Participants will receive MMC intravesically.

Participants will receive gemcitabine intravesically.

TTDW is measured as the time from randomization to cystectomy, systemic therapy, or radiation therapy (treatments of disease worsening).

TTP will be measured as the time from randomization to the time of first documented evidence of disease progression (that is, progression to muscle-invasive bladder cancer [MIBC] [T greater than or equal to {>=} 2], lymph node disease [N+], or distant disease [M+]), or death due to disease progression, whichever occurs first.

OS is defined as the time from randomization to death, due to any cause.

DFS rate that is percentage of participants with DFS at 12 and 24 months will be reported.

Number of participants with AEs by severity grade as assessed by CTCAE version 5 will be reported. Grade refers to the severity of AE as follows: Grade 1- Mild; Grade 2- Moderate; Grade 3- Severe; Grade 4- Life-threatening; Grade 5- Death related to adverse event.

Number of participants with change from baseline in laboratory abnormalities (including hematology, clinical chemistry and routine urinalysis) will be reported.

Number of participants with change from baseline in vital signs including temperature, pulse/heart rate, respiratory rate, and blood pressure (systolic and diastolic) (supine) will be reported.

EORTC QLQ-C30 is a 30-item questionnaire for evaluating the health-related quality of life (HRQoL) of participants participating in cancer clinical studies. It includes 5 functional scales (physical, role, cognitive, emotional, and social), 3 symptom scales (fatigue, pain, and nausea or vomiting), and a global health status or HRQoL scale. Ratings for each item range from 1 (not at all) to 4 (very much).

EORTC QLQ-NMIBC24 is a 24-item questionnaire for evaluating the HRQoL of participants with NMIBC. The questionnaire is designed to supplement the QLQ-C30 and incorporates 6 multi-item scales (urinary symptoms, malaise, future worries, bloating and flatulence, sexual function and male sexual problems) and 5 single items (intravesical treatment issues, sexual intimacy, worries about risk of contaminating partner, sexual enjoyment, and female sexual problems). Ratings for each item range from 1 (not at all) to 4 (very much).

Proportion of participants with meaningful change in EORTC QLQ-C30 and EORTC QLQ-NMIBC24 scores will be reported.