FDA approves use for Lymphoseek to help doctors determine extent of neck and cancer

The U.S. Food and Drug Administration today approved a new use for Lymphoseek (technetium 99m tilmanocept) Injection, a radioactive diagnostic imaging agent used to help doctors determine the extent a type of cancer called squamous cell carcinoma has spread in the body's head and neck region.

In 2013, Lymphoseek was approved to help identify lymph nodes closest to a primary tumor in patients with breast cancer or melanoma. Lymph nodes filter lymphatic fluid that flows from the body's tissues. This fluid may contain cancer cells, especially if the fluid drains a part of the body containing a tumor. By surgically removing and examining the lymph nodes that drain a tumor, a procedure called a biopsy, doctors can sometimes determine if a cancer has spread.

With today's approval, Lymphoseek can now be used to guide testing of lymph nodes closest to a primary tumor for cancer, called a "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, M.D., Ph.D., director of the Division of Medical Imaging Products in the FDA's Center for Drug Evaluation and Research. "To use Lymphoseek, doctors inject the drug into the tumor area and later, using a handheld radiation detector, find the sentinel lymph nodes that have taken up Lymphoseek's radioactivity."

For this new indication, Lymphoseek'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 Lymphoseek. Surgeons subsequently removed suspected lymph nodes-;those identified by Lymphoseek and those based upon tumor location and surgical practice-;for pathologic examination. Results showed that Lymphoseek–guided sentinel lymph node biopsy accurately determined if the cancer had spread through the lymphatic system.

The most common side effects identified in clinical trial was pain or irritation at the injection site.