Background:
PIM kinases are oncogenic FLT3 targets expressed in acute myeloid leukemia (AML) cells. Increased PIM expression is found in samples of relapsed AML patients exposed to FLT3 inhibitors ...(FLT3i). There is preclinical evidence that PIM inhibition restores cell sensitivity to FLT3i, and that dual FLT3/PIM inhibition eradicates FLT3‐ITD+ primary AML cells. SEL24/MEN1703, a potent PIM/FLT3 dual inhibitor, showed a significantly broader spectrum of activity in AML cell lines and primary AML blasts, irrespective of FLT3 status compared to FLT3 or PIM inhibitors alone
Aims:
To determine the recommended phase 2 dose (RP2D), the PK profile and the single agent activity of SEL24/MEN1703 in relapsed/refractory or newly diagnosed AML patients (excluding APL) unsuitable to chemotherapy
Methods:
First in Human, open label, non‐randomized, multi‐center, dose‐escalation (DE) and cohort expansion (CE) study of oral SEL24/MEN1703. SEL24/MEN1703 is given orally, QD, FOR 14 days in a 21‐day cycle with cycles repeated until disease progression or unacceptable toxicity. Dose escalation follows a 3+3 design to identify the RP2D; CE at RP2D is planned to confirm the safety profile and assess single agent activity. Patients are eligible for the study regardless of mutations and/or prior FLT3i treatment; prior PIM inhibitors are not allowed. White blood count (WBC) of ≤30 x 109/L is required at baseline. Key secondary objectives include PK profile and single agent anti‐leukemic activity; exploratory objectives include assessment of clinical activity in relevant AML subsets of patients (eg FLT3 mutated)
Results:
As of January 8th, 2019 (data cutoff), n = 17 patients were treated and the study is enrolling. In the RP2D expansion phase, the study (currently running in 5 US sites) will be expanded to approximately 40 sites in the US and EU
Summary/Conclusion:
SEL24/MEN1703, a first in class, oral dual PIM/FLT3‐ITD inhibitor, is completing the DE part of a two‐part FIH study in patients with relapsed/refractory or unfit newly diagnosed AML unsuitable to chemotherapy. The RP2D expansion phase is planned to involve either US and EU investigational sites. This is the first clinical trial testing a dual PIM/FLT3‐ITD inhibitor, potentially active in AML regardless of FLT3 status and able to overcome FLT3i resistance
Several antitumor drugs have been described to induce nuclear factor kappaB (NF-kappaB), but results about its role in regulating apoptotic cell death are quite controversial. In this paper, we ...studied NF-kappaB induced by the two anticancer agents Sabarubicin (MEN 10755) and paclitaxel (Taxol) and the effects of its pharmacological inhibition.
In the human colon cancer cell line HCT-116, we investigated NF-kappaB activation induced by the two anticancer agents using electrophoretic mobility shift assay (EMSA), while drug-induced cytotoxicity was measured by trypan blue staining. Apoptosis was analyzed using a cell death detection enzyme-linked immunosorbent assay (ELISA) kit, flow cytometry and caspase-3 activation assay.
The combination with the NF-kappaB inhibitorparthenolide increased Sabarubicin- but not paclitaxel-induced cell death. EMSA experiments demonstrated that the two antitumor drugs induced NF-kappaB complexes with different kinetics but similar subunit composition. Moreover, Sabarubicin elicited NF-kappaB activation definitely earlier than DNA fragmentation, whereas with paclitaxel the kinetics of the two phenomena were similar.
Chemical agents able to interfere with DNA topoisomerases are widespread in nature, and some of them have outstanding therapeutic efficacy in human cancer and infectious diseases. DNA topoisomerases ...are essential enzymes that govern DNA topology during fundamental nuclear metabolic processes. Topoisomerase-interfering compounds can be divided into two general categories based on the mechanism of drug action: poisons and catalytic inhibitors. In past years, investigations of the DNA sequence selectivity of topoisomerase II poisons have identified structural and molecular determinants of drug activity, and indicated that the drug receptor is likely to be at the protein–DNA interface. Moreover, the available results indicate that the biologically relevant DNA-binding activity of topoisomerase poisons is basically protein-mediated and this is discussed in this issue by
Giovanni Capranico and colleagues. This suggests that topoisomerase poisons may represent a useful paradigm for small compounds able to bind to protein–DNA interfacesin a site-selective manner, thus increasing the affinity of DNA-binding proteins for specific genomic sites.
Abstract
Background
The phosphatidylinositol 3-kinase (PI3K) pathway plays a central role in cell proliferation and survival in human cancer. Mutations in PIK3CA, the gene coding the p110α catalytic ...subunit of PI3K, are frequent in cancer and result in PI3K pathway activation. About 25% of HER2-positive breast cancers also carry PIK3CA mutations, known to confer resistance to anti-HER2 therapy. Here we report the preclinical characterization of MEN1611, a potent and selective orally available PI3K inhibitor, showing high activity against p110α mutant isoforms and sparing the δ isoform.
