Abstract CT120: Axitinib safety and pharmacokinetics in Child-Pugh A and Child-Pugh B patients with advanced hepatocellular cancer

Introduction: Hepatobiliary excretion is the major elimination pathway for axitinib, an oral, potent, selective inhibitor of vascular endothelial growth factor receptors 1, 2 and 3, approved for second-line treatment of advanced renal cell carcinoma. A formal hepatic impairment (HI) study was previously conducted in subjects with Child-Pugh A (CPA) and Child-Pugh B (CPB) disease but who were otherwise healthy to evaluate the effect of mild and moderate HI on the pharmacokinetics (PK) of axitinib following a single 5 mg oral dose. The safety and PK of axitinib were further evaluated in CPA and CPB patients (pts) with advanced hepatocellular carcinoma (HCC) following continuous multiple axitinib dosing.

Methods: Two study portions (randomized double-blind portion of axitinib versus placebo, and non-randomized portion) were conducted in parallel in pts with advanced HCC after failure of one prior antiangiogenic therapy. In the non-randomized portion, the effect of HI on safety and PK were evaluated in HCC CPA (starting dose: 5 mg twice a day [BID]) and CPB (Score 7, starting dose: 2 mg BID) pts. This was also intended to identify the recommended starting dose of axitinib in HCC CPB pts. Serial PK samples up to 8 hour postdose were collected at steady state (Cycle 1 Day 15).

Results: Data from 15 CPA and 7 CPB pts were available for safety analysis. Most pts were male (n = 17) and Asian (n = 21). Overall, the most frequently reported all-causality treatment emergent adverse events (TEAE) in all, CPA and CPB pts were fatigue (63.6%, 80% and 28.6%), decreased appetite (54.5%, 46.7% and 71.4%), diarrhea (45.5%, 60% and 14.3%), hypertension (45.5%, 46.7% and 42.9%), and palmar-plantar erythrodysesthesia syndrome (45.5%, 53.3% and 28.6%). Overall, the most frequently reported Grade ≥3 TEAEs in all, CPA and CPB pts were hypertension (27.3%, 26.7% and 28.6%), fatigue (18.2%, 20% and 14.3%) and hyponatraemia (18.2%, 6.7% and 42.9%). One out of 6 evaluable CPB pts treated with 2 mg BID experienced Cycle 1 dose limiting toxicity (proteinuria; >3.5 g/24 hours). PK samples were collected from 12 CPA and 7 CPB pts (AUC0-24 and CL/F reported for 8 CPA and 6 CPB pts, respectively). In CPA and CPB pts, the geometric mean (geometric% coefficient of variance [CV]) values for axitinib AUC0-24 were 311 (63) and 316 (118) ng.hr/mL, respectively. The geometric mean (geometric% CV) values for axitinib CL/F were 32.2 (63) and 12.7 (118) L/hour, respectively, indicating that axitinib CL/F is decreased with increasing HI.

Conclusions: The safety profile of axitinib in HCC CPA and CPB pts in this study was consistent with the known safety profile of axitinib. Axitinib plasma exposures were comparable in CPB pts receiving 2 mg BID axitinib and CPA pts receiving 5 mg BID axitinib. These data are in agreement with the previous single-dose HI study and further support that 2 mg BID is an appropriate axitinib starting dose for CPB pts with HCC.

Citation Format: Yoon-Koo Kang, Tara E. Seery, Mina Kato, Debasis Chakrabarti, Olga Valota, Ying Chen, Jie Tang, Yazdi K. Pithavala, Masatoshi Kudo. Axitinib safety and pharmacokinetics in Child-Pugh A and Child-Pugh B patients with advanced hepatocellular cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT120. doi:10.1158/1538-7445.AM2015-CT120

Efficacy of Imatinib in Patients with Platelet-Derived Growth Factor Receptor Alpha-Mutated Gastrointestinal Stromal Tumors

Purpose

The incidence of gastrointestinal stromal tumors (GISTs) harboring platelet-derived growth factor receptor alpha (PDGFRA) mutations is low, therefore further investigation of the efficacy of imatinib in this subgroup was needed.

