GU Symposium 2021: Novel IL-15 Superagonist for Non–Muscle-Invasive Bladder Cancer
Posted: Monday, February 22, 2021
According to Karim Chamie, MD, of the University of California, Los Angeles, and colleagues, intravesical N-803 in combination with Bacillus Calmette-Guérin (BCG) therapy seemed to induce complete responses in the majority of patients with BCG-unresponsive, high-grade, non–muscle-invasive bladder cancer (carcinoma in situ). The interim results from cohort A of the multicenter phase II/III QUILT 3.032 study were presented during the virtual edition of the 2021 Genitourinary (GU) Cancers Symposium (Abstract 510).
“Patients with [BCG-unresponsive non–muscle-invasive bladder cancer, carcinoma in situ] have limited treatment options. N-803 is a mutant interleukin-15 (IL-15)–based immunostimulatory fusion protein complex that promotes [the] proliferation and activation of natural killer cells and CD8-positive T cells, but not regulatory T cells,” the investigators commented. “With the observed strong efficacy and a serious adverse event rate of 1%, N-803 represents a novel treatment option for BCG-unresponsive carcinoma in situ with a favorable benefit-to-risk ratio, in a therapeutically challenging disease.”
Cohort A comprised 80 patients with or without Ta or T1 disease; they were administered intravesical N-803 plus BCG therapy. At any time, the complete response rate was 72%; the probability of maintaining a complete response for 12 months was 59%. In this population, the median duration of complete response was 19.2 months.
Dysuria (16%), hematuria (16%), pollakiuria (16%), urgency (14%), and bladder spasm (8%) were among the most commonly reported low-grade treatment-related adverse events. Nine patients experienced at least one treatment-emergent serious adverse event. According to the investigators, no treatment-emergent serious adverse events were considered treatment-related. Immune-related serious adverse events were not reported in this cohort. A total of 12.5% of patients proceeded to cystectomy.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
