WO2024056995A1

WO2024056995A1 - Combinations and pharmaceutical compositions comprising a pi3k/akt/mtor pathway inhibiting compound

Info

Publication number: WO2024056995A1
Application number: PCT/GB2023/052322
Authority: WO
Inventors: Robin Williams; Judith SCHAF; Sonia SHINHMAR; Nelofer SYED
Original assignee: Royal Holloway And Bedford New College
Priority date: 2022-09-12
Filing date: 2023-09-08
Publication date: 2024-03-21
Also published as: GB202213308D0

Abstract

The invention provides a combination of a PI3K/AKT/mTOR pathway inhibiting compound and a tanshinone or a derivative, an isomer or a pharmaceutically acceptable salt thereof.

Description

COMBINATIONS AND PHARMACEUTICAL COMPOSITIONS

COMPRISING A PI3K/AKT/mTOR PATHWAY INHIBITING COMPOUND

Technical Field of the Invention

The present invention relates to combinations and pharmaceutical compositions, in particular to combinations of a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone, its use as a medicament and a pharmaceutical composition thereof.

Background to the Invention

The PI3K/AKT/mT0R pathway is an intracellular signalling pathway crucial for regulating cell growth and the cell cycle. The activation of phosphatidylinositol 3- kinase (PI3K) enzymes are initiated by a range of mechanisms including the binding of extracellular growth factors to transmembrane receptor tyrosine kinases. These enzymes subsequently phosphorylate and activate protein kinase B (PKB) enzymes also known as AKT. The activated AKT can have a number of downstream effects including activating the mammalian target of rapamycin (mTOR). mTOR complexes with other proteins and forms mTOR complex 1 (mTORCl) and mTOR complex 2 (mT0RC2) which regulate different cellular processes.

The over-activation of the PI3K/AKT/mT0R pathway is often caused by mutations and this dysregulation is associated with a large number of diseases including cancers, neurological diseases and metabolic disorders. PI3K/AKT/mT0R signalling pathway mutations are responsible for 70 % of colorectal and breast cancers and the pathway is upregulated in ~ 80 % of cases of Glioblastoma or Glioblastoma multiforme

(GBM). These cancers are aggressive with low survival rates after 5 years, highlighting the importance of developing new treatments to target this pathway for more effective and novel therapies. Targeting the PI3K/mT0R pathway in disease treatment is complicated by multiple pathways regulating mTOR activity and feedback regulation decreasing drug efficacy.

There are a number of PI3K inhibitor monotherapies that are commercially available such as Paxalisib®, Zydelig®, Aliqopa®, and Piqray®. Disadvantages of these monotherapies are that they may show a reduction in efficacy over extended treatment periods, and most monotherapies using PI3K inhibitors provided some difficulties in clinical studies often with severe side effects at the effective dosage requirement. Monotherapies may also lead to drug resistance. It would therefore be advantageous to provide an alternative treatment for diseases associated with a dysregulated PI3K/AKT/mT0R pathway that addresses at least one of the disadvantages of PI3K inhibitor monotherapies.

Tanshinones are a group of bioactive components found in the perennial plant danshen (Salvia miltiorrhiza also known as red sage which is used in traditional Chinese medicine. The most abundant of these lipophilic compounds is tanshinone IIA (T2A) which has been found to reduce tumour cell growth in cancer models and tumour growth in vivo.

It would be advantageous to provide a treatment for diseases associated with a dysregulated PI3K/AKT/mT0R pathway with reduced dosage of aggressive PI3K inhibitor compounds whilst still reducing the rate of tumour growth in cancer patients.

It would be advantageous to provide a combinatory treatment wherein the compounds used synergistically inhibit the PI3K/AKT/mT0R signalling pathway such that they can be used for the treatment of diseases associated with a dysregulated PI3K/AKT/mT0R pathway.

It is therefore an aim of embodiments of the invention to overcome one or more problems of the prior art, whether expressly disclosed herein or not.

Summary of the Invention

According to a first aspect of the invention, there is provided a combination comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof.

In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound is at least one compound which inhibits the PI3K/AKT/mT0R signalling pathway. Inhibition of PI3K enzymes leads to downstream inhibition of protein kinase B (AKT) and then downstream inhibition of mTOR. mTOR may be located within the complex mTORCl. mTORCl is activated by phosphorylated protein kinase B (AKT). PI3K inhibitors may therefore in turn inhibit AKT which in turn inhibits mTORCl. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be a PI3K inhibitor. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be an AKT inhibitor. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be an AKT/mTORCl inhibitor. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be an mTORCl inhibitor.

In some embodiments the PI3K inhibitor may be at least one clinically established PI3K inhibitor selected from the group consisting of: Paxalisib®, Zydelig®,

Aliqopa®, Piqray®, Vijoice® and Copiktra®. Paxalisib® has the chemical formula 5-(6,6-dimethyl-4-morpholin-4-yl-8,9- dihydropurino[8,9-c][l,4]oxazin-2-yl)pyrimidin-2-amine. The chemical structure of Paxalisib® is shown in formula A.

Zydelig® is also known as idelalisib and has the chemical formula 5-fluoro-3- phenyl-2- [(IS)- 1 -(7H-purin-6-ylamino)propyl] -4(3H)-quinazolinone. The chemical structure of Zydelig® is shown in formula F.

Aliqopa® is also known as copanlisib and has the chemical formula 2-amino- N-[7-methoxy-8-(3-morpholin-4-ylpropoxy)-2,3-dihyadroimidazo[l,2-c]quinazolin-5- yl]pyrimidine-5-carboxamide. The chemical structure of Aliqopa® is shown in formula G.

Piqray® and Vijoice® are also known as alpelisib and have the chemical formula (2S )- 1 -N- [4-methyl-5- [2-( 1 , 1 , 1 -trifluoro-2-methylpropan-2-yl)pyridin-4-yl] - l,3-thiazol-2-yl]pyrrolidine-l,2-dicarboxamide. The chemical structure of Piqray® and

Vijoice® is shown in formula H.

