Hong, David S.

Abstract Purpose: This first-in-human, open-label phase I study evaluated AMG 337, an oral, highly selective small-molecule inhibitor of MET in advanced solid tumors. Patients and Methods: Patients enrolled into dose-escalation cohorts received AMG 337 up to 400 mg once daily or up to 250 mg twice daily, following a modified 3+3+3 design. Dose expansion was conducted in MET-amplified patients at the maximum tolerated dose (MTD). Primary endpoints included assessment of adverse events (AEs), establishment of the MTD, and pharmacokinetics; clinical response was a secondary endpoint. Results: The safety analysis set included 111 patients who received ≥1 dose of AMG 337. Thirteen patients had ≥1 AE qualifying as dose-limiting toxicity. The MTD was determined to be 300 mg once daily; the MTD for twice-daily dosing was not reached. Most frequent treatment-related AEs were headache (63%) and nausea (31%). Grade ≥3 treatment-related AEs occurred in 23 patients (21%), most commonly headache (n = 6) and fatigue (n = 5). Maximum plasma concentration occurred at 3.0 hours following 300-mg once-daily dosing, indicating AMG 337 absorption soon after treatment. Objective response rate was 9.9% (11/111; 95% CI, 5.1%–17.0%) in all patients and 29.6% (8/27; 95% CI, 13.8%–50.2%) in MET-amplified patients; median (range) duration of response was 202 (51–1,430+) days in all patients and 197 (64–1,430+) days in MET-amplified patients. Conclusions: Oral AMG 337 was tolerated with manageable toxicities, with an MTD and recommended phase II dose of 300 mg once daily. The promising response rate observed in patients with heavily pretreated MET-amplified tumors warrants further investigation. See related commentary by Ma, p. 2375

Abstract Background: MRX34 is a liposomal nanoparticle formulation with an encapsulated mimic of the naturally occurring microRNA-34 (miR-34), which is lost or expressed at reduced levels in many tumors. miR-34 inhibits key oncogenic pathways by repressing multiple important oncogenes including BCL2, E2F3, HDAC1, MET, MEK1, CDK4/6, PDGFR-ɑ/β, SIRT1, WNT1/3, NOTCH-1, β-catenin, CD44, Nanog and AXL. miR-34 also represses the expression of PD-L1 and DGKζ, thereby possibly triggering an anti-tumor immune response and cancer cell death. A multicenter Phase 1 clinical trial of MRX34 is being conducted in patients with advanced malignancies. Methods: Eligible patients were enrolled in a standard 3 + 3 dose escalation study and were given a MRX34 starting dose of 10 mg/m2, administered intravenously (IV) twice weekly (BIW) for 3 weeks in 28-day cycles. Enrollment is ongoing into a second MRX34 dosing schedule, daily x 5 (QD x 5) in 21-day cycles. The primary objectives are to determine the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D) for the two dosing schedules. Secondary objectives include assessments of safety, tolerability and the pharmacokinetic profile of MRX34 after intravenous dosing as well as to assess any biological and clinical activity. Results: As of July 2015, 75 patients with advanced solid tumors were enrolled and evaluable: 44 Caucasians, 47 males, a median age of 61 years and a median of 4 prior treatments. Histologies included 30 hepatocellular carcinoma (HCC), 7 pancreatic cancer, 4 cholangiocarcinoma, 3 each of bladder, breast, colorectal, cervix and lung. The remaining 19 patients represented various other malignancies <3 patients each. The 110 mg/m2 was deemed to be the MTD for the BIW dosing schedule. The MTD has not been determined yet for the QD x 5 schedule and dose escalation is continuing. The current dose levels are 70 mg/m2 QD x 5 for HCC and 93 mg/m2 QD x 5 for other solid tumors. The following treatment-emergent, all-causality adverse events (AEs) were most frequent among 47 patients in BIW cohorts vs 28 patients in QD x 5 cohorts: fever (64% vs 61%), fatigue (57% vs 39%), chills (57% vs 36%), back pain (55% vs 36%), nausea (49% vs 39%), diarrhea (43% vs 11%), headache (34% vs 14%), vomiting (32% vs 11%), anorexia (26% vs 14%), abdominal pain (23% vs 21%), dyspnea (23% vs 14%), insomnia (23% vs 14%), and dehydration (23% vs 4%). Most frequent grade 3/4 laboratory abnormalities were: lymphopenia (36% vs 71%), neutropenia (26% vs 36%), hyponatremia (26% vs 7%), AST elevation (26% vs 29%), leukopenia (23% vs 36%), hyperglycemia (19% vs 36%), thrombocytopenia (17% vs 29%), anemia (11% vs 21%), alkaline phosphatase elevation (11% vs 21%), and ALT elevation (9% vs 21%). One patient with HCC and another patient with melanoma achieved confirmed partial responses per RECIST. Conclusions: MRX34 has a manageable safety profile with confirmed partial responses in two patients with advanced HCC and melanoma. Due to better tolerability, QD x 5 schedule has been chosen for further study. Following MTD determination, enrollment will soon begin into the QD x 5 expansion cohorts for selected tumors. Citation Format: Muhammad Shaalan Beg, Andrew Brenner, Jasgit Sachdev, Samuel Ejadi, Mitesh Borad, Yang-Kon Kang, Ho Lim, T-Y Kim, Andreas Bader, Jay Stoudemire, Susan Smith, Sinil Kim, David Hong. Safety, tolerability, and clinical activity of MRX34, the first-in-class liposomal miR-34 mimic, in patients with advanced solid tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C43.

