Patent Description:
The present invention further relates to a controlled release formulation of Sorafenib or Sorafenib derivatives, which comprises Sorafenib PBB or Sorafenib PBB derivatives, and to the use of said formulation in the treatment of tumor diseases of the kidney, liver, thyroid, colon, breast, pancreas, lungs and/or recurrent glioblastoma.

Sorafenib, <NUM>-[<NUM>-[[<NUM>-chloro-<NUM>-(trifluoromethyl) phenyl] carbamoylamino]phenoxy]-N-methyl-pyridine-<NUM>-carboxamide, is an approved drug for the treatment of hepatocellular carcinoma (HCC). The mechanism of action is mediated by the inhibitory activity exerted on kinases overexpressed in a series of molecular pathways involved in the transformation of normal cells into tumor cells, in particular receptors with kinase activity and on Raf kinases.

The drug is commercially available as orally administered tablets. Sorafenib is poorly soluble in water and its bioavailability is low due to a strong first-pass effect. In addition, often significant gastrointestinal irritation is associated with administration (<NPL>). Other side effects such as skin rash, diarrhea, hypertension strongly limit the clinical application thereof.

<NPL> described nanoparticles for the controlled release of Sorafenib. Sorafenib was incorporated into a dextran/poly(dl-lactide-co-glycolide) copolymer (DexbLG), with a copolymer/Sorafenib ratio between <NUM>:<NUM> and <NUM>:<NUM>, resulting in rather homogeneous spherical nanoparticles. The formulation proved to be cytotoxic on cholangiocarcinoma cells with similar activity to that of free Sorafenib. The work provides no indication of a preferential distribution in tumor tissue for said nanoparticles.

<NPL> describe the preparation of liver-targeted polymeric micelles potentially able to carry sorafenib to hepatocytes for treatment of hepatocarcinoma. These micelles were prepared starting from a galactosylated polylactide-polyaminoacid conjugate.

Aiming at providing an advantageous alternative to the currently available formulations in the prior art, polymeric nanoparticles comprising Sorafenib, or Sorafenib derivatives, are described herein, which have shown surprisingly advantageous features in terms of release efficacy and stability over time.

The present invention relates to polymeric nanoparticles containing Sorafenib or Sorafenib derivatives. The present invention further relates to a method for preparing said particles and to their use in the treatment of tumor diseases of the kidney, liver, thyroid, colon, breast, pancreas, lungs and/or recurrent glioblastoma.

The nanoparticles were obtained from a biocompatible polymer, α,β-poly(N-<NUM>-hydroxyethyl)-D,L-aspartamide (PHEA) (G<NPL>; <NPL>). In summary, PHEA was derivatized with α-bromoisobutyryl bromide (BIB), and the derivative thus obtained was used as a "macroinitiator" for the polymerization of butyl methacrylate (ButMA), lateral chain polymerization and via Atom Transfer Radical Polymerization (ATRP) (<NPL>; <NPL>; <NPL>). The nanoparticles thus obtained were loaded with the drug by means of the dialysis method, without the use of surfactants, and characterized.

For loading the nanoparticles with the drug, the PBB copolymer, synthesized by ATRP as described in the aforementioned Cavallaro et al. <NUM>, Licciardi et al. <NUM>, Licciardi et al. <NUM>, and whose chemical structure is shown in <FIG>, was dissolved in a solvent, for example selected from the group comprising dimethylformamide (DMF), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF) or mixtures thereof, in the presence of Sorafenib or a derivative of Sorafenib, with a weight ratio of copolymer to Sorafenib or Sorafenib derivative between <NUM>:<NUM> and <NUM>:<NUM>, preferably between <NUM>:<NUM> and <NUM>:<NUM>, even more preferably <NUM>:<NUM>, and the solution was dialyzed for three hours against bidistilled water using a dialysis membrane with a molecular weight (MW) cut-off higher than the polymer MW, i.e. higher than <NUM>,<NUM> Da, preferably higher than or equal to <NUM>,<NUM> Da.

In a preferred embodiment, said nanoparticles are loaded with Sorafenib (Sorafenib PBB), or with Sorafenib derivatives or pharmaceutically acceptable salts thereof (Sorafenib PBB derivatives). For the purposes of the present invention, the term "Sorafenib derivatives" means the following compounds: Regorafenib, of formula (<NUM>)
<CHM>.

Dimeric derivatives, such as for example SC-<NUM> of formula (<NUM>)
<CHM>.

