In a phase III trial reported in the Journal of Clinical Oncology, Janos L. Tanyi, MD, PhD, and colleagues found that use of pafolacianine infusion for intraoperative imaging improved the detection of lesions in patients with folate receptor–positive ovarian cancer, compared with using white light and palpation.
As stated by the investigators, “The adjunctive use of intraoperative molecular imaging is gaining acceptance as a potential means to improve outcomes for surgical resection of targetable tumors. This confirmatory study examined the use of pafolacianine for real-time detection of folate receptor–positive ovarian cancer.”
Janos L. Tanyi, MD, PhD
In the study, 150 patients (safety-analysis set) with known or suspected ovarian cancer who were scheduled to undergo cytoreductive surgery were enrolled at 10 sites in the United States and 1 in the Netherlands between March 2018 and November 2020. Patients received a single pafolacianine intravenous infusion of 0.025 mg/kg at ≥ 1 hour prior to intraoperative near-infrared imaging.
A total of 109 patients with folate receptor–positive ovarian cancer constituted the efficacy full-analysis set. After infusion, patients were assessed for lesions using normal white light and palpation. Intraoperative near-infrared imaging was then performed to detect additional macroscopic folate receptor–positive cancer lesions on tissue not planned for resection and not detected by white light and palpation alone. The prespecified threshold for improvement in detection was a 10% increase compared with white light and palpation.
Pafolacianine with near-infrared imaging identified additional cancer on tissue not planned for resection and not detected by white light assessment and palpation in 36 (33.0%, 95% confidence interval [CI] = 24.3%–42.7%; P < .001) of 109 patients in the efficacy full-analysis set, exceeding the prespecified threshold of 10%. Rates were 39.7% (95% CI = 27.0%–53.4%) among patients who underwent interval debulking surgery and 17.9% (95% CI = 7.5%–33.5%) among those who underwent primary cytoreductive surgery.
The sensitivity of pafolacianine with near-infrared imaging in detecting ovarian cancer at the lesion level was 83%. False-positive rates were 24.8% at the patient level and 32.7% at the lesion level.
Complete R0 resection was achieved in 68 patients (62.4%) in the efficacy full-analysis set.
Drug-related adverse events of any grade occurred in 45 (30%) of 150 patients; of these, 97% were grade 1 or 2. A total of 35 adverse events of special interest were observed in 24 patients (17%), with 97% being grade 1 or 2; the most common included nausea (n = 14), vomiting (n = 7), and abdominal pain (n = 2). No drug-related serious adverse events were observed. Two deaths were observed, due to septic shock and worsening renal function; neither was considered drug-related.
The investigators concluded, “This phase III study of pafolacianine met its primary efficacy endpoint, identifying additional cancers not otherwise identified or planned for resection. Pafolacianine may offer an important real-time adjunct to current surgical approaches for ovarian cancer.”
Dr. Tanyi, of the Hospital of the University of Pennsylvania, Abramson Cancer Center, Philadelphia, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by On Target Laboratories, Inc. For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.