A radioactive diagnostic imaging agent called Lymphoseek (technetium Tc 99m tilmanocept) Injection has been approved for locating lymph nodes in patients who have breast cancer or melanoma and are undergoing surgery to remove tumor-draining lymph nodes, the Food and Drug Administration announced.
Lymphoseek is the first new drug for lymph-node mapping to be approved in more than 30 years. Other FDA-approved drugs used for lymph-node mapping include sulfur colloid and isosulfan blue.
"To use Lymphoseek, doctors inject the drug into the tumor area and later, using a handheld radiation detector, find lymph nodes that have taken up Lymphoseek’s radioactivity," said Dr. Shaw Chen, deputy director of the Office of Drug Evaluation IV in the FDA’s Center for Drug Evaluation and Research.
Lymphoseek is marketed by Navidea Biopharmaceuticals. The manufacturer’s website notes that the ability to rapidly locate and biopsy sentinel nodes enables surgical management to be tailored specifically to each patient’s burden of disease.
In two clinical trials, 332 patients with melanoma or breast cancer were injected with Lymphoseek and blue dye. Surgeons subsequently removed suspected lymph nodes for pathologic examination. Confirmed lymph nodes were examined for their content of blue dye and Lymphoseek. The combination of Lymphoseek and blue dye localized most lymph nodes, although a notable number of nodes were localized only by Lymphoseek.
The most common side effects identified in clinical trials were pain and irritation at the injection site.
According to the manufacturer, a clinical trial involving patients with head and neck cancer is completing enrollment and is expected to be the subject of a future New Drug Application amendment. An initial Marketing Authorization Application filing in the European Union is anticipated by the end of 2012.