Nanobiotix’s NBTXR3 meets in Phase II/III for STS

Nanobiotix S.A. (Euronext:NANO) said NBTXR3 (PEP503) met the primary and secondary endpoints in the Phase II/III act.in.sarc trial to treat locally advanced soft tissue sarcoma. The compound comprises crystalline nanoparticles of hafnium oxide activated in vivo via standard radiation therapy.

The open-label, European and Asian trial enrolled 180 patients to receive a single intratumoral injection of NBTXR3 activated by radiotherapy or radiotherapy alone followed by surgical resection. On the primary endpoint, NBTXR3 significantly improved pathological complete response rate, defined as achieving <5% of residual malignant viable cancer cells in surgically removed tissue, vs. radiotherapy alone (16.1% vs. 7.9%, one-sided p=0.0448). On the secondary endpoint, NBTXR3 increased the negative resection margin rate by 20% vs. radiotherapy alone (one-sided p=0.042). Nanobiotix said the one-sided p-value calculations were prespecified in the trial's statistical analysis plan. The company added that it used the one-sided test and not a two-sided test because there was "no need" to test for both inferiority and superiority as the goal was to "add efficacy" to radiotherapy...