WO2012069150A2

WO2012069150A2 - Cytoprotectant agents for the prevention of drug-associated side-effects

Info

Publication number: WO2012069150A2
Application number: PCT/EP2011/005721
Authority: WO
Inventors: Dominic HÜTZEN
Original assignee: Powerpore Gmbh
Priority date: 2010-11-22
Filing date: 2011-11-14
Publication date: 2012-05-31
Also published as: WO2012069150A3

Abstract

The invention relates to cytoprotectant agents as medicaments for the prevention of drug-associated osteonecrosis of the jaw and/or the femur, to pharmaceutical compositions comprising a cytoprotectant agent and a bisphosphonate or denosumab, and to a method for the treatment or prevention of osteoporosis by the concurrent or subsequent adminstration of a cytoprotectant agent and a bisphosphonate or denosumab.

Description

CYTOPROTECTANT AGENTS FOR THE PREVENTION OF DRUG-ASSOCIATED

SIDE-EFFECTS

BACKGROUND OF THE INVENTION

1. TECHNICAL FIELD

The invention relates to cytoprotectant agents as medicaments for the prevention or reduction of drug-associated side effects, in particular bisphosphonate-associated side effects such as osteonecrosis of the jaw and/or the femur, to pharmaceutical compositions comprising a cytoprotectant agent and a bisphosphonate and to a method for the treatment or prevention of cancer or osteoporosis, or osteodystrophia deformans (Morbus Paget) or of tumor-associated hypercalcemia by the concurrent or subsequent adminstration of a cytoprotectant agent and a bisphosphonate.

2. PRIOR ART

Over 190 million oral bisphosphonate prescriptions have been dispensed worldwide and intravenous application is also significant in numbers [1-3]. Bisphosphonates are synthetic analogs of pyrophosphonate that bind to the hydoxyapathite in bone. They act as specific inhibitors of osteoclast-mediated bone resorption and are an important class of drugs in oncology and osteoporosis. They inhibit the growth of bone tumors and bone loss by limiting bone remodelling and degradation [1, 3]. Approximately 70% of lung, breast and prostate cancer patients develop bone metastases during the course of the disease [1, 4]. 350.000 patients die from bone metastases annually in the USA alone. Multiple myeloma is a hematological indication for bisphosphonate therapy with an incidence rate around 4/100.000 [4-6]. Osteoporosis is the bisphosphonate indication with the highest incidences around 700/100.000 [7-11].

The bisphosphonate drugs are accumulated in the bone matrix [2, 3]. While this is the basis of the effective working mechanism, it also resulted in the main side effect of the therapy known as bisphosphonate-related osteonecrosis of the jaw (BRONJ, also called BONJ) [12, 13]. The problem is described for all indication fields. BRONJ results in significant clinical problems and sickness of the patient. This condition mostly occurs after teeth extraction in

bisphosphonate-treated patients, mostly with nitrogene-containing bisphosphonates (nBPs)

CONFIRMATION COPY and is associated with exposed jaw bone, limited healing of the mucosa, and osteomyelitis. A drug holiday with stop of bisphonate application can be beneficial for the prevention of BRONJ [14, 15]. There is no specific therapy for the prevention of the problem yet this issue is a field of ongoing research [16].

Furthermore, a similar incidence of osteonectrosis of the jaw has been observed upon subcutaneous administration of denosumab [27].

Certain cholesterol seco-norcholstan derivatives are known as cytoprotectant agents for example from the US patent applications US 2006/0217358 Al, US 2008/0275130 Al, US 2009/0186863 Al, US 2009/0203662 A1,US 2009/0203747 Al, US 2009/0312434 Al and US 2010/0099652 Al.

Olesoxime (TRO 19622) is a mitochondrial pore modulator in development phase III for the indicationsamyotrophic lateral sclerosis, multiple sclerosis and spinal muscular atrophy.

Another group of cytoprotectant agents are selected from the group consisting of

bisdioxopiperazines, quinolines, aclarubicin and acridines.