Materials and Methods

Patients with PDGFRA-mutant GISTs who received imatinib as primary therapy for advanced disease between January 2000 and June 2012 were identified from the GIST registry of Asan Medical Center, Seoul, Korea.

Results

KIT and PDGFRA genotyping in 823 patients identified 18 patients (2%) with PDGFRA mutations who were treated with first-line imatinib. Exon 18 D842V substitution, non-D842V exon 18 mutations, and exon 12 mutations were detected in nine (50%), four (22%), and five (28%) patients, respectively. Objective response rate differed significantly between patients with the D842V mutation and those with non-D842V mutations (0% [0/5] vs. 71% [5/7], p=0.03). In all patients, median progression-free survival (PFS) and overall survival (OS) was 24.8 months (95% confidence interval [CI], 0.0 to 57.2) and 51.2 months (95% CI, 37.1 to 65.3), respectively. Significantly, poorer PFS was observed for patients with D842V-mutant GISTs than those with non-D842V PDGFRA-mutant GISTs: median 3.8 months (95% CI, 1.4 to 6.3) versus 29.5 months (95% CI, 18.3 to 40.7) (p < 0.001). Patients with the D842V mutation had poorer OS than those with non-D842V PDGFRA mutations: median 25.2 months (95% CI, 12.7 to 37.8) versus 59.8 months (95% CI, 43.0 to 76.5) (p=0.02).

Conclusion

Imatinib is active against non-D842V PDGFRA-mutant GISTs, whereas GISTs harboring the D842V mutation are primarily resistant to imatinib.

FGFR2 Assessment in Gastric Cancer Using Quantitative Real-Time Polymerase Chain Reaction, Fluorescent In Situ Hybridization, and Immunohistochemistry

OBJECTIVES

Fibroblast growth factor receptor 2 (FGFR2) amplification has been reported to be a target for treatment in gastric cancer. However, an optimal tissue source and method for evaluating FGFR2 have yet to be established.

METHODS

Copy numbers were compared by quantitative polymerase chain reaction (qPCR) using frozen vs formalin-fixed, paraffin-embedded (FFPE) tissue and biopsy vs surgical specimens. We correlated the results of qPCR and immunohistochemistry (IHC) with fluorescence in situ hybridization (FISH) using stage IV gastric cancer biopsy specimens and validated the results in surgical specimens.

RESULTS

FFPE tissues were suitable for qPCR, and biopsy specimens were equivalent to or better than surgical specimens. qPCR and IHC results exhibited an excellent correlation with FISH at eight or more copies by qPCR in any kind of tissue, 5% or more by IHC in biopsy specimens, and 10% or more by IHC in surgical specimens. FGFR2 amplification was 6.6% in stage IV gastric cancers, and 42% of these showed heterogeneous amplification and overexpression. IHC indicated a good correlation with FISH even in the heterogeneous cases.

CONCLUSIONS

FFPE biopsy tissues are an adequate source for FGFR2 evaluation in gastric carcinomas, and a qPCR-based copy number assay can be used for screening. IHC is also a valid and practical method for evaluating FGFR2, considering frequent heterogeneity.

Nilotinib versus imatinib as first-line therapy for patients with unresectable or metastatic gastrointestinal stromal tumours (ENESTg1): a randomised phase 3 trial

BACKGROUND

Nilotinib inhibits the tyrosine kinase activity of ABL1/BCR-ABL1 and KIT, platelet-derived growth factor receptors (PDGFRs), and the discoidin domain receptor. Gain-of-function mutations in KIT or PDGFRα are key drivers in most gastrointestinal stromal tumours (GISTs). This trial was designed to test the efficacy and safety of nilotinib versus imatinib as first-line therapy for patients with advanced GISTs.

METHODS

In this randomised, open-label, multicentre, phase 3 trial (ENESTg1), participants from academic centres were aged 18 years or older and had previously untreated, histologically confirmed, metastatic or unresectable GISTs. Patients were stratified by previous adjuvant therapy and randomly assigned (1:1) via a randomisation list to receive oral imatinib 400 mg once daily or oral nilotinib 400 mg twice daily. The primary endpoint was centrally reviewed progression-free survival. Efficacy endpoints were assessed by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT00785785.

