Search

PDF - 101 KB

PDF - 182 KB, Table S1. Kinase selectivity profile for LY3023414 in Cerep and Life Technologies assays based on a 3-point concentration response curve; Table S2. In vitro inhibitory activity of LY3023414 against kinases in a PC3 cell lysate measured in the KiNativ assay based on a 3-point concentration response curve; Table S3. In vitro cell-based target inhibition in SKOV3, A2780, and AsPC-1; Table S4. Summary of pathway-relevant genetic alterations in cancer cell line panel and in selected patient-derived xenograft tumor models tested; Table S5. Activated caspase-3/7 levels in cell lines treated with 2.5 μM LY3023414 for 48 hours; Table S6. In vitro combination studies with LY3023414 and standard of care agents in various cancer cell lines; Table S7. Time course of in vivo target inhibition in U87 MG xenograft tumors after oral administration of 15 and 30 mg/kg LY3023414; Table S8. Summary of LY3023414 monotherapy efficacy in patient-derived xenograft tumor models; Table S9. Summary of LY3023414 combination efficacy in patient-derived xenograft squamous non-small cell lung cancer (NSCLC) tumor models.

PDF - 564 KB, Figure S1. Duodenal compound concentration profile of multiple compounds from a gastroduodenal passage simulation model; Figure S2. Kinetics of LY3023414 inhibition of PI3Kα; Figure S3. LY3023414 inhibition of mTORC1 in a concentration-dependent manner after ex vivo treatment of PMBC or whole blood; Figure S4. Activity of LY3023414 in a tumor clonogenic assay with a panel of patient-derived tumor xenografts passaged in nude mice and then grown in soft agar; Figure S5. Mean (±SD) concentrations of LY3023414 in male mice plasma, male rat plasma, and male beagle dog plasma following single dose; Figure S6. In vivo efficacy of LY3023414 and rapamycin alone and in combination using (A) H1975 and (B) 786-O xenograft tumor models.

Supplementary Methods and Supplementary Figure Legends

Preclinical Data for Emibetuzumab and DC-101

Figures S1 to S4

Supplementary Tables. Supplementary Table S1. Summary of cell lines used. Supplementary Table S2. Summary of Repeat-Dose Toxicity Study with LY2875358

Progression-free Survival in Gastric Cancer population, MET +23

Exploratory Analysis of Different MET Expression Cut-offs in HCC Cohort

Purpose: The PI3K/mTOR pathway is frequently aberrated in cancer. LY3023414 is a potent and selective ATP-competitive inhibitor of class I PI3K isoforms, mTOR, and DNA-PK. Here we report the dose-escalation results of the first-in-human phase I study of LY3023414.Patients and Methods: A 3+3 dose escalation for once-daily and twice-daily oral dosing of LY3023414 was followed by an expansion cohort for CYP3A4 drug–drug interaction (DDI) assessment. The primary objective was to determine the recommended phase 2 dose (RP2D). Additional objectives included safety, pharmacokinetics/pharmacodynamics, and antitumor activity.Results: Forty-seven patients with solid tumors received LY3023414 at once-daily (20–450 mg) or twice-daily dosing (150–250 mg). Dose-limiting toxicities were observed at 450 mg once-daily (thrombocytopenia, hypotension, hyperkalemia) in three of three patients, 250-mg twice-daily dosing (hypophosphatemia, fatigue, mucositis) in three of four patients, and in one of 15 patients at 200 mg twice-daily (nausea). Common related AEs included nausea (38%), fatigue (34%), and vomiting (32%) and were mostly mild or moderate. LY3023414 pharmacokinetics demonstrated dose-dependent increase in exposure with ≥ 90% target inhibition at doses ≥150 mg. DDI analysis demonstrated LY3023414 to be a weak inhibitor of CYP3A4. Durable partial response was observed in a patient with endometrial cancer harboring PIK3R1 and PTEN truncating mutations, and 13 additional patients (28%) had a decrease in their target lesions by up to 30%.Conclusions: LY3023414 has a tolerable safety profile and single-agent activity in patients with advanced cancers. The RP2D of LY3023414 monotherapy is 200 mg twice daily based on safety, tolerability, and pharmacokinetic/pharmacodynamic data. Clin Cancer Res; 24(14); 3253–62. ©2018 AACR.

Supplementary Figure from Phase Ib/II Study of Enzalutamide with Samotolisib (LY3023414) or Placebo in Patients with Metastatic Castration-Resistant Prostate Cancer

Supplementary figures titles and legends are placed in this document

Purpose: In this study, we tested the antitumor activity of the dual phosphoinositide 3-kinase (PI3K)/mTOR inhibitor BEZ235 against gastric cancer in vitro and in vivo.Experimental Design: Gastric cancer cell lines (N87, MKN45, and MKN28) were incubated with BEZ235 and assessed for cell viability, cell cycle, and PI3K/mTOR target inhibition. In vivo, athymic nude mice were inoculated with N87, MKN28, or MKN45 cells and treated daily with BEZ235. 3′-Deoxy-3′-[18F]fluorothymidine ([18F]FLT) uptake was measured via small animal positron emission tomography (PET).Results:In vitro, BEZ235 dose dependently decreased the cell viability of gastric cancer cell lines. The antiproliferative activity of BEZ235 was linked to a G1 cell-cycle arrest. In vivo, BEZ235 treatment resulted in PI3K/mTOR target inhibition as shown by dephosphorylation of AKT and S6 protein in all xenograft models. However, BEZ235 treatment only inhibited tumor growth of N87 xenografts, whereas no antitumor effect was observed in the MKN28 and MKN45 xenograft models. Sensitivity to BEZ235 in vivo correlated with downregulation of the proliferation marker thymidine kinase 1. Accordingly, [18F]FLT uptake was only significantly reduced in the BEZ235-sensitive N87 xenograft model as measured by PET.Conclusion: In conclusion, in vivo sensitivity of gastric cancer xenografts to BEZ235 did not correlate with in vitro antiproliferative activity or in vivo PI3K/mTOR target inhibition by BEZ235. In contrast, [18F]FLT uptake was linked to BEZ235 in vivo sensitivity. Noninvasive [18F]FLT PET imaging might qualify as a novel marker for optimizing future clinical testing of dual PI3K/mTOR inhibitors. Clin Cancer Res; 17(16); 5322–32. ©2011 AACR.

Table S1. Treatment emergent adverse events regardless of causality in {greater than or equal to}10% of patients; Table S2. Best Overall Response; Table S3. Reasons for Emibetuzumab Discontinuation.

