FDA Grants Priority Review to Pafolacianine Sodium Injection in Ovarian Cancer

The FDA has granted priority review to the new drug application (NDA) for the novel compound pafolacianine sodium injection (formerly OTL38) for use in the identification of ovarian cancer during surgery, according to an announcement from On Target Laboratories, Inc.¹

Pafolacianine sodium injection has demonstrated the ability to bind to folate receptors and illuminate intraoperatively under near-infrared light; it can be administered intravenously prior to treatment-related surgeries. Utilizing the injection in ovarian cancer surgery could help to provide greater certainty of complete disease resection, as approximately 97% of patients with ovarian cancer express clear alpha-folate receptor proteins.²

The use of pafolacianine sodium injection in ovarian cancer was investigated in phase 2 (NCT02317705) and phase 3 (NCT03180307) trials and was under Special Protocol Agreement from the FDA. Additionally, the agent has received both fast track and orphan designations from the regulatory agency.

“Our NDA is supported by our positive phase 2 and phase 3 clinical trials,” Christopher Barys, president and CEO of On Target Laboratories, stated in a press release. “As we move closer to FDA approval for ovarian cancer, we are realizing our mission to intraoperatively visualize more cancer and extend the benefits of a complete resection to patients.”

The phase 2 study enrolled 29 patients who were 18 years of age or older with a primary diagnosis, or high clinical suspicion, of ovarian cancer. Participants received pafolacianine sodium injection prior to planned debulking surgery.³

Results showed that when controlling for correlation of detection among multiple lesions within a single patient, pafolacianine sodium injection had a sensitivity of 97.97% (95% lower boundary CI = 87.75) and a positive predictive value of 94.93% (95% lower boundary CI = 86.13). Additionally, 48.3% (n = 14/29; 95% CI, 0.29–0.67) of patients had at least 1 additional lesion detected by pafolacianine sodium injection.⁴

In terms of safety, 8 patients experienced mild drug-related adverse effects (AEs). The most common AEs reported included infusion reaction, nausea, vomiting, and abdominal pain.

Data from the phase 2 trial led to the ongoing phase 3 trial, which is further evaluating the agent in that patient population.⁵

Additionally, pafolacianine sodium injection is currently being investigated in the phase 3 ELUCIDATE trial (NCT04241315) for use in the intraoperative detection of lung cancer lesions. This multicenter trial will evaluate the safety, efficacy, and tolerability of pafolacianine sodium in patients with lung cancer and is expected to enroll up to 130 patients. The first patient was enrolled in the study in July 2020, and preliminary data is expected in 2021.⁶

References

1. On Target Laboratories announces US FDA acceptance and priority review of new drug application for pafolacianine sodium injection for identification of ovarian cancer during surgery. News release. On Target Laboratories, Inc. March 3, 2021. Accessed March 3, 2021. https://prn.to/3uQTsHB

2. Markert S, Lassmann S, Gabriel B, et al. Alpha-folate receptor expression in epithelial ovarian carcinoma and non-neoplastic ovarian tissue. Anticancer Res. 2008;28(supp 6A): 3567-3572

3. Phase 2 study of OTL38 for intra-operative imaging of folate receptor-alpha positive ovarian cancer. ClinicalTrials.gov. Updated September 9, 2019. Accessed March 3, 2021. https://clinicaltrials.gov/ct2/show/NCT02317705

4. Randall L, Wenham R, Low P, et al. A phase II, multicenter, open-label trial of OTL38 injection for the intra-operative imaging of folate receptor-alpha positive ovarian cancer. Gynecologic Oncology. 2019;155(supp 1):63-68. doi:10.1016/j.ygyno.2019.07.010

5. OTL38 for Intra-operative Imaging of Folate Receptor Positive Ovarian Cancer. ClinicalTrials.gov. Updated December 8, 2020. Accessed February 3, 2021. https://clinicaltrials.gov/ct2/show/NCT03180307

6. First patient enrolled in the phase 3 ELUCIDATE trial of pafolacianine sodium (formerly OTL38) in the intraoperative identification of lung cancer lesions. News release. On Target Laboratories, Inc. July 8, 2020. Accessed March 3, 2021. https://prn.to/386WSMH