Inhibitor ARQ Research Articles

Abstract 793: The novel Bruton's tyrosine kinase inhibitor ARQ531 disrupts survival signaling and triggers apoptosis in AML cells

Abstract Introduction: Currently available therapeutics against Acute Myeloid Leukemia (AML) have improved patient outcome. However, resistance develops even to novel therapies and patient overall survival remains low, especially for patients who are not eligible for allogeneic bone marrow transplantation. Therefore, there is an urgent need to overcome the biologic mechanisms underlying drug resistance in AML, to both enhance the efficacy of existing treatments and to facilitate the design of novel approaches. The Bruton's tyrosine kinase (BTK) is emerging as new therapeutic target in a wide range of hematologic malignancies including AML, especially those carrying FLT3-ITD mutation. ARQ 531 is an ATP competitive, orally bioavailable, potent inhibitor of BTK and other relevant kinases. Herein we present preclinical data with ARQ 531 in AML and its efficacy compared with the standard BTK inhibitor Ibrutinib. Methods: Inhibitory effects of ARQ531 on cell viability were investigated in a panel of AML cell lines as well as primary tumor cells. The effect of ARQ531 on BCR signaling was investigated by western blot. Specific transcriptomic profiling of ARQ531 treated AML cells was performed by RNA-Seq. NSG mice engrafted with primary AML cells were used to determine anti-AML activity of ARQ531 in vivo. Results: ARQ531 blocked phosphorylation of BTK and downstream protein PLCγ in a panel of AML cell line regardless of their genetic background. ARQ531 also inhibited cell viability of AML cell lines (n=11) and primary AML cells (n=12) with IC50 values lower than reference compound (0.9±1 µM compared with 19±0.6 µM of Ibrutinib). Moreover, ARQ531 effects were not reduced in presence of normal or leukemic mesenchymal stromal cells (MSCs) and, more importantly such treatment showed greater therapeutic window than standard: IC50 value on CD34+ cells from healthy donors was >10µM and ±3 µM after ARQ531or ibrutinib, respectively. A transcriptome profiling analysis revealed a reversion of the oncogenic MYC-driven transcriptional program as specific event triggered by ARQ531. As result, Myc-targets inhibition was observed in AML cells treated with ARQ531 compared with ibrutinib. Finally, the anti-tumor activity of ARQ 531 was determined in AML-PDX model. At 31st day after cell transfer, flow cytometry evaluation of the circulating human CD45+ cells in the murine PB revealed a significant lower leukemia burden after ARQ531 treatment compared with Ibrutinib (10 ± 0.1% and 40 ± 0.01%, respectively; p=0.006) Conclusion: The novel BTK inhibitor ARQ 531 is a highly potent kinase inhibitor with promising activity against AML in preclinical models. Citation Format: soncini debora, stefania orecchioni, antonia cagnetta, veronica retali, samantha ruberti, paola minetto, paola contini, alessio nencioni, fiammetta monacelli, Terence Hall, marco gobbi, sudharshan eathiraj, briam schwartz, francesco bertolini, roberto lemoli, michele cea. The novel Bruton's tyrosine kinase inhibitor ARQ531 disrupts survival signaling and triggers apoptosis in AML cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 793.

Abstract 1882: Preclinical evaluation of the tyrosine kinase inhibitor ARQ 531 in AML