PDF file - 631K

Supplementary Tables 1-3

Supplemental Figures: S1-S4

Purpose:To report efficacy and safety of samotolisib (LY3023414; PI3K/mTOR dual kinase and DNA-dependent protein kinase inhibitor) plus enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC) following cancer progression on abiraterone.Patients and Methods:In this double-blind, placebo-controlled phase Ib/II study (NCT02407054), following a lead-in segment for evaluating safety and pharmacokinetics of samotolisib and enzalutamide combination, patients with advanced castration-resistant prostate cancer with progression on prior abiraterone were randomized to receive enzalutamide (160 mg daily)/samotolisib (200 mg twice daily) or placebo. Primary endpoint was progression-free survival (PFS) assessed by Prostate Cancer Clinical Trials Working Group criteria (PCWG2). Secondary and exploratory endpoints included radiographic PFS (rPFS) and biomarkers, respectively. Log-rank tests assessed treatment group differences.Results:Overall, 13 and 129 patients were enrolled in phase Ib and II, respectively. Dose-limiting toxicity was not reported in patients during phase Ib and mean samotolisib exposures remained in the targeted range despite a 35% decrease when administered with enzalutamide. In phase II, median PCWG2-PFS and rPFS was significantly longer in the samotolisib/enzalutamide versus placebo/enzalutamide arm (3.8 vs. 2.8 months; P = 0.003 and 10.2 vs. 5.5 months; P = 0.03), respectively. Patients without androgen receptor splice variant 7 showed a significant and clinically meaningful rPFS benefit in the samotolisib/enzalutamide versus placebo/enzalutamide arm (13.2 months vs. 5.3 months; P = 0.03).Conclusions:Samotolisib/enzalutamide has tolerable side effects and significantly improved PFS in patients with mCRPC with cancer progression on abiraterone, and this may be enriched in patients with PTEN intact and no androgen receptor splice variant 7.

Purpose:Inhibition of the VEGFR-2 blocks angiogenesis and attenuates tumor growth, but cancers may evade this effect through activation of the hepatocyte growth factor receptor MET. Here we report results of the phase Ib/II study of ramucirumab, a monoclonal anti-VEGFR-2 antibody, plus the anti-MET mAb emibetuzumab.Patients and Methods:A 3+3 dose escalation of emibetuzumab plus ramucirumab (phase Ib) was followed by tumor-specific expansion cohorts. Primary objectives were to determine the recommended phase II dose and to evaluate antitumor activity. Secondary objectives included safety, pharmacokinetics, and immunogenicity. Tumoral MET expression was explored by immunohistochemistry (IHC).Results:A total of 97 patients with solid tumor [6 phase Ib, 16 gastric or gastroesophageal junction adenocarcinoma, 45 hepatocellular carcinoma (HCC), 15 renal cell carcinoma, and 15 non–small lung cancer] received emibetuzumab at 750 or 2,000 mg flat dosing plus ramucirumab at 8 mg/kg every 2 weeks. No dose-limiting toxicities were observed. Common adverse events were primarily mild or moderate and included fatigue (36.1%), peripheral edema (28.9%), and nausea (14.4%). Emibetuzumab exposures were similar as in previous studies with no apparent drug–drug interactions. Five partial responses (5.2%) were observed across all tumor types. The greatest antitumor activity was noted in HCC with a 6.7% overall response rate, 60% disease control rate, and 5.42 months (95% confidence interval, 1.64–8.12) progression-free survival (PFS). HCC with high MET expression showed improved PFS with approximately 3-fold increase in PFS (8.1 vs. 2.8 months) relative to low MET expression.Conclusions:Ramucirumab plus emibetuzumab was safe and exhibited cytostatic antitumor activity. MET expression may help to select patients benefitting most from this combination treatment in select tumor types.

Treatment duration by patient and emibetuzumab dose for emibetuzumab monotherapy (A) and emibetuzumab + erlotinib (B).

Purpose: MET, the receptor for hepatocyte growth factor (HGF), has been implicated in driving tumor proliferation and metastasis. High MET expression is correlated with poor prognosis in multiple cancers. Activation of MET can be induced either by HGF-independent mechanisms such as gene amplification, specific genetic mutations, and transcriptional upregulation or by HGF-dependent autocrine or paracrine mechanisms.Experimental Design/Results: Here, we report on LY2875358, a novel humanized bivalent anti-MET antibody that has high neutralization and internalization activities, resulting in inhibition of both HGF-dependent and HGF-independent MET pathway activation and tumor growth. In contrast to other bivalent MET antibodies, LY2875358 exhibits no functional agonist activity and does not stimulate biologic activities such as cell proliferation, scattering, invasion, tubulogenesis, or apoptosis protection in various HGF-responsive cells and no evidence of inducing proliferation in vivo in a monkey toxicity study. LY2875358 blocks HGF binding to MET and HGF-induced MET phosphorylation and cell proliferation. In contrast to the humanized one-armed 5D5 anti-MET antibody, LY2875358 induces internalization and degradation of MET that inhibits cell proliferation and tumor growth in models where MET is constitutively activated. Moreover, LY2875358 has potent antitumor activity in both HGF-dependent and HGF-independent (MET-amplified) xenograft tumor models. Together, these findings indicate that the mechanism of action of LY2875358 is different from that of the one-armed MET antibody.Conclusions: LY2875358 may provide a promising therapeutic strategy for patients whose tumors are driven by both HGF-dependent and HGF-independent MET activation. LY2875358 is currently being investigated in multiple clinical studies. Clin Cancer Res; 20(23); 6059–70. ©2014 AACR.

Purpose: The MET/HGF pathway regulates cell proliferation and survival and is dysregulated in multiple tumors. Emibetuzumab (LY2875358) is a bivalent antibody that inhibits HGF-dependent and HGF-independent MET signaling. Here, we report dose escalation results from the first-in-human phase I trial of emibetuzumab.Experimental Design: The study comprised a 3+3 dose escalation for emibetuzumab monotherapy (Part A) and in combination with erlotinib (Part A2). Emibetuzumab was administered i.v. every 2 weeks (Q2W) using a flat dosing scheme. The primary objective was to determine a recommended phase II dose (RPTD) range; secondary endpoints included tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and antitumor activity.Results: Twenty-three patients with solid tumors received emibetuzumab monotherapy at 20, 70, 210, 700, 1,400, and 2,000 mg and 14 non–small cell lung cancer (NSCLC) patients at 700, 1,400, and 2,000 mg in combination with erlotinib 150 mg daily. No dose-limiting toxicities and related serious or ≥ grade 3 adverse events were observed. The most common emibetuzumab-related adverse events included mild diarrhea, nausea, and vomiting, and mild to moderate fatigue, anorexia, and hypocalcemia in combination with erlotinib. Emibetuzumab showed linear PK at doses >210 mg. Three durable partial responses were observed, one for emibetuzumab (700 mg) and two for emibetuzumab + erlotinib (700 mg and 2,000 mg). Both of the responders to emibetuzumab + erlotinib had progressed to prior erlotinib and were positive for MET protein tumor expression.Conclusions: Based on tolerability, PK/PD analysis, and preliminary clinical activity, the RPTD range for emibetuzumab single agent and in combination with erlotinib is 700 to 2,000 mg i.v. Q2W. Clin Cancer Res; 23(8); 1910–9. ©2016 AACR.