FINDINGS

Because the futility boundary was crossed at a preplanned interim analysis, trial accrual terminated in April, 2011. Between March 16, 2009, and April 21, 2011, 647 patients were enrolled; of whom 324 were allocated nilotinib and 320 were allocated imatinib. At final analysis of the core study (data cutoff, October, 2012), 2-year progression-free survival was higher in the imatinib group (59·2% [95% CI 50·9-66·5]) than in the nilotinib group (51·6% [43·0-59·5]; hazard ratio 1·47 [95% CI 1·10-1·95]). In the imatinib group, the most common grade 3-4 adverse events were hypophosphataemia (19 [6%]), anaemia (17 [5%]), abdominal pain (13; 4%), and elevated lipase level (15; 5%), and in the nilotinib group were anaemia (18; 6%), elevated lipase level (15; 5%), elevated alanine aminotransferase concentration (12; 4%), and abdominal pain (11; 3%). The most common serious adverse event in both groups was abdominal pain (11 [4%] in the imatinib group, 14 [4%] in the nilotinib group).

INTERPRETATION

Nilotinib cannot be recommended for broad use to treat first-line GIST. However, future studies might identify patient subsets for whom first-line nilotinib could be of clinical benefit.

FUNDING

Novartis Pharmaceuticals.

Improving trends in survival of patients who receive chemotherapy for metastatic or recurrent gastric cancer: 12 years of experience at a single institution

BACKGROUND

The aim of this retrospective study was to evaluate the changes in clinical features and treatment outcomes of the patients with metastatic or recurrent gastric cancer (MRGC) treated in the past 12 years.

METHODS

A total of 3888 patients who received chemotherapy for MRGC between January 2000 and December 2011 were analyzed via a prospectively collected registry. The analysis focused on the comparison among three periods: 2000-2003 (period 1), 2004-2007 (period 2) and 2008-2011 (period 3).

RESULTS

There were 880 patients (23%) in period 1, 1573 (40%) in period 2 and 1435 (37%) in period 3. The most commonly used first-line chemotherapy regimen was fluoropyrimidine with/without platinum (72%) for all periods. The use of second- and third-line chemotherapy was slightly but significantly more common in the two recent periods: 46 and 19 % in period 1, 54 and 26% in period 2, and 53 and 27% in period 3, respectively. Overall, 3494 patients (89.9%) died with a median overall survival (OS) of 10.6 months (95% CI 10.2-11.0). The OS was statistically significantly improved over the study period: 9.6 months (95% CI 9.0-10.2) in period 1, 10.3 months (95% CI 9.8-10.9) in period 2 and 11.7 months (95% CI 11.0-12.4) in period 3 (p for trend <0.001). Multivariate analysis including eight prognostic factors (performance, gastrectomy, peritoneal/bone/lung metastasis, abnormal alkaline phosphatase/albumin/total bilirubin) showed that the more recent treatment period was an independent favorable prognostic factor for OS (p < 0.001).

CONCLUSION

The OS of patients who receive chemotherapy for MRGC has been shown to improve over time.

Successful control of heavily pretreated metastatic gastric cancer with the mTOR inhibitor everolimus (RAD001) in a patient with PIK3CA mutation and pS6 overexpression

Background

Everolimus (RAD001) is an orally administered mTOR inhibitor that is well known for its antitumor efficacy and that has been approved for the treatment of several solid tumors, including renal cell carcinoma. In gastric cancer (GC), despite previous preclinical and phase I/II studies suggesting the promising efficacy of everolimus in previously treated AGC, more recent trials revealed that only certain subsets of patients might benefit from treatment with everolimus.

Case presentation

A 26-year-old man with metastatic gastric cancer with multiple liver lesions was treated with everolimus after failure of 1st-line and 2nd-line chemotherapy. A durable partial response was achieved for over 2 years. After progression from initial everolimus treatment, sequential cytotoxic chemotherapies were tried but failed rapidly. Everolimus was re-tried as salvage chemotherapy (re-treatment), and the patient achieved stable disease for 1 year until his death. Subsequent mutational analysis and immunohistochemical (IHC) staining with the tumor tissues just before re-treatment with everolimus revealed a PIK3CA hotspot mutation and pS6 overexpression in the primary tumor. After two cycles of everolimus re-treatment, the overexpression of pS6 became nearly absent in follow-up IHC staining.