Abstract Acute Myeloid Leukemia (AML) is a rapidly progressing hematopoietic malignancy arising from bone marrow myeloid progenitor cells. Treatment with cytotoxic chemotherapy has not changed for over four decades resulting in poor survival. The dismal prognosis could be attributed to the heterogeneity of this disease, where multiple genetically aberrant clones exist within the same patient. Mutations in the FMS-like tyrosine kinase (FLT3) occurs in 30% of AML patients, typically as an internal tandem duplication (ITD) resulting in a constitutively active FLT3 survival pathway. This has prompted the generation of selective FLT3 inhibitors such as Quizartinib and Gilteritinib which are currently being pursued in clinical trials. Still, acquired resistance to these selective FLT3 inhibitors due to the acquisition of tyrosine kinase domain mutations (TKD) can occur. This suggests that the use of an agent with a broader kinome inhibition profile (such as the recently granted FDA approved Midostaurin) could achieve more durable clinical benefit. ARQ 531 is a novel potent BTK inhibitor currently being investigated in a Phase 1 trial in patients with relapsed/refractory hematological malignancies (ClinicalTrials.gov Identifier: NCT03162536). We have found that ARQ 531 also has inhibitory activity against members of the Src family of kinases (SFK; including downstream target SYK) as well as FLT3. SYK directly binds to and trans-activates FLT3 which is essential for FLT3-ITD tumorigenicity, suggesting that ARQ 531 has therapeutic potential in AML. Therefore we have investigated the in vitro and in vivo efficacy of ARQ 531 in AML. Our preliminary studies demonstrate cytotoxicity for ARQ 531 in patient-derived primary AML cells harboring FLT3 wild type and FLT3-ITD, as well as multiple AML cell lines. Importantly, ARQ 531 is effective in a MOLM-13 tyrosine kinase inhibitor (TKI) resistant cell line harboring a FLT3-ITD-TKD-D835Y mutation. Furthermore, we show that ARQ 531 can reduce the level of phosphorylated FLT3, but unlike selective FLT3 inhibitors, it can also inhibit Src family phosphorylation and SYK phosphorylation. Additionally, ARQ 531 exhibited an anti-clonogenic effect on primary patient blasts using Methocult colony forming unit assay. Finally, to investigate the in vivo effect of ARQ 531, we used an aggressive AML MOLM-13 disseminated xenograft mouse model. NSG mice were randomized one-week post engraftment to either vehicle or daily oral gavage of 50 mg/kg ARQ 531. The estimated median survival for the ARQ 531 group was 23 days compared to 21 days for the vehicle group (p = 0.002) suggesting in vivo efficacy for ARQ 531 in AML. Collectively, we provide for the first time promising preclinical efficacy for ARQ 531 in AML supporting further mechanistic investigation of this agent, and potentially, expansion of the ongoing clinical studies to include AML patients. E. H. and J.C. B. contributed equally as co-senior authors to this work Citation Format: Ola A. Elgamal, Bridget Carmichael, Amy Lehman, Shelley J. Orwick, Minh Tran, Virginia M. Goettl, Shaneice Mitchell, Rosa Lapalombella, Jae Yoon Jeon, Sharyn D. Baker, Sudharshan Eathiraj, Brian Schwartz, Erin Hertlein, John C. Byrd. Preclinical evaluation of the tyrosine kinase inhibitor ARQ 531 in AML [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1882.

Combination of AKT inhibitor ARQ 092 and sorafenib potentiates inhibition of tumor progression in cirrhotic rat model of hepatocellular carcinoma.

The prognosis of patients with advanced hepatocellular carcinoma (HCC) is very poor. The AKT pathway is activated in almost half of HCC cases and in addition, long term exposure to conventional drug treatment of HCC, sorafenib, often results in over-activation of AKT, leading to HCC resistance. Therefore, it is important to assess the safety and the efficacy of selective allosteric AKT inhibitor ARQ 092 (Miransertib) in combination with sorafenib.Here, we demonstrated in vitro that the combination of ARQ 092 with sorafenib synergistically suppressed proliferation, promoted apoptosis, and reduced migration. To test the effect of the combination in vivo, rats with diethylnitrosamine-induced cirrhosis and fully developed HCC were randomized and treated with vehicle, sorafenib, ARQ 092 or the combination of ARQ 092 with sorafenib; (n=7/group) for 6 weeks. Tumor progression, size of tumors and the mean tumor number were significantly reduced by the combination treatment compared to the control or single treatments. This effect was associated with a significant increase in apoptotic response and reduction in proliferation and angiogenesis. Sirius red staining showed a decrease in liver fibrosis. Moreover, treatments improved immune response in blood and in tumor microenvironment.Thus, the combination of ARQ 092 with sorafenib potentiates inhibition of tumor progression and gives the possibility of therapeutic improvement for patients with advanced HCC.

