Keynote 966

In this interview, Prof Arndt Vogel, a GI oncologist from Toronto, discusses updates from the ASCO meeting on the KEYNOTE-966 study, which evaluated pembrolizumab in combination with gemcitabine and cisplatin for bile duct cancer. The updated results showed sustained survival benefits, with two-year and three-year survival rates improving to 19% and 13%, respectively. Additionally, the study confirmed no new safety concerns, maintaining a similar safety profile to earlier reports.

Prof Vogel emphasised the ongoing challenge of identifying predictive biomarkers for long-term survivors. Current markers like PD-L1 expression are unreliable due to the heterogeneous nature of bile duct tumours. Analysis from the TOPAZ study revealed no significant biomarkers to identify long-term survivors upfront, and similar insights are anticipated from KEYNOTE-966.

He also pointed out that intrahepatic bile duct cancers responded best to the treatment, while gallbladder cancers showed less benefit. Regarding chemotherapy duration, the KEYNOTE-966 study allowed for the continuation of gemcitabine beyond six months, unlike the TOPAZ study, which stopped chemotherapy entirely after six months. Despite this difference, both studies showed similar outcomes. In his clinical practice, Prof Vogel now favours maintenance therapy with checkpoint inhibitors alone and opts to re-induce chemotherapy only upon disease progression, reflecting a shift in treatment strategy influenced by these findings.