Lymphoseek® Technically Successful in Evaluation of Sentinel Lymph Node Biopsy in Patients Undergoing Neoadjuvant Chemotherapy

Navidea Biopharmaceuticals, Inc. (NYSE MKT: NAVB) today announced that results from an investigator-initiated retrospective analysis demonstrated Lymphoseek® (technetium Tc 99m tilmanocept) injection was successful in lymph node identification rate, node-positivity rate, and number of total nodes evaluated in sentinel lymph node biopsy (SLNB) procedures in clinically node-negative breast cancer patients undergoing neoadjuvant chemotherapy (NAT) compared to patients undergoing initial surgical treatment. These findings suggest that Lymphoseek offers breast surgeons the confidence to specifically identify and remove sentinel lymph nodes in this patient population. Results of the study conducted at the University of California, San Diego, School of Medicine, led by Anne Wallace M.D., professor of surgery, and Jonathan Unkart, M.D., Department of Surgery, UC San Diego Health, were presented today at the San Antonio Breast Cancer Conference in San Antonio, Texas. "Prior thinking suggests that neoadjuvant chemotherapy may induce fibrosis and inflammation that alters lymphatic drainage of axillary lymph nodes in breast cancer and may obscure lymphatic mapping procedures," said Dr. Wallace, who is also director of the Comprehensive Breast Health Center at UC San Diego Moores Cancer Center. "This analysis provides compelling evidence that Lymphoseek was successfully used for SLNB in the breast cancer neoadjuvant chemotherapy population and could potentially reduce the necessity for unnecessary and morbid axillary dissections, and improve the quality of life for patients. "One of the most frequently asked questions we encounter from physicians is on the effectiveness of Lymphoseek in NAT patients," commented Michael Tomblyn, M.D., Navidea's Chief Medical Officer. "These findings show Lymphoseek's usefulness in the complicated NAT population and that the outcomes are not different from the standard breast cancer population." The aim of the study was to compare identification rate, node-positivity rate and total number of nodes evaluated during SLNB with Lymphoseek and vital blue dye (VBD) in clinically node-negative patients receiving neoadjuvant endocrine or chemotherapy versus initial surgical treatment. A retrospective review of patients undergoing SLNB with Lymphoseek plus VBD from May 2013-2015 at UCSD was conducted. Of the 417 total sentinel lymph node (SLN) cases identified, 72 (17.2%) cases were in patients who had received NAT (61- chemo, 11- endocrine). The SLN identification rate was 100% in both groups (p=1.0). Overall, there were 68 (16.3%) cases of SLN-positivity, 14 (19.4%) in the NAT group versus 54 (15.7%) in the non-NAT group (p= 0.54). The median number of identified nodes was 3 in both groups. In the a zero-truncated negative binomial count model, age, surgeon and evaluating pathologist were significant predictors of the total number of SLNs evaluated. The use of NAT did not significantly affect the number SLNs evaluated.