Bortezomib in previously treated phosphatase and tension homology‐deficient patients with advanced intrahepatic cholangiocarcinoma: An open‐label, prospective and single‐centre phase II trial

Abstract

AbstractIntroductionIntrahepatic cholangiocarcinoma (ICC) is characterized by a dismal prognosis with limited therapeutic alternatives. To explore phosphatase and tension homolog (PTEN) as a biomarker for proteasome inhibition in ICC, we conducted a phase II trial to assess the second‐line efficacy of bortezomib in PTEN‐deficient advanced ICC patients.MethodsA total of 130 patients with advanced ICC in our centre were screened by PTEN immunohistochemical staining between 1 July 2017, and 31 December 2021, and 16 patients were ultimately enrolled and treated with single‐agent bortezomib 1.3 mg/m2 on days 1, 4, 8 and 11 of a 21‐day cycle. The primary endpoint was the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors v1.1.ResultsThe median follow‐up was 6.55 months (95% confidence interval [CI]: 0.7–19.9 months). Among the 16 enrolled patients, the ORR was 18.75% (3/16) and the disease control rate was 43.75% (7/16). The median progress‐free survival was 2.95 months (95% CI: 2.1–5.1 months) and the median overall survival (mOS) was 7.2 months (95% CI: 0.7–21.6 months) in the intent‐to‐treat‐patients. Treatment‐related adverse events of any grade were reported in 16 patients, with thrombopenia being the most common toxicity. Patients with PTEN staining scores of 0 were more likely to benefit from bortezomib than those with staining scores > 0.ConclusionsBortezomib yielded an encouraging objective response and a favourable OS as a second‐line agent in PTEN‐deficient ICC patients. Our findings suggest bortezomib as a promising therapeutic option for patients with PTEN‐deficient ICC.Highlights There is a limited strategy for the second‐line option of intrahepatic cholangiocarcinoma (ICC). This investigator‐initiated phase 2 study evaluated bortezomib in ICC patients with phosphatase and tension homology deficiency. The overall response rate was 18.75% and the overall survival was 7.2 months in the intent‐to‐treat cohort. These results justify further developing bortezomib in ICC patients with PTEN deficiency.