HK1132462B - Combination of an hdac inhibitor and an antimetabolite - Google Patents

Description

Field of Invention

The invention relates to a combination which comprises:

1. (a) a histone deacetylase inhibitor (HDAI); and
2. (b) an anti-metabolite,

for simultaneous, concurrent, separate or sequential use, especially for use in the treatment of myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML). The invention also relates to pharmaceutical compositions comprising such a combination and to a method of treating MDS or AML, in a mammal, particularly a human, with such a combination. Background of Invention

Reversible acetylation of histones is a major regulator of gene expression that acts by altering accessibility of transcription factors to DNA. In normal cells, histone deacetylase (HDA) and histone acetyltrasferase together control the level of acetylation of histones to maintain a balance. Inhibition of HDA results in the accumulation of hyperacetylated histones, which results in a variety of cellular responses. HDAI have been studied for their therapeutic effects on cancer cells. Recent developments in the field of HDAI research have provided active compounds, both highly efficacious and stable, that are suitable for treating tumors.

Accruing evidence suggests that HDAI are even more efficacious when used in combination with other chemotherapeutic agents. There are both synergistic and additive advantages, both for efficacy and safety. Therapeutic effects of combinations of chemotherapeutic agents with HDAI can result in lower safe dosages ranges of each component in the combination.

Summary of invention

This invention relates to the histone deacetylase inhibitor N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, in particular, to pharmaceutical compositions for use in combination with the anti-metabolite 5-azacitidine for the delay of progression or treatment of a proliferative disease which is myelo-dysplastic syndrome (MDS) or acute myeloblastic leukemia (AML).

We have now found that certain HDAIs, i.e., HDACs, are effective when used in combination with an anti-metabolite for the delay of progression or treatment of a proliferative disease, especially MDS or AML.

Detailed Description of the Drawings

• Figure 1 illustrates LBH589 in combination with 5-AzaC induced higher p21 levels and PARP cleavage than each compound as single agent.
• Figure 2 illustrates Induction of apoptosis by LBH589, 5-azacytidine or LBH589+ 5-axacytidine in the U937 AML cell line.

Detailed Description of Invention

Accordingly the invention provides a method for the delay of progression or treatment of MDS or AML in a subject in need of such treatment which comprises administering to the subject an effective amount of

N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide in combination with an anti-metabolite.

The compound described is often used in the form of a pharmaceutically acceptable salt. Pharmaceutically acceptable salts include, when appropriate, pharmaceutically acceptable base addition salts and acid addition salts, e.g., metal salts, such as alkali and alkaline earth metal salts, ammonium salts, organic amine addition salts and amino acid addition salts and sulfonate salts. Acid addition salts include inorganic acid addition salts, such as hydrochloride, sulfate and phosphate; and organic acid addition salts, such as alkyl sulfonate, arylsulfonate, acetate, maleate, fumarate, tartrate, citrate and lactate. Examples of metal salts are alkali metal salts, such as lithium salt, sodium salt and potassium salt; alkaline earth metal salts, such as magnesium salt and calcium salt, aluminum salt and zinc salt. Examples of ammonium salts are ammonium salt and tetramethylammonium salt. Examples of organic amine addition salts are salts with morpholine and piperidine. Examples of amino acid addition salts are salts with glycine, phenylalanine, glutamic acid and lysine. Sulfonate salts include mesylate, tosylate and benzene sulfonic acid salts.

The HDAI compound within the scope of the invention, and its synthesis, is disclosed in WO 02/22577 .

N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, of formula (III): or a pharmaceutically acceptable salt thereof.

The term "anti-metabolite", as used herein, relates to a compound which inhibits or disrupts the synthesis of DNA resulting in cell death. Examples of an anti-metabolite include, but are not limited to, 6-mercaptopurine; cytarabine; fludarabine; flexuridine; fluorouracil; capecitabine; raltitrexed; methotrexate; cladribine; gemcitabine; gemcitabine hydrochloride; thioguanine; hydroxyurea; DNA de-methylating agents, such as 5-azacytidine and decitabine; edatrexate; and folic acid antagonists such as, but not limited to, pemetrexed. Capecitabine can be administered, e.g., in the form as it is marketed, e.g., under the trademark XELODA; and gemcitabine as GEMZAR.

