This phase 2 randomized trial assessed stereotactic body radiation and the anti–PD-1 drug nivolumab with or without the anti-CTLA4 drug ipilimumab in patients with metastatic biliary tract cancer.
For first-line advanced biliary tract cancer (BTC), the standard chemotherapy regimen has been gemcitabine/cisplatin (GemCis). The low number of second-line options available after GemCis progression contributes to the significant mortality rate associated with this disease. Results from a phase 2 randomized trial assessing stereotactic body radiation therapy (SBRT) and the anti–PD-1 drug nivolumab with or without the anti-CTLA4 drug ipilimumab in patients with metastatic BTC were presented by Dr Alice Markussen at the 2023 ASCO Gastrointestinal Cancers Symposium.
Patients were eligible if they had had BTC and were refractory to ≥1 prior line of chemotherapy. Participants were randomly assigned 1:1 to SBRT (15 Gy) plus nivolumab or nivolumab and ipilimumab. The primary end point was clinical benefit rate (CBR), and secondary end points included overall response rate, progression-free survival (PFS), overall survival (OS), and safety. A total of 61 patients were enrolled from September 2018 to January 2022. Of these, 19 patients received SBRT plus nivolumab and 42 received SBRT plus nivolumab and ipilimumab. Of the total cohort, 79% of patients had cholangiocarcinoma and the rest had gallbladder carcinoma.
Results from a phase 2 randomized trial assessing stereotactic body radiation therapy (SBRT) and the anti–PD-1 drug nivolumab with or without the anti-CTLA4 drug ipilimumab in patients with metastatic BTC were presented by Dr Alice Markussen at the 2023 ASCO Gastrointestinal Cancers Symposium.
No responses were observed in the SBRT plus nivolumab arm, and the cohort was closed for inclusion based on a CBR of 11% (95% confidence interval [CI], 1-33), whereas the SBRT plus nivolumab and ipilimumab arm had a CBR of 31% (95% CI, 18-47). In the SBRT plus nivolumab and ipilimumab arm, 5 patients experienced a partial response, and the median duration of response was 4.4 months. The median PFS and OS in the SBRT plus nivolumab and ipilimumab arm were 1.7 months and 5.4 months, respectively.
Of the patients in the SBRT plus nivolumab arm, 16% experienced grade ≥3 treatment-related adverse events compared with 31% in the SBRT plus nivolumab and ipilimumab arm, where 1 patient also died from hepatitis. In pretreated patients with metastatic BTC, SBRT with nivolumab and ipilimumab showed anticancer efficacy; nevertheless, more research is needed to fully grasp the function of immunotherapy in this setting.
Source:
Markussen A, Johansen JS, Larsen FO, et al. Randomized phase 2 study of nivolumab with or without ipilimumab combined with stereotactic body radiotherapy in pretreated patients with metastatic biliary tract cancer. Poster presented at: ASCO Gastrointestinal Cancers Symposium, January 19-21, 2023; San Francisco, CA. Abstract 545.