YL) METHYL] -AMINE DERIVATIVES AND DNA DEMETHYLATING AGENTS AND THEIR USE AS ANTI-NEOPLASTIC DRUGS"

TECHNICAL FIELD

The present invention concerns poly-alkyl-bis-maltolic molecules and in particular [( 3-hydroxy-4-pyron-2-yl ) methyl ] - amine derivatives and their use as anti-neoplastic drugs in combination with DNA demethylating agents. In particular, for the preparation of a medicament for the treatment of neoplastic pathologies. PRIOR ART

Despite the important progress made in the treatment of neoplastic pathologies, the survival of patients affected by tumour remains, in many cases, extremely limited (e.g. Glioblastoma Multiforme - GBM, Malignant Pleural Mesothelioma - MPM) . The absence of specific therapies, resistance to the chemotherapeutic drugs currently used and the high possibility of recurrence represent the main causes of failure in the treatment of many neoplasias. In addition, the majority of the chemotherapeutic drugs currently used are cytotoxic drugs, which are known to cause significant side effects.

Studies on two maltol-derived molecules named Malten, i.e. [N, N'-bis [ ( 3-hydroxy-4-Pyron-2-yl ) methyl] -N, N'- dimethylethylenediamine ] and Maltonis [4(N), 10 (N) -bis [(3- hydroxy-4-Pyron-2-yl ) methyl ] -1 , 7-dimethyl-l , 4, 7, 10 tetraazacyclododecane ] are already known, in particular Amatori S, Bagaloni I, Macedi E, Formica M, Giorgi L, Fusi V, Fanelli M. Malten, "a new synthetic molecule showing in vitro antiproliferative activity against tumour cells and induction of complex DNA structural alterations" Br J Cancer. 2010; 103 (2) : 239-248. doi: 10.1038/sj .bj c .6605745; Amatori S, Ambrosi G, Fanelli M, Formica M, Fusi V, Giorgi L, Macedi E, Micheloni M, Paoli P, Pontellini R, Rossi P. Synthesis, basicity, "structural characterization, and biochemical properties of two [( 3-hydroxy-4-pyron-2-yl ) methyl ] amine derivatives showing antineoplastic features" J Org Chem. 2012; 77 (5) : 2207-2218. doi: 10.1021/ o202270j e Guerzoni C, Amatori S, Giorgi L, Manara MC, Landuzzi L, Lollini P-L, Tassoni A, Balducci M, Manfrini M, Pratelli L, Serra M, Picci P, Magnani M, Fusi V, Fanelli M, Scotlandi K (2014) . An aza- macrocycle containing maltolic side-arms (maltonis) as potential drug against human pediatric sarcomas BMC Cancer 14:137. doi : 10.1186/1471-2407-14-137.

Both the chemical agents belong to the class of highly versatile molecules of the hydroxypyrons , which include compounds having antiproliferative activity against a wide range of tumour cells, alone or preferably in combination with metals . In particular the compound 3-hydroxy-2-methyl-4-pyron (maltol) is a natural compound used in food products, beverages, tobacco, beer and cosmetics due to its flavour and antioxidant properties . The maltol and its derivatives reported above show antineoplastic activity attributed to the formation of reactive oxygen species (ROS) and properties of coordination towards metallic ions. For this reason, ligands containing maltol have been developed and exploited as potential new metal-based antitumour drugs. The anti-neoplastic potential was originally verified for Malten, a molecule belonging to this class of poly-alkylamino- bis-maltolic compounds, in various tumour histotypes.

In particular the effect of Malten was studied in eight different neoplastic cell models derived from tumours of both hematopoietic origin and solid tissues such as cancer of the cervix, glioblastoma, pleural mesothelioma and alveolar rhabdomyosarcoma, the latter being the most sensitive histotype with an IC50 two or three times lower than the other models .

On the basis of the above, therefore, research is currently directed at the identification of drugs that are more efficient and/or selective vis-a-vis the tumour cells.

More recently a molecule named Maltonis has been selected and characterized, belonging to the class of poly-alkylamino-bis- maltolic compounds, which has proved effective both in vitro and in vivo vis-a-vis Ewing' s sarcoma.

SUMMARY OF THE INVENTION

The object of the present invention is therefore to obtain more efficient and/or selective compounds vis-a-vis the tumour cells.

