AU624283B2 - Organic amine phosphonic acid complexes - Google Patents

Description

624283 S F Ref: 41229/85A1 FORM COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int Class eq o 0 0o« 0 0 *40 o" ««o Complete Specification Lodged: Accepted: Published: Priority: Related Art: Name and Address of Applicant:

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The Dow Chemical 2030 Dow Center, Midland Michigan UNITED STATES OF Company Abbott Road 48640

AMERICA

The Fred Hutchinson Cancer Research Center 1124 Columbia Street Seattle Washington 98104 UNITED STATES OF AMERICA Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tower, 31 Market Street, Sydney, New South Wales, 2000, Australia Address for Service: 'ii Complete Specification for the invention entitled: Organic Amine Phosphonic Acid Complexes Nj-

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The following statement is a full description of this invention, including the best method of performing it known to me/us 5846/3

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0~~ r 1 TREATMENT OF CALCIFIC TUMORS USING A RADIOACTIVE COMPLEX This is an application for a pi of addition to the invention claimed in Australian Patent No. 563 671.

Background of the Invention The present invention relates to a complex for the treatment of calcific tumors using 53Samarium-ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof (hereinafter 153 Sm-EDTMP) at a dose sufficiently high for treatment of calcific tumors 0* and having a high therapeutic index.

10 The development of bone metastasis is a common and often catastrophic S. event for a cancer patient. The pain, pathological fractures, frequent neurological deficits and forced immobility caused by these metastatic bone lesions significantly decrease the quality of life for the cancer patient.

The number of patients that contract metastatic disease is large since ,*6.15 nearly 50% of all patients who contract breast, lung or prostate carcinoma a will eventually develop bone metastasis. Bone metastasis are also seen in patients with carcinoma of the kidney, thyroid, bladder, cervix, and other tumors, but collectively, these represent less than 20% of patients who I develop bor metastasis. Metastatic bone cancer is rarely life threatening and occasionally patients live for years following the discovery of the o bone lesions. Initially, treatment 1 GSA/154

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-2goals center on relieving pain, thus reducing requirements for narcotic medication and increasing ambulation. Clearly, it is hoped that some of the cancers can be cured.

The use of radionuclides for treatment of cancer metastatic to the bone dates back to the early 1950's. It has been proposed to inject a radioactive 0,o° particle-emitting nuclide in a suitable form for the treatment of calcific lesions. It is desirable that such nuclides be concentrated in the area of the bone o- lesion with minimal amounts reaching the soft tissue and normal bone. Radioactive phosphorus (P-32 and P-33) 'compounds have been proposed, but the nuclear and biolocalization properties limit the use of these compounds. [See Kaplan, E. et al., J.Nucl.Md. 1 (1960) and U.S. Patent 3,965,254.1 Another attempt to treat bone cancer has been made using phosphorus compounds containing a boron residue. The compounds were injected into the body .ali (intravenously) and accumulated in the skeletal system.

The treatment area was then irradiated with neutrons in order to to activate the boron and give a therapeutic 25 radiation dose. (See U.S. Patent 4,399,817.) In the above mentioned procedures, it is not possible to give therapeutic doses to the tumor without substantial damage to normal tissues. In many cases, especially for metastatic bone lesions, the tumor has spread throughout the skeletal system and amputation or external beam irradiation is not practical. (See Seminars in Nuclear Medicine, Vol. IX, No. 2, April, 1979.

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3 Strontiiin-89 has also been proposed for patients with metastatic bone lesions. However, the long half-life (about 50.4 days), high blood levels and low lesion to normal bone ratios limit the utility. [See Firusian, N.

et al., J.ofUrology 116, 764 (1976); and Schmidt, C. G. et al., Int.J.

Clin.Pharmacol. 93, 199-205 (1974).] Samarium-153-ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof (hereinafter 153 Sm-EDTMP) has been prepared in Australian Patent No. 563 671, the disclosure of which is o hereby incorporated by reference. The 153 Sm-EDTMP complex has utility 10 for the relief of bone pain and for treatment of calcific tumors. The use 153 of 153 Sm-EDTMP complex for bone marrow suppression is given in Australian ,o "Patent 603 389, the disclosure of which is hereby incorporated by reference.

