A first-in-class Wiskott-Aldrich syndrome protein activator with anti-tumor activity in hematologic cancers.

Hematological cancers are among the most common cancers in adults and children. Despite significant improvements in therapies, many patients still succumb to the disease. Therefore, novel therapies are needed. The Wiskott-Aldrich syndrome protein (WASp) family regulates actin assembly in conjunction with the Arp2/3 complex, a ubiquitous nucleation factor. WASp is expressed exclusively in hematopoietic cells and exists in two allosteric conformations: autoinhibited or activated. Here, we describe the development of EG-011, a first-in-class small molecule activator of the WASp auto-inhibited form. EG-011 possesses in vitro and in vivo anti-tumor activity as a single agent in lymphoma, leukemia, and multiple myeloma, including models of secondary resistance to PI3K, BTK, and proteasome inhibitors. The in vitro activity was confirmed in a lymphoma xenograft. Actin polymerization and WASp binding was demonstrated using multiple techniques. Transcriptome analysis highlighted homology with drugs-inducing actin polymerization.

Application of an Environmental Monitoring to Assess the Practices and Control the Risk of Occupational Exposure to Cyclophosphamide in Two Sites of a French Comprehensive Cancer Center.

OBJECTIVES: The risk of chronic exposure to antineoplastic agents in hospitals, mainly by skin contact with contaminated surfaces, is well established. The aim of this study was to assess indirectly the risk of occupational exposure to antineoplastics drugs at two hospitals by using an environmental monitoring, and to suggest ways of improving the exposure to healthcare workers. METHODS: An observational study of care practices on both sites was carried out. A wipe sampling campaign was then designed to study environmental contamination throughout the chemotherapy process: receipt, storage, compounding, transport, administration, and elimination areas. Samples were analyzed by a validated LC-MS/MS method allowing trace quantification of cyclophosphamide. A guidance 'safe value' of 0.10 ng/cm2 was considered. RESULTS: A total of 293 samples were analyzed, of which 58% were found to be positive. In the compounding units, the drug vials were contaminated before [range = (non-quantifiable [NQ]-0.71) ng/cm2] and after cleaning procedure [(NQ-0.62) ng/cm2], particularly when the flip-off lid was removed during cleaning. The contamination found on manual preparations was operator-dependent: [non-detectable (ND)-3.51] ng/cm2 on infusion bag surfaces; (780.61-24 698.98) ng/cm2 on medication ports. In the case of automated preparations, the average contamination was higher on infusion bag surfaces [(2.43-36.86) ng/cm2] and lower on medication ports [(0.43-7.65) ng/cm2] than manual preparations. Contamination of the analytical control area was also highlighted. In the daily care unit, the contamination was located near the infusion area (armchairs, infusion stands, floor, and patient toilets), and varied somewhat between the two sites, especially on the floor with (0.46-27.32) compared to (ND-0.18) ng/cm2. We did not detect contamination on the transport boxes, on the door handles or in the disposal areas. CONCLUSIONS: The variability of contamination observed between the two sites can be explained in part by the difference in routine practices, especially training of the staff, and cleaning procedures. Findings were communicated to healthcare workers, and news interventions were implemented based on wipe sampling results. This study demonstrated a method for routine environmental monitoring and worker education as a strategy to reduce occupational exposure.

TAKTIC: A prospective, multicentre, uncontrolled, phase IB/II study of LY2780301, a p70S6K/AKT inhibitor, in combination with weekly paclitaxel in HER2-negative advanced breast cancer patients.