Other Sorafenib derivatives are described in <NPL>, of general formula (<NUM>), where R1, R2 and R3 are as indicated in table <NUM> below. <CHM>
<IMG>.

Described in the same work are the derivatives of general formula (<NUM>), where R1 and R2 are as described in table <NUM>. <CHM>
<IMG>.

Again described in Chen et al. are the derivatives of general formula (<NUM>) where R1, R2 and R3 are as described in table <NUM>. <CHM>
<IMG>.

Further Sorafenib derivatives are those described in <NPL>, of general formula (<NUM>):
<CHM>
where R1 and R2 are as described in table <NUM> below.

Further derivatives of Sorafenib are described in <NPL>. Among these are compounds <NUM> and <NUM> of formula (<NUM>) and compounds 14a-ke 15a-k of formula (<NUM>) and (<NUM>), respectively, where R is as described in table <NUM>. <CHM>
<CHM>
<CHM>.

Further derivatives of Sorafenib are described in <NPL>. Among these are compounds 2a-e, 3a-e, 4a-e of formula (<NUM>), (<NUM>) and (<NUM>), respectively, where R is as described in table <NUM>. <CHM>
<CHM>
<CHM>.

Further derivatives are derivatives of general formula (<NUM>), described in <NPL>, where R is as shown in table <NUM>.

In one embodiment, said Sorafenib or Sorafenib derivatives are in the form of pharmaceutically acceptable salts.

In a preferred embodiment, said Sorafenib is Sorafenib tosylate.

In the process of preparing the nanoparticles according to the present invention, the external aqueous phase is gently stirred with a magnetic stirrer, so as to favor the diffusion process. Bidistilled water is periodically replaced, typically at intervals of <NUM> hours, or <NUM> hours, or <NUM> hours. Dialysis is performed over a period of approximately <NUM> hours. At the end, a cryoprotectant is optionally added, preferably selected from the group comprising PVP (polyvinylpyrrolidone) and/or PVA (polyvinyl alcohol) and/or trehalose and/or lactose and/or mixtures thereof, preferably in a copolymer/cryoprotective weight ratio = <NUM>:<NUM>, and the resulting dispersion is filtered through a <NUM> membrane filter, so as to remove the insoluble material. The filtrate is lyophilized, so as to have lyophilized PBB nanoparticles loaded with Sorafenib (Sorafenib PBB) or Sorafenib derivatives (Sorafenib PBB derivatives).

The amount of Sorafenib or Sorafenib derivatives loaded into the PBB nanoparticles, i.e. the drug-mass portion of the nanoparticles (drug loading), is determined by high performance liquid chromatography (HPLC). The drug loading percentage (DL%) of Sorafenib PBB was calculated according to Equation (<NUM>): <MAT>.

The data obtained show a DL% between <NUM> and <NUM>%, preferably between <NUM> and <NUM>%, even more preferably between <NUM> and <NUM>%.

The efficacy of Sorafenib PBB on the growth of tumor cells was evaluated in an in vitro assay conducted on human hepatocellular carcinoma cells. The results, shown in <FIG>, show that the entrapment of Sorafenib in PBB not only does not cause a reduction in the activity of the drug but actually increases it, as shown in table <NUM>, which shows the average IC50 values for free Sorafenib and Sorafenib PBBs obtained in HepG2 and Hep3B hepatocellular carcinoma cells.

The empty nanoparticles have no cytotoxic effect on the cells tested, as shown in <FIG>.

The activity of Sorafenib PBB is confirmed by Western blot data reported in <FIG> which confirm the low cytotoxic effect of the carrier as well as the maintenance at the molecular level of the free Sorafenib activity by Sorafenib PBB.

Tests conducted in vivo on nude mice in which hepatocellular carcinoma cells were injected showed that Sorafenib PBB enhances the activity of Sorafenib in inhibiting the growth of cancer cells, as well as promoting an overall improvement in the state of the animal.

The surprisingly advantageous efficacy observed in vivo is possible due to the preferential accumulation of Sorafenib PBB in the tumor site, as shown in <FIG>.

The present invention further relates to a formulation for the controlled release of Sorafenib or Sorafenib derivatives, where said formulation comprises Sorafenib PBB or Sorafenib PBB derivatives.

