IMvigor130 study: Final OS analysis of atezo + plt/gem vs placebo + plt/gem used to treat mUC

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Published: 18 Feb 2023
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Prof Aristotelis Bamias - University of Athens, Athens, Greece

Prof Aristotelis Bamias speaks to ecancer about the final overall survival analysis of the IMvigor130 study which atezolizumab monotherapy vs chemotherapy was used to treat untreated locally advanced or metastatic urothelial carcinoma (mUC).

The IMvigor130 primary analysis demonstrated statistically significant PFS benefit with firstline atezolizumab plus platinum/gemcitabine (Arm A) vs placebo plus platinum/gemcitabine (Arm C) in patients with metastatic urothelial carcinoma.

In the final analysis, the results demonstrated an improved OS with atezolizumab plus platinum/gemcitabine, however this did not reach statistical significance in intent-to-treat patients with mUC.

IMvigor130 is a randomised phase III trial which questions the role of atezolizumab in first line therapy for patients with metastatic urothelial cancer. They randomised patients to receive either atezolizumab with chemotherapy, atezolizumab alone, or chemotherapy alone. It had a complex statistical design, including a hierarchical approach so the first two primary endpoints were progression free survival and overall survival comparing atezolizumab plus chemotherapy versus chemotherapy alone. 

The first co-primary endpoint was met, which was progression free survival but unfortunately the second co-primary endpoint of overall survival was not met. So, according to the design of the trial, all the remaining comparisons of atezolizumab monotherapy would be exploratory. 

I presented today the final overall survival analysis results for the arms of atezolizumab monotherapy versus chemotherapy alone.

What were the results of the study?

The study found eventually, in this final analysis, no significant difference, no significant benefit, in overall survival by adding atezolizumab to chemotherapy. Equally, the exploratory analysis of atezolizumab monotherapy versus chemotherapy alone did not show any survival benefit. 

Nevertheless, there have been other analyses which suggested that atezolizumab alone may prolong survival compared to chemotherapy alone in patients whose tumours express PD-L1 at high levels.  So these are the main findings of this study. 

How do you think this could affect the future treatment of bladder cancer?

First of all, the fact that regulatory-wise IMvigor130 was negative doesn’t mean that we haven’t learned a lot from IMvigor130 and we will learn more because there are other sub-analyses to come. There has been tremendous translational work in this study so there is a lot of important information to come. 

Today immunotherapy is a vital component of the treatment of metastatic urothelial cancer but the standard is chemotherapy followed by immunotherapy when there is no progression of disease. There are also other agents, non-chemotherapy, non-immunotherapy, which prolong survival in this setting. So, indeed, there have been a lot of very encouraging developments in the setting of metastatic disease. 

All these new drugs, these effective drugs, are now being tested in earlier stages of the disease, namely in non-muscle invasive bladder cancer, which is the most frequent type of bladder cancer, and also the muscle invasive bladder cancer non-metastatic where there are now studies about the use of neoadjuvant or adjuvant immunotherapy in these patients.

So we need to wait for the results of the studies but the next decade, I’m sure, will bring quite exciting things for bladder cancer.