Immunogenomic Analysis of Exceptional Responder to ALT-803 (IL-15 Analogue) in BCG Unresponsive Nonmuscle Invasive Bladder Cancer: A Case Series and Review of the Literature

The clinical validity and utility of complex biomarkers have not been extensively studied in bladder cancer. Three patients with nonmuscle invasive bladder cancer [1 patient with an exceptional response; complete response (CR) for 30 months] who failed intravesical BCG were evaluated using an NYS CLEP approved assay, Immune Report Card, which measures programmed death-ligand 1 expression, CD8+ T-cell infiltration pattern, mutational burden, and gene expression of 51 immune-related transcripts using RNA-Seq. Patients were tested before being treated under our expanded access protocol for intravesical BCG with ALT-803. Subject 1 had failed his fourth line of therapy, subject 2 had failed only his first line of therapy, and subject 3 had failed his seventh line of therapy. Surprisingly, subject 1 had an unusually prolonged CR which lasted 30 months; subject 2 had the persistent and recurrent disease until 12 months when he then developed a CR; subject 3 had disease recurrence at 3 months, along with progression noted at 6 months. Immunomutational status was extensively evaluated to identify potential alterations that might play a role as predictive markers for subject 1, who had an exceptional response. Compared with subject 3, tumor in subject 1 demonstrated a high level of expression for CTLA4 (immunosuppression) and CD39 (immunosuppressive). Together, an immunosuppressive tumor environment in nonmuscle invasive bladder cancer that have failed prior BCG may respond better to i...
Source: Journal of Immunotherapy - Category: Allergy & Immunology Tags: Clinical Studies Source Type: research