Purpose: Due to the high rate of recurrence and progression in patients with high risk nonmuscle invasive bladder cancer, there is an important unmet need to identify new therapies. This is particularly true for patients with recurrence after optimal intravesical bacillus Calmette-Guérin therapy, who are classified as having bacillus Calmette-Guérin unresponsive disease.
Materials and methods: The PubMed® database was searched for publications related to immunotherapy for the treatment of patients with nonmuscle invasive bladder cancer who have recurrent or progressive disease despite receiving intravesical bacillus Calmette-Guérin therapy. Relevant congress abstracts were identified through searches of individual congress websites. Relevant planned and ongoing studies were identified via ClinicalTrials.gov or associated web searches.
Results: We provide a summary of the currently available immunotherapy options for patients with bacillus Calmette-Guérin unresponsive nonmuscle invasive bladder cancer, and discuss planned and ongoing research of potential targeted agents and immunotherapy based combination regimens.
Conclusions: There is a clear biological and clinical rationale for the continued evaluation of immune based therapies in the setting of bacillus Calmette-Guérin unresponsive nonmuscle invasive bladder cancer. Data from early phase trials with novel immunotherapies targeting multiple immune related pathways have emerged, which support additional studies to assess the benefits of immune checkpoint inhibitors and other immunotherapy based regimens for patients with bacillus Calmette-Guérin unresponsive nonmuscle invasive bladder cancer.
Keywords: immunotherapy; mycobacterium bovis; recurrence; urinary bladder neoplasms.