A Prospective, Multi-Center, Phase 4, Single Arm Study To Assess The Safety and Tolerability of Perioperative Durvalumab in Combination With Neoadjuvant Gemcitabine Plus Cisplatin in Indian Patients With Muscle-Invasive Bladder Cancer Cle-Invasive

• * Participant must be ≥18 years of age inclusive.
• * Patients with histologically or cytologically documented muscle-invasive TCC (also known as UC) of the bladder.
• * Patients with transitional cell and mixed transitional/non-transitional cell histologies.
• * Patients with clinical tumour stage T2-T4aN0/1M0.
• * Medically fit for treatment with neoadjuvant therapy prior to radical cystectomy.
• * Medically fit to undergo a radical cystectomy at time of enrolment.
• * Have not received prior systemic chemotherapy or immunotherapy for treatment of MIBC.
• * Body weight >30 kg.
• * Male participants must use a condom plus an additional contraceptive method.
• * Female participants must be postmenopausal or have evidence of nonchildbearing status.
• * Capable of giving signed informed consent.
• * Must have a life expectancy of at least 12 weeks at Enrollement.
• * Adequate bone marrow function (Haemoglobin ≥ 9.0 g/dL, Absolute neutrophil count ≥ 1.5 × 10\^9/L, Platelet count ≥100 x 10\^9/L).
• * Adequate renal function (Creatinine clearance (CrCL) > 40 mL/min).
• * Adequate hepatic function (Total bilirubin ≤ 1.5 × ULN, AST and ALT ≤2.5 x ULN).

Exclusion Criteria:

• * Evidence of lymph node (N2-3) or metastatic TCC/UC (M1), extravesical TCC/UC (T4b), or primary non-bladder TCC/UC.
• * Any unresolved toxicity Grade ≥2 from previous anticancer therapy except for alopecia, vitiligo, and specified laboratory values.
• * Major surgical procedure within 2 weeks of starting study treatment.
• * Requirement for a nephroureterectomy at the time of enrollement for tumour of the mid ureter, renal pelvis, or collecting system.
• * Inoperable tumour(s) with fixation to the pelvic wall on clinical exam.
• * History of allogeneic organ transplantation that requires use of immunosuppressive agents.
• * Active or previously documented autoimmune or inflammatory disorders.
• * Uncontrolled intercurrent illness.
• * History of another primary malignancy, with exceptions.
• * Resting ECG indicating uncontrolled, potentially reversible cardiac conditions.
• * History of active primary immunodeficiency.
• * History of a myocardial infarction within 6 months prior to enrollement.
• * Any clinically significant systemic disease or medical condition that could interfere with the study.
• * Any clinically significant systemic disease or medical condition that could interfere with the study.
• * HIV positive.
• * Any medical contraindication to platinum (Cisplatin)-based doublet chemotherapy.
• * Concurrent chemotherapy, IMP, biologic, or hormonal therapy for cancer treatment.
• * Prior exposure to immune-mediated therapy (with exclusion of BCG).
• * Current or prior use of immunosuppressive medication within 14 days before the first dose of Durvalumab, with exceptions.
• * Prior pelvic radiotherapy treatment within 2 years of enrollement to study.
• * Receipt of live attenuated vaccine within 30 days before the first dose of study treatment.
• * Concomitant use of known strong or moderate CYP3A inhibitors.
• * Concomitant use of known strong or moderate CYP3A inducers.
• * Participation in another clinical study with a study intervention administered in the last 30 days.
• * Involvement in the planning and/or conduct of the study.
• * Involvement in the planning and/or conduct of the study.
• * For females only - currently pregnant or breastfeeding.