BACKGROUND: Hormone-resistant HER2-negative or triple-negative advanced breast cancers (ABC) are routinely treated with paclitaxel chemotherapy. LY2780301 is a dual inhibitor of p70 ribosomal protein S6 kinase and AKT. The TAKTIC study aimed at exploring the combination of paclitaxel and LY2780301 in this population. METHODS: In this multicentric phase Ib/II trial, we enrolled patients with HER2-negative ABC, with (phase IB) or without (phase II) prior to cytotoxic treatment for advanced disease. Oral LY2780301 was administered once daily in combination with intravenous weekly paclitaxel. Primary endpoints were to determine the recommended phase II dose (RP2D) of the combination of LY2780301 with weekly paclitaxel (phase Ib), and to estimate a 6 months objective response rate (ORR) (phase II) in patients with HER2-negative ABC, both in the overall patient population and in cases with activation of the PI3K/AKT pathway (PI3KAKT+). RESULTS: A total of 51 patients were enrolled; RP2D was LY2780301 500 mg QD+ paclitaxel 80 mg/m2. Main drug-related adverse events noted in phase Ib included neuropathy (75% of patients, grade 3-4 in 8%), asthenia (58% of patients, no grade 3-4), and ungual toxicity (50% of patients, grade 3-4 in 25%). They were similar in the phase II part, except that 14% of patients experienced pneumonia (grade 3-4 in 6%). In the phase II part, 6-month ORR in the overall population and in PI3KAKT+ subgroup were, respectively, 63.9% [48.8-76.8] and 55% [35-73.7]. CONCLUSION: Combining LY2780301 and weekly paclitaxel in patients with HER2-negative ABC was feasible with preliminary evidence of efficacy in both the overall population and the PI3KAKT+ subgroup. TRIAL REGISTRATION ID: NCT01980277.

A phase II randomised study of preoperative trastuzumab alone or combined with everolimus in patients with early HER2-positive breast cancer and predictive biomarkers (RADHER trial).

INTRODUCTION: Resistance to trastuzumab in breast cancer is an ongoing challenge. Clinical and biological effects of co-targeting HER2 and mammalian target of rapamycin (mTOR) in patients with HER2-positive early operable breast cancer via the addition of everolimus to preoperative trastuzumab were evaluated in a phase II randomised study. METHODS: Patients were randomised 1:1 to receive trastuzumab (4 mg/kg initial dose then 2 mg/kg weekly for 5 weeks) alone or combined with everolimus (10 mg/day for 6 weeks) and then underwent surgery. Tumours were assessed by clinical examination and echography at the baseline and on treatment. The primary end-point was the clinical response rate at 6 weeks. Pathological response and safety were also evaluated. Baseline and surgery tumour samples were assessed by immunohistochemistry and multiplex immunoanalysis for predictive downstream effectors of the PI3K/AKT/mTOR and MAP kinase (MAPK) pathways. RESULTS: Eighty-two patients were enrolled, 41 per arm. The clinical response rates were 34.1% and 43.9% with trastuzumab alone and combined with everolimus, respectively. Pathological response rates were 43.6% and 47.5%, respectively. Addition of everolimus increased toxicity, notably mucositis (82.5% versus 5.0%) and rash (57.5% versus 10.0%), but grade III/IV events were rare. No correlation between response to treatments and baseline candidate biomarkers was identified, except for PIK3CA mutations which were found to predict trastuzumab resistance. Significant changes were seen in several MAPK pathway effectors after combination therapy. CONCLUSIONS: The addition of everolimus did not improve the efficacy, but induced MAPK signalling. Combination therapy to overcome pathway cross-talk should be considered to maximise the effectiveness of trastuzumab in this setting. ClinicalTrial.gov Identifier NCT00674414.

Development of potent dual PDK1/AurA kinase inhibitors for cancer therapy: Lead-optimization, structural insights, and ADME-Tox profile.

We report the synthesis of novel first-in-class 2-oxindole-based derivatives as dual PDK1-AurA kinase inhibitors as a novel strategy to treat Ewing sarcoma. The most potent compound 12 is suitable for progression to in vivo studies. The specific attributes of 12 included nanomolar inhibitory potency against both phosphoinositide-dependent kinase-1 (PDK1) and Aurora A (AurA) kinase, with acceptable in vitro ADME-Tox properties (cytotoxicity in 2 healthy and 14 hematological and solid cancer cell-lines; inhibition of PDE4C1, SIRT7, HDAC4, HDAC6, HDAC8, HDAC9, AurB, CYP1A2, CYP2C9, CYP2C19, CYP2D6, and hERG). X-ray crystallography and docking studies led to the identification of the key AurA and PDK1/12 interactions. Finally, in vitro drug-intake kinetics and in vivo PK appear to indicate that these compounds are attractive lead-structures for the design and synthesis of PDK1/AurA dual-target molecules to further investigate the in vivo efficacy against Ewing Sarcoma.

