ASCO 2019 - Urothelial cancer (bladder and urinary tract): new evidence of the value of immunotherapy

Chicago, 3 June 2019
ASCO 2019

Urothelial cancer (bladder and urinary tract)
New evidence of the value of immunotherapy

Urothelial cancer, usually developing in the bladder, is common and serious. Its management is complex. It accounts for 90% of bladder cancers. With 12,000 new cases diagnosed each year in France, bladder cancer is the urological cancer encountered most frequently after prostate cancer.

Anti PD1 and antiPD-L1 immunotherapeutic agents such as pembrolizumab and atezolizumab are approved in Europe for the treatment of metastatic urothelial cancer but costs are still not reimbursed by the French health system. An important question for clinical research to resolve is the duration of tumour response and, in particular, that for complete response.

Long and complete responses obtained by immunotherapy

Dr Yohann Loriot, medical oncologist at Gustave Roussy, has led a joint analysis of the results of three phase I and II studies evaluating atezolizumab (an anti PD-L1 immunotherapeutic agent). This shows that a complete response is found in about 10% of patients, occurring within the first eight months after commencing the agent. Complete response duration is long. The median for this is greater than two years in one of the studies and more than three years in the study with the longest follow-up. The great majority of patients who obtained a complete response are still alive several years after treatment was initiated.

Poster
Monday 3 June, 13h15-16h15 Chicago time
▶ Read the abstract 4527
Durability of complete response (CR) with atezolizumab (atezo) in locally advanced/metastatic urothelial carcinoma (mUC).

PDL1 expression: a prognostic marker in bladder cancer

Dr Yohann Loriot is also the last author of a presentation on bladder cancer that will be discussed at ASCO 2019. This focused on two analysis criteria in the SAUL study, published in March of this year. In particular, it demonstrated that atezolizumab was effective in patients who are usually excluded from clinical trials (elderly patients, those who are too frail and those with cerebral metastases or autoimmune disease). The study showed the benefit of treating the oldest patients (over 80) because of the development of immunosenescence: age was not limiting, safety and efficacy being no different in comparisons with younger patients.   

In addition, the SAUL study showed that tissue expression of PD-L1 was a good prognostic marker: survival figures in patients with PD-L1 expression treated with atezolizumab were better than in those whose PD-L1 expression was poor. As there was no control group treated with chemotherapy in this study, it was not possible to know whether this marker has predictive value. However, its role can be explored in the large trials which are under way evaluating atezolizumab as a first line agent in combination with chemotherapy (IMvigor130 study) and when used as an adjuvant after cystectomy.
The identification of the patients who are most likely to respond favourably to immunotherapy is an important element contributing to advances in cancer treatments. The demonstration of this prognostic marker in bladder cancer will facilitate the provision of this type of treatment in routine patient care.

Poster Discussion
Monday 3 June, 16h30-18h00 Chicago time
▶ Read the abstract 4519
Clinical outcomes according to PD-L1 status and age in the prospective international SAUL study of atezolizumab (atezo) for locally advanced or metastatic urothelial carcinoma (UC) or non-UC of the urinary tract

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