A pilot study of monoclonal antibody cG250 and low dose subcutaneous IL-2 in patients (pts) with advanced renal cell carcinoma (RCC)

2558 Background: The median survival of pts with metastatic RCC is 10 months. No therapy has been shown to improve the survival of these pts. cG250 is a chimeric monoclonal antibody (MoAb) that recognizes the CAIX/MN antigen. cG250 induces Ab-dependent cellular cytotoxicity (ADCC) responses in vitro that can be enhanced by IL-2. Our previous trial using cG250 alone showed it is safe, that tumor-specific targeting is high and that the T½ of cG250 in the circulation is long. We studied the effects of adding daily low-dose subcutaneous (sc) IL-2 to cG250 for treatment of clear cell RCC. Methods: The endpoints of the trial were toxicity; immunological effects (human anti-chimeric antibodies [HACA], ADCC, natural killer [NK] and lymphokine-activated killer cell [LAK] activity); cG250 biodistribution and pharmacokinetics (PK); and antitumor effects. Eligible pts had unresectable metastastic or locally advanced clear cell RCC with measurable or evaluable disease. Nine pts were treated as follows. cG250: 10 mg/m2...