Phase I or II Study of Ribociclib in Combination With Topotecan-Temozolomide or Everolimus in Children With Advanced Malignancies: Arms A and B of the AcSé-ESMART Trial.

PURPOSE: AcSé-ESMART is a proof-of-concept, phase I or II, platform trial, designed to explore targeted agents in a molecularly enriched cancer population. Arms A and B aimed to define the recommended phase II dose and activity of the CDK4/6 inhibitor ribociclib with topotecan and temozolomide (TOTEM) or everolimus, respectively, in children with recurrent or refractory malignancies. PATIENTS AND METHODS: Ribociclib was administered orally once daily for 16 days after TOTEM for 5 days (arm A) or for 21 days with everolimus orally once daily continuously in a 28-day cycle (arm B). Dose escalation followed the continuous reassessment method, and activity assessment the Ensign design. Arms were enriched on the basis of molecular alterations in the cell cycle or PI3K/AKT/mTOR pathways. RESULTS: Thirty-two patients were included, 14 in arm A and 18 in arm B, and 31 were treated. Fourteen patients had sarcomas (43.8%), and 13 brain tumors (40.6%). Main toxicities were leukopenia, neutropenia, and lymphopenia. The recommended phase II dose was ribociclib 260 mg/m2 once a day, temozolomide 100 mg/m2 once a day, and topotecan 0.5 mg/m2 once a day (arm A) and ribociclib 175 mg/m2 once a day and everolimus 2.5 mg/m2 once a day (arm B). Pharmacokinetic analyses confirmed the drug-drug interaction of ribociclib on everolimus exposure. Two patients (14.3%) had stable disease as best response in arm A, and seven (41.2%) in arm B, including one patient with T-acute lymphoblastic leukemia with significant blast count reduction. Alterations considered for enrichment were present in 25 patients (81%) and in eight of nine patients with stable disease; the leukemia exhibited CDKN2A/B and PTEN deficiency. CONCLUSION: Ribociclib in combination with TOTEM or everolimus was well-tolerated. The observed activity signals initiated a follow-up study of the ribociclib-everolimus combination in a population enriched with molecular alterations within both pathways.

Ultra-fast liquid chromatography method coupled with ultraviolet detection to quantify dimethylsulfoxide, dimethylformamide and dimethylacetamide in short half-lives radiopharmaceuticals.

Radiolabelling with short half-lives radionuclides (e.g., fluorine-18 and carbon-11) must be as efficient and as fast as possible. Nucleophilic radiofluorinations and radiomethylations are conducted in polar aprotic solvents, such as dimethylsulfoxyde (DMSO), N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA), at high temperature. Those solvents are classified as toxic according to the ICH guidelines and must be evaluated in drug such as radiopharmaceuticals. Headspace gas chromatography is the standard method for the quantification of residual solvents but is not optimized for a rapid quantification of low vapor pressure solvents such as DMSO, DMF and DMA in radiopharmaceuticals. Direct injection gas chromatography is an interesting option without incubation step but the analysis run-time remains beyond 10 min long. In consequence, we developed a very simple ultra-high performance liquid chromatography method coupled with UV detection. Following the EMA requirements, we successfully validated a 3-min run-time analysis for quantification of three solvents in short half-lives radiopharmaceuticals. We currently use this method for the quality control of radiopharmaceuticals produced in our PET center.

Phase I trial of copanlisib, a selective PI3K inhibitor, in combination with cetuximab in patients with recurrent and/or metastatic head and neck squamous cell carcinoma.

Background The phosphatidylinositol-3 kinase pathway is often altered in head and neck squamous cell carcinoma (HNSCC), and is involved in the resistance to EGFR inhibitors. Objective We investigated the dose-limiting toxicities (DLTs), maximum tolerated dose, pharmacokinetics, and preliminary efficacy of the combination of copanlisib, an intravenous, pan-class I PI3K inhibitor, with the anti-EGFR monoclonal antibody cetuximab in recurrent and/or metastatic HNSCC patients in a phase I dose-escalation trial. Patients and methods Copanlisib was given intravenously on days 1, 8, and 15 of 28-day cycles at the dose of 45 mg and 30 mg, in combination with standard doses of weekly cetuximab (400 mg/m2 loading dose followed by 250 mg/m2 on days 8, 15, and 22, and weekly thereafter). Results Three patients received copanlisib 45 mg, of whom two experienced grade 3 hyperglycemia during Cycle 1 that met the DLT criteria. Eight patients were then treated with copanlisib at the dose of 30 mg. Because of the occurrence of hyperglycemia, a premedication with metformine was introduced on the day of the injections. No DLTs were reported at this dose level. The trial was stopped early because of the unfavourable toxicity profile of the combination. Among eight evaluable patients for response, four patients (50%) had disease stabilization according to RECIST1.1 as best response. Conclusion Copanlisib combined with cetuximab demonstrated unfavorable toxicity and limited efficacy in heavily pretreated recurrent and/or metastatic HNSCC patients.Trial registration NCT02822482, Date of registration: June 2016.

