Navidea wins expanded use of imaging agent Lymphoseek
This article was originally published in Scrip
An FDA approval generally is a high point for most companies. But Friday the 13th apparently had Navidea Biopharmaceuticals investors spooked.
Indeed, even though Navidea won the FDA's nod to expand the use of the company's receptor-targeted radiopharmaceutical agent Lymphoseek (tilmanocept) as the first and only sentinel lymph node (SLN) biopsy agent in the US for use in head and neck cancer patients with oral cavity carcinoma, the company's shares tumbled 17.3% in morning trading on 13 June.
The agent already was on the US market for use in lymphatic mapping procedures to locate lymph nodes in patients with breast cancer or melanoma who are undergoing surgery to remove tumor-draining lymph nodes – winning that approval in March 2013 (scripintelligence.com, 14 March 2014).
Lymphatic mapping is a procedure in which lymph nodes that may contain tumor metastases are identified and biopsied to determine if cancer has spread beyond the primary tumor.
Lymph nodes filter lymphatic fluid, which 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, doctors can sometimes determine if a cancer has spread.
Doctors inject Lymphoseek into the tumor area and later, using a handheld radiation detector, find the sentinel lymph nodes that have taken up the agent's radioactivity, explained Dr Libero Marzella, director of the FDA's Division of Medical Imaging Products.
While SLN mapping may be an effective alternative to elective neck dissection, adoption has been slowed in the US because of the lack of an FDA-approved agent with favorable characteristics for use in the head and neck region, said Dr Stephen Y Lai, an associate professor at the University of Texas MD Anderson Cancer Center.
"This underscores the urgent need Lymphoseek may be able to address in improving the precision of SLN mapping and decreasing nodal excision to an average of only four lymph nodes," Dr Lai said. "As a result, Lymphoseek offers the potential to more effectively stage certain cancers, direct post-surgical treatment and decrease patient morbidity."
Navidea also is seeking to expand the labeling of Lymphoseek further – asking the FDA to permit more flexible utilization practices for the agent in lymphatic mapping and lymphoscintigraphy imaging. The company is expecting to hear from the FDA by 16 October.