Search

Background WNT974 is a small molecule inhibitor of Wnt signaling that specifically inhibits porcupine O-acyltransferase. This phase Ib dose-­escalation study evaluated the maximum tolerated dose of WNT974 in combination with encorafenib and cetuximab in patients with BRAF V600E-mutant metastatic colorectal cancer with RNF43 mutations or RSPO fusions. Patients and Methods Patients received once-daily encorafenib and weekly cetuximab, in addition to once-daily WNT974, in sequential dosing cohorts. In the first cohort, patients received 10-mg WNT974 (COMBO10), which was reduced in subsequent cohorts to 7.5-mg (COMBO7.5) or 5-mg (COMBO5) after dose–limiting toxicities (DLTs) were observed. Primary endpoints were incidence of DLTs and exposure to WNT974 and encorafenib. Secondary endpoints were anti-tumor activity and safety. Results Twenty patients were enrolled (COMBO10, n = 4; COMBO7.5, n = 6; COMBO5, n = 10). DLTs were observed in 4 patients, including grade 3 hypercalcemia (COMBO10, n = 1; COMBO7.5, n = 1), grade 2 dysgeusia (COMBO10, n = 1), and lipase increased (COMBO10, n = 1). A high incidence of bone toxicities (n = 9) was reported, including rib fracture, spinal compression fracture, pathological fracture, foot fracture, hip fracture, and lumbar vertebral fracture. Serious adverse events were reported in 15 patients, most frequently bone fracture, hypercalcemia, and pleural effusion. The overall response rate was 10% and disease control rate 85%; most patients achieved stable disease as their best response. Conclusion Concerns surrounding the safety and lack of preliminary evidence of improved anti-tumor activity of WNT974 + encorafenib + cetuximab, compared with previous encorafenib + cetuximab data, ultimately led to study discontinuation. Phase II was not initiated. Trial registration ClinicalTrials.gov, NCT02278133

BACKGROUND Filanesib (ARRY-520) is a highly selective inhibitor of kinesin spindle protein, which has demonstrated preclinical antimyeloma activity. METHODS This open-label Phase 1/2 study determined the maximum tolerated dose of Filanesib administered on Days 1 and 2 of 14-Day Cycles in patients with multiple myeloma (MM) and included expansion cohorts with and without dexamethasone (40 mg/week). Patients in the dose-escalation (N = 31) and Phase 2 single-agent (N = 32) cohorts had received prior bortezomib as well as prior thalidomide and/or lenalidomide. Patients in the Phase 2 Filanesib plus dexamethasone cohort (N = 55) had received prior alkylator therapy and had disease refractory to lenalidomide, bortezomib, and dexamethasone. Prophylactic filgrastim was incorporated during dose escalation and was used throughout Phase 2. RESULTS Patients in each cohort had received a median of ≥6 prior therapies. The most common dose-limiting toxicities were febrile neutropenia and mucosal inflammation. In Phase 2, Grade 3 and 4 cytopenias were reported in approximately 50% of patients. Nonhematologic toxicities were infrequent. Phase 2 response rates (partial responses or better) were 16% (single agent) and 15% (Filanesib plus dexamethasone). All responding patients had low baseline levels of α1-acid glycoprotein, a potential selective biomarker. CONCLUSIONS Filanesib 1.50 mg/m2/day administered with prophylactic filgrastim has a manageable safety profile and encouraging activity in heavily pretreated patients This study is registered at www.clinicaltrials.gov as NCT00821249. Cancer 2017. © 2017 American Cancer Society.

Purpose Filanesib (ARRY-520) is a highly selective, targeted inhibitor of kinesin spindle protein (KSP) inhibitor that induces mitotic arrest and subsequent tumor cell death. This first-in-human Phase 1 study evaluated dose-limiting toxicities (DLTs) and determined a maximum tolerated dose (MTD) for filanesib administered as a 1-h intravenous infusion on 2 treatment schedules in patients with advanced solid tumors. The pharmacokinetics (PK), pharmacodynamics and preliminary efficacy of filanesib were also evaluated. Methods Filanesib was administered on Day 1 of each 3-week cycle (Initial Schedule) or Days 1 and 2 of each 2-week cycle (Alternate Schedule). A standard 3 + 3 dose-escalation design was employed. An expansion cohort was conducted at the MTD of the Initial Schedule. Filanesib PK was evaluated in plasma (both schedules) and urine (Initial Schedule only). Monopolar spindle formation was evaluated in biopsies taken from patients in the expansion cohort. Results Forty-one patients received filanesib. The MTD was equivalent for both the Initial and Alternate Schedules (2.50 mg/m(2)/cycle). The prevalence of neutropenia as a DLT for both schedules necessitated adding prophylactic filgrastim to another dose escalation on the Alternate Schedule (highest tolerated dose 3.20 mg/m(2)/cycle). Neurotoxicity related to filanesib was not observed. Dose-proportional increases in filanesib exposure were observed. The half-life for filanesib was ~70 h. Monopolar spindles in patient biopsy samples indicated KSP inhibition. Stable disease was the best tumor response observed in 18 % (7/39) of evaluable patients. Conclusion Filanesib provided exposures with acceptable tolerability and evidence of target-specific pharmacodynamic effects.

