NORTH-REG Dwell-Time Study

Inclusion Criteria: * ≥18 years of age at the time of signing the Informed Consent Form * Signed Informed Consent Form * Patients with NMIBC where BCG therapy including maintenance for 1 year is planned for one of the following histopathological findings: * Ta high grade without CIS * CIS with or without previous or concomitant Ta tumors * T1 with or without CIS * Is, according to the Investigator's judgement, able to comply with the trial protocol * Ability to understand the Patient Information Sheet orally and in writing Exclusion Criteria: * Previous BCG instillations within the last 2 years, because of the risk of not having cleared potential previos side effects. * T1 tumors where re-resection had not been performed * TUR-B, bladder biopsy or traumatic catheterization within 2 weeks. * Previous or current MIBC * Progression defined as progrssion to T1-tumour, T2+\_tumour or cystectomy irrespectievely of indication or development of metastatic urothelial cancer irrespectively of tumour stage * Contraindications to BCG * Incontinence * Bilateral nephrostomy catheters; unilateral nephrostomy catheter is allowed if permanent for the duration of all inistallations with BCG and a normally functioning kidney. * Need for catheter a demeure at the time of instillation * Immune Suppressing medication (cancer therapy e.g cytostatic medicinal products, radiation, local and systemic steroids like e.g. prednisolone is permitted) * Reduced immune response (leukaemia, lymphoma) * Known allergy or sensitivity to BCG * HIV infection * Signs of active tuberculosis * Any type of previosly radiation therapy involving the bladder. * Concomitant invasive cancer within 5 years other than non-melanoma skin cancer and protate cancer without metastasis * Current urinary tract infection * Patient with visible hematuria * Current alcohol and/or drug abuse * Has a mental or legal incapacitation or another condition which impair the subject's ability to participate * Has participated in another interventional clinical study and treatment with another investigational product 30 days prior to randomization * For women study subjects: Pregnancy or breastfeeding * For women Study subjects of childbearing potential: unless they are using highly effective methods of contraception from the first BCG instillations until 14 days after last dose of BCG treatment, which are defined as total abstinence, female sterilization, use of oral methods of contraception or placement of an intrauterine contraception devices. * For male Study Subjects: unless they are using highly effective methods of contraception from the first BCG instillation until for 14 days after last dose of BCG treatment, which is defined as total abstinence or use of condoms.