The IMvigor210 study demonstrated safety and efficacy of atezolizumab in metastatic UC patients. This study looked at the outcomes of 220 patients (out of 310 total in cohort 2 of the study) who developed PD after therapy. Interestingly, 137 of these patients continued on atezolizumab post-PD compared with 83 patients who either received no systemic therapy (64 patients) or other systemic therapy (19 patients).
The abstract presented at ESMO evaluated the outcomes of post-progressive disease (PD) in patients treated on the phase II IMvigor210 study.
This study suggests that patients may continue to derive benefit from atezolizumab even in the setting of progressive disease. Unfortunately, only 19 patients received alternate therapies after PD and so it would be difficult from this study to ascertain if other therapies might be more effective in the post-PD setting.
The duration of pre-PD therapy was similar in both groups of patients and the patients continuing atezolizumab after PD had higher pre-PD ORR compared to the other patients. Interestingly, median OS was better in the group that continued atezolizumb after PD versus the patients that did not (12.8 months vs. 3.6 months). Furthermore, 45 patients in the atezolizumab continuation group experienced decreases in the sum of their target lesion diameters.