Dr Tanyi on the Use of Pafolacianine for Intraoperative Molecular Imaging in FRα+ Ovarian Cancer

Janos L. Tanyi, MD, PhD, associate professor, Obstetrics and Gynecology, Hospital of the University of Pennsylvania, discusses the feasibility and efficacy of using pafolacianine sodium injections (OTL38) to enhance visualization compared with traditional methods during cytoreductive surgery in folate receptor-alpha (FRα)– positive ovarian cancer, according to a post-hoc analysis.

An open-label, phase 3 trial (NCT03180307) enrolled patients with known or suspected ovarian cancer who were scheduled to undergo cytoreductive surgery, Tanyi begins. Its main objectives were to assess the proportion of patients with at least one evaluable FRα-positive ovarian cancer lesion confirmed by central pathology, as well as to confirm the safety and efficacy of pafolacianine to detect macroscopic lesions not detected by palpation and normal white light, he details.

In the study, pafolacianine successfully identified additional malignancy in 27% of patients in the intent-to-treat population (95% CI, 19.6-35.2) and 33% (95% CI, 24.3-42.7) in the overall population, Tanyi reports. This indicates that pafolacianine may offer an important real-time adjunct to current surgical approaches for ovarian cancer.

A post-hoc analysis was subsequently planned to evaluate the time at initial imaging and at the conclusion of the case prior to closing when malignant lesions were identified by fluorescent imaging, Tanyi continues. The suitability of these fluorescent lesions for surgical removal was also assessed, Tanyi adds.

Results showed that 60% of additional malignancies were identified after the resection was completed and before closing, and 40% were identified prior to the start of resection, Tanyi states. Notably, the percentage of not removable lesions is lower for lesions that were identified by fluorescence, he says.

Moreover, the sensitivity rate of molecular imaging on the lesion level was 83% (range, 73.9-89.4), indicating its effectiveness in accurately identifying tumor lesions, Tanyi notes. However, it's noteworthy that the false positive rate on the lesion level was 32.7%, suggesting the need for further refinement in distinguishing between true and false positives to avoid unnecessary interventions. The false positive rate on the lesion level was 32.4%, suggesting the need for further refinement in distinguishing between true and false positives to avoid unnecessary interventions, Tanyi concludes.