Abstract Background: MRX34 is a liposome-formulated double-stranded mimic of tumor suppressor microRNA-34 (miR-34), which is lost or expressed at reduced levels in many solid and hematologic malignancies. miR-34 functions in the p53 tumor suppressor pathway and regulates the expression of more than 20 cancer-related genes including BCL2, E2F3, HDAC1, MET, MEK1, CDK4/6, PDGFR-ɑ, SIRT1, WNT1/3, NOTCH-1, β-catenin, CD44, Nanog and AXL. miR-34 also suppresses stem-like properties in cancer cells and sensitizes cancer cells to cytotoxic and targeted therapies. A multicenter phase I clinical trial of MRX34 is being conducted in patients with unresectable hepatocellular carcinoma or metastatic cancer with liver involvement. Methods: Eligible patients are enrolled in a standard 3 + 3 dose escalation study at MRX34 starting dose of 10 mg/m2, administered IV on days 1, 4, 8, 11, 15, and 18 of 28-day cycles. Dexamethasone premedication was added after the first 2 dose levels. The primary objective is to determine the RP2D, and secondary objectives include assessments of safety, PK and objective response rate (ORR). Response is evaluated by CT/MRI every 8 weeks. Once RP2D has been established, expansion cohort will be treated at the RP2D, with specific focus on determining biological response in tumor biopsy material. The latter will include assessing tumor uptake of miR-34 mimic and down-regulation of target gene expression as was observed in animal models of cancer. Results: Twenty-five patients received study drug, and enrollment is currently ongoing at the 5th dose level (70 mg/m2) and MTD has not been reached. There were 18 Caucasians, 15 males, with a median age of 62.5 years and a median of 4 prior treatments. Liposomal formulation-associated infusion reactions have been observed as characterized by the following treatment emergent adverse events (AEs) out of 20 patients: fever (13), chills (12), fatigue (12), thrombocytopenia (8), diarrhea (8), back/flank pain (6), nausea (6), and neutropenia (4). Most common Gr 3/4 AEs were neutropenia (4), thrombocytopenia (3), fatigue (2), AST/ALT elevation (4) and back/flank pain (2). Addition of pre-dose dexamethasone with higher dose levels ameliorated infusion reactions. One patient died on study from disease progression. One dose-limiting toxicity was observed at the 2nd dose level (20 mg/m2; Gr 3 acute kidney injury associated with nausea, vomiting, diarrhea and dehydration) and one at the 5th dose level (70 mg/m2; Gr 3 increased AST). Conclusions: MRX34 has a manageable safety profile in patients with unresectable primary liver cancer or metastatic cancer with liver involvement. Determination of the R2PD, assessment of clinical response, and analyses of molecular markers are ongoing. Citation Format: Muhammad Shaalan Beg, Mitesh Borad, Jasgit Sachdev, David S. Hong, Susan Smith, Andres Bader, Jay Stoudemire, Sinil Kim, Andrew Brenner. Multicenter phase I study of MRX34, a first-in-class microRNA miR-34 mimic liposomal injection. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT327. doi:10.1158/1538-7445.AM2014-CT327