Tumour response to TRK inhibition in a patient with pancreatic adenocarcinoma harbouring an NTRK gene fusion

E M O'Reilly, J F Hechtman, E M O'Reilly, J F Hechtman

Abstract

Background: Although rare, NTRK gene fusions are known to be oncogenic drivers in pancreatic ductal adenocarcinoma (PDAC). We report the response of a metastatic CTRC-NTRK1 gene fusion-positive PDAC to targeted treatment with the oral tropomyosin receptor kinase (TRK) inhibitor larotrectinib and the eventual development of resistance to treatment.

Patient, methods and results: A 61-year-old woman presented with a 2.5-cm mass in the body of the pancreas and a 1.2-cm liver lesion on routine follow-up for endometrial cancer that was in complete remission. Liver biopsy confirmed a primary PDAC unrelated to the endometrial cancer. The patient was treated with gemcitabine, nab-paclitaxel and ADI-PEG 20 for 12 months until disease progression and toxicity emerged [best overall response (BOR): partial response (PR)]. The patient switched to a modified regimen of folinic acid, fluorouracil, irinotecan and oxaliplatin for 4 months until neuropathy occurred. Oxaliplatin was withheld until disease progression 6 months later (BOR: stable disease). Despite recommencing oxaliplatin, the disease continued to progress. At this time, somatic profiling of the liver lesion revealed a CTRC-NTRK1 gene fusion. Treatment with larotrectinib 100 mg twice daily was commenced with BOR of PR at 2 months. The patient progressed after 6 months and was re-biopsied. Treatment was switched to the investigational next-generation TRK inhibitor selitrectinib (BAY 2731954, LOXO-195) 100 mg twice daily. After 2 months, the disease progressed and dabrafenibtrametinib combination therapy was initiated due to existence of a BRAF-V600E mutation. However, the cancer continued to progress and the patient died 2 months later.

Conclusions: Targeted TRK inhibition with larotrectinib in PDAC harbouring a CTRC-NTRK1 gene fusion is well tolerated and can improve quality of life for the patient. However, acquired resistance to therapy can emerge in some patients. Next-generation TRK inhibitors such as selitrectinib are currently in development to overcome this resistance (NCT02576431; NCT03215511).

Keywords: NTRK gene fusion; larotrectinib; TRK fusion cancer; pancreatic adenocarcinoma; selitrectinib; tropomyosin receptor kinase inhibition.

© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society for Medical Oncology.

Figures

Figure 1.
Figure 1.
Computed tomography imaging. Computed tomography taken at (A) baseline before initiation of larotrectinib and (B) showing the best overall response of partial response to treatment with larotrectinib.
Figure 2.
Figure 2.
[18F]2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) imaging. (A) FDG-PET imaging taken at baseline before initiation of larotrectinib. 2-fluoro-2-deoxy-D-glucose (FDG)-avidity is visible in the primary pancreatic tumour and liver metastases. (B) FDG-PET imaging showing the best overall response of partial response to treatment with larotrectinib. FDG-avidity in previously hypermetabolic pancreatic and liver lesions is resolved.
Figure 3.
Figure 3.
Liver biopsy analysis. (A) Haemotoxylin and eosin (H&E): A core biopsy of the patient’s liver mass demonstrated a moderately differentiated adenocarcinoma, morphologically compatible with pancreatobiliary origin (H&E, 100× original magnification). (B) TrkA immunohistochemistry (IHC): Immunohistochemical staining for TrkA (NTRK1) demonstrated diffuse, strong cytoplasmic expression (TrkA IHC, clone EP1058Y, Abcam, Cambridge, UK, 100× original magnification). (C) Archer® software: Fusion analysis was carried out on the tumoral RNA with the MSK-IMPACT™ panel and demonstrated an in-frame fusion between CTRC (NM_007272) exon1 and NTRK1 (NM_002529) exon8, including the kinase domain of NTRK1 (JBrowse software).

References

    1. Chiaravalli M, Reni M, O'Reilly EM.. Pancreatic ductal adenocarcinoma: state-of-the-art 2017 and new therapeutic strategies. Cancer Treat Rev 2017; 60: 32–43.
    1. Krantz BA, O'Reilly EM.. Biomarker-based therapy in pancreatic ductal adenocarcinoma: an emerging reality?. Clin Cancer Res 2018; 24(10): 2241–2250.
    1. Singh RR, Goldberg J, Varghese AM. et al. Genomic profiling in pancreatic ductal adenocarcinoma and a pathway towards therapy individualization: a scoping review. Cancer Treat Rev 2019; 75: 27–38.
    1. Cocco E, Scaltriti M, Drilon A.. NTRK fusion-positive cancers and TRK inhibitor therapy. Nat Rev Clin Oncol 2018; 15(12): 731–747.
    1. Kummar S, Lassen UN.. TRK inhibition: a new tumor-agnostic treatment strategy. Targ Oncol 2018; 13(5): 545–556.
    1. Vaishnavi A, Le AT, Doebele RC.. TRKing down an old oncogene in a new era of targeted therapy. Cancer Discov 2015; 5(1): 25–34.
    1. Drilon A, Laetsch TW, Kummar S. et al. Efficacy of larotrectinib in TRK fusion-positive cancers in adults and children. N Engl J Med 2018; 378(8): 731–739.
    1. American Joint Committee on Cancer. AJCC Cancer Staging Manual, 8th edition. Springer International Publishing, 2017.
    1. Middha S, Zhang L, Nafa K. et al. Reliable pan-cancer microsatellite instability assessment by using targeted next-generation sequencing data. JCO Precis Oncol 2017; 2017; (1): 1.
    1. Zehir A, Benayed R, Shah RH. et al. Mutational landscape of metastatic cancer revealed from prospective clinical sequencing of 10, 000 patients. Nat Med 2017; 23(6): 703–713.
    1. Marchiò C, Scaltriti M, Ladanyi M. et al. ESMO recommendations on the standard methods to detect NTRK fusions in daily practice and clinical research. Ann Oncol 2019; doi:10.1093/annonc/mdz204.
    1. Drilon A, Nagasubramanian R, Blake JF. et al. A next-generation TRK kinase inhibitor overcomes acquired resistance to prior TRK kinase inhibition in patients with TRK fusion-positive solid tumors. Cancer Discov 2017; 7(9): 963–972.
    1. Estrada-Bernal A, Le AT, Tuch B. et al. Abstract C65: tRK kinase domain mutations that induce resistance to a pan-TRK inhibitor. Mol Cancer Ther 2015; 14(12 Suppl 2): C65–C65.
    1. Cocco E, Schram AM, Kulick A. et al. Resistance to TRK inhibition mediated by convergent MAPK pathway activation. Nat Med 2019; 25(9): 1422–1427.

Source: PubMed

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