65: Detection of Residual Peritoneal Metastases Following Cytoreductive Surgery Using Pegsitacianine, a pH Sensitive Imaging Agent: Topline Results from a Phase 2 Study

Friday, March 24, 2023

3:58 PM – 4:10 PM

Location: Veterans Memorial Auditorium

Abstract Presenter(s)

Patrick Wagner, MD

Director, AHN Cancer Institute Division of Complex General Surgical Oncology
Allegheny Health Network
Pittsburgh, Pennsylvania, United States

Disclosure(s): No financial relationships to disclose

Author(s)

Patrick Wagner, MD

Director, AHN Cancer Institute Division of Complex General Surgical Oncology
Allegheny Health Network
Pittsburgh, Pennsylvania, United States

Disclosure(s): No financial relationships to disclose
Edward A. Levine, MD

Chief, Surgical Oncology
Wake Forest University
Winston-Salem, North Carolina, United States

Disclosure information not submitted.
Alex C. Kim, MD, PhD

Assistant Professor of Surgery
The Ohio State University Wexner Medical Center, The James Cancer Hospital and Solove Research Institute
Columbus, Ohio, United States

Disclosure information not submitted.
PS

Perry Shen, MD

Professor
Atrium Health Wake Forest Baptist, United States

Disclosure information not submitted.
NF

Nicole Fleming, MD

Associate Professor
MD Anderson Cancer Center, United States

Disclosure information not submitted.
SW

Shannon Westin, MD, MPH

Professor
MD Anderson Cancer Center, United States

Disclosure information not submitted.
MO

Madeline Olson, PhD

Clinical Scientist
OncoNano Medicine
Southlake, Texas, United States

Disclosure information not submitted.
BM

Brian Madajewski, PhD

Associate Director, Clinical Development
OncoNano Medicine, United States

Disclosure information not submitted.
BO

Brian Ostrander, MS

Vice President, Head of Clinical Operations
OncoNano Medicine, United States

Disclosure information not submitted.
KK

Kartik Krishnan, MD, PhD

Chief Medical Officer
OncoNano Medicine, United States

Disclosure information not submitted.
BS

Baran Sumer, MD

Professor
UT Southwestern Medical Center, United States

Disclosure information not submitted.
TZ

Tian Zhao, PhD

Vice President, Research and Development
OncoNano Medicine, United States

Disclosure information not submitted.
JG

Jinming Gao, MD

Chair, AHN Cancer Institute
Allegheny Health Network, United States

Disclosure information not submitted.
David L. Bartlett, MD

System Chair
Allegheny Health Network Cancer Institute
Pittsburgh, Pennsylvania, United States

Disclosure information not submitted.

Disclosure(s):

Patrick Wagner, MD: No financial relationships to disclose

Introduction: Completeness of cytoreduction is a key indicator of surgical efficacy and long-term prognosis in cytoreductive surgery (CRS). The objective of this Phase 2 study (NCT04950166) was to evaluate the ability of pegsitacianine, an ultra pH-sensitive polymeric micellar fluorescent nanoprobe, to detect residual disease intraoperatively following CRS in patients with peritoneal carcinomatosis.

Methods: In this non-randomized, open-label, multi-center U.S. study, patients were administered a single intravenous dose of pegsitacianine at 1 mg/kg within 24-72 hours prior to surgery. During surgery, a total of ten suspected tumor lesions and five normal specimens were subjected to near-infrared imaging during CRS to define the performance characteristics of pegsitacianine (including sensitivity, patient-level false positive, and negative predictive value) by comparing the fluorescence status of collected specimens with pathologic assessment of the presence of malignancy. After completion of intended CRS, the peritoneal cavity was re-examined to evaluate for residual fluorescent tissue. The primary performance metric of pegsitacianine was the rate of detection of unsuspected residual disease during the re-examination. Pegsitacianine-guided resection of additional residual tumor or a change in the completeness of cytoreduction (CC) score was defined as a clinically significant event.

Results: 32 patients have been dosed with pegsitacianine, and 29 patients have completed pegsitacianine-guided surgery across 6 primary tumor types. Pegsitacianine was well tolerated, with no drug-related SAEs. To date, a clinically significant event (resection of residual disease or a change in the CC score) occurred in 15 patients (51.7%) as a result of the pegsitacianine-guided re-examination following CRS. Pegsitacianine performance calculated at the level of the individual specimens (n= 497) demonstrated favorable sensitivity (85%), negative predictive value (78%), and a low patient-level false positive rate (27.5%).

Conclusions: Pegsitacianine was well-tolerated and facilitated the recognition of occult residual disease following CRS. The high rate of residual disease detection suggests pegsitacianine has the potential to augment surgeon performance during CRS, leading to improved completeness of cytoreduction and patient outcomes.

Learning Objectives:

Describe the utility of fluorescence-guided surgery in peritoneal metastasis
Discuss potential additional applications for pegsitacianine and fluorescence-guided surgery
Reflect on current methods for intraoperative detection of peritoneal metastases during cytoreductive surgery.