(UroToday.com) The 2024 American Urological Association (AUA) Annual Meeting held in San Antonio, TX between May 3rd and 6th, 2024 was host to a non-invasive bladder cancer moderated poster session. Dr. Patrick Soon-Shiong presented updated results of the QUILT 3.032 trial of N-803 plus BCG in patients with BCG-unresponsive high-grade NMIBC (NCT03022825).
Patients with bacillus Calmette-Guerin (BCG)-unresponsive NMIBC have limited treatment options and are at an increased risk for requiring a cystectomy. N-803 (nogapendekin alfa inbakicept: ANKTIVA®), is an interleukin-15 superagonist (IL-15)], which synergizes with BCG to elicit durable complete responses (CRs) and has recently been FDA-approved for BCG-unresponsive NMIBC CIS, with or without papillary tumors.1
Dr. Patrick Soon-Shiong presented the interim results (data cutoff: November 30, 2023) of the open-label, three-cohort, multicenter phase 2/3 study QUILT 3032 (NCT03022825), reporting on the duration of response and complete response rate for 94 subjects with BCG-unresponsive CIS.
All treated patients received intravesical N-803 plus BCG, consistent with the standard induction/maintenance treatment schedule. ANKTIVA® 400 mcg was administered intravesically with BCG once a week for six weeks. A second induction course was permitted if a complete response was not achieved after three months. Cystoscopy and cytology were performed for drug administration every three months and follow-up per office practice. With regards to maintenance, following BCG and ANKTIVA induction therapy, ANKTIVA was recommended at a dose of 400 mcg administered intravesically with BCG once a week for 3 weeks at months 4, 7, 10, 13, and 19 (for a total of 15 doses). For patients with an ongoing complete response at month 25 and later, maintenance instillations were administered once a week for 3 weeks at months 25, 31, and 37 for a maximum of 9 additional instillations.
All CIS subjects had received prior BCG, with the median number of prior BCG doses received at 12 (range, 5 to 48 doses). The median time from the last prior BCG dose to the first documented CIS disease recurrence for these patients was 2.5 months. Forty-eight subjects had received additional prior therapy including chemotherapy and checkpoint therapy, in addition to prior BCG therapy.
In this highly pre-treated group, the complete response rate was 65%. Among subjects who had received ≥12 prior BCG doses (n=74), the complete response rate was 69%. Conversely, among those who received <12 doses of prior BCG, the complete response rate was 70%. A total of 53 patients were BCG-unresponsive/BCG-relapsed. The complete response rate in this group was 72%. Thus, both BCG-unresponsive/BCG-refractory and BCG-unresponsive/BCG-relapsed had complete response rates comparable to the efficacy population.
The median duration of response was 26.6 months (95% CI: 0.9 – not reached). By the Kaplan-Meier method, 61.3% of subjects had a duration of complete response lasting >12 months and 53.2% had a duration of >24 months.
Based on these results, Dr. Soon-Shiong concluded that the combination of ANKTIVA® + BCG in patients with BCG-unresponsive high-grade NMIBC demonstrates:
- Complete response rates of 70%, consistent across all evaluated subgroups
- 67% of patients who were chemotherapy and/or checkpoint and BCG unresponsive had a complete response with this combination
- Complete responses were durable with an estimated median of 45.4 months
- The adverse event profile was consistent with that observed with BCG alone
Presented by: Patrick Soon-Shiong, MD, Executive Chairman and Global Chief Scientific and Medical Officer of ImmunityBio, Inc, California
Written by: Rashid Sayyid, MD, MSc - Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2024 American Urological Association (AUA) Annual Meeting, San Antonio, TX, May 3rd - 6th, 2024
Related content:
The Triangle Offense: Harnessing NK Cells, T-Cells, and Memory Cells in Bladder Cancer - Patrick Soon-Shiong
New Bladder Cancer Treatment: Mechanisms, Clinical Findings, and Implications - Patrick Soon-Shiong
Addressing BCG Supply Shortages, Workflow, and Enhancing Bladder Cancer Treatment through Strategic Partnerships - Patrick Soon-Shiong