Bone metastasis in urothelial cancer patients results in poorer clinical outcomes irrespective of the PD-L1 expression or treatment. However, patients with elevated PD-L1 have better overall survival (OS) after treatment with either durvalumab or durvalumab plus tremelimumab. These results were presented at the ASCO annual meeting.
Despite available treatment options, bone metastasis results in significant mortality and morbidity in patients with urothelial carcinoma. With immunotherapy at the forefront of cancer therapy, evaluating its efficacy in urothelial carcinoma patients with or without bone metastasis is important. Stecca and colleagues have addressed this by the post hoc analysis of the DANUBE phase 3 trial.
The open-label, multi-centre DANUBE trial enrolled urothelial carcinoma patients with (n=266) or without (n=766) bone metastases. The participants received either durvalumab (n=97 with metastases; n = 249 without), durvalumab plus tremelimumab (n = 80 with metastases; n = 262 without) or chemotherapy (n = 89 with metastases; n = 255 without). The post-hoc analysis analysed the treatment outcomes with PD-L1 expression and bone metastases.
Both OS (HR = 1.67; 95% CI, 1.43-1.92) and progression-free survival (HR = 1.52; 95% CI, 1.3-1.75) were lower in all the patients with or without bone metastasis. The median OS was improved in patients with higher PD-L1 expression when treated with durvalumab or durvalumab plus tremelimumab. However, no benefit was seen with the standard of care chemotherapy in patients with elevated PD-L1 with or without bone metastasis.
These findings indicate the negative impact of bone metastasis in patients with urothelial carcinoma. Additionally, PD-L1 expression can predict treatment benefits with immune checkpoint inhibitors.