Background: Alterations in fibroblast growth factor receptor 2 (FGFR2) have emerged as promising drug targets for intrahepatic cholangiocarcinoma, a rare cancer with a poor prognosis. Futibatinib, a next-generation, covalently binding FGFR1-4 inhibitor, has been shown to have both antitumor activity in patients with FGFR-altered tumors and strong preclinical activity against acquired resistance mutations associated with ATP-competitive FGFR inhibitors. Methods: In this multinational, open-label, single-group, phase 2 study, we enrolled patients with unresectable or metastatic FGFR2 fusion-positive or FGFR2 rearrangement-positive intrahepatic cholangiocarcinoma and disease progression after one or more previous lines of systemic therapy (excluding FGFR inhibitors). The patients received oral futibatinib at a dose of 20 mg once daily in a continuous regimen. The primary end point was objective response (partial or complete response), as assessed by independent central review. Secondary end points included the response duration, progression-free and overall survival, safety, and patient-reported outcomes. Results: Between April 16, 2018, and November 29, 2019, a total of 103 patients were enrolled and received futibatinib. A total of 43 of 103 patients (42%; 95% confidence interval, 32 to 52) had a response, and the median duration of response was 9.7 months. Responses were consistent across patient subgroups, including patients with heavily pretreated disease, older adults, and patients who had co-occurring TP53 mutations. At a median follow-up of 17.1 months, the median progression-free survival was 9.0 months and overall survival was 21.7 months. Common treatment-related grade 3 adverse events were hyperphosphatemia (in 30% of the patients), an increased aspartate aminotransferase level (in 7%), stomatitis (in 6%), and fatigue (in 6%). Treatment-related adverse events led to permanent discontinuation of futibatinib in 2% of the patients. No treatment-related deaths occurred. Quality of life was maintained throughout treatment. Conclusions: In previously treated patients with FGFR2 fusion or rearrangement-positive intrahepatic cholangiocarcinoma, the use of futibatinib, a covalent FGFR inhibitor, led to measurable clinical benefit.

Background: FGFR4 is a receptor tyrosine kinase shown to be commonly overexpressed in rhabdomyosarcoma (RMS). In fusion positive (FP) RMS, FGFR4 overexpression is driven by the PAX3-FOXO1 fusion oncogene. In fusion negative (FN) RMS, FGFR4 is often overexpressed and mutationally activated in 7.5% of patients. CRISPR knockout experiments have shown that many RMS cell lines are dependent on FGFR4 for survival. Thus, targeting FGFR4 with a small molecule inhibitor is a promising approach to treat RMS. Futibatinib, a highly selective, irreversible FGFR1-4 inhibitor that was recently granted FDA approval for cholangiocarcinoma, may be effective in treating RMS. Single agent small molecule therapy with kinase inhibitors commonly leads to acquired resistance through compensatory signaling pathways. We hypothesized that inhibition of FGFR4 would lead to suppression of negative feedback loops, resulting in activation of oncogenic kinase pathways. Furthermore, we hypothesized that dual inhibition of FGFR4 and one of these upregulated kinases would be synergistic in delaying or reversing RMS progression. Methods: Cell viability assay was used to determine the IC50 of futibatinib in RMS cell lines in which FGFR4 is mutationally activated (RMS559, FN RMS) or overexpressed (RH4, FP RMS). A high throughput kinome activity assay was used to discover kinases that were activated in RMS cells treated with futibatinib. A drug matrix screen combining futibatinib with 144 drugs was used to discover synergistic combinations. Incucyte live cell imaging was used to validate the synergy of the inhibitor combinations. Western blot was used to confirm the activity of the kinase inhibitors. Caspase activity assays were used to monitor apoptosis. Results: The IC50 of futibatinib was ~500 nM for RMS559 and ~10 μM for RH4. Western blot showed that futibatinib inhibited FGFR4 phosphorylation in a dose dependent manner. The kinome activity assay found that futibatinib treatment resulted in SFK, AKT, and IGF1R activation. Drug matrix screening in RMS559 found that futibatinib was synergistic with SFK, IGF1R, and AKT inhibitors at cell killing. Incucyte confluence measurements confirmed the synergy of futibatinib with SFK, IGF1R, or AKT inhibitors in both RMS559 and RH4. Apoptosis was significantly higher in RMS cells treated with these combinations compared to individual inhibitors. Conclusions and future directions: These results suggest that treating RMS with an FGFR4 inhibitor combined with an SFK, IGF1R, or AKT inhibitor is synergistic in both FGFR4 mutated FN RMS and FGFR4 overexpressed FP RMS. These dual inhibitor therapies may be an effective approach in overcoming resistance to monotherapy and lead to better outcomes in FGFR4-dependent RMS patients. Additionally, our approach may be beneficial for other FGFR-dependent cancers which may develop resistance to monotherapy. Animal studies are underway to determine the in vivo efficacy of these combinations, and top hits will be considered for translation to the clinic. Citation Format: Jerry Wu, Adam Cheuk, Jun S. Wei, Yong Kim, David Milewski, Xiaohu Zhang, Michele Ceribelli, Erin Beck, Paul Shinn, Carleen Klump-Thomas, Kelli M. Wilson, Crystal McKnight, Zina Itkin, Elizabeth Calleja, Volker Wacheck, Hiroshi Sotome, Hiroshi Hirai, Craig Thomas, Javed Khan. Inhibition of FGFR4 with futibatinib combined with inhibition of IGF1R, Src family kinases, or AKT is synergistic against rhabdomyosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB315.