Copiktra® is also known as duvelisib and has the chemical formula 8-chloro-2- phenyl-3-[(lS)-l-(3H-purin-6-ylamino)ethyl]-l(2H)-isoquinolinone. The chemical structure of Copiktra® is shown in formula J.

In some embodiments the PI3K inhibitor is LY294002. LY294002 is a synthetic molecule known to inhibit PI3K. LY294002 has the chemical formula 2-(4- morpholinyl)-8-phenyl-4H-l-benzopyran-4-one. The chemical structure of LY294002 is shown in formula B.

In some embodiments the combination may comprise more than one PI3K inhibitor.

In some embodiments the PI3K/AKT/mTOR pathway inhibiting compound may be an mTORCl inhibitor. In some embodiments the mTORCl inhibitor may comprise a pharmaceutically acceptable composition of rapamycin, also known as sirolimus. A clinical brand name for rapamycin is Rapamune®. The chemical formula of rapamycin is shown in formula C:

In some embodiments the mTORCl inhibitor may be a derivative of sirolimus such as everolimus. A clinical brand name for everolimus is Afinitor®. The chemical formula of everolimus is shown in formula D:

Tanshinones are a group of abietane diterpenoid chemical compounds which comprise three 6-membered rings fused together. Tanshinones may be extracted from danshen, also known as Salvia miltiorrhiza bunge or red sage root. Examples of tanshinones include tanshinone I, cryptototanshinone, dihydrotanshinone, tanshinone

IIA and tanshinone IIB . In some embodiments the tanshinone may be tanshinone I, cryptototanshinone, dihydrotanshinone or tanshinone IIB. In some embodiments the combination may comprise tanshinone IIA. The formula of tanshinone IIA is shown in formula E.

Tanshinone IIA may be isolated from the perennial plant danshen (Salvia miltiorrhiza), also known as red sage. It may be advantageous to use tanshinone IIA because it is the most abundant lipophilic tanshinone in the Danshen root. It may be advantageous to use tanshinone IIA because it has shown anti-inflammatory and anticancer effects in experimental animal models.

In some embodiments the tanshinone may comprise more than one tanshinone. In some embodiments the more than one tanshinone may be selected from tanshinone I, cryptotanshinone, dihydrotanshinone, tanshinone IIA and tanshinone IIB. A combination of tanshinones may be advantageous because it may show improved bioavailability over a single tanshinone.

In some embodiments the tanshinone may be a pharmaceutically acceptable salt of a tanshinone wherein the tanshinone may be tanshinone I, cryptotanshinone, dihydrotanshinone, tanshinone IIA or tanshinone IIB. In some embodiments the tanshinone salt is a salt of tanshinone sulfonate. In some embodiments the tanshinone salt is a salt of tanshinone IIA sulfonate. In some embodiments the tanshinone salt is sodium tanshinone IIA sulfonate. Sodium tanshinone IIA sulfonate may be advantageous in the combination because it may have good bioavailability and good solubility in water and therefore may be suitable for a variety of applications.

In some embodiments the tanshinone may be derived from or be present in an extract of danshen, also known as red sage. Red sage extract comprises at least one tanshinone usually in the form of tanshinone IIA. A combination comprising red sage extract may be advantageous because it is cheaper than isolated tanshinone and the tanshinone compounds in red sage may have improved water- solubility compared to isolated tanshinones. A combination comprising red sage extract may be advantageous because the oral bioavailability of tanshinone IIA may increase through consumption of the plant extract rather than purified tanshinone IIA.

In some embodiments the PI3K/AKT/mTOR pathway inhibiting compound and the tanshinone may be combined at a molar ratio of between 1:250 and 25:1. In some embodiments the molar ratio of PI3K/AKT/mTOR pathway inhibiting compound and the tanshinone may between 1:200 and 8:1, 1:150 and 6:1, 1:100 and 4:1, 1:75 and 3:1, or between 1:50 and 2:1. In some embodiments the molar ratio of the PI3K/AKT/mTOR pathway inhibiting compound and the tanshinone may be between 2:1 and 1:23. In some embodiments the molar ratio of PI3K/AKT/mTOR pathway inhibiting compound and the tanshinone may be between 1:2.5 and 1:22, 1:3 and 1:21, 1:4 and 1:20, 1:5 and 1:18, 1:5.5 and 1:16, 1:6 and 1:14, 1:6.5 and 1:13, 1:7 and 1:12,

1:7 and 1:11 or between 1:7 and 1:10. A combination comprising a highly potent PI3K/AKT/mTOR pathway inhibiting compound may require less of the PI3K/AKT/mTOR pathway inhibiting compound and more of the tanshinone. A combination comprising a less potent PI3K/AKT/mTOR pathway inhibiting compound may require more of the PI3K/AKT/mTOR pathway inhibiting compound and less of the tanshinone.

A combination wherein the tanshinone is the majority of the combination may be advantageous because the tanshinone is often cheaper than the PI3K/AKT/mTOR pathway inhibiting compound and therefore the overall combination is cheaper than if the majority of the combination is the PI3K/AKT/mTOR pathway inhibiting compound.

In some other embodiments the molar ratio of the PI3K/AKT/mTOR pathway inhibiting compound and the tanshinone may favour the PI3K/AKT/mTOR pathway inhibiting compound and the ratio may be between 25:1 and 2:1 or between 20:1 and 5:1 or between 15:1 and 10:1 molar ratio of the PI3K/AKT/mTOR pathway inhibiting compound and the tanshinone.

A combination wherein the PI3K/AKT/mTOR pathway inhibiting compound is the majority of the combination may be advantageous when using a low potency PI3K/AKT/mTOR pathway inhibiting compound as more of the compound may be required to result in a beneficial clinical effect.

According to a second aspect of the invention, there is provided a combination comprising a PI3K/AKT/mTOR pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof according to the first aspect of the invention, for use as a medicament. The combination comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof may be any combination of the first aspect of the invention.