BACKGROUND: ARRY-520 selectively inhibits the mitotic kinesin spindle protein (KSP), which leads to abnormal monopolar spindle formation and apoptosis. METHODS: A phase 1 trial was conducted to establish the safety and the maximum tolerated dose (MTD) of ARRY-520 given as a 1-hour infusion in either a single dose or on a day 1, 3, and 5 divided-dose schedule per cycle in patients with advanced or refractory myeloid leukemias. Additional objectives were to characterize pharmacokinetics, assess preliminary clinical activity, and explore biomarkers of KSP inhibition with ARRY-520. A total of 36 patients with acute myelogenous leukemia (n = 34) or myelodysplastic syndromes (n = 2) with a median age of 66 years (range, 21-88 years) were enrolled: 15 in the single-dose schedule (dose levels: 2.5, 3.75, 4.5, and 5.6 mg/m2) and 21 in the divided-dose schedule (dose levels: 0.8, 1.2, 1.5, and 1.8 mg/m2/day). RESULTS: The MTD was 4.5 mg/m2 total dose per cycle for both dose schedules. Dose-limiting toxicities included mucositis, exfoliative rash, hand-foot syndrome, and hyperbilirubinemia. Grades 3 or 4 reversible drug-related myelosuppression were observed in 33 of 36 patients. Plasma pharmacokinetic analyses revealed low clearance of ARRY-520 (∼3 L/hour), a volume of distribution of ∼450 L, and a median terminal half-life of >90 hours. Monopolar spindles were observed in blood mononuclear cells, through use of 4′,6-diamidino-2-phenylindole nucleic acid stain and antitubulin antibodies. CONCLUSIONS: On the basis of the relative lack of clinical activity, further development of ARRY-520 as an antileukemic agent was halted. (Clinicaltrials.gov identifier NCT00637052). Cancer 2012;3556–3564. © 2011 American Cancer Society.

Lance A Wollenberg,1 Donald T Corson,2,3 Courtney A Nugent,1 Farran L Peterson,1 Ann M Ptaszynski,1 Alisha Arrigo,2,3 Coralee G Mannila,2,3 Kevin S Litwiler,1 Stacie J Bell1,4 1Array BioPharma, Boulder, 2Array BioPharma, Longmont, CO, 3Avista Pharma Solutions, Longmont, CO, 4Mallinckrodt Pharmaceuticals, Ellicott City, MD, USA Background: Pexmetinib (ARRY-614) is a dual inhibitor of p38 mitogen-activated protein kinase and Tie2 signaling pathways implicated in the pathogenesis of myelodysplastic syndromes. Previous clinical experience in a Phase I dose-escalation study of myelodysplastic syndrome patients using pexmetinib administered as neat powder-in-capsule (PIC) exhibited high variability in pharmacokinetics and excessive pill burden, prompting an effort to improve the formulation of pexmetinib. Methods: A relative bioavailability assessment encompassed three parallel treatment cohorts of unique subjects comparing the two new formulations (12 subjects per cohort), a liquid oral suspension (LOS) and liquid-filled capsule (LFC) and the current clinical PIC formulation (six subjects) in a fasted state. The food-effect assessment was conducted as a crossover of the LOS and LFC formulations administered under fed and fasted conditions. Subjects were divided into two groups of equal size to evaluate potential period effects on the food-effect assessment. Results: The geometric mean values of the total plasma exposures based upon area-under-the-curve to the last quantifiable sample (AUClast) of pexmetinib were approximately four- and twofold higher after administration of the LFC and LOS formulations, respectively, than after the PIC formulation, when the formulations were administered in the fasted state. When the LFC formulation was administered in the fed state, pexmetinib AUClast decreased by

