The prognosis of advanced gall bladder carcinoma (GBC) remains poor despite the addition of newer targeted therapies. HER2 is a potential therapeutic target expressed in up to 20% GBC. We present an analysis of advanced or metastatic HER2-amplified or overexpressed GBC treated with trastuzumab and chemotherapy from an Indian cancer center.
Patients with advanced or metastatic GBC with immunohistochemical evidence of HER2 overexpression (IHC 3+) or HER2 amplification detected with FISH, treated with trastuzumab and first-line chemotherapy between 2020 and 2021 were included. Outcome measures were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).
Twenty-six patients (age range, 44-71) with GBC were treated with trastuzumab and chemotherapy. Twenty patients (76.9%) had newly diagnosed advanced disease while six patients (23.1%) had recurred after prior curative treatment. Twenty-four patients (92.3%) received gemcitabine-cisplatin and two received (7.7%) gemcitabine-oxaliplatin as chemotherapy. Partial response was seen in 11 patients (42.3%) while 10 patients (38.5%) had stable disease (objective response rate 42.3%, overall response rate 80.8%). At a median follow-up of 15.7 months, median PFS was 9.7 months (95% CI, 9.3-10) and median OS was 11.9 months (95% CI, 11.2-12.5). Grade 2 ejection fraction drop was seen in 1 patient (3.8%). No adverse events of grade 3 or more were attributable to trastuzumab.
Trastuzumab added to chemotherapy for advanced GBC demonstrated better ORR, and PFS compared to historical control of chemotherapy alone, without any additional toxicities.
The authors.
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All authors have declared no conflicts of interest.