Nanobiotix Announces Positive First Results for Novel NBTXR3 in Rectal Cancer Study at ASCO-GI 2021
PARIS & CAMBRIDGE, Mass.: NANOBIOTIX, a clinical-stage biotechnology company focused on developing first-in-class product candidates that use proprietary nanotechnology to transform cancer treatment,has announced positive first results from the complete phase Ib part of a phase Ib/II study evaluating NBTXR3 (PEP503) activated by radiotherapy with concurrent chemotherapy. This study is sponsored and administered by PharmaEngine, Inc. in Taiwan pursuant to a License and Collaboration agreement with the Company. The data were presented at the 2021 American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO-GI 2021).
A NEW RADIOENHANCER, PEP503 (NBXTR3), IN COMBINATION WITH CONCURRENT CHEMORDIATION IN LOCALLY ADVANCED OR UNRESECTABLE RECTAL CANCER: THE DOSE-FINDING PART OF A PHASE IB/II TRIAL
Authors: Jaw-Yuan Wang, Ching-Wen Huang, Ming-Yii Huang, Huang-Ming Hu, Wen-Hung Hsu, Hsiang-Yao Shih, Chiao-Yun Chen, Chou-Pin Chen, Jeffrey Yung-Chuan Chao, You-Hsin Chiu
Abstract Number: 66
Background
Radiotherapy, chemotherapy and surgery are elements of the standard of care for patients with rectal cancer. Concurrent chemoradiation (CCRT) followed by surgery, if possible, is the recommended option for patients with resectable (surgically removable) T3 to T4 tumors, or who have locally unresectable or inoperable disease. Better response to CCRT, prior to surgery, may be associated with better long-term treatment outcomes.
The potential efficacy of tumor-agnostic NBTXR3 in increasing tumor shrinkage—as observed in phase I head and neck cancer, and phase I liver cancer studies—may result in tumor downstaging and lead to an improvement in surgical outcomes.
Study Design
The complete dose-finding part of this phase Ib/II study evaluated the safety, feasibility and recommended phase II dose of NBTXR3 for patients with locally advanced (T3 to T4) or unresectable rectal cancer. The study enrolled 20 patients: with seven, four, three, and six patients at the 5%, 10%, 15%, and 22% dose levels, respectively.
Topline Results
Intratumoral injection of NBTXR3 with CCRT was feasible and the product candidate was well tolerated at all dose levels, and no adverse events (AEs) or serious adverse events (SAEs) associated with NBTXR3 were observed in the study. One dose-limiting toxicity associated with the injection procedure was observed (urinary tract infection). The most frequently reported AEs were diarrhea (approximately 45%), leukopenia (approximately 40%), and dermatitis (approximately 25%), however all were grade one or grade two.
More than 70% of patients in the study showed objective tumor response after CCRT. Around 90% of patients underwent total mesorectal excision (surgery); and 17.6% achieved pathological complete response (pCR). 50% of patients receiving surgery in the study had good tumor regression (tumor regression grade 0 or 1 according to modified Ryan scheme).
The RP2D has been defined as 22% of tumor volume and the extension phase II is ongoing in Taiwan.