ARRY-403 is a glucokinase activator developed for the treatment of diabetes. Less than dose-proportional exposure was observed during single ascending dose studies with ARRY-403. A physiologically based pharmacokinetic (PBPK) model for ARRY-403 was developed through integration of in vitro physicochemical data with precipitation time estimations based on results from the single ascending dose studies; PBPK modeling indicated that the primary cause of the less than dose-proportional exposure was dose-limited absorption because of pH-dependent solubility. The impact of dose, particle size, and fasted or fed state on ARRY-403 exposure was examined through sensitivity analyses and used to refine the PBPK model. On the basis of the marked pH-dependent solubility of ARRY- 403, the refined PBPK model was used to simulate the effects of acid-reducing agents (ARAs) on ARRY-403 exposure, as these agents are widely available and could be coadministered with ARRY-403. The simulations indicated that a clinical study with an ARA was warranted; in a clinical study, famotidine had a marked effect on ARRY-403 exposure. This approach, based on the "predict, learn, and confirm" paradigm, demonstrates the utility of integrating physicochemical properties, in vitro experiments, and clinical results using PBPK to inform formulation development and to guide clinical study design.

Purpose To assess the tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of the mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor AZD6244 (ARRY-142886) in patients with advanced cancer. Patients and Methods In part A, patients received escalating doses to determine the maximum-tolerated dose (MTD). In both parts, blood samples were collected to assess PK and PD parameters. In part B, patients were stratified by cancer type (melanoma v other) and randomly assigned to receive the MTD or 50% MTD. Biopsies were collected to determine inhibition of ERK phosphorylation, Ki-67 expression, and BRAF, KRAS, and NRAS mutations. Results Fifty-seven patients were enrolled. MTD in part A was 200 mg bid, but this dose was discontinued in part B because of toxicity. The 50% MTD (100 mg bid) was well tolerated. Rash was the most frequent and dose-limiting toxicity. Most other adverse events were grade 1 or 2. The PKs were less than dose proportional, with a median half-life of approximately 8 hours and inhibition of ERK phosphorylation in peripheral-blood mononuclear cells at all dose levels. Paired tumor biopsies demonstrated reduced ERK phosphorylation (geometric mean, 79%). Five of 20 patients demonstrated ≥ 50% inhibition of Ki-67 expression, and RAF or RAS mutations were detected in 10 of 26 assessable tumor samples. Nine patients had stable disease (SD) for ≥ 5 months, including two patients with SD for 19 (thyroid cancer) and 22 (uveal melanoma plus renal cancer) 28-day cycles. Conclusion AZD6244 was well tolerated with target inhibition demonstrated at the recommended phase II dose. PK analyses supported twice-daily dosing. Prolonged SD was seen in a variety of advanced cancers. Phase II studies are ongoing.

220 Background: The RAS/RAF/MEK/ERK pathway plays a major role in cell growth and survival and is aberrantly activated in many cancers. MEK162 (ARRY-438162) is a potent, selective, ATP-uncompetitive inhibitor of MEK1/2. The objectives of this Phase 1 expansion study were to characterize the safety, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary efficacy of MEK162 in patients (pts) with biliary tract cancer (BTC). Methods: Pts with unresectable, locally advanced or metastatic BTC who had received ≤ 1 prior systemic therapy received oral MEK162 at 60 mg twice daily (BID). Mutation status of RAS, BRAF and other relevant genes were assessed from tumor samples. Tumor response was assessed every 6 weeks. Results: Twenty-eight pts, median age 64 years (range 30-86) with gallbladder (7), intrahepatic (14) or extrahepatic (7) cholangiocarcinoma (CC) were enrolled. All pts were ECOG 0-1 and 43% received previous first-line therapy (primarily gemcitabine combinations). Of the 23 tumors assessed, 17 were wild type (WT) on all loci tested and 6 had mutations (1 MET, 1 PIK3CA, 2 KRAS, 2 PTEN null). The most common treatment-related AEs were rash, nausea, vomiting, diarrhea, peripheral edema, fatigue and central serous-like retinopathy, and most were Grade (G) 1 or 2. G3/4 treatment-related AEs were anasarca, hypokalemia, hyponatremia, upper/lower gastrointestinal hemorrhage and mucositis (1 each). Thirteen pts were dose reduced for AEs, of which, G1/2 central serous-like retinopathy was the most frequently reported event (6). Three pts were discontinued for treatment-related AEs (G2 central serous-like retinopathy, G1 nausea, G4 anasarca). Of the 26 pts evaluable for response, 1 CR, 1 PR and 11 SD (≥ 6 weeks) were observed. Of note, both responders were WT on all loci tested and had extrahepatic CC. The PK in this population was equivalent to that observed in prior studies. A consistent mean reduction (40-60%) of circulating TNFα was observed. Conclusions: MEK162 has an acceptable safety profile and desirable PK properties at 60 mg BID and RECIST responses were observed in pts with BTC. Additional expansion cohorts are ongoing in pts with KRAS- or BRAF-mutant metastatic colorectal cancer.