SHORT SUMMARY OF THE INVENTION

The problem underlying the present invention was to provide a medicament which alleviates or prevents drug-associated osteonecrosis of the jaws and / or the femur, in particular the severe side-effects associated with the administration of bisphosphonates in the treatment or prevention of cancer or osteoporosis, in particular BONJ.

Surprisingly, it has been shown in in-vitro assays that a concurrent or subsequent

administration of cytoprotectant agent with bisphosphonates or denosumab will prevent or at least drastically reduce the severe side-effects associated with the bisphosphonates without influencing its beneficial efficacy against cancer or osteoporosis.

Accordingly the invention relates to a cytoprotectant agent as medicament for the prevention or reduction of drug-associated osteonecrosis of the jaws and / or the femur, preferably the bisphosphonate -associated side-effects, in particular osteonecrosis of the jaw (BONJ) and / or femur.

Furthermore, the invention relates to a pharmaceutical composition or a kits of parts comprising

(a) one or more cytoprotectant agent or a pharmaceutically acceptable salt thereof;

(b) one or more bisphosphonate or a pharmaceutically acceptable salt thereof.

In addition, the invention relates to a pharmaceutical composition or a kits of parts comprising

(b) denosumab.

Moreover, the invention relates to a method for the treatment or prevention of cancer, osteoporosis, osteodystrophia deformans or of tumor-associated hypercalcemia in a patient and to a method of inhibiting post-menopausal bone loss in a post-menopausal woman in the treatment or prevention of post-menopausal osteoporosis, which methods comprise concurrently or subsequently administering an effective amount of at least one cytoprotectant agent and an effective amount of (i) at least one one bisphosphonate or a pharmaceutically acceptable salt thereof or (ii) denosumab to said patient or post-menopausal woman suffering from osteoporosis, osteodystrophia deformans or of tumor-associated hypercalcemia.

Furthermore, the invention relates to a method

SHORT DESCRIPTION OF THE DRAWINGS

Fig. 1 shows the results of a scratch assay in human osteoblasts (example 1).

Fig. 2 shows the results of an MTT assay in human osteoblasts (example 2).

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the invention are:

(A) A cytoprotectant agent, which is capable of reducing anthracycline-induced cardiotoxicity. (B) A cytoprotectant agent, which is bisdioxopiperazine, preferably a bis(3,5- dioxopiperazine-l-yl)alkane of formula

1 2 1

wherein R and R are each independently hydrogen or C_\ ^ alkyl, preferably R being methyl and R² being hydrogen,

most preferably selected from the group consisting of dexrazoxane, razoxane and probimane or a pharmaceutically acceptable salt thereof.

(C) A cytoprotectant agent, which is a cholesterol or seco-norcholestan derivative or a pharmaceutically acceptable salt thereof, in particular cholesterol or olesoxime (TRO 19622) of formula

or a pharmaceutically acceptable salt thereof.

(D) A pharmaceutical composition, wherein the bisphosphonate is a compound of formula 2

R¹R²C(P0₃H₂)₂ 2

wherein

R¹ represent hydrogen, chloro or hydroxy,

R² represents chloro, a Ci - C₆ alkyl group, which is optionally substituted by one or more substituents selected from the group consisting of amino, C_\ - C₆ alkylamino, di-(C! - C₆ alkyl)-amino, carboxyl, pyridinyl, imidazolyl and imidazopyridinyl, a thiophenyl group, which is optionally substituted by one or more halogen atoms, or

a C₃ - C₈ cycloalkylamino group,

or a pharmceutically acceptable salt thereof.

The term "Ci-C₆ alkyl", either alone or in combination with another radical denotes an acyclic, saturated, branched or linear hydrocarbon radical with 1 to 6 C atoms. For example the term Ci_-6-alkyl embraces the radicals H₃C-, H₃C-CH₂-, H₃C-CH₂-CH₂-, H₃C-CH(CH₃)-, H₃C-CH₂-CH₂-CH₂-, H₃C-CH₂-CH(CH₃)-, H₃C-CH(CH₃)-CH₂-, H₃C-C(CH₃)₂-, H₃C-CH₂- CH₂-CH₂-CH₂-, H₃C-CH₂-CH₂-CH(CH₃)-, H₃C-CH₂-CH(CH₃)-CH₂-, H₃C-CH(CH₃)-CH₂- CH₂-, H₃C-CH₂-C(CH₃)₂-, H₃C-C(CH₃)₂-CH₂-, H₃C-CH(CH₃)-CH(CH₃)- H₃C-CH₂- CH(CH₂CH₃)- and H₃C-CH₂-CH₂-CH₂-CH₂-CH₂-.

