Clinical response to targeted radionuclide therapy with multiple 500 mCi doses of 111 In-pentetreotide in patients with progressive neuroendocrine tumors

• Published in: Journal of clinical oncology Vol. 25; no. 18_suppl; p. 14027
• Main Authors: Delpassand, E. S., Sims-Mourtada, J., Azhdarinia, A., Ashoori, F., Sureshbabu, W., Hernandez, J., Torabi, F., Espenan, G., Woltering, E. A., Anthony, L. B.
• Format: Journal Article
• Language: English
• Published: 20.06.2007
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2007.25.18_suppl.14027

Abstract only 14027 Background: Patients with advanced stage neuroendocrine tumors have limited therapeutic options. Previous treatments with doses up to 360 mCi per fraction have shown promising results in stabilizing progressive disease. The intent of this study was to evaluate the efficacy and safety of 2 consecutive 500 mCi doses of 111 In-pentetreotide in patients with progressive neuroendocrine tumors. This study was performed according to an FDA approved IND application. Methods: In a non-randomized study, 18 patients (13 men, 5 women) with an average age of 59 (ranging from 41–83 yr.) received 2 cycles of 500 mCi 111 In-pentetreotide infused over 3 to 6 hours (avg. cumulative dose range: 955–1006.1 mCi). All patients had progressive neuroendocrine tumors and failed first line therapy. All patients had grade 3 to 5 uptake in the tumors in the pre-therapy diagnostic 111 In-pentetreotide scan. The primary endpoint was clinical, metabolic and imaging response using RECIST criteria. Early and long term hematological, renal and hepatic toxicities during the average follow up period of 9.87 months (range 3.93 to 17.23 months) was performed using NCI Common Toxicities criteria. Results: Sixteen out of 18 patients with previously progressive disseminated neuroendocrine disease achieved stable disease by imaging criteria. Metabolic response defined as 25% or more decline in Chromogranin or other markers was achieved in 72% of the patients. Clinical response defined by Functional Living Index (FLI) questionnaire and physical exam was achieved in 84% of the patients. Ten patients (55%) had grade I or II hematological toxicities, one patient had grade III thrombocytopenia, with nadir mean of 5 weeks after therapy. None of the patients required supportive therapy. Duration of hematological toxicities ranged from 1–6 weeks). One patient had grade II liver toxicity which appeared 4 weeks after therapy and resolved on week 5. No renal toxicity was observed during the follow-up period. Conclusions: Multiple 500 mCi doses of 111 In-pentetreotide therapy are effective in patients with progressive disseminated neuroendocrine tumors. Safety profile of this regimen suggests the opportunity for non-myeloablative dose escalation. No significant financial relationships to disclose.