Background: Futibatinib, an irreversible FGFR1-4 inhibitor, is indicated for the treatment of adult patients with previously treated, unresectable, locally advanced or metastatic intrahepatic cholangiocarcinoma harboring FGFR2 gene fusions or other rearrangements. As the primary elimination pathway for futibatinib is hepatic metabolism, we conducted a phase 1 study to evaluate the effect of hepatic impairment (HI) on futibatinib pharmacokinetics (PK) and safety in healthy adults. Methods: A single oral dose of 20 mg futibatinib was administered to adult subjects with mild (Child-Pugh score, 5-6), moderate (7-9), or severe (10-15) HI. Control healthy subjects were matched to each HI cohort according to age, body mass index, and sex. Intensive PK samples were collected up to 72 hours post-dose. Exposure measures (AUC0-inf, AUC0-t, and Cmax) in subjects with HI were compared with matching control cohorts and with the overall healthy-control cohort. Relationships between plasma PK and HI were examined graphically via scatter/regression plots of PK parameters versus baseline Child-Pugh score, bilirubin, albumin, international normalized ratio, and aspartate aminotransferase. Results: Overall, 38 subjects were enrolled (mild HI, n = 8; moderate HI, n = 8; severe HI, n = 6; healthy controls, n = 16). Following the administration of futibatinib, no trend was observed between the severity of HI and the extent of futibatinib exposure increase. Compared with matched controls, AUC0-inf increased by 21%, 20% and 18%, and Cmax by 43%, 15%, and 10% in subjects with mild, moderate, and severe HI, respectively. Changes in exposure were not considered clinically relevant as geometric mean ratios were within 80-125% bioequivalence limits, except for Cmax in subjects with mild HI (43%). Futibatinib PK parameters and HI measures did not appear to be associated based on visual inspection or statistical evaluation of regression plots (p-values all > 0.05). No subjects discontinued from the study due to treatment-emergent adverse events (TEAEs). Overall, two (12.5%) subjects in the healthy-control cohort reported one Grade 1 TEAE each (dyspepsia and headache) and two (25.0 %) subjects in the mild HI cohort each reported one Grade 1 TEAE (toothache and headache). All TEAEs were considered related to treatment. No subjects with moderate/severe HI reported TEAEs. Conclusions: No clinically meaningful differences in the systemic plasma exposure of futibatinib were observed based on the severity of HI. Single oral doses of futibatinib were well tolerated among subjects with varying degrees of HI and matched healthy adult subjects in this study. The data suggest that dose adjustment may not be necessary in patients with HI receiving futibatinib 20 mg QD for its approved indication. Citation Format: Ling Gao, Ikuo Yamamiya, Mark Pinti, Juan Carlos Rondón, Thomas Marbury, Gareth Tomlinson, Lukas Makris, Nanae Hangai, Volker Wacheck. Phase 1, open-label, single-dose study to evaluate the effect of hepatic impairment on the pharmacokinetics and safety of futibatinib in adult subjects [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT192.

This open-label Phase II study conducted prior to routine EGFR mutation testing, assessed whether acquired resistance to erlotinib in NSCLC patients with a given MET protein expression level enriched for EGFRmt could be overcome by emibetuzumab, an antibody against MET. Although some responses were seen, the trial did not meet its primary endpoint. Introduction: The hepatocyte growth factor receptor MET represents a resistance mechanism to epidermal growth factor receptor (EGFR) inhibition in EGFR mutant (mt) non-small cell lung cancer (NSCLC). This Phase 2 study tested whether acquired resistance to erlotinib in MET protein positive NSCLC patients enriched for EGFRmt can be overcome by emibetuzumab plus erlotinib. Patient and Methods: Patients with Stage IV NSCLC with acquired resistance to erlotinib and MET diagnostic (+) (>= 10% of cells expressing MET at >= 2+ IHC staining intensity at any time) were randomized (3:1) to receive emibetuzumab 750 mg every 2 weeks with or without erlotinib 150 mg once daily. The primary objective was to evaluate the overall response rate (ORR) relative to historic control, with a co-primary objective of ORR in patients with MET expression in >= 60% of cells >= 2+ (MET > 60%). Results: One hundred and eleven MET+ patients received emibetuzumab plus erlotinib (N = 83) or emibetuzumab monotherapy (N = 28). 89 of 111 MET+ samples were post-erlotinib. ORR was 3.0% for emibetuzumab plus erlotinib (95% CI: 0.4, 10.5) and 4.3% for emibetuzumab (95% CI: 0.1, 21.9), in patients with post-erlotinib progression biopsies available (n = 89). Similar results were observed in patients with MET >= 60% expression (n = 74). Disease control rate and progression-free survival were higher for emibetuzumab plus erlotinib (50%/3.3 months) than for emibetuzumab (26%/1.6 months). No unexpected safety signals emerged. Partial responses were observed in patients with and without EGFRmt or MET amplification. EGFR sensitizing mutations were identified retrospectively in 84.2% of those with available tissue (85/101). Conclusion: Acquired resistance to erlotinib in MET diagnostic (+) patients was not reversed by emibetuzumab plus erlotinib or emibetuzumab monotherapy, although a subset of patients obtained clinical benefit. (C) 2022 Elsevier Inc. All rights reserved.

SummaryBACKGROUND LY3023414 is a selective, ATP competitive inhibitor of class I PI3K isoforms, mTORC1/2 and DNA-PK. A Phase 1 dose escalation, 200 mg twice daily (BID) of LY3023414 was the determined recommended phase 2 dose (RP2D). We report the antitumor activity and safety of LY3023414 monotherapy in patients with advanced mesothelioma.METHODS Patients enrolled had advanced malignant pleural or peritoneal mesothelioma with measurable disease, ECOG PS 0–1, were refractory or ineligible to receive standard therapies. Patients received LY3023414 200 mg BID. This dose expansion cohort is intended to evaluate preliminary antitumor activity of LY3023414 by overall response rate. Safety, tolerability and pharmacokinetics were assessed. Biomarkers associated with treatment response was an exploratory endpoint. RESULTS Forty-two patients received LY3023414 for a median duration of 11.2 weeks (range: 1.1–53.0). One patient had a confirmed partial response (PR) (ORR 2.4%). Three patients had an unconfirmed PR. Seventeen patients had stable disease (SD) (DCR 43%). Most common adverse events (AEs) included fatigue (43%), nausea (43%), decreased appetite (38%), vomiting (33%), and diarrhea (29%). AEs were mostly mild or moderate. Grade ≥ 3 AEs were reported for 21% of patients with fatigue as the most frequent event (10%). Alterations of BAP1 were identified in 11/19 patients as the most common molecular aberration, followed by SETD2 and NF2 alterations. No obvious pattern of genetic changes/mutations in single genes or pathways was associated with anti-tumor activity. CONCLUSION LY3023414 monotherapy (200 mg BID) demonstrated an acceptable and manageable safety profile with limited single-agent activity in patients with advanced mesothelioma. ClinicalTrials.gov identifier: NCT01655225; Date of registration: 19 July 2012.