Sorafenib PBB or Sorafenib PBB derivatives are surprisingly advantageous for the treatment of tumor diseases of the kidney, liver, thyroid, colon, breast, pancreas, lungs and/or recurrent glioblastoma, preferably in the treatment of hepatocellular carcinoma. PBP Sorafenib or Sorafenib PBB derivatives proved to release the drug preferentially in the tumor site, resulting in a marked increase in drug efficacy and a reduction of the side effects due to the specific and general distribution of the drug in other organs.

A method for treating a solid tumor in an individual is also described, comprising administering to said individual an effective amount of a composition comprising Sorafenib PBB or Sorafenib PBB derivatives, where said method reduces the viability of hepatocellular carcinoma cells.

In a further embodiment, said method also comprises administering an effective amount of one or more further therapeutic agents.

A further advantage of the Sorafenib PBB or Sorafenib PBB derivatives according to the present invention is to be found in the stability of Sorafenib PBB and Sorafenib PBB derivatives. The physical interactions in the PBB nanoparticles when loaded with Sorafenib or Sorafenib derivatives are sufficiently strong to impart stability during storage at different temperatures, as shown in example <NUM> below.

The PBB copolymer (<NUM>) alone or with Sorafenib tosylate (<NUM>) (weight ratio of copolymer to Sorafenib equal to <NUM>:<NUM>) was dissolved in <NUM> of DMF and the solution was dialyzed against <NUM> of bidistilled water for <NUM> hours using a SpectraPor dialysis membrane with a <NUM>,<NUM> Da molecular weight cut-off at room temperature. The external aqueous phase was gently stirred with a magnetic stirrer to aid the diffusion process. Then, bidistilled water was replaced at <NUM>-hour intervals for <NUM> hours. After dialysis, PVP was added to the colloidal dispersion as a cryoprotectant (weight ratio of copolymer to PVP equal to <NUM>:<NUM>); the resulting dispersion was filtered through a <NUM> membrane filter (Sartorius, Minisart syringe filter, Germany) to remove the insoluble material and the filtrate was lyophilized.

The mean size, the polydispersion index (PDI) and the zeta potential of PBB nanoparticles, either empty or loaded with Sorafenib, were evaluated by Dynamic Light Scattering (DLS) measurements using the Malvern Zetasizer NanoZS instrument. Dispersions of nanoparticles were prepared by the method described in example <NUM> and were analyzed at <NUM> with a sample concentration of <NUM>/ml in bidistilled water. The PDI and average hydrodynamic diameter values (size in nm) were obtained by cumulative analysis of the correlation function. The value of the Zeta potential (mV) was calculated by measures of electrophoretic mobility using the Smoluchowsky relation and assuming that k·is greater than or equal to <NUM> (where "k" and "a" are the Debye-Hückel parameter and the radius of the particle, respectively). All measurements were made in triplicate.

Empty PBB nanoparticles showed an average diameter of about <NUM>; PBB nanoparticles loaded with Sorafenib have an average diameter of less than <NUM>, or <NUM>, preferably between <NUM> and <NUM>, even more preferably about <NUM>.

The incorporation of the drug increases the average size of the nanoparticles, presumably due to an increase in size in the hydrophobic nucleus due to the presence of the drug itself. The values of the Zeta potential for either empty or Sorafenib-containing nanoparticles are negative, thus confirming the stability of the PBB nanoparticles. Since the value of the Zeta potential does not change significantly after the incorporation of the drug, this result indicates the absence of ionic interactions between Sorafenib and the PBB nanoparticles. The physical stability of the Sorafenib-containing PBB nanoparticles (Sorafenib PBB) was then tested. Aqueous dispersions of Sorafenib PBB were lyophilized and stored at - <NUM>, <NUM> and <NUM> for three months. In the three cases, the ratio of the particle size after storage to the initial size was not greater than <NUM> ± <NUM>, thus indicating stability in all the conditions analyzed. Furthermore, Sorafenib PBB was found to maintain the Sorafenib content unchanged under the conditions analyzed.

The amount of Sorafenib loaded into the PBB nanoparticles, or drug loading, was determined by high performance liquid chromatography (HPLC), using an Agilent <NUM> Infinity system with a multiple wavelength detector, MWD, operating at <NUM>. The chromatographic procedure was conducted in isocratic at <NUM>, using an inverse phase column Gemini C6-phenyl 110A (Phenomenex <NUM>, 250x4. <NUM>), <NUM>:<NUM> methanol-water as a mobile phase, with a flow of <NUM>/min. <NUM>µl of sample were injected into the column (<NPL>). Data analysis was performed using Open Lab Chemstation software. The lyophilized nanoparticles containing Sorafenib were suspended in an appropriate amount of methanol and vigorously stirred for <NUM>-<NUM> hours to extract the drug. The resulting solution was centrifuged at <NUM> rpm for <NUM> at <NUM> and the supernatant was used to determine the drug concentration by a calibration curve obtained with standard Sorafenib solution in methanol in the range <NUM>-<NUM>µg/ml (tr = <NUM>). The DL% was found to be <NUM>±<NUM>% w/w.

