This study is an open-label dose escalation study (Phase 1a) to investigate the safety and toxicity of intravesical treatment of high-grade NMIBC (HGTa or CIS, including CIS with concomitant Ta) after transurethral resection of bladder tumor (TURBT) and/or biopsy using TARA-002 in adults unable to obtain intravesical Bacillus Calmette-Guérin (BCG), adults who have received at least one dose of intravesical BCG or adults who have received at least one dose of intravesical chemotherapy. Dosing will start in subjects with HGTa or CIS (including CIS with concomitant Ta), and all subjects will receive 6 weeks of treatment at a fixed volume with varying dose levels.

Inclusion Criteria:

• Male or female subjects 18 years of age or older at the time of signing the informed consent
• Subjects who have voluntarily given written informed consent after the nature of the study has been explained according to applicable requirements prior to study entry
• Subjects with a histologically confirmed, high-grade Ta or CIS (including CIS with concomitant Ta) urothelial cell carcinoma of the bladder on central review
• Subjects who are treatment naïve, are unable to obtain intravesical BCG for the treatment of NMIBC, have received at least one dose of intravesical BCG, or at least one dose of intravesical chemotherapy

Exclusion Criteria:

• Penicillin allergy (subjects with a questionable history of allergy to penicillin or no history of penicillin use will undergo penicillin blood allergy testing prior to inclusion in the study)
• Predominant (defined as > 50%) adenocarcinoma, squamous cell carcinoma, or histological variants including plasmacytoid, sarcomatoid, or squamous components according to central review
• Concomitant prostatic or upper tract urothelial involvement, per Investigator's assessment
• Nodal involvement or metastatic disease that existed at any time (past or present disease)
• Bladder cancer stage ≥ T1 within the last 36 months according to central histology review
• Bladder cancer stage CIS with concomitant T1

For more information on eligibility criteria, please contact the sponsor.