586 Background: Futibatinib, a covalently binding FGFR1–4 inhibitor, showed a 42% objective response rate with a 9.7 mo median duration of response in pts with advanced intrahepatic cholangiocarcinoma (iCCA) and FGFR2 fusions/rearrangements in the phase 2 FOENIX-CCA2 trial. Futibatinib treatment (tx) was safe and tolerable with a predictable and manageable side effect profile. This pooled retrospective analysis examined mgmt of futibatinib-associated AEs in pts with advanced tumors, including iCCA. Methods: Pts from a global phase 1/2 study (NCT02052778) and a Japanese phase 1 study (JapicCTI-142552) who received futibatinib 20 mg QD (recommended dose) were included. Futibatinib dose modifications and supportive medications (meds) for AE mgmt were analyzed for futibatinib-associated AEs of clinical interest (group terms: hyperphosphatemia, hepatic AEs, retinal disorders, nail disorders, rash, palmar plantar erythrodysesthesia [PPE], cataract). The Kaplan-Meier method was used for time-to-resolution (TTR) analysis. Results: As of October 1, 2020, 318 pts with advanced solid tumors (60% CCA; 98% with ≥1 prior tx) had received ≥1 futibatinib 20 mg QD dose (median tx duration, 3.6 mo). Table includes incidence and mgmt of key AEs of clinical interest. Hyperphosphatemia was the most frequent cause of futibatinib dose modifications; 85% and 30% of pts with hyperphosphatemia received phosphate binders and/or phosphaturic agents, respectively, with no obvious TTR differences. Other common supportive meds included analgesics (in 55% of pts with nail disorders; 71% with PPE) and corticosteroids (37% of pts with rash). Retinal disorders occurred in 8% of pts (all grade [gr] 1-2 and resolved). Cataract, a late-onset AE on continued tx, occurred in 12 (4%; 4 [1%] gr ≥3) pts, leading to dose modifications in 3 pts. One pt underwent cataract surgery and resumed futibatinib tx the next day. Discontinuations due to tx-related AEs were rare (2.5%) and included 1 pt each with retinal detachment, onycholysis, and cataract. Conclusions: This analysis of AE mgmt showed a consistent and manageable safety profile for futibatinib in pts with pretreated advanced tumors. Commonly observed AEs with futibatinib were well managed with dose adjustments and supportive meds and rarely led to tx discontinuation. Clinical trial information: NCT02052778 /JapicCTI-142552. [Table: see text]

Introduction The hepatocyte growth factor receptor mesenchymal-epithelial transition (MET) is reported to be a negative prognostic marker in EGFR-mutant NSCLC and involved in resistance to EGFR inhibitors. Emibetuzumab, a humanized immunoglobulin G4 monoclonal bivalent MET antibody, blocks ligand-dependent and ligand-independent hepatocyte growth factor/MET signaling. This phase 2 study compared erlotinib with and without emibetuzumab in first-line treatment of EGFR-mutant metastatic NSCLC. Methods Patients with stage IV EGFR-mutant NSCLC and disease control after an 8-week lead-in with erlotinib (150 mg daily) were randomized to continue taking erlotinib with or without emibetuzumab (750 mg every 2 weeks). The primary end point was progression-free survival (PFS). Additional end points included overall survival, overall response rate, safety, pharmacokinetics, and exploratory analysis of MET expression. Results No significant difference in median PFS was observed in the intent-to-treat population (9.3 months with emibetuzumab + erlotinib versus 9.5 months with erlotinib monotherapy [hazard ratio (HR) = 0.89, 90% confidence interval (CI): 0.64–1.23]). The median overall survival was 34.3 months with emibetuzumab plus erlotinib versus 25.4 months with erlotinib (HR = 0.74, 90% CI: 0.49–1.11). Emibetuzumab plus erlotinib was well tolerated, with peripheral edema and mucositis as the only adverse events occurring 10% or more frequently relative to erlotinib. Exploratory post hoc analysis showed an improvement of 15.3 months in median PFS for the 24 patients with the highest MET expression (MET expression level of 3+ in ≥90% of tumor cells) (20.7 with emibetuzumab + erlotinib versus 5.4 months with erlotinib [HR = 0.39, 90% CI: 0.17–0.91]). Conclusions No statistically significant difference in PFS was noted in the intent-to-treat population. Exploratory analysis confirmed that high MET expression is a negative prognostic marker for patients treated with erlotinib, indicating that emibetuzumab plus erlotinib may provide clinically meaningful benefit.

Purpose: To report efficacy and safety of samotolisib (LY3023414; PI3K/mTOR dual kinase and DNA-dependent protein kinase inhibitor) plus enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC) following cancer progression on abiraterone. Patients and Methods: In this double-blind, placebo-controlled phase Ib/II study (NCT02407054), following a lead-in segment for evaluating safety and pharmacokinetics of samotolisib and enzalutamide combination, patients with advanced castration-resistant prostate cancer with progression on prior abiraterone were randomized to receive enzalutamide (160 mg daily)/samotolisib (200 mg twice daily) or placebo. Primary endpoint was progression-free survival (PFS) assessed by Prostate Cancer Clinical Trials Working Group criteria (PCWG2). Secondary and exploratory endpoints included radiographic PFS (rPFS) and biomarkers, respectively. Log-rank tests assessed treatment group differences. Results: Overall, 13 and 129 patients were enrolled in phase Ib and II, respectively. Dose-limiting toxicity was not reported in patients during phase Ib and mean samotolisib exposures remained in the targeted range despite a 35% decrease when administered with enzalutamide. In phase II, median PCWG2-PFS and rPFS was significantly longer in the samotolisib/enzalutamide versus placebo/enzalutamide arm (3.8 vs. 2.8 months; P = 0.003 and 10.2 vs. 5.5 months; P = 0.03), respectively. Patients without androgen receptor splice variant 7 showed a significant and clinically meaningful rPFS benefit in the samotolisib/enzalutamide versus placebo/enzalutamide arm (13.2 months vs. 5.3 months; P = 0.03). Conclusions: Samotolisib/enzalutamide has tolerable side effects and significantly improved PFS in patients with mCRPC with cancer progression on abiraterone, and this may be enriched in patients with PTEN intact and no androgen receptor splice variant 7.

