Updated efficacy and safety data for durvalumab in patients with locally-advanced or metastatic urothelial cancer (UC) has been announced at the 2017 ASCO Genitourinary Cancers Symposium.

These results follow preliminary data presented at ASCO 2016 by Dr Christophe Massard, who spoke with ecancer at the conference.

Durvalumab, a human monoclonal antibody directed against PD-L1, blocks PD-L1 interaction with PD-1 and CD80 on T cells, countering the tumour's immune-evading tactics and inducing an immune response.

Updated results from the Phase I/II trial showed an objective response rate (ORR) of 20.4% in all evaluable patients (n=103) (95% confidence interval (CI): 13.1%, 29.5%) and 31.1% (95% CI: 19.9%, 44.3%) in patients whose tumours express PD-L1.

At the time of data cut-off, median overall survival (OS) was 14.1 months (95% CI: 4.7, not estimable).

Durvalumab 10mg/kg was administered intravenously every two weeks for up to 12 months, and demonstrated a manageable safety profile among all patients (n=191).

The most common adverse events (AEs) reported in 5% or more of patients were fatigue (19.4%), decreased appetite (9.4%), diarrhoea (8.4%), rash (7.3%), nausea (6.8%), arthralgia (5.8%), pyrexia (5.8%) and pruritus (5.2%).

Grade 3 or 4 adverse events occurred in 6.8% of patients, and three patients discontinued treatment due to AEs.

Professor Thomas Powles, Director of Barts Cancer Centre, London, UK, said “The clinical efficacy of durvalumab in patients with advanced UC is particularly encouraging. For the past three decades we’ve seen limited progress in therapy for bladder cancer patients, and there remains significant unmet need for new treatment options.”

In December 2016, the FDA accepted a review of the Biologics License Application (BLA) for durvalumab in patients with locally-advanced or metastatic urothelial carcinoma, whose disease has progressed during or after one standard platinum-based regimen and was granted Priority Review.

The urothelial cancer cohort from Study 1108 formed the basis for the BLA submission, which follows the FDA’s Breakthrough Therapy Designation for durvalumab for the treatment of patients with PD-L1 positive inoperable or metastatic urothelial bladder cancer whose tumour has progressed during or after one standard platinum-based regimen.

David Berman, Senior Vice President, Head of Oncology Innovative Medicines at MedImmune, the company developing durvalumab, said “The durable responses observed in this larger data set from Study 1108 confirm the promising efficacy we’ve already seen for durvalumab in patients with advanced bladder cancer. We are continuing to test durvalumab in combination with tremelimumab and as monotherapy in the bladder cancer 1st-line setting in our ongoing Phase III DANUBE trial.”

Source: ASCO GU 2017