Efficacy of AKT Inhibitor ARQ 092 Compared with Sorafenib in a Cirrhotic Rat Model with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related mortality worldwide. The AKT pathway has been found activated in 50% of HCC cases, making it a promising target. Therefore, we assess efficacy of the allosteric AKT inhibitor ARQ 092 compared with untreated control and standard treatment, sorafenib, in vitro and in vivo ARQ 092 blocked phosphorylation of AKT in vitro and strongly inhibited cell growth with significantly higher potency than sorafenib. Similarly, apoptosis and cell migration were strongly reduced by ARQ 092 in vitro To mimic human advanced HCC, we used a diethylnitrosamine-induced cirrhotic rat model with fully developed HCC. MRI analyses showed that ARQ 092 significantly reduced overall tumor size. Furthermore, number of tumors was decreased by ARQ 092, which was associated with increased apoptosis and decreased proliferation. Tumor contrast enhancement was significantly decreased in the ARQ 092 group. Moreover, on tumor tissue sections, we observed a vascular normalization and a significant decrease in fibrosis in the surrounding liver of animals treated with ARQ 092. Finally, pAKT/AKT levels in ARQ 092-treated tumors were reduced, followed by downregulation of actors of AKT downstream signaling pathway: pmTOR, pPRAS40, pPLCγ1, and pS6K1. In conclusion, we demonstrated that ARQ 092 blocks AKT phosphorylation in vitro and in vivo In the HCC-rat model, ARQ 092 was well tolerated, showed antifibrotic effect, and had stronger antitumor effect than sorafenib. Our results confirm the importance of targeting AKT in HCC. Mol Cancer Ther; 16(10); 2157-65. ©2017 AACR.

In vivo efficacy of the AKT inhibitor ARQ 092 in Noonan Syndrome with multiple lentigines-associated hypertrophic cardiomyopathy.

Noonan Syndrome with Multiple Lentigines (NSML, formerly LEOPARD syndrome) is an autosomal dominant "RASopathy" disorder manifesting in congenital heart disease. Most cases of NSML are caused by catalytically inactivating mutations in the protein tyrosine phosphatase (PTP), non-receptor type 11 (PTPN11), encoding the SH2 domain-containing PTP-2 (SHP2) protein. We previously generated knock-in mice harboring the PTPN11 mutation Y279C, one of the most common NSML alleles; these now-termed SHP2Y279C/+ mice recapitulate the human disorder and develop hypertrophic cardiomyopathy (HCM) by 12 weeks of age. Functionally, heart and/or cardiomyocyte lysates from SHP2Y279C/+ mice exhibit increased basal and agonist-induced AKT and mTOR activities. Here, we sought to determine whether we could reverse the hypertrophy in SHP2Y279C/+ mice using ARQ 092, an oral and selective allosteric AKT inhibitor currently in clinical trials for patients with PI3K/AKT-driven tumors or Proteus syndrome. We obtained echocardiographs of SHP2Y279C/+ and wildtype (SHP2+/+) littermates, either in the presence or absence of ARQ 092 at 12, 14, and 16 weeks of age. While SHP2Y279C/+ mice developed significant left ventricular hypertrophy by 12 weeks, as indicated by decreased chamber dimension and increased posterior wall thickness, treatment of SHP2Y279C/+ mice with ARQ 092 normalized the hypertrophy in as early as 2 weeks following treatment, with hearts comparable in size to those in wildtype (SHP2+/+) mice. In addition, we observed an increase in fractional shortening (FS%) in SHP2Y279C/+ mice, an effect of increased compensatory hypertrophy, which was not apparent in SHP2Y279C/+ mice treated with ARQ 092, suggesting functional improvement of HCM upon treatment with the AKT inhibitor. Finally, we found that ARQ 092 specifically inhibited AKT activity, as well as its downstream effectors, PRAS and S6RP in NSML mice. Taken together, these data suggest ARQ 092 may be a promising novel therapy for treatment of hypertrophy in NSML patients.

Multi-Chemotherapeutic Schedules Containing the pan-FGFR Inhibitor ARQ 087 are Safe and Show Antitumor Activity in Different Xenograft Models

ARQ 087 is a multi-tyrosine kinase inhibitor with potent activity against the FGFR receptor family, currently in Phase I clinical studies for the treatment of advanced solid tumors. The compound has a very safe profile and induces tumor regressions in FGFR-driven models. The feasibility of combining ARQ 087 with chemotherapy was investigated in FGFR deregulated human xenografts. Nude mice were transplanted subcutaneously with H1581, and when tumor masses reached 150 mg, were randomized to receive vehicle, ARQ 087, paclitaxel, carboplatin as single agents or in combination. Similar experimental conditions were applied in nude mice bearing SNU16 and MFE296 xenografts, with the inclusion of capecitabine in the former xenograft model. In the different xenograft models, the drugs given as single agents ranged from very active to partially active. The double combinations were more active than the single ones, but the triple combinations were the most active. In particular, the combination of ARQ 087 + paclitaxel + carboplatin in H1581 bearing mice was able to induce tumor regression in all the mice, with 6/8 mice tumor free at day 140 after tumor transplant. Of note, no toxic deaths nor premature stopping or delaying of drug administration were observed. The data herein reported demonstrated the feasibility of using xenografts models for poli-chemotherapeutic trials mimicking the best standard of care in treatment of specific tumor type and that ARQ 087, a new pan-FGFR inhibitor, can be safely combined with standard cytotoxic chemotherapeutic drugs with apparently no sign of cumulative toxicity and an associated increased antitumor effect.