The anti-metabolite is 5-azacytidine.

The invention provides use of an HDAC inhibitor in combination with an anti-metabolite for the treatment of a proliferative disease, especially MDS or AML.

In yet further aspect the invention provides an HDAC inhibitor as active ingredient for use in combination with an anti-metabolite for the treatment of a proliferative disease, especially MDS or AML.

In still yet further aspect, the invention provides a package comprising an HDAC inhibitor together with instructions for the use in combination with an anti-metabolite for the treatment of a proliferative disease, especially MDS or AML.

The term "delay of progression", as used herein, means administration of the combination to patients being in an early phase of the proliferative disease to be treated.

Combination refers to administration of an amount of HDAC inhibitor in combination with administration of an amount of an anti-metabolite such that there is a synergistic effect which would not be obtained if an HDAC inhibitor is administered without separate, simultaneous or sequential administration of an anti-metabolite. Wherein administration of an anti-metabolite can be continuous, sequential or sporadic. Or an effect which would not be obtained if there is administered an anti-metabolite without the separate, simultaneous or sequential administration of an HDAC inhibitor, wherein administration can be continuous, sequential or sporadic.

Preferably, combination refers to administration of an amount of HDAC inhibitor in combination with administration of an amount of an anti-metabolite such that there is a synergistic antiproliferative effect and/or a clonogenic cell killing effect that would not be obtained if:

1. a) The HDAC is administered without prior, simultaneous or subsequent administration of an anti-metabolite. Wherein administration can be continuous, sequential or sporadic;
2. b) There is administration of an anti-metabolite without the prior, simultaneous or subsequent administration of an HDAC inhibitor. Where in administration can be continuous, sequential or sporadic.

A combination which comprises:

1. (a) an HDAC inhibitor, which may be present in free form or in the form of a pharmaceutically acceptable salt and optionally at least one pharmaceutically acceptable carrier; and
2. (b) an anti-metabolite, will be referred to hereinafter as a COMBINATION OF THE INVENTION.

In the combination of the invention, HDAC inhibitor and pharmaceutically acceptable salts and prodrug derivatives are preferably used in the form of pharmaceutical preparations that contain the relevant therapeutically effective amount of active ingredient optionally together with or in admixture with inorganic or organic, solid or liquid, pharmaceutically acceptable carriers which are suitable for administration.

In an alternative embodiment, the anti-metabolite is given as a pre-treatment, i.e. before the treatment with the COMBINATION OF THE INVENTION is started; the anti-metabolite alone is administered to the patient for a defined period of time.

The HDAC pharmaceutical compositions may be, e.g., compositions for enteral, such as moral, rectal, aerosol inhalation or nasal administration, compositions for parenteral, such as intravenous or subcutaneous administration, or compositions for transdermal administration (e.g., passive or iontophoretic), or compositions for topical administration.

Preferably, the HDAC pharmaceutical compositions are adapted to oral administration.

The pharmaceutical compositions according to the invention can be prepared in a manner known per se and are those suitable for enteral, such as oral or rectal, and parenteral administration to mammals (warm-blooded animals), including man, comprising a therapeutically effective amount of at least one pharmacologically active combination partner alone or in combination with one or more pharmaceutically acceptable carries, especially suitable for enteral or parenteral application.

The novel pharmaceutical composition contain, e.g., from about 10% to about 100%, preferably from about 20% to about 60%, of the active ingredients. Pharmaceutical preparations for the combination therapy for enteral or parenteral administration are, e.g., those in unit dosage forms, such as sugar-coated tablets, tablets, capsules or suppositories, and furthermore ampoules. If not indicated otherwise, these are prepared in a manner known per se, e.g., by means of conventional mixing, granulating, sugar-coating, dissolving or lyophilizing processes. It will be appreciated that the unit content of a combination partner contained in an individual dose of each dosage form need not in itself constitute an effective amount since the necessary effective amount can be reached by administration of a plurality of dosage units.

