FDA Grants Priority Review to Injectable Pafolacianine Sodium to Identify Ovarian Cancer During Surgery

The FDA has accepted a New Drug Application (NDA) for pafolacianine sodium injection and granted it Priority Review as a potential adjunct for identifying ovarian cancer during surgery, announced On Target Laboratories, Inc, in a press release.¹

Pafolacianine sodium works by binding to folate receptors, which are often found in ovarian tumors. Pafolacianine sodium has been shown to illuminate intraoperatively under near-infrared light and thus provides more precision for detecting cancerous lesions during tumor resection.

"Our NDA is supported by our positive phase 2 and phase 3 clinical trials. As we move closer to FDA approval for ovarian cancer, we are realizing our mission to intra-operatively visualize more cancer and extend the benefits of a complete resection to patients," said Christopher Barys, president and chief executive officer of On Target Laboratories, in a statement.

A phase 2 study showed pafolacianine sodium to be safe and effective for intraoperative imaging during epithelial ovarian cancer surgery, regardless of folate expression. The study enrolled 44 patients and evaluated the use of pafolacianine sodium in 29 intent-to-treat patients with a collective of 225 lesions. Safety and efficacy were assessed by sensitivity and positive predictive value (PPV).²

Pafolacianine sodium had an 85.93% (95% lower boundary CI = 81.19%) estimate for sensitivity and an 88.14% (95% lower boundary CI = 83.59%) estimated positive predictive value (PPV). Sensitivity and PPV increased to 97.97% (95% lower boundary CI = 87.75%) and 94.93% (95% lower boundary CI = 86.13%), respectively, when investigators controlled for the association of detection among multiple lesions within a single patient. Finally, with the use of the injectable pafolacianine sodium, a minimum of 1 additional lesion was detected in 48.3% (95% CI, 0.29-0.67) of patients.

In terms of safety, mild drug-related adverse events occurred in 8 patients, which were infusion reaction, nausea, vomiting, and abdominal pain.

Pafolacianine sodium was previously granted Fast Track and Orphan designations from the FDA after a Special Protocol Agreement led to its investigation in ovarian cancer. Priority Review is granted by the FDA to drugs that may offer significant improvements in the treatment, diagnosis, or prevention of a specific disease. With this designation, the NDA for pafolacianine sodium will be reviewed by the FDA within 6 months.¹

_References:

_{1. On Target Laboratories announces U.S. FDA acceptance and priority review of New Drug Application for pafolacianine sodium injection for identification of ovarian cancer during surgery. News release. March 3, 2021. Accessed March 4, 2021.}

_{2. Randall LM, Wenham RM, Low PS, et al. A phase II, multicenter, open-label trial of OTL38 injection for the intra-operative imaging of folate receptor-alpha positive ovarian cancer. Gynecol Oncol. 2019;155(1):63-68. doi:10.1016/j.ygyno.2019.07.010.}