4009 Background: Survival outcomes are historically poor in patients (pts) with advanced/metastatic iCCA, with median overall survival (mOS) times of approximately 1 year with first-line gemcitabine plus cisplatin and approximately 6 months with second-line chemotherapy. Futibatinib, a highly selective, irreversible FGFR1–4 inhibitor, demonstrated efficacy with durable responses in pts with iCCA harboring FGFR2 fusion/rearrangements in the pivotal FOENIX-CCA2 phase 2 study (NCT02052778). At the primary analysis of this trial (data cutoff: October 1, 2020), an objective response rate (ORR) of 41.7% was observed, with a median duration of response (mDOR) of 9.7 mo. Here, we report updated efficacy (including mature OS data) and safety data from the final analysis with an additional 8 mo of follow-up. Methods: FOENIX-CCA2 was a single-arm phase 2 study that enrolled pts with advanced/metastatic iCCA with FGFR2 fusion/rearrangement and progressive disease (PD) after ≥1 prior treatment (tx; including gemcitabine plus platinum-based chemotherapy). Pts received futibatinib 20 mg once daily until PD/intolerability. The primary endpoint was ORR per RECIST v1.1 by independent central review. Secondary endpoints were DOR, disease control rate (DCR), progression-free survival (PFS), OS, safety, and patient-reported outcomes. Results: At the time of the final data cutoff (May 29, 2021), median follow-up was 25.0 mo, and 96/103 pts (93%) had discontinued tx. The median number of tx cycles was 13.0 for a median tx duration of 9.1 mo. The confirmed ORR was 41.7% (43/103) and thereby the same as of the primary analysis, as was the DCR (at 82.5%). The ORR was consistent across pt subgroups. The mDOR was 9.5 mo, and 74% of responses lasted ≥6 mo. mPFS was 8.9 mo, with a 12-mo PFS rate of 35.4%. Mature mOS was 20.0 mo, with a 12-mo OS rate of 73.1% . No new safety signals were identified. Common tx-related adverse events (TRAEs) included hyperphosphatemia (85%), alopecia (33%), dry mouth (30%), diarrhea (28%), dry skin (27%), and fatigue (25%). TRAEs resulted in tx discontinuation in 4 pts (4%). No tx-related deaths occurred. Quality of life was maintained from baseline to tx cycle 13. Conclusions: Findings from the final analysis of FOENIX-CCA2 confirm the results of the primary analysis and reinforce the durable efficacy and continued tolerability of futibatinib in previously treated pts with advanced/metastatic iCCA harboring FGFR2 fusion/rearrangements. Mature OS data were consistent with data from the primary analysis and far exceed historical data in this patient population. Clinical trial information: NCT02052778.

440 Background: Futibatinib, an irreversible FGFR1–4 inhibitor, is being investigated for the treatment of advanced intrahepatic cholangiocarcinoma (iCC) with FGFR2 fusions/rearrangements. We conducted an indirect treatment comparison to evaluate efficacy outcomes with futibatinib for advanced iCC patients from the FOENIX-CCA2 trial (NCT02052778) relative to published data for chemotherapy and FGFR inhibitors. Methods: A systematic literature review was conducted to identify clinical trials for FGFR inhibitors published 01/2015-02/2021, with additional targeted searches for chemotherapy data. A simulated treatment comparison was conducted using individual-level patient data from FOENIX-CCA2 and published aggregate data from comparator trials, applying regression models to adjust for between-trial differences in baseline characteristics. Population-adjusted Cox regression models were used for base case time-to-event outcomes (progression-free survival [PFS], overall survival [OS], duration of response [DOR]) and binomial-logistic regressions for binary outcomes (objective response rate [ORR]). Results: Two studies of FGFR inhibitors among previously treated patients with FGFR2 fusions/rearrangements were identified with sufficient data for analysis: FOENIX-CCA2 (n=103) and FIGHT-202 (n=107, pemigatinib). Two studies were identified for chemotherapy in this setting (an analysis of prior systemic therapy in the FIGHT-202 cohort [n=53] and a natural history study using a clinicogenomic database [n=71]). Comparisons of futibatinib with chemotherapy showed significantly lower risk of progression or death with futibatinib (table). Comparisons of futibatinib with pemigatinib showed similar outcomes between treatments (table), however, there was a numerical advantage for futibatinib in all efficacy parameters. Conclusions: Data suggest that futibatinib provides longer survival vs chemotherapy among previously treated advanced iCC patients with FGFR2 fusions/rearrangements. No statistically significant differences were observed in efficacy outcomes between futibatinib and pemigatinib, although numerical trends favored futibatinib. Molecular detail such as improved activity against co-mutated tumours and resistance mutations may explain such trends. [Table: see text]

SummaryLY3023414 is an oral, selective adenosine triphosphate-competitive inhibitor of class I phosphatidylinositol 3-kinase isoforms, mammalian target of rapamycin, and DNA-protein kinase in clinical development. We report results of a 3 + 3 dose-escalation Phase 1 study for twice-daily (BID) dosing of LY3023414 monotherapy in Japanese patients with advanced malignancies. The primary objective was to evaluate tolerability and safety of LY3023414. Secondary objectives were to evaluate pharmacokinetics and to explore antitumor activity. A total of 12 patients were enrolled and received 150 mg (n = 3) or 200 mg (n = 9) LY3023414 BID. Dose-limiting toxicities were only reported at 200 mg LY3023414 for 2 patients with Grade 3 stomatitis. Common treatment-related adverse events (AEs) across both the dose levels included stomatitis (75.0%), nausea (66.7%), decreased appetite (58.3%), diarrhea, and decreased platelet count (41.7%), and they were mostly mild or moderate in severity. Related AEs Grade ≥ 3 reported for ≥1 patient included anemia, stomatitis, hypophosphatemia, and hyperglycemia (n = 2, 16.7%). Two patients discontinued due to AEs (interstitial lung disease and stomatitis). No fatal events were reported. The pharmacokinetic profile of LY3023414 was characterized by rapid absorption and elimination. Five patients had a best overall response of stable disease (150 mg, n = 3; 200 mg, n = 2) for a 55.6% disease control rate. LY3023414 up to 200 mg BID is tolerable and safe in Japanese patients with advanced malignancies.

Purpose Mesenchymal–epithelial transition factor (MET) is expressed in gastric cancer and associated with poor clinical outcomes. We assessed activity, safety, and pharmacokinetics of emibetuzumab, a bivalent monoclonal anti-MET antibody that blocks ligand-dependent and ligand-independent MET signaling. Methods This non-randomized, single-arm, Phase 2 study enrolled Asian patients with MET diagnostic positive advanced gastric adenocarcinoma. Emibetuzumab (2000 mg, intravenous) was given on days 1 and 15 (28-day cycle). The primary endpoint was 8-week progression-free survival rate. Secondary objectives included safety, pharmacokinetics, overall survival, and change in tumor size. Results Tumors from 65 patients were immunohistochemically screened to enroll 15 MET diagnostic positive patients (23% positivity; 8 Japanese, 7 Korean; 10 male). Eight-week progression-free survival rate was 0.47 (70% CI, 0.33–0.59). Disease control rate was 40% (target lesion decreases, three patients; no complete/partial responses according to RECIST). Median overall survival was 17.1 weeks (95% CI, 6.3–not achievable). No serious emibetuzumab-related adverse events or new safety signals emerged. Grade ≥ 3 possibly drug-related adverse events were hyperkalemia, hyponatremia, and hyperuricemia (one each). Emibetuzumab’s pharmacokinetics profile was similar to that observed previously. MET expression and clinical outcomes were not obviously associated. Conclusion Emibetuzumab was well tolerated with limited single-agent activity in advanced gastric adenocarcinoma.

