Biomarkers May Predict Outcomes With Padcev to Treat Bladder Cancer Subtype

Treatment outcomes with Padcev (enfortumab vedotin) may be predicted by several biomarkers in patients with advanced urothelial carcinoma, a type of bladder cancer, according to findings from a recent analysis.

“Upon external validation, these findings can help inform clinical decision making and potential therapy sequencing in patients with advanced urothelial carcinoma,” the researchers wrote in the abstract.

Findings from the analysis were presented at the 2023 ASCO GU Cancers Symposium.

Padcev is an antibody drug conjugate (a monoclonal antibody chemically linked to a drug, which binds to proteins on cancer cells) that is widely used to treat patients with advanced urothelial carcinoma that does not respond to treatment. Despite its wide use in this patient population, data are limited regarding biomarkers to predict outcomes with this therapy.

Researchers analyzed data from the retrospective UNITE study, particularly of 170 patients from 16 sites with available next-generation sequencing. In addition, patients in this analysis were treated with Padcev alone outside of a clinical trial setting.

Investigators determined observed response to Padcev in patients with scans after one or more doses of the therapy. Several molecular biomarkers were assessed including tumor mutational burden (the number of DNA mutations found on cancer cells), somatic alterations (DNA alterations that occurs after conception) in at least 10% of patients, PD-L1 status (a protein that acts like a brake to keep immune responses under control) and the presence of one or more DNA damage response mutations.

Other factors that were assessed in this study include median progression-free survival (the length of time during and after cancer treatment that a patient lives without disease worsening), overall response rates (the proportion of patients with a partial or complete response to therapy) and overall survival (the time when a patient with cancer is still alive).

Of the patients in this study, 65% had pure urothelial histology, 69% had a primary bladder tumor and 68% had two or more lines of therapy before receiving treatment with Padcev.

The overall response rate for patients was 47%. Of note, overall response rates were higher in patients with specific alterations compared with wild type including ERBB2 and TSC1.

Patients in the study had a median progression-free survival of six months and a median overall survival of 12 months. Shorter progression-free survival times were observed in patients with CDKN2A, CDKN2B and MTAP alterations. Patients with high tumor mutation burden had longer median overall survival.

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