Single radio UHPLC analysis for the quality control of technetium-99m radiolabelled radiopharmaceuticals.

The radiochemical purity (RCP) determination of radiopharmaceuticals is routinely done with radio-thin layer chromatography (r-TLC). These methods are usually transposed and adjusted from the summary product characteristics without any analytical validation. The r-TLC method is simple but manually-performed steps could lead to RCP misinterpretation. To increase the sensitivity, radio ultra-high performance liquid chromatography (r-UHPLC) can be used. In this study, an r-UHPLC method had been validated and compared to the r-TLC method. Hydrolyzed-reduced technetium had also been studied.

Phase I-II Open-Label Multicenter Study of Palbociclib + Vemurafenib in BRAF V600MUT Metastatic Melanoma Patients: Uncovering CHEK2 as a Major Response Mechanism.

PURPOSE: In BRAF V600MUT metastatic melanoma, cyclin D-CDK4/6-INK4-Rb pathway alterations are involved in resistance to MAPK inhibitors, suggesting a clinical benefit of cyclin-dependent kinase 4 (CDK4) inhibitors. In this phase I-II study, we aimed to establish the MTD of palbociclib when added to vemurafenib. PATIENTS AND METHODS: Patients with BRAF V600E/KMUT metastatic melanoma harboring CDKN2A loss and RB1 expression were included and stratified into two groups according to previous BRAF inhibitor treatment (no:strata 1; yes:strata 2). Treatment comprised palbociclib once daily for 14 days followed by a 7-day break + continuous dosing of vemurafenib. The primary endpoint was the occurrence of dose-limiting toxicity (DLT), and the secondary endpoints included the best response, survival, pharmacokinetics, and tumor molecular profiling. RESULTS: Eighteen patients were enrolled, with 15 in strata 2. Characteristics at inclusion were American Joint Committee on Cancer stage IVM1c (N = 16; 88.9%), high lactate dehydrogenase (N = 9; 50.0%), and median number of previous treatments of 2. One and 5 patients experienced DLT in strata 1 and 2, respectively, defining the MTD at palbociclib 25 mg and vemurafenib 960 mg in strata 2. No significant evidence for drug-drug interactions was highlighted. The median progression-free survival was 2.8 months, and 5 (27.8%) patients showed a clinical response. The baseline differential mRNA expression analysis and in vitro data revealed the role of CHEK2 in the response to palbociclib. CONCLUSIONS: Although the combination of palbociclib + fixed-dose vemurafenib did not allow an increased palbociclib dosage above 25 mg, a significant clinical benefit was achieved in pretreated patients with melanoma. An association between the transcriptomic data and clinical response was highlighted.

Input of serum haptoglobin fucosylation profile in the diagnosis of hepatocellular carcinoma in patients with non-cirrhotic liver disease.

