Interim safety and tolerability of TARA-002 in patients with BCG-naïve and unresponsive high-grade non-muscle invasive bladder cancer in ADVANCED-2.

776 Background: There continues to be a significant unmet need for safe, effective, and bladder sparing treatment options for patients with non-muscle invasive bladder cancer (NMIBC). TARA-002 is a lyophilized biological preparation for intravesical instillation containing inactivated cells of Streptococcus pyogenes (Group A, type 3) Su strain. TARA-002 rapidly enters cancer cells, activating TLR2 and NOD2 to trigger innate immunity, inflammation, and potential immunogenic cell death. ADVANCED-2 (NCT05951179) is an ongoing Phase 2, open-label study to evaluate the safety and efficacy of intravesical TARA-002 in adults ≥ 18 years with high-grade (HG)-NMIBC CIS (± Ta/T1). Preliminary results showed promising complete response (CR) rates and durable responses in patients with HG NMIBC treated with TARA-002 (Jayram et al. AUA 2025). This abstract presents pooled safety data of TARA-002 from the BCG-naïve cohort and BCG-unresponsive cohort of the ADVANCED-2 study. Methods: The ADVANCED-2 study includes 2 cohorts of BCG-naïve (Cohort A) and BCG-unresponsive (Cohort B) participants. Key exclusion criteria include penicillin allergy; history of ≥ T2 bladder cancer, nodal, or metastatic disease; and concomitant prostatic or upper tract urothelial involvement. Each participant is treated with TARA-002 to receive induction (6 weekly doses), reinduction (if persistent disease at 3 months), and maintenance (through 24 months). Response is assessed every 3 months for 2 years. Long-term follow-up is conducted up to 60 months. Safety is monitored throughout the study. Results: As of 07-October-2025, 60 participants (median age: 74; range: 45 to 92), have been enrolled and exposed to TARA-002: 31 BCG-naïve (Cohort A) and 29 BCG-unresponsive (Cohort B). In both cohorts, 18/60 (30.0 %) participants reported drug-related treatment emergent adverse events (TEAEs). Related TEAEs were Grade 1 (18/60; 30.0%) and Grade 2 (3/60; 5.0%), with no reported Grade 3-5 related TEAEs. Commonly reported related TEAEs (≥ 5%) included bladder spasm (10.0%), dysuria (13.3%), fatigue (6.7%), and micturition urgency (6.7%). Most TEAEs were mild and transient. In both cohorts, 10/60 (16.7%) experienced serious AEs (SAEs); 4/60 (6.7%) were Grade 2 and 9/60 (15.0%) were Grade 3. No participants experienced drug-related SAEs or drug-related TEAEs leading to withdrawal or death. Conclusions: TARA-002 monotherapy was well tolerated, thus demonstrating a favorable tolerability profile to date for the treatment of BCG-naïve and BCG-unresponsive HG NMIBC with CIS (±Ta/T1). TARA-002 has a promising safety profile as a bladder-sparing treatment in HG NMIBC across BCG exposure status. Updated safety data will be provided based on evaluable time points at the time of the presentation. Clinical trial information: NCT05951179 .