The term "C₃-C cycloalkyl", either alone or in combination with another radical denotes an cyclic, saturated hydrocarbon radical with 3 to 8 C atoms. For example the term Ci_-6- cycloalkyl embraces the radicals cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,

cycloheptyl and cyclooctyl.

The term "thiophenyl", either alone or in combination with another radical denotes a group of formula H₅C₆-S-.

1 2

Preferably R represent hydroxy and R represents cycloheptylamino group, a (4- chlorophenyl)-thio group or a Ci - C₃ alkyl group, which is substituted by one substituent selected from the group consisting of amino, di-(C_! - C₆ alkyl)-amino, in particular N,N- dimethylamino or N-«-pentyl-N-methylamino, imidazol-l-yl, pyridin-3-yl and imidazo[1.2- a]pyridin-3-yl.

Most preferred are the bisphosphonate of formula 2 is selected from the group consisting of alendronic acid, clodronic acid, etidronic acid, ibandronic acid, incadronic acid, minodronic acid, neridronic acid, olpadronic acid, pamidronic acid, risedronic acid, tiludronic acid and zoledronic acid, or the pharmaceutically acceptable salts thereof, in particular alendronate sodium trihydrate (Fosamax®), risedronate sodium (Actonel^®), ibandronate sodium monohydrate (Boniva^®/Bondronate^®) or zoledronate disodium tetrahydrate

(Aclasta^®/Zometa^®).

The bisphosphonate producte comprising a compound of formula 2 may also contain a vitamin D compound such as cholecalciferol.

The phrase "pharmaceutically acceptable" is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, and commensurate with a reasonable benefit/risk ratio.

As used herein, "pharmaceutically acceptable salts" refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts thereof. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. For example, such salts include acetates, ascorbates, benzenesulfonates, benzoates, besylates, bicarbonates, bitartrates, bromides/hydrobromides, Ca-edetates/edetates, camsylates, carbonates, chlorides/hydrochlorides, citrates, edisylates, ethane disulfonates, estolates esylates, fumarates, gluceptates, gluconates, glutamates, glycolates, glycollylarsnilates, hexylresorcinates, hydrabamines, hydroxymaleates, hydroxynaphthoates, iodides, isothionates, lactates, lactobionates, malates, maleates, mandelates, methanesulfonates, mesylates, methylbromides, methylnitrates, methylsulfates, mucates, napsylates, nitrates, oxalates, pamoates, pantothenates, phenylacetates,

phosphates/diphosphates, polygalacturonates, propionates, salicylates, stearates subacetates, succinates, sulfamides, sulfates, tannates, tartrates, teoclates, toluenesulfonates, triethiodides, ammonium, benzathines, chloroprocaines, cholines, diethanolamines, ethylenediamines, meglumines and procaines. Further pharmaceutically acceptable salts can be formed with cations from metals like aluminium, calcium, lithium, magnesium, potassium, sodium, zinc and the like, (also see Pharmaceutical salts, Birge, S.M. et al., J. Pharm. Sci., (1977), 66, 1- 19). Denosumab is a fully human monoclonal antibody for the treatment of osteoporosis, treatment induced bone loss, bone metastases, rheumatoid arthritis, multiple myeloma and giant cell tumor of bone. It was developed by the company Amgen. Denosumab is designed to target RANKL (RANK ligand), a protein that acts as the primary signal to promote bone removal. In many bone loss conditions, RANKL overwhelms the body's natural defense against bone destruction.