The use of the combination as a medicament may be advantageous because the dosage requirement of the PI3K/AKT/mT0R pathway inhibiting compound may be reduced. This may reduce side effects associated with the PI3K/AKT/mT0R pathway inhibiting compound. The use of the combination may also be advantageous because it reduces the cost of the medicament as the amount of the PI3K/AKT/mT0R pathway inhibiting compound, which is often expensive, is reduced when used in combination with the tanshinone, the isomer, the derivative or the pharmaceutically acceptable salt thereof, whilst still showing superior performance as a medicament. The use of the combination may be advantageous because the PI3K/AKT/mT0R pathway inhibitor and the tanshinone may synergistically interact with cells such that the performance of the combination is superior to the performance of the individual compounds additively, when used as a medicament. The use of the combination of the PI3K/AKT/mT0R pathway inhibitor and the tanshinone may also be advantageous over the use of single components because the use of single components or monotherapies can result in drug resistance over time, likely through cells responding to treatments by reducing the activity of the targeted (inhibited) pathway, thus reducing sensitivity to a drug targeting that pathway following extended treatment. By employing a combinatory treatment, with the two compounds targeting different pathways (the PI3K/AKT/mT0R pathway inhibitor targeting the PI3K/PKB/mT0R pathway and tanshinone targeting sestrin), the combinatory treatment is less likely to give rise to treatment resistance caused by reduced signalling in a single pathway. In some embodiments the combination may be used to treat a disease associated with the PI3K/AKT/mT0R pathway. In some embodiments the disease may be associated with a dysregulated PI3K/AKT/mT0R signalling pathway. In some embodiments the disease may be associated with a mutation in the PI3K/AKT/mT0R signalling pathway. In some embodiments, the disease may be a cancer. In some embodiments the cancer may be leukaemia, breast cancer, colorectal cancer, osteosarcoma, bladder cancer, ovarian cancer or non-small cell lung cancer. In some embodiments the cancer may be acute myeloid leukaemia. In some embodiments the cancer may be glioblastoma, also known as glioblastoma multiforme. Glioblastoma is an aggressive cancer with a low survival rate beyond 12 to 18 months. The use of the combination as a medicament as a treatment for glioblastoma may be advantageous because the combination contains a lower amount of the PI3K/AKT/mT0R pathway inhibiting compound than PI3K inhibitor monotherapy and therefore may result in less severe side effects typical to PI3K inhibitor monotherapy whilst offering a non-invasive tumour treatment option. The side effects may be any one of hyperglycaemia, dermatitis, stomatitis, diarrhoea, nausea or fatigue.

The use of the combination as a medicament for glioblastoma also may be advantageous because it may result in a significant reduction in the rate of tumour growth compared to using a PI3K/AKT/mT0R pathway inhibiting compound. In some embodiments the combination may result in tumour shrinkage which may be advantageous because it may increase survival rates and increase life expectancy in patients diagnosed with cancer. In some embodiments the combination as a treatment for glioblastoma tumours may result in tumour shrinkage which may be advantageous because glioblastoma tumours are often difficult to fully remove by surgery and the use of PI3K/AKT/mT0R pathway inhibiting compounds alone is not thought to shrink tumours, merely reduce their growth rate; therefore, non-invasive treatment that may result in tumour shrinkage may increase survival rates and life expectancy in patients diagnosed with glioblastoma.

In some embodiments the disease associated with the PI3K/AKT/mT0R pathway may be an mTOR-opathy. mTOR-opathies are associated with over activation of the mTOR kinase in the mTORCl complex. In some embodiments the mTOR- opathy may be a neurological disease. In some embodiments the neurological disease may be epilepsy, autism spectrum disorder, multiple sclerosis, tuberous sclerosis complex, focal cortical dysplasia, focal cortical dysplasia type II, hemimegalencephaly, polyhydramnios, megalencephaly and symptomatic epilepsy syndrome, attention deficit hyperactivity disorder, megalencephaly, subependymal nodules, subependymal giant cell astrocytomas, PTEN hamartoma tumor syndrome or neurofibromatosis type 1.

In some embodiments the disease associated with the PI3K/AKT/mT0R pathway may be an inflammatory disease. In some embodiments the inflammatory disease may be restenosis, neointimal hyperplasia or rheumatoid arthritis.

In some embodiments the disease associated with the PI3K/AKT/mT0R pathway may be a metabolic disorder. In some embodiments the metabolic disorder may be type-II diabetes, type-I diabetes, insulin resistance or obesity.

In some embodiments the disease associated with the PI3K/AKT/mT0R pathway may be a coronavirus infection such as MERS-CoV, SARS-CoV or SARS-

CoV-2. In some embodiments the combination of the PI3K/AKT/mT0R pathway inhibiting compound and the tanshinone for use as a medicament may be administered as two separate compounds taken at the same time or within a short period of time.

In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered orally or parenterally. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered orally in any suitable form such as a tablet, capsule, powder, lozenge, pill, troche, elixir, lyophilized powder, aqueous solution, oily solution, emulsion, granule, suspension, emulsion, syrup or tincture. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered parenterally as a sterile aqueous or oily solution for intravenous, subcutaneous or intramuscular dosing.

In some embodiments the tanshinone, the isomer, the derivative or the pharmaceutically acceptable salt thereof may be administered orally or parenterally. In some embodiments the tanshinone may be administered orally in any suitable form such as a tablet, capsule, powder, lozenge, pill, troche, elixir, lyophilized powder, aqueous solution, oily solution, emulsion, granule, suspension, emulsion, syrup or tincture. In some embodiments the tanshinone may be administered parenterally as a sterile aqueous or oily solution for intravenous, subcutaneous or intramuscular dosing.

