Richard A. Walgren

Docetaxel As Monotherapy or Combined With Ramucirumab or Icrucumab in Second-Line Treatment for Locally Advanced or Metastatic Urothelial Carcinoma: An Open-Label, Three-Arm, Randomized Controlled Phase II Trial

PURPOSE This trial assessed the efficacy and safety of docetaxel monotherapy or docetaxel in combination with ramucirumab (vascular endothelial growth factor receptor 2 antibody) or icrucumab (vascular endothelial growth factor receptor 1 antibody) after progression during or within 12 months of platinum-based regimens for patients with locally advanced or metastatic urothelial carcinoma. PATIENTS AND METHODS Patients were randomly assigned (1:1:1) to receive docetaxel 75 mg/m(2) intravenously (IV) on day 1 of a 3-week cycle (arm A), docetaxel 75 mg/m(2) IV plus ramucirumab 10 mg/kg IV on day 1 of a 3-week cycle (arm B), or docetaxel 75 mg/m(2) IV on day 1 plus icrucumab 12 mg/kg IV on days 1 and 8 of a 3-week cycle (arm C). Treatment continued until disease progression or unacceptable toxicity. The primary end point was investigator-assessed progression-free survival (PFS). RESULTS A total of 140 patients were randomly assigned and treated in arms A (n = 45), B (n = 46), or C (n = 49). PFS was significantly longer in arm B compared with arm A (median, 5.4 months; 95% CI, 3.1 to 6.9 months v 2.8 months; 95% CI, 1.9 to 3.6 months; stratified hazard ratio, 0.389; 95% CI, 0.235 to 0.643; P = .0002). Arm C did not experience improved PFS compared with arm A (1.6 months; 95% CI, 1.4 to 2.9; stratified hazard ratio, 0.863; 95% CI, 0.550 to 1.357; P = .5053). The most common grade 3 or worse adverse events (arms A, B, and C) were neutropenia (36%, 33%, and 39%), fatigue (13%, 30%, and 20%), febrile neutropenia (13%, 17%, and 6.1%), and anemia (6.7%, 13%, and 14%, respectively). CONCLUSION The addition of ramucirumab to docetaxel met the prespecified efficacy end point for prolonging PFS in patients with locally advanced or metastatic urothelial carcinoma receiving second-line treatment and warrants further investigation in the phase III setting.

Failure Modes in Anticancer Drug Discovery and Development

The development of cancer therapy is witnessing a host of technology changes and new insights into the biology of neoplasia. Despite these advances, testing of new molecules in the clinical stages of development remains a lengthy process associated with a high failure rate. This chapter will discuss reasons why failures occur in the clinical development stages of drug development.

Inhibition of Tumor Growth and Metastasis in Non–Small Cell Lung Cancer by LY2801653, an Inhibitor of Several Oncokinases, Including MET

Purpose: Lung cancer is the leading cause of cancer-related death worldwide. Sustained activation, overexpression, or mutation of the MET pathway is associated with a poor prognosis in a variety of tumors, including non–small cell lung cancer (NSCLC), implicating the MET pathway as a potential therapeutic target for lung cancer. Previously, we reported on the development of LY2801653: a novel, orally bioavailable oncokinase inhibitor with MET as one of its targets. Here, we discuss the evaluation of LY2801653 in both preclinical in vitro and in vivo NSCLC models. Experimental Design/Results: Treatment with LY2801653 showed tumor growth inhibition in tumor cell lines and patient-derived tumor xenograft models as a single agent (37.4%–90.0% inhibition) or when used in combination with cisplatin, gemcitabine, or erlotinib (66.5%–86.3% inhibition). Mechanistic studies showed that treatment with LY2801653 inhibited the constitutive activation of MET pathway signaling and resulted in inhibition of NCI-H441 cell proliferation, anchorage-independent growth, migration, and invasion. These in vitro findings were confirmed in the H441 orthotopic model where LY2801653 treatment significantly inhibited both primary tumor growth (87.9% inhibition) and metastasis (64.5% inhibition of lymph node and 67.7% inhibition of chest wall). Tumor-bearing animals treated with LY2801653 had a significantly greater survival time (87% increase compared with the vehicle-treated mice). In the MET-independent NCI-H1299 orthotopic model, treatment with LY2801653 showed a significant inhibition of primary tumor growth but not metastasis. Conclusions: Collectively, these results support clinical evaluation of LY2801653 in NSCLCs and suggest that differences in the MET activation of tumors may be predictive of response. Clin Cancer Res; 19(20); 5699–710. ©2013 AACR.