Conclusions

Everolimus monotherapy was satisfactory in a patient with refractory metastatic GC harboring PIK3CA and pS6 aberrations. These molecular alterations might be potential biomarkers that can predict the treatment response of everolimus, particularly in the terms of durable disease control. This case suggests and emphasizes that close evaluation of biomarkers in tumor tissue may be essential for identifying highly favorable groups among various subpopulations with AGC.

SEARCH: a phase III, randomized, double-blind, placebo-controlled trial of sorafenib plus erlotinib in patients with advanced hepatocellular carcinoma

PURPOSE

To compare the clinical outcomes of sorafenib plus either erlotinib or placebo in patients with advanced hepatocellular carcinoma (HCC) in a multicenter, multinational, randomized, phase III trial.

PATIENTS AND METHODS

Patients with advanced HCC and underlying Child-Pugh class A cirrhosis, who were naive to systemic treatment (N = 720), were randomly assigned to sorafenib plus either erlotinib (n = 362) or placebo (n = 358). The primary end point was overall survival (OS).

RESULTS

Median OS was similar in the sorafenib plus erlotinib and sorafenib plus placebo groups (9.5 v 8.5 months, respectively; hazard ratio [HR], 0.929; P = .408), as was median time to progression (3.2 v 4.0 months, respectively; HR, 1.135; P = .18). In the sorafenib/erlotinib arm versus the sorafenib/placebo arm, the overall response rate trended higher (6.6% v 3.9%, respectively; P = .102), whereas the disease control rate was significantly lower (43.9% v 52.5%, respectively; P = .021). The median durations of treatment with sorafenib were 86 days in the sorafenib/erlotinib arm and 123 days in the sorafenib/placebo arm. In the sorafenib/erlotinib and sorafenib/placebo arms, the rates of treatment-emergent serious AEs (58.0% v 54.6%, respectively) and drug-related serious AEs (21.0% v 22.8%, respectively) were similar. AEs matched the known safety profiles of both agents, but rates of rash/desquamation, anorexia, and diarrhea were higher in the sorafenib/erlotinib arm, whereas rates of alopecia and hand-foot skin reaction were higher in the sorafenib/placebo arm. Withdrawal rates for AEs during cycles 1 to 3 were higher in the sorafenib/erlotinib arm.

CONCLUSION

Adding erlotinib to sorafenib did not improve survival in patients with advanced HCC.

Intraoperatively assessed macroscopic serosal changes in patients with curatively resected advanced gastric cancer: clinical implications for prognosis and peritoneal recurrence

BACKGROUND

This study aimed to validate the prognostic relevance of macroscopic serosal changes in patients with resected gastric cancer. Prospectively collected databases of two multicenter randomized phase III trials of adjuvant chemotherapy were analyzed.

METHODS

For this study, 655 patients in the control groups of AMC 0101 and 0201 trials were selected. Macroscopic serosal changes were determined according to disruptions in serosal continuity, such as changes in color or nodular texture by the operating surgeon. Correlations with recurrence-free survival (RFS), overall survival (OS), and time to peritoneal recurrence were analyzed.

RESULTS

Macroscopic serosal changes were identified intraoperatively in 432 patients (66 %) and found to be significantly associated with multifocal or diffuse involvement (p = 0.001), Borrmann type 4 (p = 0.005), advanced pathologic T (p < 0.001), N (p < 0.001), overall stage (p < 0.001), and total gastrectomy (p < 0.001). In multivariate analyses, which included prognostic factors of localized gastric cancer, macroscopic serosal changes were significantly associated with poor RFS [hazard ratio (HR) 2.0; 95 % confidence interval (CI), 1.4-2.7; p < 0.001] and OS (HR 2.1; 95 % CI 1.5-3.0; p < 0.001). The changes also were significantly related to shorter time to peritoneal recurrence (HR 2.9; 95 % CI 1.7-5.0; p < 0.001).