Abstract 1860 Background: ARRY-520 is a potent, selective inhibitor of kinesin spindle protein (KSP, eg5) which is required for cell cycle progression through mitosis. Treatment with ARRY-520 arrests cells in mitosis with subsequent induction of apoptosis due to degradation of survival signals during mitotic arrest. Cancers, such as multiple myeloma (MM), that depend on the short-lived survival protein Myeloid cell leukemia (MCL)-1 are highly sensitive to treatment with ARRY-520 in preclinical MM models, providing a strong rationale for its clinical investigation in this disease. Methods: This Phase 1 study was designed to evaluate the safety, pharmacokinetics (PK), preliminary efficacy and biological activity of ARRY-520 administered intravenously on Days 1 and 2 every 2 weeks without/with granulocyte colony-stimulating factor (G-CSF) support. Eligible patients (pts) had relapsed or refractory MM with ≥ 2 prior lines of therapy (including both bortezomib [BTZ] and an immunomodulatory [IMiD] agent), unless refusing or ineligible for this therapy. Cohorts were enrolled in a classical 3+3 dose escalation design. Results: Enrollment in this Phase 1 study is complete. Thirty-one pts have been treated, with a median age of 60 years (range 43–79) and a median of 6 prior regimens (range 2–16). All pts received a prior proteasome inhibitor (30 pts BTZ, 4 pts carfilzomib) and an IMiD-based agent (28 pts lenalidomide, 23 pts thalidomide). Twenty-four pts had an autologous stem cell transplant. The maximum tolerated dose (MTD) was determined to be 1.25 mg/m2/day without G-CSF. As neutropenia was the dose-limiting toxicity (DLT), dose escalation with G-CSF support was conducted and the MTD for ARRY-520 with G-CSF was determined to be 1.5 mg/m2/day. At the MTD, 1 of 7 pts had a DLT of febrile neutropenia. At doses above the MTD, additional DLTs of Grade 3 mucositis and Grade 3 corneal disorder were observed. ARRY-520 demonstrated an acceptable safety profile. The most commonly reported treatment-related adverse events (AEs) included hematologic events (anemia, leukopenia, neutropenia, thrombocytopenia), as well as anorexia, blurred vision, diarrhea, dizziness, fatigue, febrile neutropenia, mucositis, nausea and rash. No treatment-related AEs of neuropathy or alopecia were reported at the MTD. ARRY-520 has been dosed over extended periods of time (to date, median 7 cycles [range 1–44]), with no evidence of cumulative toxicity. The plasma concentrations of ARRY-520 were determined over a 7-day period during Cycle 1 following the Day 1 and 2 infusions of ARRY-520. The preliminary noncompartmental PK parameter estimates in this population were similar to those observed in prior oncology studies. The PK was characterized by low clearance (CL = 2.2 L/hr/m2) and a large volume of distribution (Vss = 232 L/m2). The t1/2 of elimination was very long (67 hrs). Concentrations were typically maintained above the in vitro IC50 for KSP inhibition for ≥ 7 days suggesting therapeutically active concentrations of drug were maintained in pts for sustained periods. Further analyses of PK relative to safety and activity are on-going. ARRY-520 showed activity as a single agent across a range of doses in this heavily pretreated population (31 evaluable pts) with 3 confirmed partial responses (PR) and 1 confirmed minimal response (MR) per International Melanoma Working Group (IMWG) and European Group for Blood and Marrow Transplantation (EMBT) criteria. PRs had a median of 7 prior therapies (range 2–8). Responses were durable; to date, the durations of responses for PRs were 3.4+ months (mos), 11.9+ mos and 12.0 mos, respectively. Of interest, the time to response with ARRY-520 was prolonged, with a median time to PR of 3.7 mos (range 3.7–8.1). Notably, responses were observed in pts refractory to multiple standard-of-care agents. In addition, 4 pts experienced a best response of stable disease (SD) lasting ≥ 10 mos. To date, 5 pts remain on study, including 2 of 3 PRs. Conclusions: In this Phase 1 study, ARRY-520 shows promising evidence of clinical activity, with a long duration of response and an acceptable safety profile in heavily pretreated MM Patients. A Phase 2 portion of the study is ongoing to obtain additional information on the efficacy, safety and biological effects of ARRY-520 at 1.5 mg/m2/day with G-CSF support. Disclosures: Shah: Array BioPharma: Consultancy, Research Funding; Celgene: Consultancy; Onyx: Consultancy, Research Funding. Off Label Use: ARRY-520. Zonder:Millenium: Consultancy, Research Funding, Speakers Bureau; Celgene: Speakers Bureau; Medtronics: Honoraria; Amgen: Consultancy. Cohen:Celgene: Consultancy, Honoraria; Millenium: Consultancy, Honoraria; Onyx: Consultancy, Honoraria. Orlowski:Array BioPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. Alexanian:Array BioPharma: Research Funding. Thomas:Array BioPharma: Research Funding; Centecor: Research Funding; Novartis: Research Funding; Immunomedics: Research Funding; Celgene: Research Funding; Millenium: Research Funding. Weber:Array BioPharma: Research Funding. Kaufman:Keryx: Consultancy; Celgene: Research Funding; Merck: Research Funding. Walker:Array BioPharma: Employment, Equity Ownership. Litwiler:Array BioPharma: Employment. Karan:Array BioPharma: Employment. Hilder:a: Employment. Ptaszynski:Array BioPharma Inc.: Consultancy. Lonial:Millenium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Bristol Myers Squibb: Consultancy; Onyx: Consultancy; Merck: Consultancy.

