Lymphoseek Approval Expanded to Pediatric Patients

The approval was based on data from a phase 2 trial that assessed Lymphoseek in pediatric patients with melanoma, RMS, or other solid tumors.

The Food and Drug Administration (FDA) has approved Lymphoseek® (technetium Tc 99m tilmanocept) injection for lymphatic mapping using a handheld gamma counter to locate lymph nodes draining a primary tumor site in pediatric patients age 1 month and older with solid tumors for which this procedure is a component of intraoperative management. Previously, the radioactive diagnostic agent was only approved for adults 18 years of age and older.

The approval was based on data from an open-label, multicenter, single arm phase 2 trial ( Identifier: NCT02509598) that assessed the efficacy and safety of Lymphoseek in pediatric patients with melanoma, rhabdomyosarcoma (RMS), or other solid tumors. Among 23 patients who received Lymphoseek, 5 (22%) had melanoma, 4 (17%) had RMS, 12 (52%) had non-RMS soft tissue sarcomas, and 2 (9%) had atypical Spitz nevi. The mean age of the patients was 11.6 years (range, 1.7-17 years) and 65% were female.

Results showed an overall rate of lymph node detection (defined as at least 1 lymph node detected) of 96% (22/23). The average number of lymph nodes detected was approximately 3 per patient. No differences in safety were identified between pediatric patients and older patients; the most common adverse reactions reported with Lymphoseek included injection site irritation and/or pain.

“This new indication opens the door for physicians, oncologists and nuclear medicine specialists to more accurately stage the spread of disease using lymphatic mapping in pediatric cancer patients,” said Tiffany Olson, President of Nuclear & Precision Health Solutions at Cardinal Health. “Ultimately, this may help more families to be able to get answers to some of their most concerning questions.”

Lymphoseek is available as a kit containing 5 multiple dose vials; each vial consists of 250mcg of tilmanocept powder.


  1. Cardinal Health™ Nuclear & Precision Health Solutions receives U.S. Food and Drug Administration approval for new Lymphoseek® pediatric indication. [press release]. Dublin, Ohio: Cardinal Health; June 10, 2021.
  2. Lymphoseek® [package insert]. Dublin, Ohio: Cardinal Health; 2021.