 study showed encouraging results for Hepatocellular Carcinoma (HCC) patients, which are significant as they increase the scope of patients NBTXR3 may treat beyond Soft Tissue Sarcoma and Head and Neck cancer. 

PARIS & CAMBRIDGE, Mass.–(BUSINESS WIRE)–NANOBIOTIX (Paris:NANO):

“The patient population in this study has significant unmet needs primarily due to pre-existing issues with hepatic function. When you combine that with the fact that there is low life expectancy for this group, you have a critical need for innovative treatment solutions. These data provide promising evidence that NBTXR3 activated by SBRT could be a valuable option with excellent safety and increased efficacy, presenting a new way to improve outcomes for these patients.” – Dr. Enrique Chajon, ASTRO 2019 Presenter for NANORAY-103

NANOBIOTIX (Euronext : NANO – ISIN : FR0011341205 – the ‘‘Company’’), today announced encouraging findings from the Company’s phase I study evaluating first-in-class radioenhancer NBTXR3 activated by stereotactic body radiation (SBRT). These data were presented at the ASTRO 2019 Annual Meeting by investigator Dr. Enrique Chajon.

Hafnium oxide nanoparticles activated by SBRT for the treatment of hepatocellular carcinoma and liver metastasis: a phase I/II trial

The population for this study included (i) hepatocellular carcinoma (HCC) patients with a minimum life expectancy of three (3) months that were unsuitable for local surgery or local treatment and (ii) liver metastasis (mets) patients with a minimum life expectancy of six (6) months whose tumors are unresectable. The total number of HCC patients was 11, the total numbers of mets patients was 6.

The HCC patient population has high unmet medical needs as they have underlying liver dysfunction and concomitant malignancies that limit treatment options. Stereotactic body radiation therapy (SBRT) is a well-tolerated alternative therapy, however the dose is limited by hepatic function which is widely impaired in this group. Therefore, these patients need a way to increase the dose delivered to the tumor while sparing surrounding healthy tissues without additional strain on the liver. Moreover, given the short life expectancy of these patients, the need is particularly urgent.

Given that NBTXR3 is inert unless exposed to radiotherapy, is not metabolized by the liver, and can be administered regardless of liver and renal function, the first-in-class treatment offers an opportunity to increase

the efficacy of SBRT while maintaining tolerable dose levels for the patient. In this study, the safety profile of NBTXR3 activated by SBRT was similar to SBRT alone with no dose-limiting toxicity (DLT). Additionally, NBTXR3 also proved to remain within the injected tumor with no leakage to surrounding tissue.

To date, 62.5% of evaluable HCC patients have shown a complete response while the rest have shown partial response. These results show that NBTXR3 activated by SBRT may present as a valuable option in patients with HCC not amenable to curative local treatment or with unresectable liver metastases.

In liver mets, 50% of patients have shown partial response and 50% show stable disease.

Given that the safety profile was very good and there were no DLTs, the protocol was amended to include a fifth dose escalation level of 42%. Three (3) patients have already been recruited and recruitment is expected to be complete in Q4. Results for all patients are expected in Q1 2020.

The Company remains focused on its head and neck plan but will now accelerate integration of HCC into its go-to-market strategy.