The USA Food and Drug Administration (FDA) approved on 13 June 2014 a new indication for Lymphoseek (technetium 99m tilmanocept) Injection, a radioactive diagnostic imaging agent that helps in determining the extent of spread of squamous cell carcinoma of the oral cavity in head and neck region.
Lymphoseek represents a new class of receptor-targeted lymphatic mapping agents. Given its consistent pharmacodynamic properties, Lymphoseek may facilitate benefits such as predictable scheduling of lymphatic mapping procedures and efficient resource utilisation.
In 2013, Lymphoseek was approved to help identify lymph nodes closest to a primary tumour in patients with breast cancer or melanoma.
With new approval, Lymphoseek can now be used to guide testing of lymph nodes closest to a primary tumour for cancer, a procedure called sentinel lymph node biopsy, in patients with cancer of the oral cavity. 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,” according to Dr Libero Marzella, who is a 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.”
Approval based on clinical trial results
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 tumour 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.