A dose-escalation-study according ICH/GCP (International Conference on Harmonisation/Good Clinical Practice) with different concentrations of abnobaVISCUM® Fraxini is conducted in two hospitals in Germany and Egypt. Patients with superficial bladder cancer TaG1/G2 or T1G1/G2 are enclosed after TUR-B (transurethral resection bladder). The tolerability of the different concentrations is assessed after weekly instillations into the urinary bladder for 6 weeks. A direct antitumoral effect is assessed on a single marker tumor left in the bladder after a complete TUR of all other lesions according a study design established by the EORTC-GENITO-URINARY GROUP (European Organisation for Research and Treatment of Cancer). A re-TUR is conducted after 12 weeks. Tumor response is measured by biopsy of the marker lesion and by cytology. Safety of the instillations is measured by analysis of adverse events, vital signs and clinical laboratory tests. After treatment of a cohort is finished a safety evaluation is conducted to decide about the increase to the next dosage.