Release studies of Sorafenib from Sorafenib PBB were performed in vitro in the following receiving media: hydrochloric acid solution (pH <NUM>) to simulate gastric fluid (SGF); phosphate buffer (pH <NUM>), to simulate intestinal fluid (SIF) and phosphate buffer solution (PBS) (pH <NUM>), i.e. in physiological fluid, using the dialysis tube method with a cut-off of <NUM>-<NUM> Da under sink conditions.

An adequate amount of lyophilized Sorafenib PBB was dispersed in <NUM> of the receiving medium at room temperature. The dispersion was then introduced into a dialysis tube which was immersed in an external vessel containing <NUM> of the same medium in the presence of Tween <NUM> (<NUM>% v/v), added as a solubilizer of Sorafenib, slightly soluble in water. During the experiment, the temperature was maintained at <NUM> in a thermostatic stirrer and with stirring of <NUM> rpm. At scheduled time intervals, <NUM> aliquots were taken from the external medium and replaced with an equal volume of fresh receiving medium. The released Sorafenib was quantified by HPLC analysis. Each in vitro release experiment was repeated in triplicate.

A control experiment was also carried out to determine the dissolution of the free drug: an appropriate amount of Sorafenib was dispersed in the receiving medium, in order to have a final concentration of Sorafenib equal to that present in the nanoparticles, the dispersion was then introduced into a dialysis tube (cut-off <NUM>-<NUM> Da) which was immersed in a container containing the receiving medium. The amount of Sorafenib in the receiving medium was detected by HPLC analysis.

The amount of released Sorafenib was expressed as a percentage ratio between the released drug weight and the total amount of Sorafenib loaded into the nanoparticles. <FIG> shows the release profiles of Sorafenib from Sorafenib PBB and the dissolution of the free drug in SGF (A), SIF (B) and PBS (C). It is observed, in panel A, that after <NUM> minutes incubation in SGF the cumulative release of Sorafenib from the nanoparticles was about <NUM>%. The cumulative release of Sorafenib in <NUM> hours was about <NUM>% in SIF (panel B) and about <NUM>% in PBS (panel C). In the three release conditions, the dissolution of free Sorafenib is almost complete within two hours. Therefore, in all release media, Sorafenib PBB shows a prolonged release compared to the dissolution of free Sorafenib.

The human hepatocellular carcinoma cell lines, HepG2 and Hep3B, were obtained from the American Type Culture Collection (ATCC). Cells were kept in <NUM>% CO<NUM> and grown in Roswell Park Memorial Institute (RPMI) medium (SIGMA, Milan, Italy), supplemented with <NUM>% (v/v) fetal bovine serum (FBS) (Gibco, Life Technologies, Monza MB, Italy), <NUM> L-glutamine, <NUM> U/ml of penicillinstreptomycin and <NUM> of sodium pyruvate (SIGMA, Milan, Italy). Cell lines were regularly checked for possible mycoplasma contamination.

<NUM>×<NUM><NUM> cells/well were distributed in <NUM>-well plates, dispensing <NUM>µl of cell suspension per well and incubated at <NUM> in <NUM>% CO<NUM>. The cells were incubated for further <NUM> hours with fresh medium containing free Sorafenib (Sorafenib tosylate solubilized in dimethyl sulfoxide, DMSO), Sorafenib PBB or empty PBB nanoparticles. The latter were resuspended in sterile conditions in sterile H<NUM>O, sonicated for <NUM> in a water sonicator, and diluted with a complete RPMI volume (2X). At the end of the treatment, cell viability assays were performed using the OneSolution aqueous CellTiter kit (Promega Corporation, Madison, WI, USA). The percentage of cell viability was calculated with reference to the absorbance measured in the control cells. The experiments were performed in triplicate and the values expressed as mean ± SD of three independent experiments. No bacterial growth was observed in any sample, confirming the complete sterility of the handling conditions and of the samples themselves.

