(UroToday.com) The 2026 American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting, held in Chicago, IL, will host the Kidney and Bladder Cancer - Posters. Dr. Zhisong He will present Abstract 4626: Updated efficacy and safety of SHR-1501, an IL-15RaFc superagonist, with or without BCG for high-risk non-muscle invasive bladder cancer (NMIBC): A phase 1/2 study.
SHR-1501 is an IL-15 agonist fusion protein composed of a humanized antibody Fc region fused with IL-15 and the IL-15Rα sushi domain. Prior results presented at ASCO 2025 showed promising efficacy, good tolerability, and an acceptable safety profile with SHR-1501, either alone or in combination with BCG, in patients with BCG-naïve and BCG-unresponsive high-risk NMIBC. In this updated analysis, they reported additional results from the ongoing phase 1/2 study (NCT05410730).
The study included dose-escalation phase 1a and 1b cohorts evaluating SHR-1501 monotherapy or SHR-1501 plus BCG, followed by a phase 2 expansion enrolling three distinct patient populations:
- Cohort A: BCG-naïve NMIBC
- Cohort B: BCG-unresponsive CIS
- Cohort C: BCG-unresponsive high-grade Ta/T1 disease without CIS
Patients received SHR-1501 600 μg plus BCG 120 mg during a 6-week induction phase, followed by maintenance therapy administered weekly for three weeks at months 3, 6, 12, 18, and 24.
As of October 31, 2025, a total of 112 patients had been enrolled, including 30 patients in cohort A, 25 in cohort B, and 43 in cohort C during the phase 2 portion. Median follow-up was 23.0 months in BCG-naïve patients, 6.5 months in BCG-unresponsive CIS, and 13.5 months in patients with BCG-unresponsive high-grade Ta/T1 disease without CIS.
Among patients with BCG-unresponsive CIS (cohort B), the complete response rate was 80.0% (20/25), with a median DFS of 12.0 months (95% CI 6.0–NR).
In the BCG-naïve cohort, the 12-month DFS rate reached 90.3% (95% CI 72.8–96.8), which remained stable at 18 months. In patients with BCG-unresponsive high-grade Ta/T1 disease without CIS, the 12-month DFS rate was 62.7% (95% CI 44.9–76.1), while the 18-month DFS rate was 58.2% (95% CI 39.6–72.9).
Treatment-related adverse events occurred in 86.5% of patients treated with SHR-1501 plus BCG, with grade 3 TRAEs reported in 18.3%. The most common adverse events included urinary tract infection (62.5%) and pollakiuria (35.6%). Importantly, no treatment-related deaths were observed.
Key Messages:
- SHR-1501 demonstrated promising efficacy both as monotherapy and in combination with BCG in patients with BCG-naïve and BCG-unresponsive high-risk NMIBC
- An 80% complete response rate was observed in patients with BCG-unresponsive CIS
- Durable DFS outcomes were observed in both BCG-naïve and BCG-unresponsive papillary disease cohorts
- The safety profile remained manageable, with no treatment-related deaths reported
- Two randomized phase 3 trials evaluating SHR-1501 plus BCG are currently ongoing in both BCG-naïve and BCG-unresponsive high-risk NMIBC populations
Presented by: Zhisong He, MD, Chief Physician, First Hospital of Peking University, Beijing, China
Written by: Julian Chavarriaga, MD, Clinical Assistant Professor, Urologic Oncologist, Department of Urology at Penn State Health @chavarriagaj on X during the American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting held in Chicago, IL between May 29th and June 1st, 2026