Inclusion Criteria:

• Patient with histologically confirmed or suspected (based on cystoscopy) initial presentation or recurrence of Stage Ta, T1, or Tis transitional cell bladder cancer of any histological grade requiring TURBT.
• Patient believed to be a candidate for immediate post-operative chemotherapy regardless of the need for additional intravesical therapy.
• ECOG performance status of Grade 0 or 1.
• Age ≥ 18 years.
• A negative urine or serum pregnancy test (if female of child-bearing potential) within 14 days prior to Day 1/Week 1.
• Acceptable liver function within 14 days prior to Day 1/Week 1 defined as:
• Total bilirubin ≤ 1.5 times upper limit of normal (ULN), and
• AST (SGOT), ALT (SGPT), and alkaline phosphatase ≤ 2.5 times ULN.
• Acceptable renal function within 14 days prior to Day 1/Week 1 defined as serum creatinine ≤ 1.5 x ULN.
• Acceptable hematologic status within 14 days prior to Day 1/Week 1 defined as:
• Absolute neutrophil count (ANC) ≥ 1,500/dL,
• Platelet count ≥ 100,000/dL, and
• Hemoglobin ≥ 10.0 g/dL.
• Urinalysis showing no clinically significant abnormalities, except those attributable to bladder cancer.
• For men and women of child-producing potential, agreement to use an effective contraceptive method during the study from enrollment until 2 weeks after the administration of study drug.
• Signed, written, IRB-approved informed consent.

Exclusion Criteria:

• Large resected area (estimated total area > 50 cm²) or suspected deep resection, even in the absence of signs of perforation beyond the muscularis propria or ongoing significant bleeding.
• Known or suspected bladder perforation during TURBT.
• Failure to completely resect all cancerous lesions or suspected presence of muscle-invasive cancer (Stage T2 or higher).
• Previous diagnosis or current presence of bladder fibrosis/contracture, or total bladder capacity estimated at cystoscopy or by other means to be < 150 mL.
• Urinary incontinence or severe irritative voiding symptoms such as urgency, frequency, or nocturia of a severity that would compromise the ability of the patient to retain the study drug intravesical instillation for one hour.
• Bladder cancer recurrence less than 3 months after a previous TURBT.
• Major surgery, other than TURBT or diagnostic surgery, within 28 days prior to Day 1/Week 1.
• Known active, uncontrolled bacterial, viral, or fungal infections, including urinary tract infection.
• Any intravesical therapy within 3 months prior to Week 1/Day 1.
• Systemic therapy including radiation therapy, surgery, chemotherapy, or investigational therapy within one month prior to Day 1/Week 1 (two months for nitrosoureas or MMC), unless given as standard treatment for bladder cancer and provided that patient is free of all treatment-related toxicities as of Day 1/Week 1.
• Known infection with HIV.
• Known active infection with hepatitis B or hepatitis C virus.
• Serious disease (e.g., hydronephrosis, liver failure, or other conditions) that could compromise protocol objectives in the opinion of the Investigator and/or the Sponsor (Halozyme).
• History of hypersensitivity or idiosyncratic reaction to, or other contraindication to, MMC.
• Known allergy to bee or vespid venom.
• Known coagulation disorder or bleeding tendency.
• Ongoing treatment with heparin or other anticoagulation therapy, or anticipation of such therapy during the treatment period in this study.
• Unwillingness or inability to comply with procedures required in this protocol.