4097 Background: In FOENIX-CCA2 (NCT02052778), a pivotal phase 2 study among iCCA patients (pts) with FGFR2 fusions/rearrangements, the highly selective, irreversible FGFR1–4 inhibitor futibatinib demonstrated a confirmed objective response rate of 41.7%, with a 9.7-month median duration of response. Adverse events were manageable with dosing modifications that did not adversely impact on response. We report outcomes for the preplanned analysis of Patient-Reported Outcomes (PROs) during futibatinib treatment as a secondary objective of FOENIX-CCA2. Methods: Pts enrolled in FOENIX-CCA2 had locally advanced/metastatic unresectable iCCA with FGFR2 fusions/rearrangements, ≥1 prior line of therapy (including gemcitabine/cisplatin) and ECOG PS 0-1. Pts received oral futibatinib 20 mg continuous QD dosing per 21-day cycle. PRO measures included EORTC-QLQ-C30 (1 global health, 5 functional, 9 symptom scales), EQ-5D-3L, and EQ visual analogue scale (VAS). PROs were collected at screening, cycles 2 and 4, every 3 cycles thereafter, and end of treatment. PRO data were evaluated up to cycle 13, the last visit before data were missing for >50% of the PRO population (PRO primary assessment time point). Results: 92/103 (89.3%) pts enrolled had PRO completion data at baseline and a minimum of 1 follow-up assessment (median age 58 y, 56.5% female), with 48 pts having PRO data at cycle 13. At baseline, mean (SD) EORTC QLQ-C30 global health status score was 70.1 (19.4) and EQ VAS score 71.7 (20.3). Mean EORTC QLQ-C30 global health status scores were maintained from baseline to cycle 13, corresponding to 9.0 months on treatment, with no clinically meaningful (≥10-point) changes in individual functional measures (Table). EORTC QLQ-C30 scores across individual symptom measures were also stable from baseline through cycle 13; only constipation showed an average of 10.0-point worsening at only cycle 4. Mean EQ VAS scores were sustained from baseline to cycle 13 (mean change ranging -1.8 to +4.8 across cycles), with values maintained within the population norm range from across 20 countries. Conclusions: Quality of life data from the phase 2 FOENIX-CCA2 trial show that physical, cognitive and emotional functioning, and overall health status were maintained among pts with advanced iCCA receiving futibatinib. Clinical trial information: NCT02052778. [Table: see text]

The PI3K/AKT/mTOR pathway is among the most frequently altered pathways in cancer cell growth and survival. LY3023414 is a complex fused imidazoquinolinone with high solubility across a wide pH range designed to inhibit class I PI3K isoforms and mTOR kinase. Here, we describe the in vitro and in vivo activity of LY3023414. LY3023414 was highly soluble at pH 2–7. In biochemical testing against approximately 266 kinases, LY3023414 potently and selectively inhibited class I PI3K isoforms, mTORC1/2, and DNA-PK at low nanomolar concentrations. In vitro, inhibition of PI3K/AKT/mTOR signaling by LY3023414 caused G1 cell-cycle arrest and resulted in broad antiproliferative activity in cancer cell panel screens. In vivo, LY3023414 demonstrated high bioavailability and dose-dependent dephosphorylation of PI3K/AKT/mTOR pathway downstream substrates such as AKT, S6K, S6RP, and 4E-BP1 for 4 to 6 hours, reflecting the drug's half-life of 2 hours. Of note, equivalent total daily doses of LY3023414 given either once daily or twice daily inhibited tumor growth to similar extents in multiple xenograft models, indicating that intermittent target inhibition is sufficient for antitumor activity. In combination with standard-of-care drugs, LY3023414 demonstrated additive antitumor activity. The novel, orally bioavailable PI3K/mTOR inhibitor LY3023414 is highly soluble and exhibits potent in vivo efficacy via intermittent target inhibition. It is currently being evaluated in phase I and II trials for the treatment of human malignancies. Mol Cancer Ther; 15(10); 2344–56. ©2016 AACR.

PURPOSE: Olaratumab is a human monoclonal immunoglobulin G1 antibody against platelet-derived growth factor receptor-α. We report the nature and frequency of infusion-related reactions (IRRs) with olaratumab in clinical trials and postmarketing reports. METHODS: Data from patients exposed to olaratumab across nine clinical trials were reviewed for IRRs. Blood samples were also analyzed for pre-existing immunoglobulin E anti–galactose-α-1,3-galactose (anti–α-Gal) antibodies. RESULTS: In the clinical trials, IRRs were identified in 70 of 485 patients (14.4%). The most frequent symptoms included flushing, fever or chills, and dyspnea. For 68 of 70 patients (97.1%), the first IRR occurred during the first two cycles of treatment. Grade 3 or worse IRRs were reported in 11 patients (2.3%), all during the first infusion and usually within 15 minutes of the start of the infusion. One IRR-related fatality (0.2%) occurred in a nonpremedicated patient with grade 3 or worse cardiac comorbidities. There was an association between grade 3 or worse IRRs and pre-existing anti–α-Gal antibodies, with a trend toward higher IRR rates in US geographies known to have a higher prevalence of anti–α-Gal antibodies. IRRs in postmarketing reports were consistent in nature and severity with those in the clinical trials. CONCLUSION: Premedication with corticosteroids and antihistamines should occur in all patients before olaratumab infusion, as indicated in labels in the United States and the European Union. Patients receiving olaratumab should be monitored for IRRs in a setting where resuscitation equipment is available for the treatment of IRRs.