FRI-106 - Effect of novel AKT inhibitor ARQ 751 as single agent and its combination with sorafenib on hepatocellular carcinoma in a cirrhotic rat model

FRI-106 - Effect of novel AKT inhibitor ARQ 751 as single agent and its combination with sorafenib on hepatocellular carcinoma in a cirrhotic rat model

SAT-131 - AKT inhibitor ARQ 092 and sorafenib additively inhibit progression of hepatocellular carcinoma and improve immune system in cirrhotic rat model

SAT-131 - AKT inhibitor ARQ 092 and sorafenib additively inhibit progression of hepatocellular carcinoma and improve immune system in cirrhotic rat model

The Bruton's Tyrosine Kinase (BTK) Inhibitor ARQ 531 Effectively Inhibits Wild Type and C481S Mutant BTK and Is Superior to Ibrutinib in a Mouse Model of Chronic Lymphocytic Leukemia

Introduction: The Bruton's tyrosine kinase inhibitor ibrutinib improves survival in chronic lymphocytic leukemia (CLL) compared to standard chemotherapy or immune therapy. In a subset of patients, somatic mutation (C481S) of its binding site results in acquired resistance to ibrutinib therapy with poor clinical outcome. ARQ 531 is an ATP competitive, orally bioavailable, potent inhibitor of BTK and other relevant kinases including the majority of Src and Tec family kinases. Herein we present preclinical data with ARQ 531 in CLL including C481S mutated BTK and its efficacy versus ibrutinib in the TCL1 mouse model of CLL.Methods: Potency of ARQ 531 and its binding kinetics were measured in enzymatic and Surface Plasmon Resonance (SPR) binding assays. Primary CLL B cells were negatively selected and treated with 1μM ARQ 531. BCR signaling was investigated by immunoblot following a 1 hour drug incubation. CLL cells migrating towards CXCL12 and CXCL13 after 4 hours across a 5.0 micron transwell insert were counted by flow cytometry. Annexin V and propidium iodide flow cytometry was used to measure CLL viability over a range of drug concentrations and time. CpG mediated CLL cell activation was measured by CD40 and CD86 expression by flow cytometry. In vivo investigation utilized B6 mice engrafted with 1E7 CD5+/CD19+ TCL1 lymphocytes via tail vein injection. Mice were randomized to treatment with vehicle, ARQ 531, or ibrutinib following the establishment of a CD5+/CD19+ population >10% in peripheral blood.Results: At 72 hours the viability of CLL cells treated with 0.1µM, 1.0µM, or 10.0µM ARQ 531 was found to be 94%, 67%, and 50% that of untreated samples, respectively (p=0.76, p<0.001, p=0.016) in comparison to the 71% relative viability seen with 1µM ibrutinib (p<0.001). ARQ 531 demonstrates dose dependent inhibition of BTK, AKT, and ERK phosphorylation. Stimulation through TLR9 by CpG ligand increases expression of the activation markers CD40 and CD86; ARQ 531 decreased CpG induced expression of CD40 by 25% and CD86 by 40% (p=0.022, p=0.041). ARQ 531 in the presence of CXCL12 or CXCL13 decreased migration by 51% and 66%, respectively (p=0.015, p=0.025), below baseline migration of untreated CLL.Unlike ibrutinib, ARQ 531 inhibits both wild type and C481S BTK with an IC50 less than 1nM in a biochemical assay, and inhibits phosphorylation of C481S mutated BTK in LV125 transfected HEK293T cells. Cytotoxicity was also observed in CLL cells isolated from patients with C481S BTK mutations, where the viability of cells treated with 1µM ARQ 531 was 72% that of untreated cells at 72 hours (p=0.038). SPR binding assay showed a residence time of 51 minutes in wild type BTK and 56 minutes in C481S mutated BTK.The TCL1 mouse model displays active BCR signaling and responds to treatment with the BTK inhibitors ibrutinib and acalabrutinib (Ponader S, 2012; Herman SEM, 2015). Following establishment of leukemia in the TCL1 transfer model, we randomized mice to treatment with vehicle (n=14), 25 mg/kg ibrutinib (n=6), 50 mg/kg ARQ 531 (n=14) or 75 mg/kg ARQ 531 (n=14) given by daily gavage. ARQ 531 significantly improved survival over both ibrutinib and vehicle (median survival: 36 days vehicle, 53 days ibrutinib, not reached by 74 days 50mg/kg and 75 mg/kg ARQ 531, p<0.0001). Mice receiving ARQ 531 have consistently lower lymphocyte counts on microscopic examination and reduced CD5+/CD19+ populations via flow cytometry compared to vehicle or ibrutinib. Additionally, we have observed increases in absolute neutrophil count over time in mice receiving ARQ 531. Pharmacokinetic studies are pending; however, in a single oral dose study of 10mg/kg in monkeys, the bioavailability was 72.4% with a CMax of 9µM and a half-life greater than 24 hours.Conclusion: The BTK inhibitor ARQ 531 is a potent inhibitor of BTK with promising activity both in vitro and in vivo. Multi-targeted inhibition of cytokine, chemokine, and BCR pathways by ARQ 531 decreases activation, migration, and viability of CLL cells. Unlike ibrutinib, ARQ 531 inhibits activation of C481S mutated BTK variants and maintains cytotoxicity in ibrutinib resistant clones. Additionally, ARQ 531 has demonstrated remarkable efficacy in an in vivo TCL1 adoptive transfer model, improving survival to a greater extent than ibrutinib and potentially restoring granulocyte production. These data justify continued preclinical work and development to facilitate transition to clinical trials. DisclosuresEathiraj:ArQule, Inc: Employment. Abbadessa:ArQule, Inc: Employment. Schwartz:ArQule, Inc: Employment. Woyach:Acerta: Research Funding; Morphosys: Research Funding; Karyopharm: Research Funding.