Survival Patterns in United States (US) Medicare Enrollees with Non-CML Myeloproliferative Neoplasms (MPN)

Purpose Non-CML myeloproliferative neoplasms (MPN) include essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF). Reported median overall survival (OS) ranges from a few to several years for MF, a decade or more for ET and PV. The study objective was to compare US survival rates of ET, PV, and MF patients with matched non-MPN/non-cancer controls in a nationally representative database. Patients and Methods Data were taken retrospectively from the Survey, Epidemiology, and End Results (SEER)-Medicare linked database. Medicare enrollees with a new SEER MPN diagnosis between Jan 1, 2001 and Dec 31, 2007 were eligible. First MPN diagnosis was required at or after Medicare enrollment to allow for continuous follow-up. Non-MPN/non-cancer control groups were selected from Medicare separately for each MPN subtype and demographically matched to cases at a ratio of 5∶1. Survival was determined starting from the case diagnosis date using the Kaplan-Meier method. Results A total of 3,364 MPN patients (n = 1,217 ET; 1,625 PV; 522 MF) met the inclusion criteria and were matched to controls. Mean age was 78.4, 76.1, and 77.4 years for ET, PV, and MF, respectively, and percent female was 63, 50, and 41. Median OS was significantly (p<0.05) lower for MPN cases vs. controls (ET: 68 vs. 101 months; PV: 65 vs. 104; MF: 24 vs. 106). Conclusions In the US Medicare population, survival in MF patients was worse than that of patients with ET or PV and significantly worse than matched controls. Survival of patients with ET or PV was substantially inferior to matched controls. These findings have implications for the clinical management of MPN patients and underscore the need for effective therapies in all MPN subtypes.

A phase 1 study of the Janus kinase 2 (JAK2)V617F inhibitor, gandotinib (LY2784544), in patients with primary myelofibrosis, polycythemia vera, and essential thrombocythemia

Mutations in Janus kinase 2 (JAK2) are implicated in the pathogenesis of Philadelphia-chromosome negative myeloproliferative neoplasms, including primary myelofibrosis, polycythemia vera, and essential thrombocythemia. Gandotinib (LY2784544), a potent inhibitor of JAK2 activity, shows increased potency for the JAK2V617F mutation. The study had a standard 3+3 dose-escalation design to define the maximum-tolerated dose. Primary objectives were to determine safety, tolerability, and recommended oral daily dose of gandotinib for patients with JAK2V617F-positive myelofibrosis, essential thrombocythemia, or polycythemia vera. Secondary objectives included estimating pharmacokinetic parameters and documenting evidence of efficacy by measuring clinical improvement. Thirty-eight patients were enrolled and treated (31 myelofibrosis, 6 polycythemia vera, 1 essential thrombocythemia). The maximum-tolerated dose of gandotinib was 120mg daily, based on dose-limiting toxicities of blood creatinine increase or hyperuricemia at higher doses. Maximum plasma concentration was reached 4h after single and multiple doses, and mean half-life on day 1 was approximately 6h. Most common treatment-emergent adverse events were diarrhea (55.3%) and nausea (42.1%), a majority of which were of grade 1 severity. Best response of clinical improvement was achieved by 29% of myelofibrosis patients. A ≥50% palpable spleen length reduction was observed at any time during therapy in 20/32 evaluable patients. Additionally, ≥50% reduction in the Total Symptom Myeloproliferative Neoplasm Symptom Assessment Form Score was seen in 11/21 (52%) and 6/14 patients (43%) receiving ≥120mg at 12 and 24 weeks respectively. Gandotinib demonstrated an acceptable safety and tolerability profile, and findings at the maximum-tolerated dose of 120mg supported further clinical testing. Clinicaltrials.gov identifier: NCT01134120.