In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered as a tablet or capsule and the tanshinone may be administered as a separate tablet or capsule. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered orally as a solution and the tanshinone may be administered as a tablet or capsule. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered as a tablet or capsule and the tanshinone may be administered orally as a solution. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered orally as a solution and the tanshinone may be administered orally as a solution.

In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered orally as a tablet, capsule or solution and the tanshinone may be administered parenterally. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered parenterally and the tanshinone may be administered orally as a tablet, capsule or solution. In some embodiments the PI3K/AKT/mT0R pathway inhibiting compound may be administered parenterally and the tanshinone may be administered parenterally.

According to a third aspect of the invention, there is provided a pharmaceutical composition comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone or a derivative, an isomer or a pharmaceutically acceptable salt thereof.

The PI3K/AKT/mT0R pathway inhibiting compound and the tanshinone or a derivative, an isomer or a pharmaceutically acceptable salt thereof may be according to the first and/or second aspect of the invention.

In some embodiments the pharmaceutical composition may comprise the PI3K/AKT/mT0R pathway inhibiting compound and the tanshinone, the derivative, isomer or pharmaceutically acceptable salt, and at least one pharmaceutically acceptable carrier, solvent or substrate. In some embodiments, the carrier, solvent or substrate may be water, DMSO, an oil, a liposome, a polymeric micelle, a microsphere or a nanoparticle. In some embodiments the pharmaceutically acceptable carrier may be an ion exchanger, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, sucrose, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, polyethylene-polyoxypropylene-block polymers, and polyethylene glycol, or a combination thereof. The presence of a pharmaceutically acceptable carrier, solvent or substrate may be advantageous because it may improve the bioavailability of the pharmaceutical composition.

In some embodiments the pharmaceutical composition may comprise at least one pharmaceutically acceptable buffer, stabilizer agent, binder, disintegrating agent, diluent, preservatives, lubricants, time delay agent, dispersing agent and/or suspending agent or a combination thereof.

In some embodiments the pharmaceutical composition may be used as a medicament for the treatment for a disease associated with the PI3K/AKT/mT0R pathway as described in the second aspect of the invention.

In some embodiments the pharmaceutical composition may be administered orally or parenterally. In some embodiments the pharmaceutical composition may be administered orally in any suitable form such as a tablet, capsule, powder, lozenge, pill, troche, elixir, lyophilized powder, aqueous solution, oily solution, emulsion, granule, suspension, emulsion, syrup or tincture. In some embodiments the pharmaceutical composition may be administered parenterally as a sterile aqueous or oily solution for intravenous, subcutaneous or intramuscular dosing.

According to a fourth aspect of the invention, there is provided a method of treating a disease associated with the PI3K/AKT/mT0R pathway, comprising administering to the subject a combination comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone or a derivative, an isomer or a pharmaceutically acceptable salt thereof.

The disease associated with the PI3K/AKT/mT0R pathway may be any disease of the second aspect of the invention.

The method may comprise administering the compounds by any administration method according to the second aspect of the invention.

According to a fifth aspect of the invention, there is provided a method of treating a disease associated with the PI3K/AKT/mT0R pathway comprising administering to the subject a pharmaceutical composition comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone or a derivative, an isomer or a pharmaceutically acceptable salt thereof according to the third aspect of the invention.

The disease associated with the PI3K/AKT/mT0R pathway may be any disease of the second aspect of the invention. The method may comprise administering the compounds by any administration method according to the third aspect of the invention.

Detailed Description of the Invention

In order that the invention may be more clearly understood embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 is a bar graph which illustrates the cell proliferation of patient-derived glioblastoma cells (GBM59 and GBM31) and mouse-derived glioblastoma cells (GL261) when exposed to Paxalisib® (Pax), Tanshinone IIA (T2A), as single components or a combination and no active ingredients or medicaments (-).

Figure 2 is a graph which illustrates the spheroid volume of 3D spheroids cultured from patient-derived glioblastoma cells (GBM59) when exposed to solvent only (control) or Paxalisib® (P) at concentrations between 0.002 pM and 0.46 pM and tanshinone IIA (T) at concentrations between 0.02 pM and 3.77 pM as single components or as a combination, measured 0, 3, 6 and 9 days after exposure. Figure 3 is a bar graph which illustrates the normalised spheroid volume of 3D spheroids cultured from patient-derived glioblastoma cells (GBM59) when exposed to solvent only (control) or to Paxalisib® (P) at concentrations between 0.002 pM and 0.46 pM and tanshinone IIA (T) at concentrations between 0.01 pM and 3.77 pM, as single components or as a combination, measured 9 days after exposure.

Figure 4 is a bar graph which illustrates the spheroid volume of 3D spheroids cultured from mouse-derived glioblastoma cells (GL261) when exposed to solvent only (control) or to Paxalisib® (P) at concentrations between 0.002 pM and 0.48 pM and tanshinone IIA (T) at concentrations between 0.02 pM and 3.78 pM, as single components or as a combination, measured 6 days after exposure.

Figure 5 is a graph which illustrates the relative membrane fluorescence of transient PHerac-GFP membrane localisation, as a measure of PIP3 production, in D. discoideum 10 seconds after activation by a single pulse of cAMP wherein the D. discoideum is exposed to tanshinone IIA (T2A) at 25 pM for 4 hours or LY294002 (PI3K inh.) at 60 pM for 4 hours or 100 pM for 10 minutes.

Figure 6 is a graph which illustrates the maximum membrane fluorescence of D. discoideum following a single pulse of cAMP wherein the D. discoideum is exposed to solvent only (control) or tanshinone IIA (T2A) as a single component at concentrations between 0.5 pM and 25 pM or LY294002 (PI3K inh.) for 15 minutes as a single component at concentrations between 1 pM and 100 |iM or combinations of the two compounds.

Figure 7 is a graph which illustrates the cell density of wild type D. discoideum cell measured after 5 days exposure to tanshinone IIA (T2A) at 12 pM, LY294002 (LY) at 14 pM as single compounds and in combination.

