Liquid biopsy and multi-analyte testing guided treatment of HER2 positive periampullary adenocarcinoma with durable complete response after trastuzumab based therapy.

Periampullary adenocarcinomas are rare neoplasm that originates from the pancreatic head, the ampulla of vater, the distal bile duct or the duodenum. Surgical resection followed by adjuvant therapy is considered as the standard of care treatment for these carcinomas. Despite several advances in diagnostics and therapeutics, only 5% of these patients have an overall survival of five years or more. Currently, there is a dearth of viable therapeutic targets for this disease. The role of HER2 in cancer biology has been studied extensively in several tumour subtypes, and HER2 based targeted therapies have shown to have therapeutic benefits on different cancers. In this case report, we present a case of HER2 positive distal common bile duct carcinoma - a subtype of periampullary carcinoma with multiple relapses where multi-analyte testing with Encyclopedic Tumor Analysis (ETA) (Exacta®) identified amplification and over expression of HER2 gene which was used as a potential target to treat the patient with trastuzumab. Synchronous in vitro chemosensitivity profiling on Circulating Tumor Asscociated Cells (C-TACs) isolated from blood aided us to design the personalized chemotherapeutic regimen with cyclophosphamide and methotrexate. The combination of trastuzumab with cyclophosphamide and methotrexate yielded excellent treatment response with the patient remaining in complete response till the last follow-up. Our study suggests HER2 directed therapy as a potent pathway for treatment in the subset of HER-2 amplified distal common bile duct carcinomas.

Encyclopedic tumor analysis for guiding treatment of advanced, broadly refractory cancers: results from the RESILIENT trial.

RESILIENT (CTRI/2018/02/011808) was a single arm, open label, phase II/III study to test if label agnostic therapy regimens guided by Encyclopedic Tumor Analysis (ETA) can offer meaningful clinical benefit for patients with relapsed refractory metastatic (r/r-m) malignancies. Patients with advanced refractory solid organ malignancies where disease had progressed following ≥2 lines of systemic treatments were enrolled in the trial. Patients received personalized treatment recommendations based on integrational comprehensive analysis of freshly biopsied tumor tissue and blood. The primary end points were Objective Response Rate (ORR), Progression Free Survival (PFS) and Quality of Life (QoL). Objective Response (Complete Response + Partial Response) was observed in 54 of 126 patients evaluable per protocol (ORR = 42.9%; 95% CI: 34.3%-51.4%, p < 0.0001). At study completion, Disease Control (Complete Response + Partial Response + Stable Disease) was observed in 114 out of 126 patients evaluable per protocol (CBR = 90.5%; 95% CI: 83.9% - 95.0%, p < 0.00001) and Disease Progression in 12 patients. Median duration of follow-up was 138 days (range 31 to 379). Median PFS at study termination was 134 days (range 31 to 379). PFS rate at 90 days and 180 days were 93.9% and 82.5% respectively. The study demonstrated that tumors have latent vulnerabilities that can be identified via integrational multi-analyte investigations such as ETA. This approach identified viable treatment options that could yield meaningful clinical benefit in this cohort of patients with advanced refractory cancers.