FRI-051 - Efficacy of AKT Inhibitor ARQ 092 Compared with Sorafenib in a Cirrhotic Rat Model with Hepatocellular Carcinoma

FRI-051 - Efficacy of AKT Inhibitor ARQ 092 Compared with Sorafenib in a Cirrhotic Rat Model with Hepatocellular Carcinoma

Abstract B111: Efficacy of AKT inhibitor ARQ 092 compared with Sorafenib in a cirrhotic rat model with hepatocellular carcinoma

Abstract Background and aim: Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide. PI3K/AKT pathway is activated in 50% of HCC. The aim of this study was to assess toxicity and efficacy of a new AKT inhibitor (ARQ 092) compared to sorafenib. Method: In vitro experiments were realized with viability, apoptosis and migration assays in 5 different cell lines to analyze the effects of ARQ 092 and sorafenib on the different mechanisms of carcinogenesis. Furthermore, an in vivo study with a diethylnitrosamine (DEN)-induced rat model of HCC on cirrhosis was performed. After 14 weeks of DEN, rats were randomized in 3 groups: control, sorafenib, or ARQ 092 and treated during 6 weeks. Tumor volume and progression were assessed by MRI before treatment, after 3 and 6 weeks of treatment. After euthanasia, pathological analysis of livers was performed assessing tumor numbers and volumes. Results: ARQ 092 showed a dose-dependent decrease in cell viability, induction of apoptosis, and inhibition of migration. In vivo study on 26 rats showed a significantly lower tumor volume in ARQ 092 group: 45.9% of the control versus 60.4% of the control with sorafenib (p = 0.022). Number of tumors per liver was also significantly lower in ARQ 092 group with a mean of 53.9 tumors versus 96.3 tumors in control group (p = 0.001) and 96.8 tumors in sorafenib group (p = 0.015). MRI analysis showed a lower tumor progression in ARQ 092 group with 57.0% versus 155.3% in control group (p&amp;lt;0.0001), and 80.2% in sorafenib group (p = 0.08). Conclusion: ARQ 092 was more significantly control tumor progression in a DEN-induced cirrhotic rat model with HCC compared to sorafenib. Citation Format: Gael S. Roth, Ayca Zeybek, Zusana Macek-Jilkova, Giovanni Abbadessa, Yi Yu, Patrice Marche, Vincent Leroy, Thomas Decaens. Efficacy of AKT inhibitor ARQ 092 compared with Sorafenib in a cirrhotic rat model with hepatocellular carcinoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B111.