BACKGROUND: Haptoglobin bifucosylated tetra-antennary glycan have been identified in patients with early stage hepatocellular carcinoma, but its specificity according to the presence or not of cirrhosis has never been assessed. The aims of this study were to determine if haptoglobin bifucosylated tetra-antennary glycan (1) could be a marker of HCC in patients without cirrhosis; (2) could increase the performance of standard alpha-fetoprotein (AFP) or recent blood tests for HCC detection, i.e., lectin-reactive alpha-fetoprotein (AFP-L3), des-gamma-carboxy prothrombin (DCP) and Liver-Cancer-Risk-test (LCR1-test). METHODS: We retrospectively selected patients, 102 with HCC (21 without cirrhosis), matched by stages with 140 controls without HCC (81 without cirrhosis). Haptoglobin fucosylation was assessed by MALDI-TOF. LCR-glycan algorithm was constructed combining components of the LCR-1 test (haptoglobin, gammaglutamyl-transpeptidase, apolipoproteinA1, alpha-2-macroglobulin) with AFP, AFP-L3, DCP and haptoglobin bifucosylated tetra-antennary glycan. RESULTS: In 102 patients without cirrhosis (21 HCC and 81 controls), the intention-to-diagnose analyses showed that haptoglobin bifucosylated tetra-antennary glycan alone had a sensitivity of 71% (15/21;95%CI 50-86), significantly better (P=0.02) than standard AFP (43%;9/21;95%CI 24-63), and a specificity of 96% (78/81;95% 90-99). The sensitivity of LCR-glycan, in patients without cirrhosis, was 86% (18/21; 95%CI 63-95) significantly better (P=0.001) than standard AFP (43%; 9/21; 95%CI 24-63), with an AUROC of 0.943 (95%CI 0.806-0.98) compared to 0.811 (95%CI 0.630-0.908) for AFP (P=0.06). CONCLUSION: Haptoglobin bifucosylated tetra-antennary glycan is associated with the presence of HCC in patients with chronic liver disease including those without cirrhosis. Its combination with existing HCC biomarkers could improve the performance of standard AFP for HCC detection.

Targeting Adrenomedullin in Oncology: A Feasible Strategy With Potential as Much More Than an Alternative Anti-Angiogenic Therapy.

The development, maintenance and metastasis of solid tumors are highly dependent on the formation of blood and lymphatic vessels from pre-existing ones through a series of processes that are respectively known as angiogenesis and lymphangiogenesis. Both are mediated by specific growth-stimulating molecules, such as the vascular endothelial growth factor (VEGF) and adrenomedullin (AM), secreted by diverse cell types which involve not only the cancerogenic ones, but also those constituting the tumor stroma (i.e., macrophages, pericytes, fibroblasts, and endothelial cells). In this sense, anti-angiogenic therapy represents a clinically-validated strategy in oncology. Current therapeutic approaches are mainly based on VEGF-targeting agents, which, unfortunately, are usually limited by toxicity and/or tumor-acquired resistance. AM is a ubiquitous peptide hormone mainly secreted in the endothelium with an important involvement in blood vessel development and cardiovascular homeostasis. In this review, we will introduce the state-of-the-art in terms of AM physiology, while putting a special focus on its pro-tumorigenic role, and discuss its potential as a therapeutic target in oncology. A large amount of research has evidenced AM overexpression in a vast majority of solid tumors and a correlation between AM levels and disease stage, progression and/or vascular density has been observed. The analysis presented here indicates that the involvement of AM in the pathogenesis of cancer arises from: 1) direct promotion of cell proliferation and survival; 2) increased vascularization and the subsequent supply of nutrients and oxygen to the tumor; 3) and/or alteration of the cell phenotype into a more aggressive one. Furthermore, we have performed a deep scrutiny of the pathophysiological prominence of each of the AM receptors (AM1 and AM2) in different cancers, highlighting their differential locations and functions, as well as regulatory mechanisms. From the therapeutic point of view, we summarize here an exhaustive series of preclinical studies showing a reduction of tumor angiogenesis, metastasis and growth following treatment with AM-neutralizing antibodies, AM receptor antagonists, or AM receptor interference. Anti-AM therapy is a promising strategy to be explored in oncology, not only as an anti-angiogenic alternative in the context of acquired resistance to VEGF treatment, but also as a potential anti-metastatic approach.

Epigenetic Control of Mitochondrial Fission Enables Self-Renewal of Stem-like Tumor Cells in Human Prostate Cancer.

