Dr. Bonvalot on the Long-Term Safety of NBTXR3 Plus Radiotherapy in Locally Advanced Soft Tissue Sarcoma

Sylvie Bonvalot, MD, PhD, HDR, the head of sarcoma surgery at Institut Curie, in Paris, France, discusses the long-term safety of NBTXR3 plus radiotherapy in patients with locally advanced soft tissue sarcoma who were treated in the phase 2/3 Act.In.Sarc trial (NCT02379845).

There were no significant differences in serious adverse effects (AEs) related to radiotherapy between both groups enrolled on the study, according to Bonvalot. In total, 11.2% of patients who received NBTXR3 plus radiotherapy, and 13.3% of those who received radiotherapy alone, experienced serious AEs related to radiotherapy.

In soft tissue sarcoma, very often in patients with advanced-stage disease, surgical morbidities leading to rehospitalization are common. The rate of hospitalization due to serious AEs related to surgery was 15.7% and 24.4% in both groups, respectively, which was not a significant difference, Bonvalot says.

The findings are interesting, as previous data indicated that grade 3 morbidities leading to rehospitalization or reoperation due to perioperative radiotherapy occurred in approximately 30% of patients, Bonvalot explains. The rate of hospitalization was less in the Act.In.Sarc trial vs older findings, as well as less in the NBTXR3 cohort, Bonvalot concludes.