Bropirimine (U-54461S) late phase II clinical study for carcinoma in situ of the bladder. Japan Bropirimine Study Group]

Late Phase II clinical study with bropirimine (U-54461S), a novel oral antitumor agent that has interferon inducing and anti-proliferative activities, was conducted in patients with bladder CIS at 38 institutions nationwide. To investigate the efficacy and safety of the treatment, bropirimine was administered to the patients at the dose of 750 mg every two hours, three times a day, for three consecutive days with four-day drug withdrawal, based on the results of the preceding clinical studies up to early phase II. Among the 48 patients registered, 41 patients were evaluable for antitumor efficacy. Complete response (CR) was observed in 17 of them, no change (NC) in 18 patients, and progressive disease (PD) in 6 patients; so the efficacy rate was 41.5%. Classified by patient background, the efficacy rates were 58.3% (7/12) in patients with primary bladder CIS, 34.5% (10/29) in those with secondary bladder CIS, 45.5% (10/22) in those with Grade 3, and 23.8% (5/21) in those previously given chemotherapeutic agents or BCG by intravesical or other routes. Adverse drug reactions frequently observed were influenza-like symptoms such as fever and generalized malaise and gastrointestinal symptoms like anorexia and nausea/vomiting; these symptoms were all Grade 2 or milder. Abnormalities in laboratory tests, such as an elevation in GOT/GPT, neutropenia, and leukopenia were observed. These adverse effects were all tolerated by the patients. From the above results, bropirimine was considered to be a useful oral agent for the treatment of bladder CIS.