The U.S. Food and Drug Administration (FDA) recently approved a new use for technetium 99m tilmanocept (Lymphoseek Injection), a radioactive diagnostic imaging agent used to help doctors determine the extent to which squamous cell carcinoma has spread in the body’s head and neck region.
In 2013, tilmanocept was approved to help identify lymph nodes closest to a primary tumor in patients with breast cancer or melanoma. With the recent approval, the agent can now be used to guide sentinel lymph node biopsy in patients with cancer of the head and neck. This new indication will allow for the option of more limited lymph node surgery in patients with sentinel nodes negative for cancer.
“For some patients with head and neck cancer, removal and pathological examination of lymph nodes draining a primary tumor is an important diagnostic evaluation,” said Libero Marzella, MD, PhD, Director of the Division of Medical Imaging Products in the FDA’s Center for Drug Evaluation and Research. “To use [tilmanocept], doctors inject the drug into the tumor area and later, using a handheld radiation detector, find the sentinel lymph nodes that have taken up [tilmanocept]’s radioactivity.”
Clinical Trial Results
For this new indication, tilmanocept’s safety and effectiveness were established in a clinical trial of 85 patients with squamous cell carcinoma of the lip, oral cavity, and skin. All patients were injected with tilmanocept. Surgeons subsequently removed suspected lymph nodes—those identified by the imaging agent and those based upon tumor location and surgical practice—for pathologic examination. Results showed that tilmanocept–guided sentinel lymph node biopsy accurately determined if the cancer had spread through the lymphatic system.
The most common side effect identified in the clinical trial was pain or irritation at the injection site. ■