This is an open-label, randomized phase II trial comparing treatment with a monoclonal antibody (mAb) drug immunoconjugate, SGN-15, administered weekly in combination with weekly Gemzar® (Gemcitabine) to treatment with Gemzar® alone. The primary objectives of this study are to determine the toxicity and safety profile of the combination of SGN-15 and Gemzar®, to estimate the clinical response rate and to estimate the duration of response of this combination therapy administered to patients with advanced ovarian cancer, compared to treatment with Gemzar® alone.

Brief Overview of Inclusion Criteria:

• Patients must have pathologically confirmed ovarian cancer, which is advanced or recurrent carcinoma, who have failed at least two, but no more than three prior therapies for metastatic disease

• Patients must have > 20% Lewis-y antigen expression documented by immunohistochemistry

• LVEF > 50% by echo or MUGA

• Must be platinum resistant as defined by:

  • Progression while on initial platinum therapy or
  • Progression while on retreatment with initial platinum regimen or
  • Relapse < 6 months after initial therapy

Brief Overview of Exclusion Criteria:

• Patients who have had prior therapy with Gemzar®
• Cumulative anthracycline exposure > 300 mg/m2
• More than three prior chemotherapy regimens for ovarian cancer (Retreatment with Taxane/Platinum after initial combination is considered only one regimen)