Merestinib (LY2801653) inhibits neurotrophic receptor kinase (NTRK) and suppresses growth of NTRK fusion bearing tumors

Merestinib is an oral multi-kinase inhibitor targeting a limited number of oncokinases including MET, AXL, RON and MKNK1/2. Here, we report that merestinib inhibits neurotrophic receptor tyrosine kinases NTRK1/2/3 which are oncogenic drivers in tumors bearing NTRK fusion resulting from chromosomal rearrangements. Merestinib is shown to be a type II NTRK1 kinase inhibitor as determined by x-ray crystallography. In KM-12 cells harboring TPM3-NTRK1 fusion, merestinib exhibits potent p-NTRK1 inhibition in vitro by western blot and elicits an anti-proliferative response in two- and three-dimensional growth. Merestinib treatment demonstrated profound tumor growth inhibition in in vivo cancer models harboring either a TPM3-NTRK1 or an ETV6-NTRK3 gene fusion. To recapitulate resistance observed from type I NTRK kinase inhibitors entrectinib and larotrectinib, we generated NIH-3T3 cells exogenously expressing TPM3-NTRK1 wild-type, or acquired mutations G595R and G667C in vitro and in vivo. Merestinib blocks tumor growth of both wild-type and mutant G667C TPM3-NTRK1 expressing NIH-3T3 cell-derived tumors. These preclinical data support the clinical evaluation of merestinib, a type II NTRK kinase inhibitor (NCT02920996), both in treatment naïve patients and in patients progressed on type I NTRK kinase inhibitors with acquired secondary G667C mutation in NTRK fusion bearing tumors.

Abstract 2820: LY2784544, a small molecule JAK2 inhibitor, induces apoptosis in inflammatory breast cancer spheres through targeting IL-6-JAK-STAT3 pathway

Inflammatory breast cancer (IBC) is more aggressive and deadly than other breast cancers (K Rowan. JNCI. 2009;101(19):1302-1304). IBC cells secrete angiogenic and vasculogenic growth factors, such as VEGF, bFGF, IL-6 and IL-8, resulting in a cluster of tumor cells, termed anembolus. Through maintaining cell-cell interactions, the IBC emboli can become resistant to “anoikis”, a cell death process following the loss of contact from their neighboring cells. It is hypothesized that this resistance may allow IBC cells to survive the migration through lymphatic vessels and facilitate development of skin and lymph node metastasis. With current therapy, the disease-free survival for IBC patients is only about 35% (SD Merajver et al. J Clin Oncol. 1997;15(8):2873-81). Clearly better therapy is needed for patients with IBC and insights may be gained from exploration of and subsequent interventions in the roles these growth factors play in the biology of IBC. In this study, we investigated the role of IL-6 in activating the signal transducer and activator of transcription 3 (STAT3), conferring resistance to anoikis, and promoting cell proliferation in IBC SUM-149 tumor spheres. Moreover, we targeted JAK2, a transducer of IL-6 signaling to STAT3, by a small molecule JAK2 inhibitor, LY2784544, to inhibit the IL-6-Stat3 pathway and induce apoptosis in SUM-149 tumor spheres. In brief, SUM-149 cells were grown to form tumor spheres under low adherence culture conditions. IL-6 mediated-Stat3 activation and the induction of the cleavage of PARP were evaluated by Western Blotting. Anoikis and cell viability were measured by calcein-AM accumulation and the expression of IL-6 was examined by RT-PCR. We found that exogenous IL-6 activated STAT3, conferred resistance to anoikis and promoted the cell proliferation in SUM-149 cells under the low adherent culture condition. Furthermore, the expression of IL-6 was increased by 50-fold in IBC tumor spheres as measured by RT-PCR. The autocrine production of IL-6 activated STAT3 and inhibited anoikis- induced apoptosis in SUM-149 tumor spheres. Very importantly, we showed that targeting JAK2 by LY2784544 potently inhibited the phosphorylation of STAT3 in a dose dependent manner with an IC50 of 0.25 µM. Blockage of this signal pathway by LY2784544 resulted in potent induction of apoptosis (EC50=0.49 µM). Taken together, these studies suggest the IL-6-JAK-STAT3 pathway may serve as a molecular signature of IBC and as a potential therapeutic target. LY2784544 is currently in clinical studies for the treatment of myeloid proliferative neoplasm indications and the results reported here support clinical investigation for the treatment of IBC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2820. doi:10.1158/1538-7445.AM2011-2820