Background: The RAS/RAF/MEK/ERK pathway plays a major role in cell growth and survival, and is often aberrantly activated in many cancers. MEK162 (ARRY-438162) is a potent, selective, ATP-uncompetitive inhibitor of MEK1/2. The objectives of this completed Phase 1 dose-escalation study were to determine the maximum tolerated dose (MTD) and characterize the safety profile, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary efficacy of MEK162 in patients (pts) with advanced solid tumors. An expansion phase of the study is ongoing in order to further explore toxicity and PK in pts with biliary cancer and in pts with KRAS- or BRAF-mutant metastatic colorectal cancer. Methods: Pts were enrolled in successive cohorts using a 3 + 3 design and received MEK162 as a single oral dose on Day (D) 1 followed by twice daily (BID) dosing starting on D2. Safety was assessed by adverse events (AEs), clinical laboratory tests, physical exams, ECGs, ECHO/MUGA scans and ophthalmic exams. Plasma samples were used to assess PK. Levels of circulating cytokines and growth factors in serum and expression and/or phosphorylation status changes in relevant growth factor pathway proteins in skin were evaluated to assess PD. Mutation status of RAS, RAF and other relevant genes and expression and/or phosphorylation status of MEK pathway protein were assessed from archival tumor samples. Tumor response was assessed every 6 weeks. Results: Nineteen pts of median age 57 years (range 33–79) were enrolled in 4 dose cohorts (30 [4], 45 [4], 60 [7] and 80 [4] mg BID). All pts had prior chemotherapy and were ECOG 0–1. Tumor types included colorectal (7), pancreatic (3), cholangiocarcinoma (2) and other (7). The most common treatment-related AEs were rash, diarrhea, nausea, vomiting and peripheral edema, and most were Grade (G) 1/2. G3/4 treatment-related AEs included G3 rash (2), G3 palmar-planter syndrome (1), G3 central serous-like retinopathy (1) and G3/4 creatine kinase elevation (1 each). Seventeen pts were evaluable for MTD determination (30 [4], 45 [3], 60 [7] and 80 [3] mg BID). All DLTs occurred at 80 mg BID (G3 rash and central serous-like retinopathy, 1 pt each); thus, the MTD was 60 mg BID. Of the 17 pts evaluable for response, 1 pt with NRAS-mutant cholangiocarcinoma achieved a PR, and SD was achieved in 9 pts. Of the 11 other evaluable pts with known mutational status, 2 were wild type on all loci tested, plus 5 KRAS, 1 NRAS, 1 BRAF, 1 PIK3Ca and 1 dual KRAS/PIK3Ca mutants. Exposure increased in a dose-proportional manner with good inter-pt variability (∼30% CV). Exposure by D15 averaged 36% > corresponding D1 values indicating modest accumulation. The median t1/2 was ∼5 hr. Mean steady-state plasma concentrations were continuously maintained above the in vitro IC50 value for cell proliferation at all dose levels. In 7 paired skin biopsies from the 60 mg cohort, decreases in pERK and Ki67 were observed post-dose by immunohistochemistry. In serum, a decrease in TNFα was also observed across all dose cohorts. Conclusions: MEK162 had an acceptable safety profile at doses up to the MTD of 60 mg BID and showed preliminary signs of clinical activity. MEK162 displayed desirable PK properties with dose-dependent exposures. MEK162-induced changes in PD markers of MEK activity suggest that MEK162 has target-related PD activity at multiple-dose levels at and below the MTD. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B243.