Results measured after treatment with increasing concentrations (<NUM> - <NUM>) of the indicated compounds are shown in <FIG>. Cell viability is strongly decreased in a dose-dependent manner in the presence of free Sorafenib and, even more markedly, Sorafenib PBB.

<NUM>×<NUM><NUM> cells/well were seeded in <NUM>-well plates and kept for <NUM> hours at <NUM> in <NUM>% CO<NUM>. The cells were then treated for <NUM> hours with <NUM>, <NUM> and <NUM> of free Sorafenib (solubilized in DMSO), empty PBB nanoparticles or Sorafenib PBB, solubilized as reported in cell viability assays. After treatment, cell lysates were obtained using the RIPA buffer (Cell Signaling Technologies Inc. , Beverly, MA, USA). The protein concentrations of the supernatants were determined with the Bio-Rad "Protein assay" kit (Bio-Rad Laboratories Srl, Milan, Italy). Western blotting analyzes were performed using as primary antibodies anti β-actin (SIGMA), anti ERK1/<NUM>, anti p-ERK1/<NUM> (phospho-ERK1/<NUM>), anti PARP (poly(ADP)-ribose polymerase) and anti-Mcl-<NUM> (myeloid cell leukemia <NUM>) (Cell Signaling).

As shown in <FIG>, free Sorafenib and Sorafenib PBB induce, at concentrations of <NUM> and <NUM>, the fragmentation of the PARP protein, indicative of the induction of apoptosis. Similarly, the decrease in the p-ERK1/<NUM> signal is apparent after treatment with free Sorafenib and after treatment with Sorafenib PBB, especially at <NUM> concentration. A decrease in the expression levels of pERK1/<NUM> is indicative of a decrease in cell proliferation.

Inhibition of Mcl-<NUM> expression levels, an anti-apoptotic protein, is apparent at the highest concentrations of free Sorafenib and Sorafenib PBB. Treatment with the carrier (PBB) alone does not show any effect on the expression levels of all the proteins analyzed.

Male nude mice (fox1 nu/nu) of <NUM> weeks of life were purchased at Envigo (Udine, Italy) and left to acclimatize for <NUM> week. Hep3B cells (<NUM>×<NUM><NUM> in <NUM> PBS), undergoing logarithmic growth, were inoculated in the right flank of the animals. When the tumors were palpable (about <NUM><NUM>), the mice were randomly divided into four groups of five animals each, with the various tumor volumes equally distributed between the four groups. Each group was treated for <NUM> days as indicated below.

Group <NUM>: daily treatment (<NUM> days/week) by intraperitoneal (IP) injection with <NUM>/kg of Sorafenib tosylate resuspended in DMSO and further diluted in a <NUM>% solution of ethanol (DMSO-EtOH).

Group <NUM>: daily treatment (<NUM> days/week) with <NUM>/kg of Sorafenib PBB resuspended in RPMI.

Group <NUM>: daily treatment (<NUM> days/week) with <NUM>/kg of empty PBB nanoparticles resuspended in RPMI.

The lyophilized nanoparticle samples were resuspended and sonicated as reported in cell viability assays. Tumor volumes and body weight were recorded twice a week as previously described (<NPL>). The mice were sacrificed by cervical dislocation when the tumor mass exceeded <NUM>% of the body weight of the animals, or when the tumor mass appeared ulcerated or other morbid conditions were found, in accordance with the institutional guidelines and in accordance with the national law (Legislative Decree No. <NUM><NUM>-<NUM> -<NUM>) and international laws and policies (ECC Council Directive <NUM>/<NUM>, OJ L358. <NUM>, December <NUM>, <NUM>). This study was authorized by the Ministry of Health with authorization number <NUM>/<NUM>-PR. At the end of the trial, tumors, liver, kidneys, lungs and spleen were collected from each animal. Half of each tumor, or organ, was frozen in liquid nitrogen and stored at -<NUM> for biodistribution analyzes, while the other half was fixated in formalin and used for immunohistochemistry analysis.

To quantify the Ki-<NUM> cell proliferation marker expression, the ImmunoRatio® software (http://jvsmicroscope. fi/immunoratio/) was used which, using a color deconvolution algorithm, calculates the percentage of positively marked area (area stained with diaminobenzidine) towards the total nuclear area. The hematoxylin stains were also acquired to analyze the neo-vascularization of the tumor, using the Leica DMR microscope equipped with a Leica DFC <NUM> digital camera.

