Mistletoe Plant Extract in Patients with Nonmuscle Invasive Bladder Cancer: Results of a Phase Ib/IIa Single Group Dose Escalation Study

Purpose: We determined the maximum tolerated dose, safety and effectiveness of intravesical instillation of mistletoe extract after transurethral resection of nonmuscle invasive bladder cancer.Materials and Methods: In this single group dose escalation study patients with nonmuscle invasive bladder cancer were treated with weekly instillations of mistletoe extract for 6 weeks. Four weeks before instillation therapy all patients underwent transurethral resection of bladder tumors. During this procedure a marker tumor was left. At 12 weeks after the start of instillation therapy transurethral resection of the marker tumor or biopsy of the former marker tumor location was done so that patients were tumor free when entering followup until week 48. During the followup clinical assessment laboratory tests for safety and cystoscopy were done every 12 weeks.Results: A total of 36 patients were treated with increasing doses of mistletoe extract. We found no dose limiting toxicity up to a dose of 675 mg of plant ex...