Methods
In vivo efficacy studies were evaluated through Tumour Volume Inhibition % (TVI%) and mRECIST criteria using cancer cell lines and patient-derived xenograft (PDX) models. Pathway activation and protein degradation analyses were performed by western blot and capillary electrophoresis immunoassay. Immune modulation was evaluated using murine macrophages differentiated in vitro.
Results
Consistent with its mechanism of action, MEN1611 down-modulates the PI3K/AKT signaling as well as selected downstream targets, both in vitro and in vivo. MEN1611 acts synergistically when combined with trastuzumab in several HER2-positive PIK3CA-mutated breast cancer cell lines and patient-derived xenograft models. The in vivo efficacy in trastuzumab-resistant models is supported by a long-lasting antitumor activity, paralleled by mechanistic down-regulation of pharmacodynamic biomarkers. Moreover, MEN1611 showed the ability to induce a dose-dependent alpha-isoform depletion, and to modulate the macrophage polarization towards a pro-inflammatory phenotype, consistent with its capability to co-inhibit P110γ.
Conclusions
Overall, these preclinical data support the progression in the development of MEN1611 in breast cancer and pave the way to the B-Precise-01 clinical study, a multicentre phase Ib study.
Clinical trial identification
NCT03767335.
Legal entity responsible for the study
Menarini Ricerche S.p.A.
Funding
Menarini Ricerche S.p.A.
Disclosure
A. Fiascarelli: Full / Part-time employment: Menarini RIcerche S.p.A. G. Merlino: Full / Part-time employment: Menarini Ricerche S.p.A. S. Capano: Full / Part-time employment: Menarini Ricerche S.p.A. A. Paoli: Full / Part-time employment: Menarini Ricerche S.p.A.. A. Bressan: Full / Part-time employment: Menarini Ricerche. M. Bigioni: Full / Part-time employment: Menarini Ricerche S.p.A.. M. Scaltriti: Advisory / Consultancy: Memorial Sloan-Kettering Cancer Center. J. Arribas: Advisory / Consultancy: Vall d’Hebron Institute of Oncology. C. Bernadó Morales: Advisory / Consultancy: Vall d’Hebron Institute of Oncology. A. Pellacani: Leadership role, Full / Part-time employment: Menarini Ricerche S.p.A.. M. Salerno: Leadership role, Full / Part-time employment: Menarini Ricerche. M. Binaschi: Leadership role, Full / Part-time employment: Menarini Ricerche S.p.A.
A multidrug-resistant variant of the P388 leukemia cell line exhibits multiple biochemical changes, including reduced drug accumulation and markedly reduced DNA strand breakage induced by ...anthracyclines. To investigate whether the reduced formation of drug-induced DNA breaks was due to alteration of DNA topoisomerase II activity, nuclear extracts and partially purified enzymes from the sensitive line and the resistant subline were compared. DNA topoisomerase II activity in 0.35 M NaCl nuclear extracts from sensitive cells was approximately 1.7 times higher than that found in extracts from resistant cells, as determined by ability to unknot P4 phage DNA. In addition, it was found that teniposide-stimulated topoisomerase II DNA cleavage activity of nuclear extract from resistant cells was at least 10-fold lower than that from sensitive cells. This differential sensitivity paralleled a similar drug response of nuclei, as determined by the alkaline elution method. However, partially purified DNA topoisomerase II showed similar drug sensitivity in both cell lines. This finding suggests the presence of a modulating factor, which may be lost during purification. These results, indicating a reduction of both catalytic activity and DNA cleavage activity of DNA topoisomerase II in P388 multidrug-resistant cells, emphasize the importance of DNa topoisomerase function in the resistance mechanism. Thus, the concomitant involvement of multiple mechanisms could explain the high degree of resistance of these cells.
The cardiovascular profile of the racemate
d/
l-nebivolol and its enantiomers administered by intravenous (i.v.) or by intracerebroventricular (i.c.v.) route was investigated in anaesthetized ...normotensive rats.
d/
l-Nebivolol (0.1–0.5 mg/kg) induced a dose-related reduction in blood pressure when administered by i.c.v. route. These hypotensive effects were more marked as compared to those achieved by peripheral administration of
d/
l-nebivolol (0.1–1 mg/kg i.v.). Both enantiomers contributed to the hypotensive effect of
d/
l-nebivolol by i.c.v. route, while the effects of the drug on blood pressure by i.v. route were due to the
d-enantiomer. The bradycardic effect of the racemic form given i.v. was dose-related and, at the highest dose (1 mg/kg), was more pronounced as compared to i.c.v. route.
d-Nebivolol was responsible for chronotropic effects by both the i.v. and i.c.v. route, although by i.c.v. route
l-nebivolol also induced a reduction in heart rate. The nitric oxide synthase inhibitor
N
ω-nitro-
l-arginine methyl ester (
l-NAME) administered at 5 mg/kg i.v. bolus+0.1 mg/kg/min infusion or at 2.5 mg/kg i.c.v. counteracted the effects of
d/
l-nebivolol (either 1 mg/kg i.v. or 0.5 mg/kg i.c.v.) on blood pressure, while it did not inhibit the cardiovascular changes induced by isoprenaline (300 ng/kg i.v.) or calcitonin gene-related peptide (CGRP; 400 ng/kg i.v.). In addition, i.c.v. effects of
d/
l-nebivolol on blood pressure and heart rate were not affected by pre-treatment with atropine (2 mg/kg i.v.). The present findings demonstrate that
d/
l-nebivolol produced haemodynamic changes following both peripheral and central administration; these latter findings are mainly due to its
l-enantiomer and these effects involve the
l-arginine/nitric oxide pathway.