CONCLUSIONS

Intraoperatively assessed macroscopic serosal changes confer a poor prognosis and increased peritoneal recurrence for patients with curatively resected gastric cancer. Macroscopic assessment of serosal changes may be a useful indicator that allows better risk stratification of patients with resected gastric cancer in terms of prognosis and peritoneal recurrence.

Randomized phase II study of FOLFOX +/- MET inhibitor, onartuzumab (O), in advanced gastroesophageal adenocarcinoma (GEC)

2

Background: Aberrant up-regulation of the MET/HGF pathway is associated with poor prognosis in multiple malignancies, including GEC. Onartuzumab (O) is a fully humanized, monovalent anti-MET antibody that inhibits HGF binding and receptor activation. We examined the efficacy and safety of mFOLFOX6 and O in the first-line setting for metastatic, HER2-negative GEC. Methods: This was a double-blind, placebo controlled phase II study in which patients were randomized 1:1 to mFOLFOX6 + O 10 mg/kg. Eligibility included no prior treatment for metastatic disease, age >18, ECOG 0-1, retained organ function, HER2-negative, and evaluable disease. The primary objectives were to detect a meaningful improvement in progression free survival (PFS) in the ITT population or the MET-positive (≥ 50% of tumor with moderate-strong intensity staining by IHC based on central review) subgroup. With 120 patients enrolled and 84 PFS events observed, the target HR was 0.7 in the ITT population, and 0.6 in the MET-positive subgroup (estimated 50% of total). Results: 123 patients (83 Asia/Pacific, 40 US) from 25 sites were from 7/2012-5/2013. The treatment arms were well balanced: median age (57 placebo (P), 58.5 O), male (n=36 (59%) P, n=40 (65%) O), and MET-positive (n=19 (33%) P, n=16 (28%) O). Serious adverse events were more frequent with O (55%) vs placebo (40%). Selected grade 3-5 adverse events observed at least 5% more commonly with O included neutropenia (58% vs 45%), thrombocytopenia (10% vs 3%), peripheral edema (10% vs 0), and pulmonary embolism (7% vs 2%). At data cutoff (29 Jan 2014), 96 patients had PFS events (n=46 (74%) O, n=50 (82%) P), with median PFS of 6.77 and 6.97 months, respectively (HR 1.08, 95% CI 0.71-1.63). In the MET-positive subgroup, median PFS was 5.95 months for O and 6.8 months for placebo (HR 1.38 [0.60-3.20]). No difference in efficacy was noted with alternate MET-positive definitions (50% vs 90% MET staining, and 1, 2, or 3+ intensity). Conclusions: The addition of O to mFOLFOX6 in metastatic GEC did not improve PFS in either an unselected population or in MET-positive patients as defined by IHC. Additional biomarker analyses are ongoing to identify patients that may benefit from MET inhibition. Clinical trial information: NCT01662869.

INTEGRATE: A randomized phase II double-blind placebo-controlled study of regorafenib in refractory advanced oesophagogastric cancer (AOGC)—A study by the Australasian Gastrointestinal Trials Group (AGITG), first results