In preparing the compositions for oral dosage form, any of the usual pharmaceutical media may be employed, such as, e.g., water, glycols, oils, alcohols, flavouring agents, preservatives, colouring agents; or carriers such as starches, sugars, microcrystalline cellulose, diluents, granulating agents, lubricants, binders, disintegrating agents and the like in the case of oral solid preparations, such as, e.g., powders, capsules and tablets, with the solid oral preparations being preferred over the liquid preparations. Because of their ease of administration, tablets and capsules represent the most advantageous oral dosage unit form in which case solid pharmaceutical carriers are obviously employed.

In particular, a therapeutically effective amount of each combination partner of the COMBINATION OF THE INVENTION may be administered simultaneously our sequentially and in any order, and the components may be administered separately or as a fixed combination. For example, the method of delay of progression or treatment of a proliferative disease according to the invention may comprise:

1. (i) administration of the first combination partner; and
2. (ii) administration of the second combination partner,

wherein administration of a combination partner may be simultaneous or sequential in any order, in jointly therapeutically effective amounts, preferably in synergistically effective amounts, e.g., in daily or weekly dosages corresponding to the amounts described herein. The individual combination partners of the COMBINATION OF THE INVENTION can be administered separately at different times during the course of therapy or concurrently. Furthermore, the term administering also encompasses the use of a pro-drug of an HDAC inhibitor that converts in vivo to the combination partner as such. The instant invention is therefore to be understood as embracing all such regimes of simultaneous or alternating treatment and the term "administering" is to be interpreted accordingly.

The dosage of an anti-metabolite and an HDAC inhibitor in relation to each other is preferably in a ratio that is synergistic.

If the warm-blooded animal is a human, the dosage of a compound of formula (I) is preferably an appropriate dose in the range from 100-1500 mg daily, e.g., 200-1,000 mg/day, such as 200, 400, 500, 600, 800, 900 or 1,000 mg/day, administered in one or two doses daily. Appropriate dosages and the frequency of administration of the death receptor ligand will depend on such factors, as the nature and severity of the indication being treated, the desired response, the condition of the patient and so forth.

The particular mode of administration and the dosage of an HDAC inhibitor may be selected by the attending physician taking into account the particulars of the patient, especially age, weight, life style, activity level, etc.

The dosage of an HDAC inhibitor may depend on various factors, such as effectiveness and duration of action of the active ingredient, mode of administration, effectiveness and duration of action of the ionizing radiation and/or sex, age, weight and individual condition of the subject to be treated.

The dosage of ionizing radiation may depend on various factors, such as effectiveness and duration of action of the ionizing radiation, mode of administration, location of administration, effectiveness and duration of action of the HDAC inhibitor and/or sex, age, weight and individual condition of the subject to be treated. The dosage of ionizing radiation is generally defined in terms of radiation absorbed dose, time and fraction, and must be carefully defined by the attending physician.

The combination comprises 5-azacitidine and N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, of formula (III) above or a pharmaceutically acceptable salt thereof.

Moreover, the present invention relates to a method of treating a warm-blooded animal having a proliferative disease comprising administering to the animal a COMBINATION OF THE INVENTION in a way that is jointly therapeutically effective against a proliferative disease and in which the combination partners can also be present in the form of their pharmaceutically acceptable salts.

Furthermore, the present invention pertains to the use of a COMBINATION OF THE INVENTION for the delay of progression or treatment of a proliferative disease and for the preparation of a medicament for the delay of progression or treatment of a proliferative disease.