It has been approved by FDA for use in postmenopausal women with risk of osteoporosis in June 2010, under the trade name Prolia® and for the prevention of skeletal -related events in patients with bone metastases from solid tumors in November 2010, as Xgeva®.

Another aspect of the present invention is a kit of parts comprising two separate

pharmaceutical compositions for subsequent administration to a patient, consisting of

(i) a pharmaceutical composition comprising one or more cytoprotectant agent or a pharmaceutically acceptable salt thereof;

(iia) a pharmaceutical composition comprising one or more bisphosphonate or a pharmaceutically acceptable salt thereof; or

(iib) a pharmaceutical composition comprising denosumab;

(iii) optionally a leaflet, in which the administration regimen of components (i) and

(ii) is described.

The application of the cytoprotectant agents can include preventive medication under bisphosphonate or denosumab therapy as well as the therapy of bisphosphonate-associated osteonecrosis of the jaws (BRONJ).

Preventive medication can be a maintainance therapy over the whole time of bisphosphonate or denosumab therapy and even after stop of bisphosphonate medication due to long biological half-life of the bisphoshonates.

Preventive medication can also be the medication at events of immanent BRONJ risk (e.g. tooth extraction). BRONJ therapy includes the application of the cytoprotective drug to heal BRONJ alone or in combination with other therapies and medications.

The application form can include systemic administration as well as local application as fluid, cream, gel, injection or in any kind of release form/device.

The dose range of the cytoprotectant agent applicable per day varies between the different types of compounds. In case of the cholesterol derivative or a seco-norcholestan it is usually in the range from 50.0 to 1000.0 mg, preferably from 100.0 to 750.0 mg, more preferably from 150.0 to 500.0 mg, most preferably about 330 mg. Each dosage unit may conveniently contain from 25.0 to 500.0 mg, preferably 75.0 to 250.0 mg.

In case of the bisdioxopiperazines, quinolines, aclarubicin and acridines the daily dose is usually in the range from 100.0 to 4000.0 mg, preferably from 250.0 to 3000.0 mg, more preferably from 500.0 to 2500.0 mg, most preferably about 1000.0 or 2000.0 mg. Each dosage unit may conveniently contain from 50.0 to 2000.0 mg, preferably 250.0 to 750.0 mg.

The dose range of the bisphosphonates applicable per day varies between the different types of compounds. The daily dose is usually in the range from 1.0 to 50.0 mg, preferably from 2.0 to 20.0 mg, more preferably from 4.0 to 15.0 mg, most preferably about 5.0 or 10.0 mg. The bisphosphonates may be administered once daily, once weekly, once monthly or even once a year (for example zolendronate). Accordingly, each dosage unit may conveniently contain from 1.0 to 250.0 mg, preferably 2.5 to 150.0 mg.

The dose range of denosumab applicable per 6 months is in the range from 10 to 100 mg, preferably from 20 to 800 mg, more preferably from 30 to 75 mg, most preferably about 55 to 65 mg. The most recommended dose of denosumab is 60 mg administered as a single subcutaneous injection once every 6 months into the thigh, abdomen or back of arm.

The actual pharmaceutically effective amount or therapeutic dosage will of course depend on factors known by those skilled in the art such as age and weight of the patient, route of administration and severity of disease. In any case the combination of cytoprotectant agents and bisphosphonates will be administered at dosages and in a manner which allows a pharmaceutically effective amount to be delivered based upon patient's unique condition.

A preferred application is the systemic application as long-term medication or temporarily at times of high risk for drug induced osteonecrosis of the jaw for example at tooth extrations or other surgery in the mouth.

Suitable preparations for administering the cytoprotectant agents and bisphosphonates will be apparent to those with ordinary skill in the art and include for example tablets, pills, capsules, suppositories, lozenges, troches, oral solutions, infusion solutions, syrups, elixirs, sachets, injectables, inhalatives and powders etc.