9

Background: Advanced Oesophago-Gastric Carcinoma (AOGC) has limited options following failure of first or second line chemotherapy (CT). Regorafenib (REG) is an oral multi-kinase inhibitor of kinases involved in angiogenesis, tumor microenvironment, and oncogenesis. This study examined whether REG has sufficient activity and safety for further evaluation. Methods: International (Australia & New Zealand (ANZ), Korea, Canada (NCIC CTG)) randomised phase II trial with 2:1 randomisation and stratification by: (1) Lines of prior CT for advanced disease (1 vs. 2) and (2) Region. Eligible patients received best supportive care plus 160mg REG or matching PBO orally on days 1-21 each 28-day cycle until disease progression or prohibitive adverse events. Primary endpoint was progression free survival (PFS) in the REG arm, assuming median 8 weeks (wks) in PBO arm, aiming for 13.2 wks with REG to be of interest. Results: From Nov 2012 to Feb 2014, 152 patients were enrolled, 147 evaluable [pre-specified primary analysis population]: (REG n=97: PBO n=50); well matched for key baseline prognostic indicators; male:female (118:29); primary location: OG Junction (56), stomach (85); lines of prior therapy: 1 (63), 2 (84); ECOG 0 (62): 1 (85). Time on treatment: Median: 7.9 (REG) v 4 (PBO) wks. In the evaluable population median PFS was 11.1 wks (95% CI: 7.7 - 12.3) (REG) and 3.9 wks (95% CI: 3.7 - 4.0) (PBO), log-rank p <0.0001; HR 0.41 (95% CI: 0.28 to 0.59). PFS results were maintained for secondary analysis including all randomized patients (n = 152). REG was well tolerated, with the spectrum of toxicity in keeping with previous reports. Conclusions: PFS was clearly significantly longer with REG than PBO, though PBO PFS was less than anticipated. The pre-specified exploratory comparisons provide compelling evidence that REG has sufficient activity with acceptable tolerability in refractory AOGC to warrant phase III evaluation. Mature OS results will be presented at the meeting. Clinical trial information: 12612000239864.

Intraoperatively assessed macroscopic serosal changes in patients with curatively resected advanced gastric cancer (GC): Clinical implications for prognosis and peritoneal recurrence

23

Background: To validate the prognostic relevance of macroscopic serosal changes in patients with resected GC, we analyzed prospectively collected databases of two multicenter randomized phase III trials on adjuvant chemotherapy. Methods: In total, 655 patients in the control groups of AMC 0101 (NCT00296322) and 0201 (NCT00296335) trials were selected. Macroscopic serosal changes were determined according to disruptions in serosal continuity, such as changes in color or nodular texture by the operating surgeon. Correlations with recurrence-free survival (RFS), overall survival (OS), and time-to-peritoneal recurrence were analyzed. Results: About two-thirds of the patients were male (69%), and the median age was 55 years (range = 29–70 years). According to Lauren’s classification, 215 patients (33%) showed intestinal type. After a median follow-up period of 61.6 months (range = 2.6–113.9 months), the 5-year RFS and OS rates were 55.0% (95% CI = 51.2–58.9%) and 59.9% (95% CI = 56.2–63.6%), respectively. Intraoperatively assessed macroscopic serosal changes were identified in 432 patients (66%). This was significantly associated with multifocal or diffuse gastric cancer (p = 0.001), Borrmann type IV (p = 0.005), advanced pathological T stage (p < 0.001), advanced pathological N stage (p < 0.001), advanced pathological stage (p < 0.001), and total gastrectomy (p < 0.001). In multivariate analyses, which included prognostic factors of localized gastric cancer, macroscopically serosal changes were significantly associated with poor RFS (hazard ratio [HR] = 2.0, 95% CI 1.4–2.7; p < 0.001) and OS (HR = 2.1, 95% CI 1.5–3.0; p < 0.001). It was also significantly related with shorter time-to-peritoneal recurrence (HR = 2.9; 95% CI = 1.7–5.0; p< 0.001). Conclusions: Intraoperatively assessed macroscopic serosal changes confer a poor prognosis and increased peritoneal recurrence in patients with curatively resected GC. Macroscopic assessment of serosal changes may be a useful indicator that allows better risk stratification of patients with resected GC in terms of prognosis and peritoneal recurrence.

Phase I study of ABT-700, an anti-c-Met antibody, in patients (pts) with advanced gastric or esophageal cancer (GEC)