Cancer stem cells (CSCs) contribute to disease progression and treatment failure in human cancers. The balance among self-renewal, differentiation, and senescence determines the expansion or progressive exhaustion of CSCs. Targeting these processes might lead to novel anticancer therapies. Here, we uncover a novel link between BRD4, mitochondrial dynamics, and self-renewal of prostate CSCs. Targeting BRD4 by genetic knockdown or chemical inhibitors blocked mitochondrial fission and caused CSC exhaustion and loss of tumorigenic capability. Depletion of CSCs occurred in multiple prostate cancer models, indicating a common vulnerability and dependency on mitochondrial dynamics. These effects depended on rewiring of the BRD4-driven transcription and repression of mitochondrial fission factor (Mff). Knockdown of Mff reproduced the effects of BRD4 inhibition, whereas ectopic Mff expression rescued prostate CSCs from exhaustion. This novel concept of targeting mitochondrial plasticity in CSCs through BRD4 inhibition provides a new paradigm for developing more effective treatment strategies for prostate cancer.

Cyclophosphamide dose adjustment based on body weight and albuminemia in elderly patients treated with R-mini-CHOP.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in elderly patients, and R-CHOP chemotherapy is the standard treatment protocol for DLBCL. Elderly patients (often defined as 75 years of age) are treated with anticancer drugs with precaution; however, the pharmacokinetics and pharmacodynamics (PK and PD) of these agents have not been thoroughly investigated in this population. In this study, we investigated the PK of cyclophosphamide (CP) and doxorubicin (DOXO) in elderly patients in order to verify if there is an influence of age on the PK of these anticancer drugs. MATERIALS AND METHODS: This is a prospective multi-center clinical trial investigating the PK of CP and DOXO in elderly and very elderly patients with DLBCL treated by R-mini-CHOP regimen. Dose levels were 25 mg/m2, 0.7-1.4 mg/m2, 750 mg/m2, and 375 mg/m2 for DOXO, Vincristine (VCR), CP, and Rituximab, respectively. For PK analysis, 7 time point samples were collected over 48 h post-administration on cycle 3. CP and VCR plasma concentrations were measured using UPLC-MS/MS validated method. DOX plasma concentrations were measured using UPLC coupled with fluorescence detection-validated method. PK-POP modeling has been performed with a non-linear mixed-effect model program (Monolix). RESULTS: 31 patients (15 males and 16 females), 75 to 96 years old, were treated with R-miniCHOP protocol. Among them, 19 patients were treated with VCR. A one-compartment (1cpt) open model with linear elimination adequately described CP concentration-time courses. The population PK parameters for CP were: CL = 3.58 L/h, Vmale = 32.2 L, and Vfemale = 28.7 L. Body weight (BW), albuminemia, and gender demonstrated a significant impact on CP PK. A 2-compartment (2cpt) open model with linear elimination best described DOXO concentration-time courses. The population PK parameters for DOXO obtained for the structural model were: CL = 51.1 L/h, Q = 49.6 L/h, V1 = 29.4 L, V2 = 1,130 L (clearances: CL, Q, volumes of distribution: V1, V2). The main covariate effects on DOXO PK were related to gender, BW, and VCR administration. VCR increases DOXO V1 from 29.4 L to 57.5 L (p = 0.02). No hematologic and cardiac grade 3 or 4 toxicity were recorded. CONCLUSIONS: Usually, in the absence of specific data, the majority of the physicians empirically reduce anticancer drug dose in the elderly patients (Tourani in J Geriatr Oncol 3(1): 41-48, 2012), or even does not treat these very-old patients. A better knowledge of the pharmacokinetics in very-old patients should allow a better dose adjustment based on the most significant physiological factors that modify the pharmacokinetic parameters. In this study, no serious toxicity was observed in these very elderly patients (84.1 years). This indicates that dose adjustment of chemotherapies should not only be based on age and creatinine clearance, but also, based upon appropriate physiological and biological data. Our findings indicate that, CP dose adjustment should be done according to serum albumin levels and patients BW and gender.

Phase I study of onapristone, a type I antiprogestin, in female patients with previously treated recurrent or metastatic progesterone receptor-expressing cancers.