Suitable tablets may be obtained, for example, by mixing one or more compounds according to formula I with known inactive ingredients, for example inert diluents, carriers,

disintegrants, adjuvants, surfactants, binders and/or lubricants. Preferred inactive ingredients are lactose, povidone, crospovidone, croscarmellose sodium, stearic acid, magnesium stearate, microcrystalline cellulose, silicon dioxide, hypromellose, titanium dioxide, talc, polyethylene glycol.

The tablets comprising both a cytoprotectant agent and a bisphophonate may also consist of several layers, in which one layer contains the cytoprotectant agent and the other layer contains the bisphophonate.

Another preferred embodiment of the invention is the local administration of the

cytoprotectant agent on a biomaterial to be placed in the bone, for example collagen or gelatin carrier to be placed in extraction alveola of extracted teeth [24].

Accordingly the invention relates to a biomaterial comprising a cytoprotectant agent or a pharmaceutically acceptable salt thereof as medicament for the prevention or reduction of drug-associated osteonecrosis of the jaws and / or the femur.

A further is preferred embodiment of the invention the local administration on a dental implant due to the higher risk during the healing phase of dental implants or later on the abudment, the connection device between implant and dental supraconstruction for example crown material as long-term local medication with sustained release, for example a dental implant with silan coating [25].

Accordingly the invention relates to a dental implant comprising a cytoprotectant agent or a pharmaceutically acceptable salt thereof as medicament for the prevention or reduction of drug-associated osteonecrosis of the jaws and / or the femur.

The following Example serves to illustrate the present invention in more detail without restricting the scope of the invention to the exemplifying embodiments that follow.

In vitro screening tests

The following well established standard tests for the screening of a cytoprotective effect on cells under the influence of bisphosphonates have been carried out:

Example 1

Scratch assay in human osteoblasts (hOB, PromoCell, Heidelberg, Germany: No. C- 12720) [23].

Scratch assay evaluates the potential of the cells in a culture dish to overgrow a scratched defect in the monolayer compared to a control group indicating the health and activity of the cells. A sterile pipette tip device is used to generate a standardized defect in the monolayer.

The effects of the cytoprotectant agents are shown by measuring the scratch gap healing in the various groups. The potential of the cells in culture to close this gap under the influence of applied drugs is measured and compared relative to the control group.

A monolayer of human osteoblasts is cultivated under standard conditions in round culture dishes. Zoledronate at a concentration of 50 pmol/L was added in all groups. Group (A) was the control only receiving zolendronate, group (B) consisted of zolendronate and dexrazoxane (200 μηιοΙ/L) and group (C) of zolendronate and cholesterol (3 μι^ηοΙ/L). Cholesterol has been obtained from Sigma Aldrich Chemie GmbH, Germany (product number C-8667). The results of this assay are shown in Fig. 1, wherein the different lines indicate the scratched defect compared to control at start after 1 and 2 days:

— ·— control

— o— cholesterol + zolendronate

—X— dexrazoxane + zolendronate

Example 2

MTT assay

The MTT assay is a commercially available colorimetric assay evaluating the cell viability (MTT colorimetric assay (Sigma, Munchen, Germany: M5655)).

The results of this assay are shown in Fig. 2, wherein the different points indicate the osteoblast density (OD) at 550 nm:

• (A) control

■ (B) cholesterol + zolendronate

▲ (C) dexrazoxane + zolendronate.

The graphs of Fig. 1 and 2 show that dexrazoxane and cholesterol exhibit a cytoprotective effect in bisphosphonate treated human osteoblasts in vitro, which clearly proves that they are suitable to prevent or reduce bisphosphonate-associated side-effects.

In-vivo tests

Example 3 Study design

The animal study applied three experimental groups on a collagen carrier (Bio-Oss Collagen) in 6 female chinchilla bastard rabbits using the tibia model on both sides (n=4 samples per group). Samples were taken after 7 days representing the early bone healing (early hard callus formation) in rabbits.

Sample preparation We applied zolendronate (Zometa, Novartis AG, Basel, CH) and dexrazoxane (Cardiozoxane, Novartis AG, Basel, CH) in the experiments. 25nmol zoledonic acid with and without 300 nmol dexrazoxane were applied on the Bio-Oss Collagen 0.5ccm cubes (collagen- hydroxylapatite matrix) under sterile conditions. The materials were stored at 3°C for 3 hours before implantation in the tibia drill hole defects.

