Navidea Biopharmaceuticals, Inc. announced that data from its Phase 3 clinical study investigating 99m-Tc-Tilmanocept (Lymphoseek®) in oral and squamous cell cancers (SCC) were presented as a poster presentation at the 65th Annual Cancer Symposium of the Society of Surgical Oncology (SSO) meeting held in Orlando, Florida, March 21-24, 2012. The data presented by investigator Stephen Y. Lai, M.D., Ph.D., FACS, of the University of Texas MD Anderson Cancer Center, describe the Center’s initial experience with Lymphoseek in Sentinel Lymph Node (SLN) mapping in nine patients with head and neck SCC (HNSCC).
Frederick O. Cope, Ph.D., FACN, Navidea’s Senior Vice President of Pharmaceutical Research and Clinical Development commented, “These data comprise the first presentation of Lymphoseek’s potential utility in oral cancers. The presentation by Dr. Lai suggests that Lymphoseek’s previously reported ability to accurately facilitate identification of primary draining nodes necessary to properly stage patients with breast cancer or melanoma may also apply in patients with HNSCC. We believe this is due to Lymphoseek’s rapid transit through lymphatic vessels and targeted binding to the mannose binding receptors (MBR) within key predictive nodes. The results in these nine patients demonstrated a false negative rate of zero, the same as obtained with full nodal dissection. However, using Lymphoseek, substantially fewer lymph nodes are removed than with full nodal dissection. This may enable surgeons to reduce the need for more extensive lymph node dissection, potentially sparing them from the morbidity and side effects of full nodal dissection while not sacrificing accuracy in the detection of key predictive lymph nodes identified by more aggressive full regional dissection.”
The ongoing trial (NEO3-06; NCT00911326) is a multicenter, open-label, non-randomized, single arm, within-group trial of Lymphoseek for the detection of tumor-draining Sentinel Lymph Nodes in subjects with known cutaneous or mucosal SCC of the head and neck. All subjects received a single dose of Lymphoseek. The presented data represent the findings from nine subjects who were injected, underwent surgery, and completed a 30-day follow up at MD Anderson. Most subjects were injected on the day prior to their surgical procedure. In the NEO3-06 trial, all subjects received the standard treatment of a full regional nodal dissection and the results of Lymphoseek-identified nodes were compared to pathology-positive nodes obtained from the full regional nodal dissection. In the nine subjects reported on by Dr. Lai, a total of 360 nodes were excised (22-55 non-SLNs identified per patient, median 39, average 40). The data show preoperative imaging with Lymphoseek provided accurate correlation of lymphatic drainage to tumor-involved anatomic regions and nodes, including SLNs contralateral to (opposite) the primary tumor. The 0% false negative rate (FNR) in this small initial cohort indicates that Lymphoseek accurately identifies those nodes with the highest probability of accurately reflecting the status of regional/cervical metastases (i.e., SLNs). There have been no significant adverse events related to the use of Lymphoseek.
“Patients with HNSCC may have more than one sentinel (or primary drainage) lymph node, and all of these lymph nodes need to be excised and evaluated in order to accurately stage and manage our patients,” said Dr. Lai. “Our initial clinical experience with Lymphoseek demonstrates the utility, diagnostic predictive value, and safety of 99m-Tc-Tilmanocept for both preoperative lymphoscintigraphy and intraoperative localization. The 100% agreement of Sentinel Lymph Node status with the pathology findings in the complete neck dissection supports the efficacy of both Lymphoseek and the Sentinel Lymph Node approach for the care of our patients.”
The results presented by Dr. Lai are interim results from his clinical site’s participation in NEO3-06 that may or may not be consistent with the complete data that will be available when the trial is completed, and the percentage agreement between the nodes identified by Lymphoseek and the pathology results from a complete neck dissection may decline upon analysis of the data from the completed trial.