MET-targeting antibody (emibetuzumab) and kinase inhibitor (merestinib) as single agent or in combination in a cancer model bearing MET exon 14 skipping

SummaryPurpose Approximately 3% of lung cancer bears mutations leading to MET exon 14 skipping, an oncogenic driver which is further evidenced by case reports of patient response to MET kinase inhibitor treatment. Approximately 15% of tumors harboring MET exon14 skipping have concurrent MET amplification. Experimental Design Merestinib is a type II MET kinase inhibitor. Emibetuzumab, a bivalent anti-MET antibody, internalizes MET receptor. Each single agent and the combination were evaluated in the Hs746t gastric cancer line bearing MET exon14 skipping and MET amplification. Results Merestinib inhibited Hs746t cell proliferation (IC50=34 nM) and totally eliminated pMET at 100nM. Emibetuzumab showed little anti-proliferative activity against Hs746t cells (IC50>100nM), did not reduce pMET, and slightly reduced cell surface MET. In the Hs746t xenograft model, dose dependent differences in durability of response were seen with merestinib including durable tumor regression (91.8%) at 12 mg/kg qd. Emibetuzumab treatment (10mg/kg qw) provided transient tumor regression (37.7%), but tumors re-grew while on treatment. Concurrent combination of merestinib (6 mg/kg qd) and emibetuzumab resulted in 85% tumor regression, while a sequential combination (initiating merestinib first) resulted in longer duration of treatment response. Conclusions Data in this study support a clinical evaluation of merestinib in patients with MET exon 14 skipping (NCT02920996). As a type II MET kinase inhibitor, merestinib may provide a therapeutic option to treatment naïve patients or to patients who progress on type I MET inhibitor treatment. Data also support clinical evaluation of the sequential combination of merestinib with emibetuzumab when patients progress on single agent merestinib.

Abstract 1738: Assay development for detecting cMET expression in circulating tumor cells (CTC), a potential patient tailoring marker for evaluation of cMET inhibitors

