Navidea Biopharmaceuticals’ Lymphoseek (technetium Tc 99m tilmanocept) injection has received a Food and Drug Administration (FDA) expanded approval for the inclusion of lymphatic mapping in solid tumors and sentinel lymph node (SLN) detection for breast cancer and melanoma.
Furthermore, the FDA has approved Lymphoseek’s use independently of scintigraphic imaging for pre-operative mapping of lymph nodes.
This approval transforms Lymphoseek into the only FDA-approved radiopharmaceutical agent for SLN detection and the only FDA-approved agent for lymphatic mapping of solid tumors.
“We are highly encouraged by the expanded FDA approval and believe that Lymphoseek now has the potential to become a standard-of-care in lymphatic mapping and SLN biopsy for the staging and prognosis of upwards of 1.2 million patients diagnosed with solid tumors annually in the US,” Michael Goldberg, MD, interim chief executive officer of Navidea, said in a company’s news release.
Lymphoseek is designed to specifically assist in lymphatic imaging, enabling the localization of lymph nodes draining a primary tumor site in patients with breast cancer or melanoma. This radioactive diagnostic agent can tightly bind to receptors present in the lymph nodes, allowing SLN detection.
The expanded approval derived from promising results of several Phase III clinical trials, that evaluated the efficacy of Lymphoseek versus vital blue dye (VBD) in the total number of nodes detected.
A total of 154 melanoma patients were studied in two different trials, both of them showing a 98.7% concordance rate between Lymphoseek and VBD. The results demonstrated that out of the 235 SLNs detected by VBD, 232 of them were also detected by Lymphoseek. Furthermore, SLNs efficiently diagnosed melanoma cells in 22.1% of patients, with Lymphoseek proving 100% effective in the detection of all cases, while VBD identified only 80% of the patients.
Toxic side-effects were considered mild, with 0.7% of patients developing injection site irritation and 0.2% experiencing pain.
“The ability of Lymphoseek to accurately identify sentinel lymph nodes in patients, demonstrated in clinical evidence from more than 500 patients, may not only improve diagnostic accuracy, but also enable more efficient and appropriate patient care and provide us with greater precision during surgery to detect lymph nodes with the highest likelihood of harboring tumor metastases,” Stephen Y. Lai, MD, PhD, FACS, associate professor, The University of Texas MD Anderson Cancer Center, added in the news release.
“The success of lymphatic mapping and sentinel lymph node biopsy is dependent upon a radiopharmaceutical’s ability to concentrate in the lymph nodes most likely to contain cancer,” H. William Strauss, M.D., Attending Physician Emeritus, Molecular Imaging and Therapy Service at Memorial Sloan-Kettering Cancer Center explained. Dr. Strauss went on to explain that this approval, based on Lymphoseek’s ability to target molecular markers in tumor-draining lymph nodes with high precision and accuracy, “opens up potential diagnostic imaging opportunities broadly across all forms of solid tumors.”
