PD09-05 PHASE 2/3 CLINICAL RESULTS OF IL-15RΑFC SUPERAGONIST N-803 WITH BCG IN BCG-UNRESPONSIVE NON-MUSCLE INVASIVE BLADDER CANCER (NMIBC) CARCINOMA IN-SITU (CIS) PATIENTS.

Abstract

You have accessJournal of UrologyBladder Cancer: Non-invasive I (PD09)1 Sep 2021PD09-05 PHASE 2/3 CLINICAL RESULTS OF IL-15RΑFC SUPERAGONIST N-803 WITH BCG IN BCG-UNRESPONSIVE NON-MUSCLE INVASIVE BLADDER CANCER (NMIBC) CARCINOMA IN-SITU (CIS) PATIENTS. Karim Chamie, Sam Chang, Mark Gonzalgo, Eugene Kramolowski, Sandeep Reddy, Paul Bhar, Patrick Soon-Shiong, and Chad Garner Karim ChamieKarim Chamie More articles by this author , Sam ChangSam Chang More articles by this author , Mark GonzalgoMark Gonzalgo More articles by this author , Eugene KramolowskiEugene Kramolowski More articles by this author , Sandeep ReddySandeep Reddy More articles by this author , Paul BharPaul Bhar More articles by this author , Patrick Soon-ShiongPatrick Soon-Shiong More articles by this author , and Chad GarnerChad Garner More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001977.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Patients with NMIBC CIS unresponsive to BCG have limited treatment options. N-803 (Anktiva) is an mutant IL-15-based immunostimulatory fusion protein complex (IL-15RαFc) that promotes proliferation and activation of natural killer (NK) cells and CD8+ T cells, but not regulatory T cells. Phase 1b data in BCG-naïve patients with NMIBC demonstrate that intravesical administration of N-803 with BCG induced complete response in all patients, without recurrences for the study duration of 24 months. An open-label, 3 cohort multicenter Phase 2/3 study (QUILT 3.032) of intravesical BCG plus N-803 in patients with BCG-unresponsive high-grade NMIBC (NCT03022825) was opened. We report here the interim analysis of Cohort A, BCG-unresponsive (CIS) [with or without Ta or T1 disease], as of December 2020 data cutoff. METHODS: All treated patients received intravesical N-803 plus BCG, consistent with the standard induction/maintenance treatment schedule. The primary endpoint for Cohort A of this phase 2/3 study is incidence of complete response (CR) of CIS at any time. RESULTS: To date, 80 patients have enrolled in cohort A of this phase 2/3 trial. Evaluable analysis at this time shows CR rate at any time of 72% (N=51/71); for patients achieving CR, the probability of maintaining a CR for 12 months is 59%, with a median duration of complete response of 19.2 (7.6, 26.4) months. Low grade treatment related AEs include dysuria, hematuria, and pollakiurua (all 16%), urgency (14%), and bladder spasm (8%), all other AEs were seen at 6% or less. A total of 9 subjects experienced at least 1 treatment emergent SAE (Severe Adverse event), the SAE rate is 1% for any given AE. No treatment emergent SAE’s were considered treatment related. No immune related SAE’s have been seen. To date, 10/80 (12.5%) patients proceeded to cystectomy in this BCG unresponsive population. Updated data on all 80 subjects will be presented at AUA. CONCLUSIONS: With a CR rate of 72%, N-803 has met its primary endpoint with 59% probability of CR patients maintaining CR for at least 12 months. With the observed strong efficacy and an SAE rate of 1%, N-803 represents a novel treatment option for BCG unresponsive CIS with a favorable benefit:risk ratio, in a therapeutically challenging disease. Source of Funding: ImmunityBio © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e120-e121 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Karim Chamie More articles by this author Sam Chang More articles by this author Mark Gonzalgo More articles by this author Eugene Kramolowski More articles by this author Sandeep Reddy More articles by this author Paul Bhar More articles by this author Patrick Soon-Shiong More articles by this author Chad Garner More articles by this author Expand All Advertisement Loading ...