Background: Neoadjuvant chemotherapy (NACT) is a well-established treatment modality in MIBC but suffers from limited activity and significant toxicity. Neoadjuvant immunotherapy (I/O) demonstrated clinical safety and efficacy in various solid tumors including MIBC, with potentially less toxicity. Results from previous studies of single-agent I/O indicated a proportion of pathologic complete responses (ypT0N0) similar to that reported with NACT. Therefore, improving ypT0N0 responses remains a major task for treatment of MIBC. Increasing evidence emerged that Growth and Differentiation Factor 15 (GDF-15) plays a critical local immunosuppressive role. Apart from blocking immune-cell entry into tissues GDF-15 also has major impact on the formation of the immune synapse. Many tumors overexpress GDF-15 and have hijacked this mechanism to block I/O therapy success. Various translational research efforts indicated that GDF-15 may play a significant role for immunosuppression and T-cell exclusion in urothelial carcinoma (UC). Visugromab (CTL-002) is a GDF-15 neutralizing IgG4 monoclonal antibody that demonstrated in Phase 1 a favorable safety profile and promising clinical activity with durable and deep responses in PD-1/PD-L1 relapsed/refractory metastatic solid tumors in combination with the anti-PD1 antibody Nivolumab (Nivo)*. The Neo-GDFather trial is intended to investigate the combination of Visugromab with Nivo vs. Nivo monotherapy as neoadjuvant therapy for MIBC in patients (pts) who are ineligible for or elect not to undergo NACT. Primary endpoints are the complete pathologic response rate and radiologic response. Methods: Multi-center, parallel-cohorts and single-blinded Phase 2 study of neoadjuvant therapy in pts planned for radical cystectomy (RC). A total number of 30 subjects with stage T2-T4N0M0 MIBC will be enrolled and assigned 1:1 to receive either Nivo + Visugromab or Nivo + Placebo after stratification for CPS PD-L1 expression and cT-stage. Other inclusion criteria comprise an ECOG performance status 0-1 and a pure/predominant UC histology. No statistical assumptions were undertaken at this stage.Treatment consists of three 4-week cycles [i.v., Q4Wk], and RC is planned 4-8 weeks after last dose of study drug. After RC, pts will follow standard recommendations of EAU guidelines. Primary endpoints are the proportion of ypT0N0 response and radiologic response rate. Secondary endpoints comprise additional efficacy parameter, surgical and medical safety, PK and PD assessments. Translational research includes evaluation of immunologic parameters in the tumor, other immune-correlates and molecular profiles, as well as evaluation of treatment-emergent cytokine and chemokine profiles in peripheral blood. * Melero et al., #2501 ASCO Annual Meeting 2023 Oral Abstract Session. Clinical trial information: Not yet available.