Animal experiments

The animal study was approved by the government of Moldova in compliance with the guidelines for animal experimentation in the animal experimentation institute of the

University of Moldova (Chisinau, Moldova). Female ex-breeder Chinchilla bastard rabbits ensureing normal bone healing were held in appropriate paddocks under unrestricted mobility. Ketamine 100 mg/ xylazin 20 mg/ 5 kg was used for anaesthesia and was adapted to the individual animal weight. The implants were placed in both medial tibia bones of the six animals via an anterior transdermal approach (n=4 samples per group resulting in 12 samples all in all) after drilling of a 3.2mm defect with a standard Astratech implant drill at 800 rpm and water rinsing. Wound closure with Vicryl 3-0 sutures was done in two layers (fascia and skin). Animals received up to 30 mg phenylbutazone after the operation. The rabbits were sacrificed by an overdose of ketamine (200 mg) and thorax opening after 10 days. Samples were harvested and fixated with 4% paraformaldehyde.

Histological examination

Samples were cut in appropriate bony pieces after immersion fixation for 4 weeks as described above. Histological preparation was described elsewhere [26]. Dehydration with increasing percentages of alcohol (70-100%) was followed by Techno vit® embedding, toluidine blue staining and diamond grinding of microscopic samples down to a thickness of 20 μιη. Light microscopic examination was performed under a Leica DM8000 M microscope was performed for descriptive histology.

RESULTS

Animal experiments in the tibia of female ex-breeder Chinchilla bastard rabbits after 10 days (toluidine blue staining) showed newly formed bone trabeculae directly growing towards the implanted hydroxylapatite particles and cortical bone interface resorption activities in the control and the experimental group, while this could not be observed in the implant area of the group with only zoledronic acid. LITERATURE:

1. Roodman GD: Mechanisms of bone metastasis. N EnglJ Med 2004;350:1655

2. Surgeons AAoOaM: American Association of Oral and Maxillofacial Surgeons position paper on bisphosphonate-related osteonecrosis of the jaws. J Oral Maxillofac Surg 2007;65:369

3. Green JR: Bisphosphonates: preclinical review. Oncologist 2004;9 Suppl 4:3

4. Phekoo KJ, Schey SA, Richards MA et al.: A population study to define the incidence and survival of multiple myeloma in a National Health Service Region in UK. Br J Haematol 2004; 127:299

5. Marx RE: Pamidronate (Aredia) and zoledronate (Zometa) induced avascular necrosis of the jaws: a growing epidemic. J Oral Maxillofac Surg 2003;61 : 1115

6. Ural AU, Avcu F: Therapeutic role of bisphosphonate and radiation combination in the management of myeloma bone disease. Clin Cancer Res 2007; 13:3432

7. Handler RP: Prior bisphosphonate therapy of osteoporosis attenuates and blocks response to subsequent parathyroid hormone. J Clin Rheumatol 2008; 14: 122

8. Goettsch WG, de Jong RB, Kramarz P, Herings RM: Developments of the incidence of osteoporosis in The Netherlands: a PHARMO study. Pharmacoepidemiol Drug Saf 2007;16:166

9. Burge R, Dawson-Hughes B, Solomon DH et al.: Incidence and economic burden of osteoporosis-related fractures in the United States, 2005-2025. J Bone Miner Res 2007;22:465

10. Watts NB, Diab DL: Long-term use of bisphosphonates in osteoporosis. J Clin Endocrinol Metab 2010;95:1555

11. Sebba A: Osteoporosis: how long should we treat? Curr Opin Endocrinol Diabetes Obes 2008; 15:502

12. Schmidt GA, Horner KE, McDanel DL et al.: Risks and benefits of long-term bisphosphonate therapy. Am J Health Syst Pharm 2010;67:994

13. Sawatari Y, Marx RE: Bisphosphonates and bisphosphonate induced osteonecrosis. Oral Maxillofac Surg Clin North Am 2007; 19:487