According to the present invention said object is achieved by a compound according to claim 1. BRIEF DESCRIPTION OF THE FIGURES

For a better understanding of the present invention, it is now described also with reference to the attached figures which illustrate :

- figure 1 a series of graphs that illustrate the combination of some examples of molecules according to the present invention; and

- figure 2 a further series of graphs which illustrate the combination of some examples of molecules according to the present invention,

- figure 3 a series of graphs which illustrate the combination of some examples of molecules according to the present invention; and

- figure 4 a further series of graphs which illustrate the combination of some examples of molecules according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

By combined preparation we mean that the composites can be used in combination simultaneously or sequentially both in the same pharmaceutical formulation or in a different pharmaceutical formulation, for treatment of the same pathology .

By pharmaceutical composition we mean not only one single pharmaceutical formulation comprising two different compounds, but also that the two compounds can be present in different pharmaceutical formulations and can be used for combined preparation as defined above and therefore for simultaneous or sequential administration. Merely by way of example, a first pharmaceutical formulation may therefore contain a first compound, for example comprising a compound according to formula I below, and in a second pharmaceutical formulation a second compound. The second pharmaceutical formulation is administered sequentially and after a certain time from the first pharmaceutical formulation. Alternatively, the two compounds can be present in the same pharmaceutical formulation and be administered simultaneously.

Compounds comprising compounds with formula I are the subject of the present invention:

Where : X ₁ , X ₂ , X ₃ , X ₄ = NR ₃ , O

R3 = H, C _m H _2m+1 , m = 1, 2, 3, 4, 5, 6

n, f, 1 , v = 0,1

j, k, q, t, z = 1, 2

R ₁ , R ₂ = C _m H _2m+1 , m = 1, 2, 3, 4, 5, 6

or alternatively form a cycle and have the following meaning: where :

Y = NR ₃ , 0

R ₃ = H, C _m H _2m+1 , m = 1, 2, 3, 4, 5, 6

p= 0, 1, 2, 3, 4;

s= 0, 1, 2

r= 1, 2

and their pharmaceutically acceptable salts in combination with DNA demethylating agents and their pharmaceutically acceptable salts in particular for the preparation of a medicament and more preferably for combined preparation for the treatment of a pathology. By DNA demethylating agents, in the context of the present invention we mean compounds able to inhibit methylation, causing expression of the silenced genes.

Preferably the demethylating agents are analogues of cytidine, 5-aza-cytidine (AZA) and 5-aza-2 ' -deoxycytidine (DAC) .

Generally the DNA demethylating agents act by binding with the enzymes that catalyze the methylation reaction.

In combination with the DNA demethylating agents, the compounds with formula II are particularly preferred:

where

X = NR ₃ , O

R ₃ = H, C _m H _2m+1 , m = 1, 2, 3, 4, 5, 6

n = 0, 1, 2, 3, 4

j, k = 1, 2

R ₄ , R ₅ = C _m H _2m+1 , m = 1, 2, 3, 4, 5, 6.

The compounds with formula III are also preferred:

where :

X ₁ , Y = NR ₃ , 0

R ₃ = H, C _m H _2m+1 , m = 1, 2, 3, 4, 5, 6

n = 0, 1, 2, 3

j , s = 0, 1, 2

p= 0, 1, 2, 3

r, k= 1, 2

and their pharmaceutically acceptable salts. Among the compounds with formula I, examples of R ₃ C1-C6 aliphatic substituents are methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, ter-butyl, pentyl and hexyl. Among the compounds with formula II, those in which X is N- CH3, and n is 0 or 1 are preferred.

Among the compounds with formula III, the preferred ones are those in which X ₁ and Y are NH, N-methyl and N-ethyl or alternatively in which X or Y are equal to 0 so as to obtain poly-oxa-aza crown ether compounds . The parameters n, p can be modulated by inserting multiple ethers in amine groups obtaining compounds also with 8 functional groups. The parameters j , k, can be varied in order to separate these functions with ethyl or propyl aliphatic chains. By varying several parameters, it is possible to modulate the dimension of the ring starting from the smallest 1 , 4 , 7-cyclononanes substituted .

Among the compounds of formula III, a first group of preferred compounds comprises those based on macrocycles of cyclododecanes in which X and Y are N-CH3 or 0, and n = k = j = p = s = r = l (all ethyl chains) .

Persons skilled in the art are able to synthesize and characterize all the compounds with formula I, II, III, carrying out appropriate substitutions in the various groups. The pharmaceutically acceptable salts are all those organic and inorganic salts capable of salifying the base centres present and which do not have a toxic effect or other undesired effects.

