Successful Targeted Therapy with Alectinib in ALK-Positive Metastatic Pancreatic Cancer
Background
Pancreatic cancer has one of the highest mortality rates due to its typical late-stage diagnosis and subsequent limited surgical options. However, recent advances in molecular profiling offer hope for targeted therapies. We present a case of locally advanced pancreatic adenocarcinoma which progressed despite surgery and chemotherapy yet showed a positive respond to Alectinib.
Case Description
A 79-year-old male with medical history of tobacco use and ulcerative colitis presented to the clinic with 15lb unintentional weight loss over the past few months in 04/2021. Computed tomography (CT) showed dilated common bile duct due to 2.2 x 1.9 x 1.7 cm mass with no metastatic disease. Biopsy was consistent with pancreatic adenocarcinoma and patient completed 6 cycles of dose-reduced neoadjuvant gemcitabine and paclitaxel in late 2021 due to his severe neuropathy and ECOG. Subsequent CT and PET-CT showed stable disease prior to undergoing pylorus-sparing pancreatoduodenectomy and cholecystectomy with portal vein resection in 05/2022 with surgical pathology grading yPT4N2cM0. The follow- up PET scan in 09/2022 revealed new pulmonary and liver metastases, along with increased uptake in the pancreatic region, suggesting recurrent disease. Next generation sequencing (NGS) identified an ELM4-ALK chromosomal rearrangement on the surgical pathology. Given the patient’s cancer progression and concerns about chemotherapy tolerance, Alectinib, a second-generation ALK inhibitor more commonly used in lung cancer, was considered as a treatment option. Patient began Alectinib 10/2022 with no significant side effects and PET scan on 03/2023 and 06/2023 showing resolution of his lung nodules and liver lesions. Patient remained on Alectinib until he transitioned to hospice after an ischemic stroke in 03/2024.
Discussion
Pancreatic cancer urgently requires novel therapies as about 25% of patients harbor actionable molecular alterations that have led to the success of targeted therapies. ALK fusion genes are identified in multiple cancers, but the prevalence is only 0.16% in pancreatic ductal adenocarcinoma. Alectinib provided an extended progression free survival compared with standard chemotherapy in our patient. ALK inhibitors may demonstrate a remarkable response in metastatic pancreatic cancer even in poor candidates for standard chemotherapy highlighting the emphasis of NGS and targeted therapy options for pancreatic cancer to improve survival.