Microwave Ablation and Immunotherapy Combination Shows Promise in Treating Biliary Tract Cancer

Patients with advanced biliary tract cancer (BTC) may potentially be treated with tremelimumab in combination with microwave ablation, according to a study published in Hepatology.

The authors had previously seen promising results by combining tremelimumab with radiofrequency ablation for treatment of advanced hepatocellular carcinoma (HCC). For the current pilot study, they decided to investigate whether tremelimumab, which is an anti CTLA-4 monoclonal antibody, and microwave ablation together could offer a safe and efficacious treatment possibility for patients with advanced biliary tract cancer, which currently has limited treatment options.

The study included 20 patients (median age of 56.5 years) who had refractory BTC. Patients were treated monthly for 6 months with 10/mg/kg of intravenously administered tremelimumab, followed by infusions that occurred every 3 months until off-treatment criteria were met. Subtotal microwave ablation occurred 36 days following the first dose of tremelimumab, and patients underwent interval imaging studies every 8 weeks.

The investigators noted no dose-limiting toxicities. Common adverse events related to treatment included lymphopenia, diarrhea, and elevated transaminases. Efficacy analysis revealed that 2 of the 16 patients available had a confirmed partial response, and disease in 5 patients stabilized.

Median progression-free survival was 3.4 months, and median overall survival was 6.0 months. Additionally, peripheral blood immune cell subset profiling indicated increased circulating activated (HLA-DR positive) CD8+ T cells, and TCRβ screening showed tremelimumab expanded TCR repertoire, though this did not achieve statistical significance.

“Tremelimumab in combination with tumor ablation is a potential new treatment strategy for patients with advanced BTC. Increased circulating activated CD8+ T cells and TCR repertoire expansion induced by tremelimumab may contribute to treatment benefit,” the authors concluded.

Reference                                  

Xie C, Duffy AG, Mabry-Hrones D, et al. Tremelimumab in combination with microwave ablation in patients with refractory biliary tract cancer. Hepatology. 2018 Dec 22. doi: 10.1002/hep.30482. [Epub ahead of print]