INTRODUCTION: Onapristone is a type I progesterone receptor (PR) antagonist, which prevents PR- mediated DNA transcription. Onapristone is active in multiple preclinical models and two prior studies demonstrated promising activity in patients with breast cancer. We conducted a study of extended release (ER) Onapristone to determine a recommended dose and explore the role of transcriptionally-activated PR (APR), detected as an aggregated subnuclear distribution pattern, as a predictive biomarker. METHODS: An open-label, multicenter, randomized, parallel-group, phase 1 study (target n = 60; NCT02052128) included female patients ≥18 years with PRpos tumors. APR analysis was performed on archival tumor tissue. Patients were randomized to five cohorts of extended release (ER) onapristone tablets 10, 20, 30, 40 or 50 mg BID, or immediate release 100 mg QD until progressive disease or intolerability. Primary endpoint was to identify the recommended phase 2 dose. Secondary endpoints included safety, clinical benefit and pharmacokinetics. RESULTS: The phase 1 dose escalation component of the study is complete (n = 52). Tumor diagnosis included: endometrial carcinoma 12; breast cancer 20; ovarian cancer 13; other 7. Median age was 64 (36-84). No dose limiting toxicity was observed with reported liver function test elevation related only to liver metastases. The RP2D was 50 mg ER BID. Median therapy duration was 8 weeks (range 2-44), and 9 patients had clinical benefit ≥24 weeks, including 2 patients with APRpos endometrial carcinoma. CONCLUSION: Clinical benefit with excellent tolerance was seen in heavily pretreated patients with endometrial, ovarian and breast cancer. The data support the development of Onapristone in endometrial endometrioid cancer. Onapristone should also be evaluated in ovarian and breast cancers along with APR immunohistochemistry validation.

BET bromodomain inhibitor birabresib in mantle cell lymphoma: in vivo activity and identification of novel combinations to overcome adaptive resistance.

BACKGROUND: The outcome of patients affected by mantle cell lymphoma (MCL) has improved in recent years, but there is still a need for novel treatment strategies for these patients. Human cancers, including MCL, present recurrent alterations in genes that encode transcription machinery proteins and of proteins involved in regulating chromatin structure, providing the rationale to pharmacologically target epigenetic proteins. The Bromodomain and Extra Terminal domain (BET) family proteins act as transcriptional regulators of key signalling pathways including those sustaining cell viability. Birabresib (MK-8628/OTX015) has shown antitumour activity in different preclinical models and has been the first BET inhibitor to successfully undergo early clinical trials. MATERIALS AND METHODS: The activity of birabresib as a single agent and in combination, as well as its mechanism of action was studied in MCL cell lines. RESULTS: Birabresib showed in vitro and in vivo activities, which appeared mediated via downregulation of MYC targets, cell cycle and NFKB pathway genes and were independent of direct downregulation of CCND1. Additionally, the combination of birabresib with other targeted agents (especially pomalidomide, or inhibitors of BTK, mTOR and ATR) was beneficial in MCL cell lines. CONCLUSION: Our data provide the rationale to evaluate birabresib in patients affected by MCL.

Phase Ib Trial With Birabresib, a Small-Molecule Inhibitor of Bromodomain and Extraterminal Proteins, in Patients With Selected Advanced Solid Tumors.

PURPOSE: Birabresib (MK-8628/OTX015) is a first-in-class bromodomain inhibitor with activity in select hematologic tumors. Safety, efficacy, and pharmacokinetics of birabresib were evaluated in patients with castrate-resistant prostate cancer, nuclear protein in testis midline carcinoma (NMC), and non-small-cell lung cancer in this phase Ib study. PATIENTS AND METHODS: Forty-seven patients were enrolled to receive birabresib once daily at starting doses of 80 mg continuously (cohort A) or 100 mg for 7 consecutive days (cohort B) in 21-day cycles using a parallel dose escalation 3 + 3 design. The primary objective was occurrence of dose-limiting toxicities (DLTs) and determination of the recommended phase II dose. RESULTS: Of 46 treated patients, 26 had castrate-resistant prostate cancer, 10 NMC, and 10 non-small-cell lung cancer. For cohort A, four of 19 (21%) evaluable patients had DLTs at 80 mg once daily (grade 3 thrombocytopenia [n = 3], ALT/hyperbilirubinemia [n = 1]) and two of three had DLTs at 100 mg once daily (grade 2 anorexia and nausea with treatment delay > 7 days [n = 1], grade 4 thrombocytopenia [n = 1]). No DLTs occurred in cohort B. Of 46 patients, 38 (83%) had treatment-related adverse events (diarrhea, 17 [37%]; nausea, 17 [37%]; anorexia, 14 [30%]; vomiting, 12 [26%]; thrombocytopenia 10 [22%]). Three patients with NMC (80 mg once daily) had a partial response (Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1) with duration of 1.4 to 8.4 months. Pharmacokinetic analysis indicated a dose-proportional increase in birabresib exposure and rapid absorption. CONCLUSION: The recommended phase II dose of birabresib in patients with select solid tumors is 80 mg once daily with continuous dosing. Birabresib has dose-proportional exposure and a favorable safety profile, with clinical activity observed in NMC. Future studies of birabresib must consider intermittent scheduling to possibly mitigate the toxicities of chronic dosing.

