Treatment Efficacy and Molecular Dynamics of Neoadjuvant Durvalumab and Olaparib in Resectable Urothelial Bladder Cancer: The NEODURVARIB Trial.

PURPOSE: Neoadjuvant treatment of bladder cancer is evolving, with immunotherapy demonstrating promising activity. PARP inhibition combined with immune activation has been proposed as a synergistic strategy. We conducted a comprehensive molecular characterization of tumors treated with this combination in the neoadjuvant setting to provide crucial results for rational development.

PATIENTS AND

METHODS

A phase II clinical trial was designed to evaluate the combination of anti-PDL1 inhibitor durvalumab and PARP inhibitor olaparib, focusing on biomarker dynamics in both pre- and post-treatment settings. A total of 29 patients were enrolled. Genomic and transcriptomic profiling, as well as analyses of immune cell populations, was conducted at baseline and at the time of cystectomy.

RESULTS

Of the 29 patients treated, a pathologic complete response was observed in 13 cases (44.8%). No major safety concerns were associated with the treatment, and 26 patients (90%) underwent cystectomy. Mutational patterns, tumor mutation burden, and homologous recombination deficiency remained stable throughout treatment and were not predictive of outcomes. However, a shift toward stromal phenotypes and increased expression of epithelial-mesenchymal transition signatures were observed following therapy, particularly in resistant tumors. Moreover, an increase in circulating CD4+ CD27- CD28- T cells was noted among responders.

CONCLUSIONS

The combination of neoadjuvant durvalumab and olaparib shows therapeutic activity in bladder cancer. Resistance mechanisms seem to be driven by transcriptional adaptations rather than the emergence of new mutations.