AACR 2021 | IMvigor130: OS data for atezolizumab plus chemo versus chemo alone

My name is Enrique Grande, from the MD Anderson Cancer Center in Madrid, Spain. It was my pleasure to present at the AACR 2021 virtual meeting the results of the subgroup analysis we perform at the IMvigor130, according to the overall survival, depending on the response the patient had during the induction phase with chemotherapy.

At this time, well, we did a retrospective analysis of what was the outcome in between two of the arms of treatment treated in the IMvigor130 patients. Those patients with metastatic urothelial carcinoma were randomized into three arms, but we will not talk about atezolizumab as a single agent. We will focus on the two arms with chemotherapy as seen as a standard treatment, or in those patients randomized into chemotherapy plus atezolizumab in combination during the induction phase, followed by maintenance atezolizumab.

We think this retrospective analysis is timely, appropriate, as far as, well, the landscape of the metastatic urothelial tumors in the upfront treatment has changed after the results of the JAVELIN Bladder trial, in which the maintenance treatment with avelumab after an induction phase of four to six cycles of chemotherapy has become the referenced standard of care. What we observe in the retrospective analysis in this exploratory analysis of the IMVigor130 is that where there was a trend to improve the overall survival for those patients who were initially randomized to the combination of chemo plus atezo followed by maintenance atezolizumab, there should be a standard monotherapy alone without any maintenance treatment.

The overall results are aligned and consistent with the intention to treat data we have for overall survival. This trend to improve the overall survival unfortunately did not reach a statistical significant. In the same way that happened in the intention-to-treat population, those patients who were randomized to cisplatin plus gemictabine plus atezolizumab seems to be better than those patients who were treated with carboplatin-based chemotherapy.

It is also interesting to remark that those patients who progress during the induction phase of chemotherapy, either as chemotherapy alone, or in combination with atezolizumab, well, of course they have a poorer prognosis. But those patients who received the combination of chemo plus atezo and progressed during the induction phase of chemotherapy, they tend to do it better when they were treated with maintenance atezolizumab.

I think these data are consistent with a publication of the JAVELIN Bladder 100 in the maintenance avelumab in this field, and reinforces the idea that the maintenance with immunotherapy after an induction phase of chemotherapy of at least four cycles are translating into a benefit in a better overall survival.