14. Vescovi P, Nammour S: Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) therapy. A critical review. Minerva Stomatol 2010;59:181

15. Kwon YD, Kim YR, Choi BJ et al.: Oral bisphosphonate-related osteonecrosis of the jaws: favorable outcome after bisphosphonate holiday. Quintessence Int 2009;40:277 16. Epstein MS, Wicknick FW, Epstein JB et al.: Management of bisphosphonate- associated osteonecrosis: pentoxifylline and tocopherol in addition to antimicrobial therapy. An initial case series. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:593

17. Epstein S, Zaidi M: Biological properties and mechanism of action of ibandronate: application to the treatment of osteoporosis. Bone 2005;37:433

18. Gill PS, Espina BM, Muggia F et al.: Phase I/II clinical and pharmacokinetic evaluation of liposomal daunorubicin. J Clin Oncol 1995; 13:996

19. Lipshultz SE, Scully RE, Lipsitz SR et al.: Assessment of dexrazoxane as a cardioprotectant in doxorubicin-treated children with high-risk acute lymphoblastic leukaemia: long-term follow-up of a prospective, randomised, multicentre trial. Lancet Oncol 2010;11 :950

20. Ocal B, Oguz D, Karademir S et al.: Myocardial performance index combining systolic and diastolic myocardial performance in doxorubicin-treated patients and its correlation to conventional echo/Doppler indices. Pediatr Cardiol 2002;23:522

21. Lipshultz SE, Rifai N, Dalton VM et al.: The effect of dexrazoxane on myocardial injury in doxorubicin-treated children with acute lymphoblastic leukemia. N Engl J Med 2004;351:145

22. Xiao WH, Zheng FY, Bennett GJ et al.: Olesoxime (cholest-4-en-3-one, oxime): analgesic and neuroprotective effects in a rat model of painful peripheral neuropathy produced by the chemotherapeutic agent, paclitaxel. Pain 2009; 147:202

23. Walter C, Klein MO, Pabst A, Al-Nawas B, Duschner H, Ziebart T. Influence of bisphosphonates on endothelial cells, fibroblasts, and osteogenic cells. Clin. Oral Investig. 2010 Feb;14(l):35-41.

24. Raiche AT, Puleo DA. In vitro effects of combined and sequential delivery of two bone growth factors. Biomaterials. 2004;25:677-85.

25. Chatzinikolaidou M, Lichtinger TK, Miiller RT, Jennissen HP. Peri-implant reactivity and osteoinductive potential of immobilized rhBMP-2 on titanium carriers. Acta

Biomaterialia. 2010;6:4405-21.

26. Donath, K., Breuner, G., 1982. A method for the study of undecalcified bones and teeth with attached soft tissues. The Sage-Schliff (sawing and grinding) technique.

Journal of oral pathology 11, 318-326. 27. Stopeck AT, Lipton A, Body JJ. et al., Denosumab compared with zoledronic acid for the treatment of of bone metastasis in patients with advanced breast cancer. A randomized double-blind study. J. Clin. Oncol. 28 5132-5139, 2010.

Claims

1. A cytoprotectant agent or a pharmaceutically acceptable salt thereof as medicament for the prevention or reduction of drug-associated osteonecrosis of the jaws and / or the femur.

2. A cytoprotectant agent according to claim 1, wherein the drug-associated osteonecrosis is induced by the treatment with one or more bisphosphonate

3. A cytoprotectant agent according to claim 1, wherein the drug-associated osteonecrosis is induced by the treatment with denosumab.

4. A cytoprotectant agent according to any one of claims 1 to 3, which is capable of reducing anthracycline-induced cardiotoxicity.

5. A cytoprotectant agent according to any one of claims 1 to 4, which is selected from the group consisting of bisdioxopiperazines, quinolines, aclarubicin and acridines.

6. A cytoprotectant agent according to any one of claims 1 to 5, wherein the bisdioxopiperazine is a compound of formula I

wherein R¹ and R² are each independently hydrogen or C_1-4 alkyl.