The following compounds are particularly preferred:

Furthermore, the N, N' -bis [( 3-hydroxy-4-pyron-2-yl ) methyl ] Ν,Ν' -dimethylethylenediamine (L ¹ ) and 4(N),10(N)- bis [(3 hydroxy-4-pyron-2-il) methyl] -1, 7-dimethyl-1 , 4, 7, 10- tetraazacyclododecane (L ⁹ ) compounds are particularly preferred .

Preferably the compounds show the presence of [ ( 3-hydroxy-4- pyron-2-yl ) methyl ] -amine units also designated as "MALT") .

The MALT units are separated by different aliphatic spacers having or not having a cyclic skeleton.

All the classes of compounds I, II and III, merely by way of example, can be prepared following a known analogous synthetic approach.

The compounds of the present invention and the relative pharmaceutically acceptable salts are preferably used in combination with the DNA demethylating agents and can be used as pharmaceutical compositions together with carriers, stabilizers, diluents or pharmaceutically acceptable excipients .

The compounds and the relative pharmaceutical compositions can be used for the preparation of a medicament.

Use as an antibiotic or for the preparation of a medicament for the treatment of neoplasias is particularly advantageous. Use for the preparation of a medicament to inhibit the proliferation of neoplastic cells is particularly preferred, in particular for the preparation of a medicament to induce the differentiation of tumour cells in a tumour. Even more advantageously, they are used for the treatment of primary or secondary cancers, for example rhabdomyosarcoma or cancers of hemopoietic origin, in particular leukemias and lymphomas . Even more advantageously, they are used for the treatment of sarcomas . The examples of preparation of the following compounds further illustrate the invention, clearly without limiting the invention to them.

EXAMPLE 1

HL-60 cells (promyelocytic leukemia) were treated for 72 hours with different concentrations of 5-aza-cytidine (AZA) and Malten or Maltonis as illustrated in Figure 1 or 5-aza-2'- deoxycytidine (DAC) and Malten or Maltonis as illustrated in Figure 2. At the end of the treatment the cell viability was evaluated by means of Trypan Blue dye exclusion test. The synergic effect of the combined treatments was evaluated by calculating the Fa (Fraction affected) and the Combination Index (CI) . The Fa-CI graph and the isobologram, shown in figures 1 and 2, report the values relative to the synergic effect of the combined treatments. The Fa-CI graph derives from the values presented in the corresponding table and highlights the effect, whereas the isobologram expresses the synergy, highlighting the dose. A CI value below 1 indicates synergy. Both the graphs were generated using the CompuSyn software (Chou TC, Pharmacol. Rev. 2006, 58 ( 3 ) : 621- 681 ) .

In all the cases tested, the synergic biological effect (CI < 1) is clear, in particular using low concentrations of the single molecules used.

Example 2

Figure 3 illustrates the synergic effect obtained by means of combined treatments of bis-maltolates (malten or maltonis) with the DNA (AZA) demethylating agent and U937 cells (histiocytic lymphoma) . U937 cells were treated for 72 hours with different concentrations of AZA and malten (A) or AZA and maltonis (B) and then evaluated for viability by means of Trypan Blue dye exclusion test. The Fa-CI graphs (left-hand panels) and normalized isobolograms (right-hand panels) show the synergic biological effect. The Fa-CI graphs were derived from the values indicated in the corresponding table. Fa (fraction affected) represents the fraction of cells affected by the treatment. Combination index (CI) <1 indicates synergy. All the experiments were carried out in triplicate and the mean value is displayed. The Fa-CI graphs and the normalized isobolograms were generated using the CompuSyn software (Chou, 2006) .

Figure 4 illustrates the synergic effect triggered by combined treatments of bis-maltolates (malten or maltonis) with the DNA (DAC) demethylating agent. U937 cells were treated for 72 hours with different concentrations of DAC and malten (A) or DAC and maltonis (B) and then evaluated for viability by means of Trypan Blue dye exclusion test. The Fa-CI graphs (left-hand panels) and normalized isobolograms (right-hand panels) show the synergic biological effect. The Fa-CI graphs were derived from the values indicated in the corresponding table. Fa (fraction affected) represents the fraction of cells affected by the treatment. The combination index (CI) <1 indicates an unexpected synergic effect .

All the experiments were performed in triplicate and the mean value is displayed. The Fa-CI graphs and the normalized isobolograms were generated using the CompuSyn software (Chou, 2006) .