Lymphoseek (technetium Tc 99m tilmanocept) Injection, a radioactive imaging agent that assists doctors in locating lymph nodes in breast cancer or melanoma patients who are having tumor-draining lymph nodes removed, has been approved by the US FDA (Food and Drug Administration).

Lymphatic fluid flows from the body’s tissues and is filtered by the lymph nodes. If the fluid is draining from a part of the body that contains a tumor, it may contain cancer cells.

Doctors can sometimes determine whether a cancer has metastasized (spread) by surgically removing the lymph nodes that drain a tumor and examining them.

Lymphatic mapping involves identifying which lymph nodes might contain tumor metastases, taking them out to be examined in order to determine whether the cancer has spread beyond the primary tumor. Then the doctor can accurately stage the cancer. Accurate staging of lymph nodes is vital, because only then can the oncologist make the best therapy recommendations, and determine patient prognosis and risk of recurrence.

The American Cancer Society estimates that about 232,000 patients will be diagnosed with breast cancer and 77,000 with melanoma in 2013.

Anne Wallace, M.D., Professor of Surgery, UC San Diego School of Medicine; Director of the Breast Care Unit; UC San Diego Moores Cancer Center; and Principal Investigator for breast cancer in the Lymphoseek Phase 3 clinical trials, said:

“We recommend lymphatic node mapping and sentinel node biopsy for patients with early stage breast cancer and in select cases of ductal carcinoma in situ. The ability to reliably identify multi-node pathology-positive patients is important to optimize their post-surgery management and to spare certain patients from unnecessary surgery and potentially debilitating side effects.

Products specifically designed to address reliable lymph node uptake and retention can provide significant clinical utility and help standardize the process of lymph node mapping.”

Lymphoseek is an imaging medication that helps doctors determine exactly where the lymph nodes are.

The FDA says that Lymphoseek is the first medication used for locating lymph nodes to be approved in the USA in over three decades. Sulfur colloid was approved in 1974 and isosulfan in 1981.

Shaw Chen, M.D., deputy director of the Office of Drug Evaluation IV in the FDA’s Center for Drug Evaluation and Research, said:

“Removal and pathological examination of lymph nodes draining a primary tumor is an important diagnostic evaluation for some patients with breast cancer or melanoma. 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.”

FDA experts assessed the findings from two clinical trials involving 332 patients with breast cancer or melanoma. The trials focused on the radioactive imaging agent’s safety and efficacy. They were all injected with blue dye and Lymphoseek.

The suspected lymph nodes were subsequently surgically removed for pathologic examination. Confirmed lymph nodes were examined to determine whether they had Lymphoseek and/or blue dye.

The researchers found that both the blue dye and Lymphoseek had mapped the locations of most of the lymph nodes. However, a significant number of nodes were localized by just Lymphoseek.

The most commonly reported side effects included pain and/or irritation at the injection site.

Lymphoseek was created by Navidea Biopharmaceuticals Inc. Lymphoseek will be sold and distributed in the United States on an exclusive basis by Cardinal Health, Inc.

Mark J. Pykett, V.M.D., Ph.D., President and CEO of Navidea, said:

“We believe today’s approval of Lymphoseek validates our ability to advance the field of precision diagnostics. Our vision is to improve diagnostic accuracy, clinical decision-making and patient care. We are gratified that our scientific achievements may benefit thousands of patients diagnosed with breast cancer and melanoma each year. We look forward to continuing the development of Lymphoseek into additional indications and to progressing our oncology and neurology pipeline.”

Full prescribing information can be found at www.lymphoseek.com.

Written by Christian Nordqvist