Author: By Shreeya Nanda, Senior medwireNews Reporter
medwireNews: An exploratory analysis of the TOPAZ-1 trial suggests that patients with advanced biliary tract cancer (BTC) benefit from the addition of durvalumab to chemotherapy irrespective of the location of the primary tumour.
“Though the magnitude of efficacy improvement varied slightly between primary tumour locations, the benefit of durvalumab was observed consistently”, presenting author Aiwu Ruth He, from the Lombardi Comprehensive Cancer Center in Washington, DC, USA, told delegates of the ESMO World Congress on Gastrointestinal Cancer 2022 in Barcelona, Spain.
She continued: “These findings support durvalumab plus [gemcitabine–cisplatin] as a first-line treatment option for advanced BTC, irrespective of primary tumour location.”
In the double-blind, phase III trial, participants were randomly assigned to receive either durvalumab 1500 mg or placebo every 3 weeks alongside up to eight cycles of gemcitabine 1000 mg/m2 plus cisplatin 25 mg/m2 given on days 1 and 8 of each 21-day cycle, followed by durvalumab 1500 mg or placebo every 4 weeks until disease progression.
The investigators previously reported an interim analysis of the study, which showed a significant 20% reduction in the risk of death with the addition of durvalumab to gemcitabine plus cisplatin in the overall trial population comprising 685 patients with untreated locally advanced or metastatic BTC.
For the current exploratory analysis, they stratified participants by tumour site and found that overall survival (OS) favoured the durvalumab–chemotherapy combination over chemotherapy alone regardless of whether the primary tumour was intrahepatic cholangiocarcinoma (IHCC; n=383), extrahepatic cholangiocarcinoma (EHCC; n=131) or gallbladder cancer (GBC; n=171).
Specifically, the hazard ratio (HR) for death was 0.76 in favour of durvalumab in both the IHCC and EHCC subgroups, and 0.94 in the GBC subgroup.
Aiwu Ruth He explained that to further understand the higher HR in the GBC subgroup, they analysed the group by geographical region, finding an HR for death of 0.82 among Asian participants and 0.78 among those from Europe and North America. The HRs were not calculable for the North American subset alone and the South American subset alone “due to an insufficient number of events”, she said.
The addition of the PD-L1 inhibitor to gemcitabine plus cisplatin also improved progression-free survival regardless of tumour site, with HRs for progression or death of 0.79, 0.52 and 0.90 in the IHCC, EHCC and GBC subgroups, respectively.
And the likelihood of achieving an objective response was also higher with durvalumab plus chemotherapy than with chemotherapy alone, with corresponding odds ratios of 1.79, 2.18 and 1.08.
The presenter highlighted that the incidence of adverse events or treatment-related adverse events (TRAEs) of grade 3 or 4 “was generally comparable among treatment groups, irrespective of primary tumour location.”
For instance, grade 3 or 4 TRAEs occurred in 57.4% of durvalumab-treated patients with IHCC and 58.5% of their counterparts given chemotherapy alone, while the rates in the EHCC and GBC subgroups were 60.6% versus 75.0% and 69.0% versus 65.9%, respectively.
Speaking to the future, Aiwu Ruth He told medwireNews that durvalumab – alone and/or in combination with chemotherapy – “should be studied in the earlier stages of biliary tract cancer.”
She noted that the combination of durvalumab and gemcitabine plus cisplatin “is quite well tolerated”, and therefore could be further combined with novel therapies “to improve the outcome of advanced biliary cancer further.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2022 Springer Healthcare Ltd, part of the Springer Nature Group
Reference
- He AR, Valle JW, Lee C-k et al. Outcomes by primary tumour location in patients with advanced biliary tract cancer treated with durvalumab or placebo plus gemcitabine and cisplatin in the phase 3 TOPAZ-1 study. Ann Oncol 2022; 33 (suppl 4): S378. doi: 10.1016/j.annonc.2022.04.442
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2022 Springer Healthcare Ltd, part of the Springer Nature Group