167

Background: MET is a receptor tyrosine kinase associated with treatment resistance. MET amplification (MA) results in c-Met overexpression and activation through autodimerization, and may be an important oncogenic driver in patients (pts) with advanced GEC. MA is relatively rare in primary tumors (<5%), but may increase under the selective pressure of systemic therapy. ABT-700 is an anti-c-Met antibody with significant preclinical single-agent activity against MA human xenograft tumors. Efficacy and safety data for ABT-700 in patients with MA advanced GEC are presented. Methods: MA was assessed in tumor biopsy tissue by fluorescence in situ hybridization (FISH; Abbott Molecular Diagnostics) or DNA sequencing. MA, identified by FISH, was defined as a MET/CEP7 ratio>2 in ≥20% of cells. The dose of ABT-700 is 15 mg/kg IV, once every 3 weeks, established during the dose escalation phase of the study. Responses were assessed using RECIST version 1.1. Results: As of May 31, 2014, 6 pts with chemotherapy refractory GEC have been treated with ABT-700. All pts had disease progression on 3 or more prior lines of chemotherapy. 4/6 pts had MA. 1 pt had MA identified retrospectively, and 3 pts had MA identified through a prospective screening effort. Among the 4 pts with MA GEC, 3 pts had a partial response (PR) and 1 pt had progressive disease (PD) as best response (ORR= 75%). Of the 3 pts who responded, the best response in target lesions was –56%,-52%, and –58%, and the PFS was 27, 18, and 24 weeks, respectively. Each of these three responders had a longer PFS with ABT-700 than with their preceding chemotherapy. In each of the 4 cases of MA identified in this study, MA was only detected in metastatic recurrent tumors and not the primary tumor tissue. The 2 pts without MA had PD as best response. ABT-700 was well tolerated, with no treatment related Grade 3-5 adverse events. Conclusions: In 4 pts with MA GEC, ABT-700 was well tolerated and appeared to have substantial single-agent activity. In this small cohort of gastric patients MA appears to be more common in treatment-refractory tumors than in primary untreated tumors, suggesting that screening efforts should focus on this treatment-refractory patient population. Clinical trial information: NCT01472016.

Phase II study of front-line dovitinib (TKI258) versus sorafenib in patients (Pts) with advanced hepatocellular carcinoma (HCC)

237

Background: HCC is a highly vascularized tumor, and inhibition of angiogenesis by sorafenib (Sor)—a VEGFR and PDGFR inhibitor—delays tumor progression. However, angiogenic escape from Sor may result from activation of the FGFR pathway, which also plays an important role in angiogenesis. Dovitinib (Dov) inhibits FGFR as well as VEGFR and PDGFR. Here, we study frontline Dov vs Sor in pts with advanced HCC. Methods: Eligible pts in this open-label study had ≥ 1 measurable lesion at baseline. All pts were ineligible for or had disease progression after surgical and/or locoregional therapies. Prior systemic HCC therapy was not allowed. Pts were randomized to receive Dov (500 mg/day, 5 days on/2 days off) or Sor (400 mg twice daily) until disease progression, unacceptable toxicity, or death. No treatment crossover was allowed. The primary endpoint was overall survival (OS). The key secondary endpoint was time to tumor progression (TTP) by local investigator’s assessment (per RECIST v1.1). Results: Pts received Dov (n = 82) or Sor (n = 83). Most pts—43 (52.4%) in the Dov arm and 60 (72.3%) in the Sor arm—discontinued treatment due to progressive disease. Median OS (95% CI) was 34.6 wk (28.6-39.4 wk) for Dov and 36.7 wk (23.3-49.3 wk) for Sor; Kaplan-Meier HR, 1.27; 95% CI, 0.89-1.80. Median TTP (95% CI) was 17.6 wk (12.3-18.4 wk) and 17.9 wk (12.3-18.9 wk), respectively. In pts who received ≥ 1 dose of study drug, median duration of exposure was 2.5 mo for Dov (n = 79) and 3.2 mo for Sor (n = 83). The most common adverse events, regardless of cause, were diarrhea (62.0%), decreased appetite (43.0%), nausea and vomiting (40.5% each), fatigue (35.4%), rash (34.2%), and pyrexia (30.4%) in the Dov arm and palmar-plantar erythrodysesthesia syndrome (66.3%), diarrhea (42.2%), and decreased appetite (31.3%) in the Sor arm. VEGFR1 and HGF baseline plasma levels appear to be associated with OS only in the Dov arm. Median OS in the lower biomarker group for both VEGFR1 and HGF was 11 mo while it was 5.6 and 5.9 mo for VEGFR1 and HGF, respectively, in the higher biomarker group. Conclusions: Activity of Dov was not greater than that of Sor in frontline HCC. The safety profile was similar to that observed in other single-agent Dov trials. Clinical trial information: NCT01232296.