As shown in <FIG>, treatment with <NUM>/kg of free form Sorafenib reduced tumor growth compared to the carrier alone, although this difference was not significant. Treatment with Sorafenib PBB significantly inhibited tumor growth compared to treatment with the free drug (p <<NUM>). During treatment, changes in the body weight of the animal were also monitored. As shown in <FIG>, mice treated with <NUM>/kg of Sorafenib did not show a significant loss of body weight, compared to mice treated with the carrier alone, suggesting a satisfactory level of cytotoxicity of the drug at the concentration used in this study. Mice treated with Sorafenib PBB showed a significant increase in their body weight (p <<NUM>).

Mobility was also assessed in treated animals, observing better physical mobility in the group of animals treated with Sorafenib PBB.

To evaluate the anti-proliferative activity, the expression levels of the Ki67 nuclear marker were analyzed. The number of Ki67-positive cells decreases in tumor tissues from animals treated with Sorafenib PBB compared to that in tumor tissues of animals treated with the free drug, with empty PBBs or with carrier alone (<FIG>). Furthermore, the tumor vascularization was evaluated in tumor tissues after staining of blood vessels with hematoxylin (<FIG>). The number and size of blood vessels decreases dramatically in tumor tissues from animals treated with Sorafenib PBB compared to those seen in the tissues of animals treated with free drug, with empty PBBs or with the carrier alone.

Sorafenib was extracted from the tissues of the treated animals following the procedure described in Craparo EF et al.

Briefly, each tissue sample was mixed with Tris buffer (<NUM>, <NUM>, pH <NUM>) in a <NUM> glass tube and homogenized using an Ultraturrax T <NUM> (Janke & Kunkel Ika - Labortechnik) at <NUM> rpm for <NUM>. Then, methanol (<NUM>) was added to precipitate the proteins. The samples were extracted three times with ethyl ether (<NUM>), and each extraction was followed by centrifugation at <NUM> rpm for <NUM> at room temperature. After each addition of solvent, the centrifuge tubes were stirred for <NUM> at room temperature and centrifuged for <NUM> at <NUM> rpm. The organic layers were transferred to a glass tube and evaporated to dryness.

Each dry residue was treated with methanol (<NUM>) and, after stirring, a volume of <NUM>µl was injected into the HPLC system. The data shown in <FIG> surprisingly show an accumulation of Sorafenib in the analyzed organs such as liver, spleen, lungs and kidneys and said accumulation decreases when the animals are treated with Sorafenib PBB (gray column) compared to when treatment is performed with free Sorafenib (white column). In particular, the amount of Sorafenib detected when mice were treated with the free drug was significantly higher in the kidneys (p <<NUM>), spleen (p <<NUM>) and lungs (p <<NUM>) than the accumulation occurring after the administration of Sorafenib PBB.

Claim 1:
Nanoparticles loaded with Sorafenib (Sorafenib PBB) or Sorafenib derivatives or pharmaceutically acceptable salts thereof (Sorafenib PBB derivatives), wherein said nanoparticles are polymeric PBB nanoparticles, (PHEA-BIB-pButMA, α,β-poly(N-<NUM>-hydroxyethyl)-co-{N-<NUM>-ethylene-[<NUM>-(poly(butylmethacrylate)-isobutyrate]}-D,L-aspartamide and wherein said Sorafenib derivatives are selected from the group comprising:
- Regorafenib, of formula (<NUM>)
<CHM>
- dimeric derivatives, such as for example SC-<NUM> of formula (<NUM>)
<CHM>
- HLC-<NUM>, of formula (<NUM>)
<CHM>
- compounds of formula (<NUM>), where R1, R2 and R3 are as indicated in the table:
<CHM>

<TAB>

- compounds of formula (<NUM>), where R1 and R2 are as described in the table
<CHM>

<TAB>

- compounds of formula (<NUM>) where R1, R2 and R3 are as described in the table
<CHM>

<TAB>

- compounds of formula (<NUM>) where R1 and R2 are as described in the table
<CHM>

<TAB>

- compounds <NUM> and <NUM> of formula (<NUM>) and compounds 14a-k and 15a-k of formula (<NUM>) and (<NUM>), where R is as described in the table
<CHM>
<CHM>
<CHM>

<TAB>

- compounds 2a-e, 3a-e, 4a-e of formula (<NUM>), (<NUM>) and (<NUM>), where R is as described in the table
<CHM>
<CHM>
<CHM>

<TAB>

<TAB>

<TAB>

- compounds of formula (<NUM>) where R is as described in the table
<CHM>

<TAB>

.