The following examples are merely illustrative and not meant to limit the scope of the present invention in any manner:

Example 1: Combination of LBH589 With the Demethylation Agent 5-Aza Induces More Apoptosis of Tumor Cells Than Each Agent Alone

Silencing of tumor suppressor genes at the chromatin level is a major feature of tumorigenesis. LBH589 and 5-azacytidine are both compounds which enhance the expression of tumor suppressor genes through modulation of chromatin structure. LBH589, a HDAI causes increased acetylation of histone leading to relaxed chromatin structure that is favorable to transcription factor binding and activity. Many tumor suppressor genes are also silenced by DNA methylation at CpG islands and 5-azacytidine causes demethylation of CpG islands leading to the re-expression of these genes. Several studies have reported crosstalk and synergy between these two major epigenetic mechanisms and we postulated that combining LBH589 with 5-azacytidine might enhance the tumor cell death induced by each compound alone.

Materials, Methods and Results

The AML cell line U937 is incubated with LBH589 or 5-aza as single agents or in combination. As can be seen in Figure 1. LBH589, but not 5-aza, induces increased acetylation of alpha-tubulin, each compound induces the expression of the cell growth inhibitor p21 but a combination of both compounds induces higher levels of p21 than each compound alone. Furthermore, whereas each compound induces only a slight PARP cleavage as a measure of apoptotic cell death, combination of both compounds induces a super-additive PARP cleavage. Thus mechanistically, LBH589 when combined with 5-aza enhances the expression of the growth suppressor p21 and synergistically induces more apoptosis as compared with each compound alone.

U937 cells are treated with 2 µM 5-aza, 10 nM LBH589 or with a combination of 5-aza + LBH589 for 24 hours. Cells are lysed, proteins separated by SDS-PAGE and western immunoblotting anaysis done with antibodies against acetylated tubulin, p21, PARP and β-actin (control for loading).

Induction of apoptosis by LBH589, 5-aza or LBH589+ 5-aza in the U937 AML cell line and in primary human AML blast cells

To further test the combination of LBH589 + 5-aza to induce cell death in AML, the U937 AML cell lines and fresh leukemia blast cells from AML patients are incubated with the compounds either as a combination or as single agents. Cell death is either monitored by cells staining for Annexin V (signifying apoptosis) or by counting live cells by trypan-blue exclusion. As shown in Figures 2, U937 cells treated with the LBH589 + 5-aza combination produce much higher apoptosis (measured by annexin V staining) than that induced by the single agents. As well, a higher percentage of cell death is induced by the LBH589 + 5-aza combination than single agents in the primary human AML blast cells isolated from patients as shown in Table1. Importantly, no antagonism is observed when the two compounds are combined.

U937 cells are incubated with 1 µM, 2 µM, 5 µM 5-aza, 10 nM, 20 nM LBH589 or with a combination of LBH589 and 5-aza for 24 hours. Annexin V staining is conducted and percentages of cells staining green (apoptotic) are calculated and plotted.

1	13.4	35.9		19.3	40.4	39.5	48.6	45.6	54
3	16.7	22.3	34.2	16.5	19.3	26.5	49.2	43	55
5	12.9	19.5	41.6	13.1	15.9	34	54.2	42.4	62.6
6	18.1	73.7	85.6	15	22.6	80.7	89.4	86.3	92

Primary leukemic blasts isolated from AML patients are incubated 10 nM, 20 nM LBH589,1 1 µM, 2 µM 5-aza or with combination of LBH589 + 5-aza. Trypan-blue exclusion is used to count number of viable cells and percentage of dead cells for each treatment calculated and tabulated.

Example 2: A Phase I, Open-label, Multi-center, Dose-escalation Study of Oral N-Hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide Administered with 5-Aza in Adult Patients with MDS or AML

During the dose escalation phase in both arms, 5-Aza is administered on a 4-6 week schedule at 75 mg/m² SQ on a once daily schedule for 7 days to patients either with MDS (RAEB or CMML) who are relapsed or refractory to 5-Aza therapy, and are considered inappropriate candidates for standard therapy, or patients with AML relapsed after or refractory to standard therapy or patients previously untreated due to age, poor prognosis, or concurrent medical conditions and those who are considered inappropriate candidates for standard induction therapy, or who refuse standard induction therapy. N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide is administered on two schedules depending upon the arm.

