Navidea Biopharmaceuticals, Inc., a biopharmaceutical company focused on precision diagnostic radiopharmaceuticals, has submitted a supplemental New Drug Application (sNDA) to the US Food and Drug Administration (FDA) seeking approval for the marketing and sale of Lymphoseek (technetium 99m tilmanocept) injection for sentinel lymph node (SLN) detection in patients with head and neck cancer, an indication for which Lymphoseek was also granted Fast Track designation earlier this month. Lymphoseek is currently approved for use in lymphatic mapping procedures that are performed to aid in the diagnostic evaluation of potential cancer spread for patients with breast cancer and melanoma.

"Our sNDA submission for Lymphoseek is an important step toward Navidea’s goal of helping this patient population who generally face extensive surgery to properly stage their cancer," said Mark Pykett, VMD, PhD, Navidea CEO. "The filing follows the FDA approval and US launch of Lymphoseek for use in lymphatic mapping procedures that are performed to aid in the diagnostic evaluation of potential cancer spread in patients with breast cancer and melanoma. If this sNDA is approved, Lymphoseek will be the only approved agent for SLN detection in this patient population, and representing another step forward in Navidea’s efforts to develop precision diagnostics that improve the accuracy of diagnosis."

“Identification of sentinel lymph nodes in selected patients with head and neck cancer represents an important unmet need. Today, many patients may undergo unnecessary full regional lymph node dissection, which removes an entire chain of lymph nodes, in order to see if cancer has spread from the primary tumor into the lymphatic system. These surgeries are lengthy, costly and may often be associated with considerable morbidity and potential long-term side effects for the patient,” commented Dr Stephen Y Lai, MD, PhD, FACS, associate professor, Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center and a lead investigator on the NEO3-06 Head and Neck phase III clinical trial.

Dr Lai further added, “Unfortunately, there are no approved imaging agents available today to minimize this surgery and its morbidity, while identifying and removing only the key predictive lymph nodes. The ability of Lymphoseek to accurately identify sentinel lymph nodes in these patients, such as demonstrated in the NEO3-06 phase III study, may not only improve diagnostic accuracy, but also make the procedure more efficient and minimize the morbidity and side effects associated with more extensive regional dissections.”

The sNDA submission is based on previously announced data from the NEO3-06 phase III study that showed with statistical significance the ability of Lymphoseek to correctly identify patients with pathology-positive lymph nodes compared with this assessment using multiple level lymph node dissection and pathology assessment, the current “gold standard”.

The phase III trial NEO3-06 was a prospective, open-label, multicenter, within-patient study. It was designed to identify sentinel lymph nodes and determine the false negative rate (FNR) associated with Lymphoseek-identified SLNs relative to the pathological status of non-SLNs in head and neck and intraoral squamous cell carcinoma. The primary endpoint for the NEO3-06 trial was based on the number of subjects with pathology-positive lymph nodes (lymph nodes found to harbor cancer) following a multiple level lymph node dissection and required a minimum of 38 subjects whose lymph nodes contained pathology-confirmed disease.

FNR is the rate of occurrence of negative test results in subjects known to have the disease for which the individual is being tested. Of the more than 80 subjects enrolled in the NEO3-06 trial, 39 subjects were determined to have pathology-positive lymph nodes. Results demonstrated that Lymphoseek correctly identified 38 of these 39 patients, for an overall FNR of 2.56%, which met the predefined statistical threshold. These findings indicate that Lymphoseek accurately identified SLNs in these trial subjects, and is likely to be predictive of overall node pathology status. Moreover, multiple level nodal dissection of patients in the trial with cancer-positive lymph nodes led to an average removal of 38 lymph nodes per patient, whereas Lymphoseek on average led to the removal of approximately 4 lymph nodes, representing a substantial reduction in potential morbidity for patients with head and neck cancer undergoing single lymph node biopsy.

As part of the sNDA submission package, Navidea also provided study results that demonstrated the ability of Lymphoseek to detect SLNs in same-day or subsequent-day surgery following injection, as well as being used in lymph node imaging, or lymphoscintigraphy.