Figure 8 is a graph which illustrates the estimated additive and the observed synergistic inhibition of cell proliferation (after 5 days) using isobolographic analysis at a 90 % reduction of cell proliferation in D. discoideum.

Figure 9 is a bar graph which illustrates the concentration of p-4E-BPl protein, normalised to the total amount of protein in D. discoideum 5 days after exposure to tanshinone IIA (T2A) at 12 pM, LY294002 (LY) at 14 pM and a combination of the two compounds.

In a first embodiment of the invention, a combination comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone, an isomer, a derivative or a pharmaceutically acceptable salt thereof was prepared, wherein the PI3K/AKT/mT0R pathway inhibiting compound was the PI3K inhibitor commercially named Paxalisib® and the tanshinone was tanshinone IIA. The components of the combination were tested individually and in combination.

Paxalisib® was tested at clinically relevant concentrations of between 0.002 pM and 0.48 pM. Tanshinone IIA was tested at a concentration range of between 0.01 pM and 3.78 pM. In vitro glioblastoma, also known as glioblastoma multiforme (GBM), systems were used to test the combinations of Paxalisib® and tanshinone IIA to observe the efficacy of the combinations on glioblastoma cell proliferation in 2D and 3D cell cultures.

GBM cell lines

The following testing was completed with two human patient-derived GBM cell lines (GBM59 and GBM31) and one mouse-derived cell line (GL261). GBM59 and GBM31 were primary human cell lines derived from surgically removed fresh tumour tissues or stereotactic biopsies. These tissues were initially minced through a strainer resulting in a suspension of single cells which were rapidly treated with sterile water to remove red blood cells. Remaining single cells were cultured as primary cell lines and maintained in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with F-12 nutrient mixture and 10 % FBS. GE261, an established mouse-derived cell line, was grown in DMEM supplemented with 10 % FBS.

GBM59, GBM31 and GE261 were used to test Paxalisib® and tanshinone IIA as single component treatments at clinically relevant concentrations, and to test combinations comprising Paxalisib® and tanshinone IIA. Cell proliferation and cultured spheroid volumes were measured and analysed.

GBM cell proliferation

GBM cell proliferation was measured using the sulforhodamine B assay (SRB). 500 cells per well were incubated at 37 °C with 5 % CO2 in 100 pl growth media in 96 well plates. After 24 hours, Paxalisib® or tanshinone IIA, or combinations thereof were added. The cells were incubated for 3, 6 and 9 days. The cells were fixed using tricarboxylic acid (TCA) and stained using 0.4 % SRB in 1 % acetic acid. The cells were then dried. 10 mM Tris solution was used to dissolve the SRB dye. Cell proliferation was quantified at 490 nm using the BioTek ELX800 Microplate Reader. Data is derived from 3 biological repeats, with each experiment comprising 3 technical repeats. All data is shown as mean ± SEM, ns = p>0.05, p<0.0001 (Mann-Whitney test).

Figure 1 shows the GBM cell proliferation results in the two patient-derived cell lines and the mouse-derived cell line following no exposure to Paxalisib® or tanshinone IIA (control) and exposure to a low and high concentration of Paxalisib® or tanshinone IIA and a combination thereof. In the patient-derived GBM59 cell line, Paxalisib® single treatment at doses of 0.12 pM and 0.5 pM reduced cell proliferation to 61 % and 43 % of the control, respectively. Tanshinone IIA single treatment at doses of 0.7 pM and 3.8 pM reduced cell proliferation to 58 % and 34 % of the control respectively. Combinatory treatment using both high and low doses of tanshinone IIA with the high and low doses of Paxalisib® enhanced the effect of Paxalisib® by around two-fold, providing a reduction in cell proliferation to 36 % of the control with the low doses and 19 % of the control with the high doses. Both combinatory treatment concentrations showed superior inhibition of cell proliferation compared to the single treatments. This suggests that the combinatory treatment could be advantageous to patients with glioblastoma as the presence of tanshinone IIA with the Paxalisib® may improve inhibition of cell proliferation without increasing the concentration of the Paxalisib® which is known to have severe side effects at high concentrations.

The patient-derived GBM31 cell line and the mouse-derived GL261 cell line both also showed the same correlation with a high and low concentration of Paxalisib® and tanshinone IIA. In all three cell lines, the cell proliferation was reduced when the cells were exposed to the combination of components compared to the individual components.

GBM cell cultured spheroid volumes

Cultured spheroid expansion was used to examine the effect of compounds on glioblastoma cell proliferation in 3D cultures. Spheroids were prepared using 5 x 10⁷ cells from the GBM59 cell line and the GL261 cell line. The cells were cultured in individual wells of a 96 U-shaped well plate at 37 °C for 4 days to allow spheroid formation. Control spheroid diameter was measured using an Echo Revolver microscope prior to compound treatment. The spheroids were then exposed to Paxalisib® and tanshinone IIA as single component treatments and to combinations comprising Paxalisib® and tanshinone IIA as defined in table 1 and the spheroid dimensions were measured at 3, 6 and 9 days after exposure. Images were analysed using ImageJ to measure the area of each spheroid and calculate approximate spheroid size change based on a spherical volume.

Figure 2 and figure 3 show the results of the GBM spheroid volume measurements in the patient-derived GBM59 cells. As shown in figure 2, the control sample, which was only exposed to DMSO, resulted in an increased spheroid volume after 3, 6 and 9 days. All samples exposed to the single component Paxalisib® at doses between 0.46 pM and 0.002 pM showed a reduced rate of spheroid growth at 9 days. All samples exposed to the single component tanshinone IIA at doses between 3.77 pM and 0.02 pM showed a reduced rate of spheroid growth at 9 days. All samples exposed to a combination of Paxalisib® and tanshinone IIA at concentrations of greater than 0.002 pM and 0.02 pM respectively, showed dose dependent superior inhibition of spheroid growth compared to the compounds as single treatments. In addition, the two highest concentration combinations (Paxalisib® at 0.46 pM and tanshinone IIA at 3.77 pM, and Paxalisib® at 0.22 pM and tanshinone IIA at 1.84 pM) reversed tumour volume expansion during the treatment period such that the spheroids decreased in size by approximately 40 % and 30 % respectively. This is surprising because at equivalent concentrations as single components, neither the Paxalisib® or the tanshinone IIA resulted in spheroid volume reduction. The use of the combination to reduce spheroid volume size is therefore advantageous because it could correlate to tumour shrinkage in glioblastoma patients which may offer a non-invasive treatment option to reduce tumour size.