481 In vitro and vivo evaluation of the pan FGFR inhibitor ARQ 087 and selective pan AKT inhibitor ARQ 092 in endometrial cancer: potential for combination therapy

481 In vitro and vivo evaluation of the pan FGFR inhibitor ARQ 087 and selective pan AKT inhibitor ARQ 092 in endometrial cancer: potential for combination therapy

O1-070 - Phase I Trials of a C-MET Inhibitor ARQ 197 in Combination with an EGFR Inhibitor Erlotinib in Advanced/Metastatic Non-Small Cell Lung Carcinoma (ARQ 197-003/005 Trial)

O1-070 - Phase I Trials of a C-MET Inhibitor ARQ 197 in Combination with an EGFR Inhibitor Erlotinib in Advanced/Metastatic Non-Small Cell Lung Carcinoma (ARQ 197-003/005 Trial)

Efficacy in selected tumor types in a phase I study of the c-MET inhibitor ARQ 197 in combination with sorafenib.

3034 Background: ARQ 197 (A) is a selective, oral, non-ATP competitive inhibitor of c-MET, a RTK implicated in tumor cell proliferation, invasion and metastasis, currently in phase II/III clinical ...

Phase Ib results of c-MET inhibitor ARQ 197 in combination with gemcitabine in a cohort of patients (pts) with advanced breast, ovarian, and uterine tumors.

3077 Background: ARQ 197 is a non-ATP competitive selective inhibitor of c-MET. In vitro data suggest its synergy with gemcitabine. This study evaluates safety, pharmacokinetics (PK), biomarkers, and preliminary efficacy of the combination treatment in pts with advanced solid tumors. Here we present results of the cohort of pts with metastatic breast, ovarian, and uterine carcinoma. Methods: Multicenter, phase Ib 3+3 dose escalation trial. Oral ARQ 197 administered at doses of 120-360 mg bid across different schedules (continuous vs. continuous with 1 week [wk] break every 2 or 3 wks) in combination with a fixed gemcitabine at 1,000 mg/m2/weekly 3 every 4 wks. Results: As of January 4, 2011, a total of 32 pts with metastatic breast (12), ovarian (14), and uterine (6) carcinoma were enrolled in the study (ECOG 0:1 = 21:11; mean age 61, range 35-77 yrs; with median number of prior systemic therapies = 4 [1–9]). Seven pts had progressed to prior gemcitabine. Adverse events (AEs) considered at least possibly treatment-related were reported in 29 (91%) of these pts. Most commonly observed AEs (>10%) included thrombocytopenia (21; 66%, 4 G 3-4), anemia (21; 66%, 6 G 3-4), neutropenia (20; 63%, 7 G 3-4), fatigue (11; 34%, 3 G 3-4), nausea (9; 31%, 2 G 3-4), vomiting (6; 19%, 1 G 3-4), and leucopenia (4; 13%, 2 G 3-4). Three pts experienced treatment-related serious AEs (pancytopenia, thrombocytopenia, hypotension and interstitial lung disease, grade 3). Post-baseline tumor assessment was done in 27 evaluable pts; of them, 12 remained on study for >10 wks (mean 22; range 10-36), 5 (2 breast, 1 uterine, 2 ovarian) attained partial response (response rate 19%), and 15 demonstrated decline (4-87%) in tumor markers (CA15.3, CA125, CEA). In this study, 2 pts (ovarian and breast) with PR and 2 with SD (breast) had failed prior gemcitabine. Details on efficacy and scheduling will be presented. Conclusions: Orally administered ARQ 197 at the MTD of 360 mg bid in combination with gemcitabine is generally well tolerated and shows encouraging signs of antitumor activity in the presented tumor types.