Hepatocyte growth factor and its receptor c-MET have been implicated in tumor formation and progression as well as drug treatment resistance to targeted agents such as EGFR inhibitors. cMET over-expression or gene amplification has been reported in a wide variety of human malignancies correlating with poor patient prognosis. A reasonable hypothesis for experimental agents targeting the cMET receptor is that patients with tumors expressing high levels of cMET may respond better. CTC counts are prognostic of survival in metastatic breast, colorectal, and prostate cancers (NEJM 2004;351:781-91; J Clin Oncol 2008;26:3213-21; Clin Can Res 2008;14:6302-9). CTCs are shed from tumors and are believed to be representative of cells migrating to form distal metastasis. The presence of these cells in blood provides an attractive and easy source for serial monitoring of tumors without the limitations of traditional solid tumor biopsy. We describe here the development of an assay that measures cMET expression in CTCs. The CTC assay was developed using the Veridex CellSearch® System, and RUO reagents for enumeration of CTCs and a Lilly proprietary cMET antibody (Ab) optD11. For assay development, cultured tumor cell lines with differing cMET expression levels representing solid epithelial tumor types were spiked into whole blood drawn into a CellSave tube. For initial assay development, mouse whole blood was used and results reproduced subsequently with human whole blood from healthy subjects. The spiked tumor cells in blood samples were recovered using the CellCapture™ Mouse/Rat CTC kit (for mouse blood) or CellSearch® CXC kit (for human blood), supplemented with the fluorescent dye (R- phycoerythrin) conjugated anti-cMET Ab. cMET in the recovered tumor cells was detected in the open/fourth channel on the CellTrack® Analyzer II®. Several proprietary and commercial cMET antibodies were screened for specificity and sensitivity. A commonly used commercially available cMET Ab (Santa Cruz Biotechnology C28) was not able to discriminate between cMET negative and positive cell lines. Results were confirmed by flow cytometry and by western blot analyses. optD11 was selected for CTC cMET expression assay development for the following reasons: a) ability to detect different cMET levels among positive cell lines (H441, MKN45, SNU5, SKOV3) while identifying SKBR3 as cMET negative; b) high affinity for cMET to allow for an image acquisition time of 0.02-0.04 second in the open channel; c) tolerance to the presence of LY2875358 (LA480), an experimental therapeutic anti-cMET Ab, allowing evaluation of cMET levels in CTCs post-treatment. The CTC assay for cMET expression, as well as a CTC assay measuring cMET gene amplification are currently being implemented in the early phase clinical studies for Lilly cMET inhibitors (JSBA, NCT01285037 & JTBA, NCT01287546). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1738. doi:1538-7445.AM2012-1738

Ramucirumab Plus Pembrolizumab in Patients with Previously Treated Advanced or Metastatic Biliary Tract Cancer: Nonrandomized, Open‐Label, Phase I Trial (JVDF)

Abstract Lessons Learned. Ramucirumab plus pembrolizumab revealed no unexpected safety findings in patients with advanced or metastatic biliary tract cancer, which is consistent with reports of other tumor cohorts within this phase Ia/b trial. Ramucirumab plus pembrolizumab did not demonstrate an improvement in overall survival when compared with historical controls in biomarker unselected, heavily pretreated patients with advanced or metastatic biliary tract cancer. Patients with programmed death‐ligand 1 (PD‐L1)‐positive tumors had improved overall survival compared with patients with PD‐L1‐negative disease. Background. Few treatment options exist for patients with advanced biliary tract cancer (BTC) following progression on gemcitabine‐cisplatin. Preclinical evidence suggests that simultaneous blockade of vascular endothelial growth factor receptor 2 (VEGFR‐2) and programmed death 1 (PD‐1) or programmed death‐ligand 1 (PD‐L1) enhances antitumor effects. We assessed the safety and efficacy of ramucirumab, an IgG1 VEGFR‐2 antagonist, with pembrolizumab, an IgG4 PD‐1 antagonist, in biomarker‐unselected patients with previously treated advanced or metastatic BTC. Methods. Patients had previously treated advanced or metastatic adenocarcinoma of the gallbladder, intrahepatic and extrahepatic bile ducts, or ampulla of Vater. Ramucirumab 8 mg/kg was administered intravenously on days 1 and 8 with intravenous pembrolizumab 200 mg on day 1 every 3 weeks. The primary endpoint was safety and tolerability of the combination. Secondary endpoints included objective response rate (ORR), progression‐free survival (PFS), and overall survival (OS). Results. Twenty‐six patients were treated at 12 centers in five countries. Hypertension was the most common grade 3 treatment‐related adverse event (TRAE), occurring in five patients. One patient experienced a grade 4 TRAE (neutropenia), and no treatment‐related deaths occurred. Objective response rate was 4%. Median progression‐free survival and overall survival were 1.6 months and 6.4 months, respectively. Conclusion. Ramucirumab‐pembrolizumab showed limited clinical activity with infrequent grade 3–4 TRAEs in patients with biomarker‐unselected progressive BTC.