5-Aza is administered on a 4-6 week schedule.

Arm 1 dose-escalation: Arm 1: PM dosing LBH589 15 mg (starting dose level), po, MWF weeks 1-3, Q4-6 weeks. AM dosing 5-Aza 75 mg/m² days 1-7 Q4-6 weeks.

N-Hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide is administered as 15 mg orally on Monday, Wednesday, Friday on weeks 1, 2, and 3. If toxicity is acceptable, N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide is increased according to a 3-parameter Bayesian logistic regression model with overdose control. For Arm 1, the MTD dose-level is defined at a lower dose of N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide using this 3-week schedule. An additional 6-patient cohort is treated using the 3-week N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide DLT dose-level for only 2 weeks to assess toxicity.

Arm 2 dose-escalation: N-Hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide is administered as 15 mg orally Monday, Wednesday, Friday on weeks 2 and 3. If toxicity is acceptable, N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide is increased by 5-10 mg per cohort. For Arm 2, the MTD dose-level is defined at a lower dose of N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide using this 2-week schedule. An additional 6-patient cohort is treated using one dose level below the N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide MTD dose-level for 3 weeks to assess toxicity.

Arm 1 and 2 cohort expansion: Arm 2: LBH58915 mg (starting dose level), po, MWF weeks 2-3, Q4-6 weeks. 5-Aza 75 mg/m²days 1-7 Q4-6 weeks.

The dose expansion phase is initiated at the MTD for each arm to treat the same patient populations as in the dose-escalation phase and expanding to include all MDS patients eligible for treatment with 5-Aza who were previously untreated due to age, poor prognosis, or concurrent medical conditions and those who are considered inappropriate candidates for standard induction therapy, or who refuse standard induction therapy.

Each schedule addresses the issues of combining 2 drugs with overlapping toxicity (i.e., myelosuppression) and sequence of administration.

Dose escalation Bayesian Logistic Regression. A 3-parameter Bayesian logistic regression model with overdose control is used for the dose escalation. This model includes slope and intercept parameters describing the dose-toxicity curve of each agent involved singly, plus an additional parameter to describe any additional toxicity associated with the more dose-dense schedule (Arm 1). The distribution summarizes the probability that each dose combination fall into the following categories:

1. 1) Under dosing: DLT rate under 20%
2. 2) Targeted toxicity: DLT rate between 20% and < 35% (exclusive)
3. 3) Excessive toxicity: DLT rate between 35% and < 60% (exclusive)
4. 4) Unacceptable toxicity: DLT rate of 60% or greater.

The overdose control mandates that any dose of LBH589A that has more than a 25% dose escalation ends for each arm when at least 12 MTD-evaluable patients have been enrolled at the recommended dose for that arm.

Claims (8)

1. A combination of (a) a histone deacetylase inhibitor (HDAI) and (b) an anti-metabolite, wherein (a) is N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, or a pharmaceutically acceptable salt thereof, and (b) is 5-azacitidine for use in the treatment of a proliferative disease which is myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML).
2. The combination for use according to claim 1, wherein the use is simultaneous, concurrent, separate or sequential use.
3. The combination for use according to claim 1, wherein the disease is acute myeloblastic leukemia.
4. The combination for use according to claim 1, wherein the disease is myelodysplastic syndrome.
5. A pharmaceutical composition comprising (a) N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, or a pharmaceutically acceptable salt thereof, and (b) 5-azacitidine for use in the treatment of a proliferative disease which is myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML).
6. Use of N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide, or a pharmaceutically acceptable salt thereof, for the preparation of a medicament for use in combination with an anti-metabolite which is 5-azacitidine, for the treatment of a proliferative disease which is myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML).
7. The use of claim 6 wherein the disease is acute myeloblastic leukemia.
8. The use of claim 6 wherein the disease is myelodysplastic syndrome.