Purpose: Inhibition of the VEGFR-2 blocks angiogenesis and attenuates tumor growth, but cancers may evade this effect through activation of the hepatocyte growth factor receptor MET. Here we report results of the phase Ib/II study of ramucirumab, a monoclonal anti-VEGFR-2 antibody, plus the anti-MET mAb emibetuzumab. Patients and Methods: A 3+3 dose escalation of emibetuzumab plus ramucirumab (phase Ib) was followed by tumor-specific expansion cohorts. Primary objectives were to determine the recommended phase II dose and to evaluate antitumor activity. Secondary objectives included safety, pharmacokinetics, and immunogenicity. Tumoral MET expression was explored by immunohistochemistry (IHC). Results: A total of 97 patients with solid tumor [6 phase Ib, 16 gastric or gastroesophageal junction adenocarcinoma, 45 hepatocellular carcinoma (HCC), 15 renal cell carcinoma, and 15 non–small lung cancer] received emibetuzumab at 750 or 2,000 mg flat dosing plus ramucirumab at 8 mg/kg every 2 weeks. No dose-limiting toxicities were observed. Common adverse events were primarily mild or moderate and included fatigue (36.1%), peripheral edema (28.9%), and nausea (14.4%). Emibetuzumab exposures were similar as in previous studies with no apparent drug–drug interactions. Five partial responses (5.2%) were observed across all tumor types. The greatest antitumor activity was noted in HCC with a 6.7% overall response rate, 60% disease control rate, and 5.42 months (95% confidence interval, 1.64–8.12) progression-free survival (PFS). HCC with high MET expression showed improved PFS with approximately 3-fold increase in PFS (8.1 vs. 2.8 months) relative to low MET expression. Conclusions: Ramucirumab plus emibetuzumab was safe and exhibited cytostatic antitumor activity. MET expression may help to select patients benefitting most from this combination treatment in select tumor types.

The article Phase 1 dose-escalation study of a novel oral PI3K/mTOR dual inhibitor, LY3023414, in patients with cancer, written by Shunsuke Kondo, Masaomi Tajimi, Tomohiko Funai, Koichi Inoue, Hiroya Asou, Vinay Kumar Ranka, Volker Wacheck, Toshihiko Doi, was originally published electronically on the publisher's internet portal on 23 June 2020 without open access.

Background and objectives Although MET amplification/overexpression was observed in a subset of gastric cancer (GC) patients, the relationship between MET amplification/overexpression in primary GC and liver metastasis was unclear. Methods GC samples and matched liver metastases (N = 47) were analyzed by fluorescence/silver in-situ hybridization (FISH/SISH) and by immunohistochemistry for MET amplification and MET expression, respectively. MET-copy number (CN) and Met expression data from The Cancer Genome Atlas Stomach Adenocarcinoma (TCGA-STAD, N = 356) were also analyzed. Results Significant overlap existed between MET amplification and Met expression in both primary stomach tumors (P = 0.013) and liver metastasis (P = 0.001). In TCGA-STAD, MET-CN (≥4 copies) and MET expression were also positively correlated (r = 0.761; P = 0.017). Comparative analysis revealed a strong association between MET expression and MET amplification (85% concurrence) in primary stomach tumors and matched liver metastasis. MET status in synchronous liver metastasis (N = 36) was correlated with primary stomach tumors. However, a significant correlation between primary tumors and liver metastases was not observed in patients with metachronous liver metastasis. Survival analyses revealed that both MET amplification and MET overexpression were prognostic of poor outcomes. Conclusions MET amplification and Met overexpression were positively correlated in GC. MET status should be re-evaluated in GC patients with liver metastasis, especially for metachronous metastasis.

Purpose: The PI3K/mTOR pathway is frequently aberrated in cancer. LY3023414 is a potent and selective ATP-competitive inhibitor of class I PI3K isoforms, mTOR, and DNA-PK. Here we report the dose-escalation results of the first-in-human phase I study of LY3023414. Patients and Methods: A 3+3 dose escalation for once-daily and twice-daily oral dosing of LY3023414 was followed by an expansion cohort for CYP3A4 drug–drug interaction (DDI) assessment. The primary objective was to determine the recommended phase 2 dose (RP2D). Additional objectives included safety, pharmacokinetics/pharmacodynamics, and antitumor activity. Results: Forty-seven patients with solid tumors received LY3023414 at once-daily (20–450 mg) or twice-daily dosing (150–250 mg). Dose-limiting toxicities were observed at 450 mg once-daily (thrombocytopenia, hypotension, hyperkalemia) in three of three patients, 250-mg twice-daily dosing (hypophosphatemia, fatigue, mucositis) in three of four patients, and in one of 15 patients at 200 mg twice-daily (nausea). Common related AEs included nausea (38%), fatigue (34%), and vomiting (32%) and were mostly mild or moderate. LY3023414 pharmacokinetics demonstrated dose-dependent increase in exposure with ≥ 90% target inhibition at doses ≥150 mg. DDI analysis demonstrated LY3023414 to be a weak inhibitor of CYP3A4. Durable partial response was observed in a patient with endometrial cancer harboring PIK3R1 and PTEN truncating mutations, and 13 additional patients (28%) had a decrease in their target lesions by up to 30%. Conclusions: LY3023414 has a tolerable safety profile and single-agent activity in patients with advanced cancers. The RP2D of LY3023414 monotherapy is 200 mg twice daily based on safety, tolerability, and pharmacokinetic/pharmacodynamic data. Clin Cancer Res; 24(14); 3253–62. ©2018 AACR.

Summary Purpose 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.

Purpose: MET, the receptor for hepatocyte growth factor (HGF), has been implicated in driving tumor proliferation and metastasis. High MET expression is correlated with poor prognosis in multiple cancers. Activation of MET can be induced either by HGF-independent mechanisms such as gene amplification, specific genetic mutations, and transcriptional upregulation or by HGF-dependent autocrine or paracrine mechanisms. Experimental Design/Results: Here, we report on LY2875358, a novel humanized bivalent anti-MET antibody that has high neutralization and internalization activities, resulting in inhibition of both HGF-dependent and HGF-independent MET pathway activation and tumor growth. In contrast to other bivalent MET antibodies, LY2875358 exhibits no functional agonist activity and does not stimulate biologic activities such as cell proliferation, scattering, invasion, tubulogenesis, or apoptosis protection in various HGF-responsive cells and no evidence of inducing proliferation in vivo in a monkey toxicity study. LY2875358 blocks HGF binding to MET and HGF-induced MET phosphorylation and cell proliferation. In contrast to the humanized one-armed 5D5 anti-MET antibody, LY2875358 induces internalization and degradation of MET that inhibits cell proliferation and tumor growth in models where MET is constitutively activated. Moreover, LY2875358 has potent antitumor activity in both HGF-dependent and HGF-independent (MET-amplified) xenograft tumor models. Together, these findings indicate that the mechanism of action of LY2875358 is different from that of the one-armed MET antibody. Conclusions: LY2875358 may provide a promising therapeutic strategy for patients whose tumors are driven by both HGF-dependent and HGF-independent MET activation. LY2875358 is currently being investigated in multiple clinical studies. Clin Cancer Res; 20(23); 6059–70. ©2014 AACR.