PIKHER2: A phase IB study evaluating buparlisib in combination with lapatinib in trastuzumab-resistant HER2-positive advanced breast cancer.

BACKGROUND: Phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin pathway is frequently activated in HER2-positive breast cancer and may play a major role in resistance to trastuzumab. Buparlisib is a pan-class-I PI3K inhibitor with potent and selective activity against wild-type and mutant PI3K p110 isoforms. PATIENTS AND METHODS: PIKHER2 phase IB study aimed primarily to determine a maximum tolerated dose (MTD) and propose a recommended phase II dose (RP2D) for buparlisib in combination with lapatinib in HER2-positive, trastuzumab-resistant, advanced breast cancer. Oral buparlisib (40, 60 or 80 mg) and lapatinib (750, 1000 or 1250 mg) were administered daily. A modified continuous reassessment method using an adaptive Bayesian model guided the dose escalation of both agents. Secondary end-points included antitumour activity and pharmacokinetic (PK) assessments. RESULTS: A total of 24 patients were treated across five dose levels. Dose-limiting toxicities included transaminases elevation, vomiting, stomatitis, hyperglycemia and diarrhoea. MTD was declared at buparlisib 80 mg/d + lapatinib 1250 mg/d, but toxicities and early treatment discontinuation rate beyond cycle 1 led to select buparlisib 80 mg + lapatinib 1000 mg/d as the RP2D. Main drug-related adverse events included diarrhoea, nausea, skin rash, asthenia, depression, anxiety and transaminases increase. There was no significant evidence for drug-drug PK interaction. Disease control rate was 79% [95% confidence interval [CI] 57-92%], one patient obtained a complete remission, and six additional patients experienced stable disease for ≥ 24 weeks (clinical benefit rate of 29% [95% CI 12-51%]). CONCLUSION: Combining buparlisib and lapatinib in HER2-positive trastuzumab-resistant advanced breast cancer was feasible. Preliminary evidence of antitumour activity was observed in this heavily pre-treated population. TRIAL REGISTRATION ID: NCT01589861.

The bromodomain inhibitor OTX015 (MK-8628) exerts anti-tumor activity in triple-negative breast cancer models as single agent and in combination with everolimus.

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous subgroup of breast tumors clinically defined by the lack of estrogen, progesterone and HER2 receptors, limiting the use of the targeted therapies employed in other breast malignancies. Recent evidence indicates that c-MYC is a key driver of TNBC. The BET-bromodomain inhibitor OTX015 (MK-8628) has potent antiproliferative activity accompanied by c-MYC down-regulation in several tumor types, and has demonstrated synergism with the mTOR inhibitor everolimus in different models. The aim of this study was to evaluate the anti-tumor activity of OTX015 as single agent and in combination with everolimus in TNBC models. OTX015 was assayed in three human TNBC-derived cell lines, HCC1937, MDA-MB-231 and MDA-MB-468, all showing antiproliferative activity after 72 h (GI50 = 75-650 nM). This was accompanied by cell cycle arrest and decreased expression of cancer stem cells markers. However, c-MYC protein and mRNA levels were only down-regulated in MDA-MB-468 cells. Gene set enrichment analysis showed up-regulation of genes involved in epigenetic control of transcription, chromatin and the cell cycle, and down-regulation of stemness-related genes. In vitro, combination with everolimus was additive in HCC1937 and MDA-MB-231 cells, but antagonistic in MDA-MB-468 cells. In MDA-MB-231 murine xenografts, tumor mass was significantly (p < 0.05) reduced by OTX015 with respect to vehicle-treated animals (best T/C = 40.7%). Although everolimus alone was not active, the combination was more effective than OTX015 alone (best T/C = 20.7%). This work supports current clinical trials with OTX015 in TNBC (NCT02259114).