7. A cytoprotectant agent according to claim 6, which is bisdioxopiperazine selected from the group consisting of dexrazoxane, razoxane and probimane or a

pharmaceutically acceptable salt thereof. A cytoprotectant agent according to any of the claims 1 to 4, which is a derivative or a seco-norcholestan or a pharmaceutically acceptable salt thereof.

9. A cytoprotectant agent according to claim 8, which is cholesterol or olesoxime (TRO 19622) of formula

or a pharmaceutically acceptable salt thereof.

10. A biomaterial comprising a cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any one of the claims 1 to 9 as medicament for the prevention or reduction of drug-associated osteonecrosis of the jaws and / or the femur.

1 1. A dental implant comprising a cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any one of the claims 1 to 9 as medicament for the prevention or reduction of drug-associated osteonecrosis of the jaws and / or the femur.

12. A pharmaceutical composition comprising

(a) one or more cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 9;

(b) one or more bisphosphonate or a pharmaceutically acceptable salt thereof.

13. A pharmaceutical composition according to claim 12, wherein the

bisphosphonate is a compound of formula 2

R^CCPOaH^ 2

wherein

R¹ represent hydrogen, chloro or hydroxy,

R² represents chloro, a Ci - C₆ alkyl group, which is optionally substituted by one or more substituents selected from the group consisting of amino, Cj - C₆ alkylamino, di-(Ci - C₆ alkyl)-amino, carboxyl, pyridinyl, imidazolyl and imidazopyridinyl, a thiophenyl group, which is optionally substituted by one or more halogen atoms, or

a C₃ - C₈ cycloalkylamino group,

or a pharmceutically acceptable salt thereof.

14. A pharmaceutical composition according to claim 12, wherein the

bisphosphonate of formula 2 is selected from the group consisting of alendronic acid, clodronic acid, etidronic acid, ibandronic acid, incadronic acid, minodronic acid, neridronic acid, olpadronic acid, pamidronic acid, risedronic acid, tiludronic acid and zoledronic acid, or a pharmaceutically acceptable salt thereof.

15. A pharmaceutical composition comprising

(b) denosumab.

16. A kit of parts comprising two separate pharmaceutical compositions for subsequent administration to a patient, consisting of

(i) a pharmaceutical composition comprising one or more cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 9;

(ii) a pharmaceutical composition comprising one or more bisphosphonate or a pharmaceutically acceptable salt thereof or denosumab;

(iii) optionally a leaflet, in which the administration of components (i) and (ii) is described.

17. A method for the treatment or prevention of cancer, osteoporosis,

osteodystrophia deformans or of tumor-associated hypercalcemia in a patient, which method comprises concurrently or subsequently administering an effective amount of at least one cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any of the claims 1 to 9 and an effective amount of at least one bisphosphonate or a pharmaceutically acceptable salt thereof to said patient suffering from cancer, osteoporosis, osteodystrophia deformans or of tumor-associated hypercalcemia.

18. A method of inhibiting post-menopausal bone loss in a post-menopausal woman in the treatment or prevention of post-menopausal osteoporosis, which method comprises concurrently or subsequently administering an effective amount of at least one cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any of the claims 1 to 9 and an effective amount of at least one bisphosphonate or a pharmaceutically acceptable salt thereof to said post-menopausal woman suffering from osteoporosis.

19. A method for the treatment or prevention of cancer, osteoporosis,

osteodystrophia deformans or of tumor-associated hypercalcemia in a patient, which method comprises concurrently or subsequently administering an effective amount of at least one cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any of the claims 1 to 9 and an effective amount of denosumab to said patient suffering from cancer, osteoporosis, osteodystrophia deformans or of tumor-associated hypercalcemia.

20. A method of inhibiting post-menopausal bone loss in a post-menopausal woman in the treatment or prevention of post-menopausal osteoporosis, which method comprises concurrently or subsequently administering an effective amount of at least one cytoprotectant agent or a pharmaceutically acceptable salt thereof according to any of the claims 1 to 9 and an effective amount of denosumab to said post-menopausal woman suffering from osteoporosis.