The GDFATHER-NEO study was an exploratory, stratified, placebo-controlled, single-blinded, nonrandomized phase 2a trial that enrolled 31 patients with newly diagnosed muscle-invasive bladder cancer (MIBC). Patients were cisplatin-ineligible or had refused cisplatin; clinical staging was T2–T4aN0M0. The study team stratified participants by tumour stage and PD-L1 combined positive score (CPS) and then allocated them sequentially into the two treatment arms. The trial design and patient selection focused on a population that often lacks cisplatin-based neoadjuvant options and therefore represents an important clinical subgroup for immunotherapy investigation.
Participants received three cycles of neoadjuvant nivolumab at 480 mg every four weeks together with either the GDF-15 neutralizing antibody visugromab (20 mg kg−1 every four weeks) or placebo. The protocol specified definitive local therapy after neoadjuvant treatment: patients underwent radical cystectomy or repeat transurethral resection of the bladder tumour based on clinical decision-making. The source reported these dosing schedules and the sequential allocation but did not provide additional details on dose modifications, pharmacokinetics, or long-term adjuvant strategies within the published abstract.
Dual primary endpoints were locally assessed pathologic complete response (pCR, defined as ypT0N0/x) and radiographic response per RECIST v1.1. The cohort treated with nivolumab plus visugromab achieved a pCR rate of 33% (5 of 15; 95% CI 12–62%). By comparison, the nivolumab plus placebo arm had a pCR of 8% (1 of 13; 95% CI 0–36%). The study team also reported major pathologic response rates of 60% (95% CI 32–84%) with the combination versus 23% (95% CI 5–54%) with placebo. These pathologic outcomes were presented as locally assessed; centralized pathology review or longer-term pathologic validation were not described in the abstract.
Radiographic overall response rate favored the visugromab-containing arm: 60% (95% CI 32–84%) versus 15% (95% CI 2–45%) in the placebo arm. The investigators examined baseline immune parameters and found that responses to nivolumab plus visugromab were associated with higher baseline densities of total and proliferating (Ki-67+) CD8+ T cells. The source stated that these associations were independent of PD-L1 CPS and baseline GDF-15 levels measured in serum and tumour tissue. The abstract did not report specific numeric thresholds for those immune biomarkers, nor did it provide detailed longitudinal immune monitoring data beyond these baseline associations.
No treatment-related discontinuations occurred, and there were no treatment-related delays to definitive surgery reported in the abstract. Grade 3–4 treatment-related adverse events (TRAEs) were reported in two patients (13%) in the nivolumab plus visugromab arm and in three patients (20%) in the nivolumab plus placebo arm. The published report did not list individual TRAE types or durations in the abstract; likewise, there were no details provided about immune-related adverse event management strategies or late toxicity surveillance. Overall, the study team reported that the neoadjuvant regimens were feasible in this cisplatin-ineligible/refusing population.
The trial was exploratory, nonrandomized and single-blinded, and enrolled a small number of patients (31 total). These design features limit definitive efficacy comparisons and the generalizability of the observed differences in pCR, major pathologic response and radiographic response. The abstract did not report long-term survival or disease-free survival outcomes, and it provided limited granular safety and biomarker thresholds; centralized pathology and extended follow-up were not described in the source. The authors noted that the findings support further evaluation of visugromab in MIBC and referenced ClinicalTrials.gov identifier NCT06059547 for the trial. Subsequent randomized studies, larger cohorts, and more complete biomarker and survival reporting will be required to confirm these early signals and to define a clinical role for GDF-15 blockade in the perioperative management of MIBC.