Phase Ib dose-escalation trial evaluating c-MET inhibitor ARQ 197 administered in combination with gemcitabine to patients (pts) with advanced solid tumors.

e13008 Background: ARQ 197 is a selective, non-ATP competitive inhibitor of c-MET, the exclusive receptor tyrosine kinase for hepatocyte growth factor. Preclinical data suggest combinability of ARQ 197 with gemcitabine. This study aims to evaluate the safety, pharmacokinetics (PK), biomarkers, and preliminary efficacy of the combination in pts with advanced solid tumors. Methods: Multicenter, phase Ib 3+3 dose escalation trial. Oral ARQ 197 is administered at doses of 120-360mg bid across different schedules (continuous vs. continuous with 1 week [wk] break every 2 or 3 wks) in combination with fixed gemcitabine dosing and frequency (1000mg/m2/weekly 3 every 4 wks). Results: 25 metastatic pts (F:M = 13:12; ECOG 0:1 = 12:13; mean age 61, range 44-75 yrs) with mean number of prior systemic treatments = 3.7 (1–9) were treated. No dose-limiting toxicities were observed. Adverse events (AEs) considered at least possibly drug-related were reported in 14 (56%) pts. Most commonly observed (>10%) AEs include neutropenia (10; 40%), thrombocytopenia (6; 24%), anemia (5; 20%), fatigue (4; 16%), leukopenia, nausea, and anorexia (2; 10%). One pt experienced a drug-related serious AE (anemia grade 4). One nonrelated death secondary to hemorrhage occurred on study. Of 16 evaluable pts, 4 pts obtained confirmed partial response by RECIST (ovarian, breast, uterine, NSCLC) and tumor marker decrease (38-83% reduction); 9 pts achieved stable disease (mean duration 15.5, range 8–28+ wks); 4 of these 9 pts had prior progression on gemcitabine (cholangio, ovarian, pancreatic), of whom 3 have now tumor marker decrease (33-80% reduction). PK analysis (patients dosed at 360 mg bid) show a day 1 mean Cmax of 1176 ± 882 ng/mL and AUC(0-12) of 9146 ± 8752 hr*ng/mL. Additional data will be available for presentation. Conclusions: To date, orally administered ARQ 197 in combination with gemcitabine appears well tolerated and without clinically apparent drug-drug interaction or significant exacerbation of known gemcitabine toxicity. Further efficacy is being explored in expanded cohorts for specific tumor types. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration ArQule ArQule

Phase I trial to determine the dose range for the c-Met inhibitor ARQ 197 that inhibits c-Met and FAK phosphorylation, when administered by an oral twice-a-day schedule

3584 Background: ARQ 197 is a non-ATP competitive small molecule inhibitor of c-Met, a receptor tyrosine kinase activated by hepatocyte growth factor/scatter factor and implicated in cell migration, invasion, proliferation and angiogenesis. Methods: Patients (pt) with advanced, safely biopsiable, solid tumors were enrolled to determine safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics and preliminary antitumor activity. Pre and post therapy tumor biopsies were mandated for immunohistochemical studies (IHC) for total and phosphorylated (p) c-Met and its downstream target p-FAK. Tumor biopsies were analyzed for c-Met amplification by FISH and c-Met mutation by sequencing. Circulating endothelial cell (CEC) and circulating tumor cell enumeration were undertaken. Results: To date 14 pt have been treated (8 M; median age 64y) at 100, 200, 300 and 400mg bid continuously. A dose limiting toxicity (DLT) of CTCAEv3 grade (G) 3 fatigue was reported at 200mg bid, which resolved ≤ 24 h of drug cessation and no other DLT was seen after cohort expansion to 6 pt. Other adverse events were ≤ G2 such as fatigue, nausea, vomiting, diarrhea and anorexia. AUC and Cmax increased linearly with dose, but each increase was less than dose proportional. Mean values for t1/2, Cl/F and Vd/F were relatively constant and mean plasma drug concentrations were above the in vitro IC50. Baseline tumor biopsies from 3 of 11 pt had high p-c-Met expression (Aperio digital scanning IHC score > 50) and 6 had high p-FAK (score > 50). Post therapy, 3 of these pt (at 100, 200, 300mg bid) had 72, 73, 66% declines in p-c-Met and 69, 73, 30% declines in p-FAK expression. Another pt at 200mg bid with advanced melanoma and c-Met mutation T276T/A had declines in p-c-Met (21%) and p-FAK (29%) expression and RECIST stable disease (SD) for 20+ weeks (w). Total c-Met expression did not alter significantly. CEC counts declined by a mean of 60% (range 6 - 100%) post therapy in 6 of 9 pt. The best tumor efficacy response has been SD in 5 pt for up to 20+ w. Conclusions: ARQ 197 can inhibit c-Met and FAK phosphorylation in serial tumor biopsies with minimal toxicity up to 300 mg bid, decreasing CEC counts. MTD has not been reached and dose escalation continues. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration ArQule ArQule ArQule