Successful Treatment of Metastatic Fibrolamellar Hepatocellular Carcinoma with Temsirolimus in Vitro and in Vivo

Successful Treatment of Metastatic Fibrolamellar Hepatocellular Carcinoma with Temsirolimus In Vitro and In Vivo

Jennifer L Leiting1, Matthew C Hernandez1, Amro M Abdelrahman1 Jennifer A Yonkus1, Michael S Torbenson2, Rondell P Graham2, Mark J Truty1 1Department of Surgery, 2Department of Pathology Mayo Clinic, Rochester, MN

BACKGROUND PDX VALIDATION mTOR IN PATIENT TISSUE Patient • Rare liver tumor with distinct morphology Patient LN Met PDX Tumor PDX Tumor PDX Tumor Composite IHC Scores and a specific gene fusion 1° Tumor from LN from LN from LN Patient 10 • Prognosis dependent on surgical Patient 9 resection Control Patient 8 • 80-100% will recur following resection Patient 7 • No recommended treatment regimens A H&E H&E H&E CD68 CK7 Patient 6 Median Scores • Patient-derived xenografts (PDXs) Patient 5 Primary = 2 recapitulate original tumor and can A: Only metastatic lesions from the Patient 4 Metastatic = 4 predict therapeutic regimen efficacy B C patient grew in the mice and morphology and IHC staining was Patient 3 consistent with FL-HCC Patient 2 B: Tumor bearing PDX model AIM Fusion Protein Patient 1 Native Protein C: The fusion protein was present in 0123456 Validate a PDX model of FL-HCC the PDX tumor but was absent in the normal adjacent liver Average Scores Identify effective therapeutic regimens Metastatic Lesions Primary Lesion TEMSIROLIMUS AND mTOR ACTIVITY Patient metastatic lesions had increased mTOR METHODS Gemcitabine / Oxaliplatin FOLFIRINOX Temsirolimus expression when compared to primary lesions (p = 0.003) PDX VALIDATION 1°and metastatic patient tissue was implanted into immunodefficient mice CONCLUSIONS Viability Relative Successfully grown tumors were harvested and • Successfully established a FL-HCC PDX stained with H&E, CD68, and CK7 0 nM 1 nM 10 nM 100 nM 1000 nM 0 nM 1 nM 10 nM 100 nM 1000 nM 0 nM 1 nM 10 nM 100 nM 1000 nM A model Western blots were performed to assess for the Drug Concentration Drug Concentration Drug Concentration presence of the characteristic fusion protein • Identified alteration of mTOR pathway with increased expression in metastatic ) PDX In Vivo Treatment Study TEMSIROLIMUS AND mTOR ACTIVITY 3 lesions 1000 Vehicle • Significant in vivo response to single PDX tumors were dissociated and treated with Temsirolimus chemo regimens and cell viability was assessed 800 agent temsirolimus in FL-HCC PDX model Gem/Ox after 72 hours Phospho-mTOR • mTOR overexpression in metastatic lesions 600 FOLFIRINOX ns Western blots were performed on patient and PDX seen in larger patient cohort tumors for mTOR expression B Total mTOR 400 * Mice were treated with one of four regimens for 30 * mTOR Inhibition may be a beneficial days with biweekly assessment of tumor growth 200 treatment for metastatic FL-HCC A: Of the many therapeutic regimens tested, only mTOR IN PATIENT TISSUE Gem/Ox, FOLFIRINOX, and Temsirolimus (mTOR 0 inhibitor) had a significant treatment effect 10 patients were identified in the pathology -200 REFERENCES database with both metastatic and primary tumors B: Increased mTOR expression was seen in metastatic available for mTOR IHC staining lesions when compared to primary lesions -400 1. El-Serag HB, et al. Hepatology. 2004;39(3): 798-803

Change in Tumor Volume (mm Volume Change in Tumor 1 5 9 13 17 21 25 29 Staining was scored by a pathologist 2. Graham RP, et al. Mod Pathol. 2018;31: 141-149. C: In vivo treatment with Temsirolimus in FL-HCC PDX ns = not significant Treatment Day 3. Craig JR, et al. Cancer. 1980; 46(2): 372-379. Composite Score: Density Score x Intensity Score mice resulted in significantly reduced tumor volumes C * p = 0.04 4. Mavros MN, et al. J Am Coll Surg. 2012; 215(6): 820-830.