Figure 4 shows the results of the mouse-derived GL261 spheroid volume measurements at 6 days following exposure to Paxalisib® and tanshinone IIA as single compounds and as a combination. Similarly to the GBM59 spheroid experiments, the combinatory treatment showed superior inhibition of spheroid growth compared to the compounds as single treatments.

In this 3D cancer model, the patient-derived glioblastoma spheroids showed greater sensitivity to tanshinone IIA exposure, and combined Paxalisib® and tanshinone IIA exposure, than the mouse-derived model, although both showed superior reduction in spheroid volume with combinatory treatment.

Bliss is a statistical model used to determine drug combination efficacy. Table 1 and table 2 show Bliss data for glioblastoma spheroid volume following treatment with indicated levels of Paxalisib® (P, pM) and tanshinone IIA (T, pM). Table 1 shows the Bliss data for GBM59 cells and table 2 shows the Bliss data for GL261 cells. Y_ab,P is the predicted combined percentage inhibition of the combination of Paxalisib® and tanshinone IIA. Y_ab,0 is the observed percentage spheroid volume growth inhibition of the combination of Paxalisib® and tanshinone IIA. Synergy is indicated when Y_ab,0 is greater than Y_ab ,P .

Table 1

Table 2

Synergy is indicated for combinations of tanshinone IIA (concentrations between 0.06 |iM and 3.77 |aM) and Paxalisib® (concentrations between 0.007 |aM and 0.468 |iM) in patient-derived GBM59 cells as shown in table 1. Synergy is indicated for combinations of tanshinone IIA (concentrations between 0.02 pM and 3.78 pM) and Paxalisib® (concentrations between 0.002 pM and 0.48 pM) in mouse-derived GL261 cell line as shown in table 2. The combinatory treatment of Paxalisib® and tanshinone IIA showed superior inhibitory performance when compared to single compound treatment and also when compared to the estimated additive effect of the two compounds. The combination of Paxalisib® and tanshinone IIA is advantageous over the use of Paxalisib® or tanshinone IIA as single components because single components may lead to drug resistance over time. By employing a combinatory treatment, with the two compounds targeting different pathways (Paxalisib® targeting the PI3K/PKB pathway and tanshinone IIA targeting sestrin), the combinatory treatment is less likely to give rise to treatment resistance caused by reduced signalling in a single pathway.

In a second embodiment of the invention, a combination comprising a PI3K/AKT/mTOR pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof was prepared wherein the PI3K/AKT/mTOR pathway inhibiting compound is the PI3K inhibitor LY294002 and the tanshinone is tanshinone IIA. The components of the combination were tested individually and in combination. LY294002 was tested at a concentration range of between 1 pM and 100 pM. The tanshinone IIA was tested at a concentration range of between 0.5 pM and 25 pM. The compositions were tested in Dictyostelium discoideum cell proliferation assays. D. discoideum is a tractable model system with reduced genetic redundancy which contains various proteins and signalling pathways that are evolutionarily conserved in humans and that have been linked to various diseases, such as cancer and related treatments. The ability to genetically ablate these pathways has provided important insights. Furthermore, D. discoideum has been employed as a model system to analyse the effects of medicines on mTORCl activity to identify the underlying molecular mechanisms and translate to patient-derived cells and new clinical approaches.

PI3K inhibition in D. discoideum

Activated PI3K generates transient phosphatidylinositol (3,4,5)-trisphosphate (PIP3) therefore PI3K activity can be measured in D. discoideum by quantifying the PIP3. The PIP3 can be quantified by assessing the translocation of the green fluorescence protein PHerac-GFP, which, following stimulation with a single pulse of cAMP, moves from the cytosol to the cell membrane where it binds to the PIP3 which is located on the cell membrane.

D. discoideum cells expressing PHerac-GFP, were made chemotactically competent by repeated stimulation with cAMP (6 min pulses of 100 nM) for 4 hours. The cellular location of PHerac-GFP was then visualised using a fluorescence microscope (Olympus 1X71 fluorescence microscope) following a single pulse of 10 pM cAMP. Tanshinone IIA or LY294002 compounds or 0.2 % DMSO (control sample) were either added either during the 4 hours pulsing step or 10 or 15 minutes prior to the time-lapse imaging. Fluorescent intensities on the cell membrane and in the cytosol were calculated as relative to the whole cell and normalised to the fluorescence intensity before cAMP stimulation as shown in figure 5. Fluorescence was quantified using Image J.

Figure 5 illustrates that tanshinone IIA blocked PIP3 production when tested at 25 pM for 4 hours, and the PI3K inhibitor LY294002 blocked PIP3 production when tested at 60 pM for 4 hours or at 100 pM for 10 minutes as shown by the low relative membrane fluorescence compared to the control sample.

Figure 6 shows dose dependent inhibition of PIP3 production by tanshinone IIA (0 - 25 pM) and LY294002 (0 - 100 pM) 15 minutes after treatment, indicated by maximum membrane fluorescence values. The combination treatment with tanshinone IIA (1 pM) and LY294002 (5 pM or 10 pM) reduced PI3K activity in a potent manner compared to the treatment with single components. This may be advantageous because PI3K inhibitors can have severe side effects at high dosages and the combinatory treatment demonstrates significant PI3K inhibition with a fraction of the PI3K inhibitor dosage required in single treatments. This could therefore result in a possible treatment option for diseases wherein the PI3K/AKT/mT0R signalling pathway is dysregulated, whilst also minimising side effects to the patients.

