Objectives: This study was designed to assess the pharmacokinetics, safety, and antitumor activity of intravesically administered AD 32, a novel anthracycline, in patients with transitional cell carcinoma (TCC) of the bladder.
Methods: Six weekly doses of AD 32 (200 to 900 mg) were administered to 32 patients with superficial TCC who were candidates for intravesical treatment. Serum drug levels were measured during the 6-hour period after administration of the first, third, and sixth doses. Patients underwent bladder evaluations at 3-month intervals to determine responses to treatment.
Results: Very low levels of unmetabolized AD 32 and its two primary metabolites were measured in serum. The lack of systemic exposure was confirmed by the finding of only a few minor systemic adverse events. Local bladder irritation, the main toxicity associated with intravesical administration of AD 32, persisted for several days after each instillation. The maximum tolerated dose was 800 mg. Thirteen patients had complete responses to treatment, including 8 who remained disease free for 12.1 to 38.5 months.
Conclusions: AD 32 is an active drug for the treatment of superficial bladder cancer. Further studies of intravesical administration of AD 32 are warranted.