Abstract: Olaparib has been applied as monotherapy to treat ovarian and breast cancer patients with malignant or suspected malignant BRCA1/2  mutations. Pembrolizumab has been approved to treat unresectable or metastatic tumors in patients who exhibited progression after previous treatment, regardless of histology. However, there are no reports on the use of olaparib and pembrolizumab for the treatment of BRCA1/2 -mutated and PD-L1-positive intrahepatic cholangiocarcinoma (iCCA). This case report aimed to observe the safety and efficacy of olaparib and pembrolizumab in treating BRCA1 -mutated and PD-L1-positive iCCA recurrence and metastasis. This case report describes a patient with BRCA1 -mutated and PD-L1-positive iCCA recurrence and metastases who received olaparib and pembrolizumab. Olaparib (400 mg orally twice daily) and pembrolizumab (100 mg iv every 3 weeks) were administered to the patient for 9 months. The patient achieved complete response (CR) confirmed by liver magnetic resonance imaging (MRI)+ perfusion-weighted imaging (PWI)+ diffusion-weighted imaging (DWI), and the carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), carbohydrate antigen 125 (CA-125), and carbohydrate antigen 199 (CA19-9) tumor marker levels were normal after treatment. There were no significant adverse events, and routine blood counts, coagulation function, and liver and kidney function were normal. The Eastern Cooperative Oncology Group (ECOG) performance status decreased from a score of 1 to a score of 0. Olaparib and pembrolizumab can effectively treat BRCA1 -mutated and PD-L1-positive iCCA patients, and adverse effects were largely unobserved. More studies should be performed to promote the development of tumor genomics because the findings from these studies may help clinicians select suitable biomarkers to treat iCCA patients. As the use of immunotherapy alone to treat tumors may not achieve the expected effect, targeted therapy combined with immunotherapy has become a new approach in cancer treatment strategies.
Keywords: intrahepatic cholangiocarcinoma, olaparib, pembrolizumab, BRCA1/2  mutations, PD-L1 positive