Cell proliferation in D. discoideum

LY294002 and tanshinone IIA and combinations thereof were dosed into samples of D. discoideum with a constant solvent level (DMSO, 0.8%). Cell density, as a measurement of cell proliferation, was then measured in liquid culture (HL5 media, Formedium), maintained in the dark at 22 °C in 24-well plates (with 5000 cells in 500 pl HL5 media per well). Cells were incubated for seven days at 22 °C in the dark, and cell densities were determined using 10 pl of resuspended well sample added to a haemocytometer from day 3 to day 7, and the results were normalised to the solvent- only control.

The cell density of wild type D. discoideum cells was measured after 5 days of exposure to LY294002 and tanshinone IIA as single compounds and in combination as shown in figure 7. LY294002 monotreatment (14 pM) had no effect on cell proliferation as a single component and tanshinone IIA monotreatment (12 pM) showed some reduction in cell density. Combinatory treatment with LY294002 and tanshinone IIA significantly decreased cell proliferation.

Figure 8 shows the isobolographic analysis using a range of tanshinone IIA (T2A) and LY294002 (PI3K inhibitor [LY]) concentrations required to provide a 90% reduction in cell proliferation after 5 days of treatment. This data confirmed a strong synergistic effect in reducing cell proliferation in D. discoideum. This synergistic effect is advantageous because it suggests that the combination of LY294002 and tanshinone IIA shows a better than expected inhibition of the cell proliferation which could correlate to improved inhibition of the PI3K/AKT/mT0R pathway. This improved inhibition of the PI3K/AKT/mT0R pathway could result in the combination of tanshinone IIA and LY294002 offering a superior treatment option for patients with a dysregulated PI3K/AKT/mT0R signalling pathway such as patients with cancer, inflammatory diseases, metabolic disorders or coronavirus infections. mTORCl activity and phosphorylated 4E-BP1 quantification mTOR signalling regulates cell proliferation and metabolism and is often activated in tumours. mTORCl activity therefore provides a key pharmacological target for cancer treatment and other diseases. mTORCl activity is regulated by PI3K/AKT pathway and by sestrin expression. Both tanshinone IIA and LY294002 reduce PI3K activity. Sestrin expression increases in starvation or following cellular stress and leads to the inhibition of mTORCl. mTORCl phosphorylates the multifunctional protein 4E-BP1. When 4E-BP1 is phosphorylated, it is released from the binding protein therefore when mTORCl is activated, the concentration of released p-4E-BPl is higher. p-4E-BPl protein samples were prepared by directly lysing cells in 2 x Laemmli buffer (0.004 % bromophenol blue, 10 % 2- mercaptoethanol, 20 % glycerol, 4 % SDS, 0.125 M Tris-HCl) (7.5 x 10⁷ cells/ml) followed by boiling at 96 °C for 6.5 minutes. 6 to 10 pl of each sample was separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (stacking gel: 5 %, resolving gel: 10 - 15 %). After proteins were transferred to the appropriate membrane (polyvinylidene difluoride or nitrocellulose, pore size: 0.2 pm), membranes were stained with Ponceau S dye and then blocked for 1 hour with intercept (TBS) blocking buffer (LI-COR). Membranes were incubated overnight at 4 °C with primary antibodies detecting phospho(Thr37/46)-4E-BPl (1:1000, Cell Signalling Technology, 9459). Primary antibodies were dissolved in intercept (TBS) blocking buffer containing 0.1 % Tween. As a loading control, streptavidin Alexa Fluor 680 conjugate (1:5000, Invitrogen, S21378) for methylcrotonyl-CoA carboxylase (MCCC1), or Ponceau S stained total protein was used. Membranes were washed with TBST and subsequently incubated for 1 hour with IRDye800CW goat anti-rabbit IgG (1:10000, LI-COR) diluted in intercept (TBS) blocking buffer containing 0.1 % Tween 20 and 0.01 % SDS. After membranes were washed with TBST, protein levels were visualised using the Odyssey CLx imaging system (LI-COR). Levels of the protein of interest were either normalised to the

MCCC1 or to total protein (Ponceau S stain). mTORCl activity was assessed by quantification of p-4E-BPl in the D. discoideum cells after exposure to LY294002, tanshinone IIA and a combination thereof at 5 days after exposure. Reduction in the p-4E-BPl concentration suggests inhibition of the mTORCl signalling pathway. The results of the experiment are shown in figure 9. After 5 days, LY294002 mono treatment at concentration of 14 pM showed no effect on the concentration of 4E-BP1. Exposure to tanshinone IIA at concentration of 12 pM reduced the percentage of p-4E-BPl by approximately 25 % suggesting some inhibition of the mTORCl signalling pathway. Surprisingly, when the LY294002 and tanshinone IIA were dosed in combination at concentrations of 14 pM and 12 pM respectively, the p-4E-BPl phosphorylation was reduced by approximately 50 % suggesting the combination of tanshinone IIA and LY294002 provides enhanced mTORCl inhibitory effects compared to single compound treatment. Superior inhibition of the mTORCl signalling pathway could be advantageous to patients with diseases that are associated with overactivated mTORCl such as cancers, inflammatory diseases, metabolic disorders or mTOR-opathies. mTOR-opathies include neurodevelopmental disorders such as epilepsy or autism spectrum disorder.

The combination of LY294002 and tanshinone IIA is advantageous over the use of LY294002 as a single component because single component use may lead to drug resistance over time. By employing a combinatory treatment, with the two compounds targeting different pathways (LY294002 targeting the PI3K/PKB/mTOR pathway and tanshinone IIA targeting sestrin), the combinatory treatment is less likely to give rise to treatment resistance caused by reduced signalling in a single pathway. In a third embodiment of the invention, a combination comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof was prepared wherein the PI3K/AKT/mT0R pathway inhibiting compound is PI3K inhibitor Paxalisib® and the tanshinone is sodium tanshinone IIA sulfonate. Suitable concentrations of sodium tanshinone IIA sulfonate may be between 1-1000 ug/L in a suitable liquid carrier. This combination provides improved bioavailability of the tanshinone such that it reaches higher concentration in the body, allowing greater synergy.