Doxorubicin and idarubicin are very effective anticancer drugs in the treatment of human hematological malignancies and solid tumors. These agents are well known topoisomerase II poisons; however, ...some anthracycline analogs recently have been shown to poison topoisomerase I. In the present work, we assayed novel disaccharide analogs and the parent drug, idarubicin, for their poisoning effects of human topoisomerase I and topoisomerases IIalpha and IIbeta. Drugs were evaluated with a DNA cleavage assay in vitro and with a yeast system to test whether the agents were able to poison the enzymes in vivo. We have found that the test agents are potent poisons of both topoisomerases IIalpha and IIbeta. The axial orientation of the second sugar relative to the first one of the novel disaccharide analogs was shown to be required for poisoning activity and cytotoxicity. Interestingly, idarubicin and the new analogs stimulated topoisomerase I-mediated DNA cleavage at low levels in vitro. As expected, the cytotoxic level of the drug was highly affected by the content of topoisomerase II; nevertheless, the test agents had a yeast cell-killing activity that also was weakly dependent on cellular topoisomerase I content. The results are relevant for the full understanding of the molecular mechanism of topoisomerase poisoning by anticancer drugs, and they define structural determinants of anthracyclines that may help in the rational design of new compounds directed against topoisomerase I.
The role of the site selectivity of topoisomerase II poisoning in the cytotoxic activity of anthracyclines has not been established. In this article, we have thus studied the levels and persistence ...of double-stranded DNA breaks (DSB) along with the cytotoxic activity in human leukemic HL60 cells of seven anthracyclines, including doxorubicin, daunorubicin, and idarubicin, as well as sugar-modified analogues characterized by an altered sequence specificity. Epimerization at the 3' position of the sugar moiety markedly affected the biological activity; indeed, a dramatic reduction of drug effects was evident for 3'-deamino-3'-epi-hydroxy-4'-deoxy-4'-amino-daunorubicin. The studied analogues could be gathered into three groups based on the DSB/cytotoxicity ratio. At equitoxic concentrations: (a) parent drugs and 3'-deamino-3'-epi-hydroxy-4'-deoxy-4'-amino-daunorubicin endowed with the same sequence specificity stimulated low DSB levels; (b) 3'-epi-daunorubicin and 3'-deamino-4'-deoxy-4'-epi-amino-idarubicin, which have a different sequence specificity, and teniposide (a structurally unrelated poison) stimulated higher amounts of DSB; and (c) 4-demethoxy-3'-deamino-3'-hydroxy-4'-epi-doxorubicin stimulated the highest DSB levels. For the last agent, a faster rate of cleavage resealing, which is consistent with a reduced DNA binding affinity, could account for the increased DSB/cytotoxicity ratio compared with parent drugs. However, for other analogues, the observed differences in DSB persistence/resealing could not completely explain the different DSB/cytotoxicity ratios. The results thus suggest that the cytotoxic potency of anthracyclines may be the result of an interplay of the level, the persistence, and the genomic localization of topoisomerase II-mediated DNA cleavage.
Anthracycline antibiotics play an important role in cancer chemotherapy. The need for an improvement of their therapeutic index has stimulated an ongoing search for anthracycline analogues with ...improved properties. Analogue development was originally limited by a lack of information on the cellular drug target, nevertheless almost 20 years ago the mechanism of action of doxorubicin and daunorubicin was revealed and DNA topoisomerase II was recognised to be their main cellular target. Several anthracyclines interfere with topoisomerase II functions by stabilizing a reaction intermediate in which DNA strands are cut and covalently linked to tyrosine residues of the enzyme. Investigations on the sequence specificity of doxorubicin in vitro and in nuclear chromatin of living cell have led to a molecular model of drug receptor on the topoisomerase II-DNA complex. Anthracyclines are likely placed at the interface between the DNA cleavage site and the active site of the enzyme, forming a DNA-drug-enzyme ternary complex. Moreover, a quite detailed structure-function relationship has been established for anthracyclines. First, drug intercalation is necessary but not sufficient for topoisomerase II poisoning; second, the removal of the 4-methoxy and 3'-amino substituents greatly increases the drug activity and third, the 3' substituent of the sugar moiety markedly influences the sequence selectivity of anthracycline-stimulated DNA cleavage. These relationships have been exploited during the last decade by several groups, including ours, in the search for new anthracycline drugs with lower side effects and higher activity against resistant cancer cells. This review will focus on areas of the anthracycline field including synthesis of new analogues, new strategies of synthesis and recent developments in the area of drug delivery.
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