3-year update of the TOPAZ-1 study

Dr Willem Lybaert, a medical oncologist affiliated with VITAZ Sint-Niklaas and University Hospital Antwerp, provides an extensive update on the TOPAZ-1 study.

The primary analysis of the TOPAZ-1 study demonstrated that the combination of durvalumab with gemcitabine and cisplatin (GC) significantly improved OS compared to placebo plus GC in patients with advanced BTC. At ESMO GI, an updated analysis including 3-year OS data, an extended long-term survivor (eLTS) analysis and a safety profile assessment was presented. 

Within the full analysis set (FAS), the 3-year OS rates were 14.6% for the durvalumab + GC group versus 6.9% for the placebo + GC group. Patients achieving complete or partial response, as well as those with stable disease, exhibited better 3-year OS outcomes, with complete and partial responders faring better than those with stable disease.

In the FAS, 88/685 (12.8%) patients were eLTS, comprising patients who survived for at least 30 months. There were more eLTS in the durvalumab + GC group (17.0%) than in the placebo +GC group (8.7%). The eLTS group demonstrated superior outcomes compared to the FAS. All clinically relevant subgroups were represented in the eLTS group. A higher proportion of patients in the eLTS group achieved an objective response compared to the FAS, with approximately one-third of patients responding to durvalumab classified as eLTS.

Subsequent anticancer therapy, including immunotherapy, was more commonly utilized in the placebo + GC eLTS group compared to the durvalumab + GC eLTS group. Despite a longer duration of exposure, serious adverse events in the eLTS were comparable between both groups and were less frequent than in the FAS.