In a fourth embodiment of the invention, a combination comprising a PI3K/AKT/mTOR pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof was prepared wherein the PI3K/AKT/mTOR pathway inhibiting compound is PI3K inhibitor LY294002 and the tanshinone is sodium tanshinone IIA sulfonate. This combination provides evidence that the synergistic inhibition of growth by tanshinone IIA is effective with multiple PI3K inhibitors (and thus also PKB and mTORCl inhibitors), beyond Paxalisib®.

In a fifth embodiment of the invention, a combination comprising a PI3K/AKT/mTOR pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof was prepared wherein the PI3K/AKT/mTOR pathway inhibiting compound is the mTORCl inhibitor rapamycin or a rapamycin derivative and the tanshinone is tanshinone IIA. Suitable concentrations of rapamycin may be between 1 and 13 mg/m²d^-1. This combination is advantageous for diseases associated with a dysregulated PI3K/AKT/mTOR pathway, in particular, diseases with over activated mTORCl signalling, because it may provide an advantage over rapamycin or a rapamycin derivative as a monotherapy. Rapamycin derivatives may be advantageous because they may more specifically target the mTOR in the mTORCl complex. This combination may be advantageous because it may result in less severe side effects than rapamycin monotherapy whilst still inhibiting the dysregulated PI3K/AKT/mT0R pathway. The combination of Rapamycin and tanshinone IIA is advantageous over the use of Rapamycin as a single component because single component use may lead to drug resistance over time. By employing a combinatory treatment, with the two compounds targeting different pathways (Rapamycin targeting the PI3K/PKB/mT0R pathway and tanshinone IIA targeting sestrin), the combinatory treatment is less likely to give rise to treatment resistance caused by reduced signalling in a single pathway.

In a sixth embodiment of the invention, a pharmaceutical composition comprising a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone, an isomer or a derivative or a pharmaceutically acceptable salt thereof was prepared wherein the PI3K/AKT/mT0R pathway inhibiting compound is Paxalisib®, LY294002, rapamycin or a rapamycin derivative and the tanshinone is tanshinone IIA. The amount of the compounds may be according to any previous embodiment of the invention. The pharmaceutical composition additionally comprises a pharmaceutically acceptable carrier such as DMSO. The pharmaceutically acceptable carrier may alternatively be any suitable carrier as defined in the third aspect of the invention.

The above embodiment is/embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.

Claims

1. A combination of a PI3K/AKT/mT0R pathway inhibiting compound and a tanshinone or a derivative, an isomer or a pharmaceutically acceptable salt thereof.

2. A combination according to claim 1 wherein the PI3K/AKT/mT0R pathway inhibiting compound is a PI3K inhibitor.

3. A combination according to claim 2 wherein the PI3K inhibitor is Paxalisib® or LY294002.

4. A combination according to claim 1 wherein the PI3K/AKT/mT0R pathway inhibiting compound is a mTORCl inhibitor.

5. A combination according to claim 4 wherein the mTORCl inhibitor is a pharmaceutically acceptable composition of rapamycin or a derivative of rapamycin.

6. A combination according to any preceding claim wherein the tanshinone is tanshinone IIA.

7. A combination according to any one of claims 1 to 6 wherein the pharmaceutically acceptable salt of the tanshinone is a salt of tanshinone IIA sulfonate preferably sodium tanshinone IIA sulfonate.

8. A combination according to any one of claims 1 to 6 wherein the tanshinone is present in or derived from an extract of red sage comprising at least one tanshinone. A combination according to any preceding claim wherein the molar ratio of the PI3K/AKT/mT0R pathway inhibiting compound and the tanshinone is between 25:1 and 1:250, preferably between 2:1 and 1:23. A pharmaceutical composition comprising a combination as claimed in any one of claims 1 to 9. A pharmaceutical composition according to claim 10 wherein the ratio of the PI3K/AKT/mTOR pathway inhibiting compound and the tanshinone is between 25:1 and 1:250, preferably between 2:1 and 1:23. A combination according to any one of claims 1 to 9 or a pharmaceutical composition according to claim 10 or 11 for use as a medicament. A combination as claimed in any one of claims 1 to 9 or a pharmaceutical composition according to claim 10 or 11 for use in the treatment of a disease associated with the PI3K/AKT/mTOR pathway. A combination or pharmaceutical composition for use according to claim 13 wherein the disease associated with the PI3K/AKT/mTOR pathway is a cancer, preferably selected from glioblastoma, acute myeloid leukaemia, breast cancer, colorectal cancer, osteosarcoma, bladder cancer, ovarian cancer or non-small cell lung cancer and is more preferably glioblastoma. A combination or pharmaceutical composition for use according to claim 13 wherein the disease associated with the PI3K/AKT/mTOR pathway is a neurological disease, an inflammatory disease or a metabolic disorder.

16. A combination or pharmaceutical composition for use according to any one of claims 12 to 15 wherein the amount of the PI3K/AKT/mT0R pathway inhibiting compound used is between 0.001 pM and 15 pM and the amount of tanshinone used is between 0.01 pM and 15 pM. 17. A method of treating a disease associated with the PI3K/AKT/mTOR pathway by administering a patient with a combination according to any one of claims 1 to 9.

18. A method as claimed in claim 17 wherein the PI3K/AKT/mT0R pathway inhibiting compound and the tanshinone or a derivative, an isomer or a pharmaceutically acceptable salt thereof are administered simultaneously, or sequentially in any order.

19. A method of treating a disease associated with the PI3K/AKT/mTOR pathway by administering a patient with a pharmaceutical composition according claim

10 or 11.