1 Surprisingly, the present invention overcomes many of the above noted problems. The present invention concerns using 1 3 Sm-EDTMP at a dose sufficiently high to be an effective amount for treatment of calcific tumors and having a high therapeutic index. 153 Sm-EDTMP can be .ooo administered as a formulation with suitable pharmaceutically acceptable ooo carriers. The present invention includes the use of the complex or composition in combination with other drugs and/or radiation sources.

20 Summary of the Invention The present invention concerns a complex for the treatment of Scalcific tumors using 153 Sm-EDTMP at a dose sufficiently high to be an effective amount for treatment of calcific tumors, particularly at a dose of from greater than 2.0 to about 30 millicuries (mCi) per kilogram (kg) of 25 body weight of an animal. 153 Sm-EDTMP complex also displays a high therapeutic index. For the purposes of this invention, "high therapeutic index" means preferably more preferably>9, most preferably about 53! In addition the present invention also includes formulations having 153Sm-EDTMP and a pharmaceutically acceptable carrier, excipient or vehicle therefor. The methods for preparing such formulations are well known. The formulations are sterile and may be in the form of a suspension, injectable solution or other suitable pharmaceutically o acceptable formulations. Pharmaceutically acceptable suspending media, with or without adjuvants, may be used.

j The present invention contemplates the use of one or more other agents or treatments which assist in therapy of calcific tumors when used GSA/1554W Ll 1 yrr

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-4 in conjunction with the compositions or formulations described herein.

153 1 Sm-EDTMP complexes can be administered at high doses, particularly when compared to the art, and a patient shows excellent tolerance. The compositions of the invention have a high therapeutic index, tolerance and mild toxicity.

Detailed Description of the Invention In a first embodiment, the invention provides a sterile composition suitable for administration to an animal comprising 1) a complex which comprises Sm-153 and ethylenediaminetetramethylenephosphonic acid or a 10 physiologically acceptable salt thereof and 2) ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof, in excess of that required to make the complex, and wherein the resulting composition is therapeutically effective, having a high therapeutic index and wherein the Sm-153 in dosage form is present in an amount containing greater than 2 mCi per kilogram of body weight of said animal.

In a second embodiment, the invention provides a method for the therapeutic treatment of an aminal having one or liore calcific tumors which comprises administering to said animal a therapeutically effective amount of a composition comprising 1) a complex which comprises Sm-153 and ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof and 2) ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof, in excess of that required to make the complex, and wherein the resulting composition is therapeutically effective, having a high therapeutic index and wherein the Sm-153 in dosage form is present in an amount containing greater than 2 mCi per kilogram of body weight of said animal.

In a third embodiment, the invention provides a method for the therapeutic treatment of an animal having bone pain which comprises administering to said animal a therioeutic&lly effective amount of a composition comprising 1) a complex which comprises Sm-153 and ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof and 2) ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof, in excess of that required to make the complex, and wherein the resulting composition is therapeutically effective, having a high therapeutic index and wherein the Sm-153 in dosage GSA/1554W i Vt:s 1 t itt t3 t *i z t *I r tt.

il+ Ir tP i~r; i I Li~ii~~ n~ 4a form is present in an amount containing greater than 2 mCi per kilogram of body weight of said animal.

When radioactive drugs are administered to a patient having cancer, it is of importance that the drug go preferentially to the site of the cancer where it would be therapeutic and not to the normal tissue where it could cause damage to that tissue. This site location of the drug is called the radiolocation index. Obviously, it is desirable that the radioactive complex goes to the desired site for treatment in preference to normal tissues, is stable when administered so tC it t titit I' ii ~fi GSA/1554W

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pp~ *9 9 0*9 *4 0* *4 9 A S 9* 0 9 0* 44 0 044* 04*4 0 o 0 94 *4 4 *4 94* *4 9 9 44*404 9 94 4 94 that it does not readily fall apart and dissipate in unwanted areas of the body, e.g. liver, clears from the body rapidly after treatment without deleterious side effects, and is not too toxic to the patient.

When radioactive agents are used for calcific tumors, one concern is thja. rad.iation of the bone marrow such that bone marrow suppression occurs. Surprisingly, the 153 Sm-EDTMP complex of the present invention has been found to not unduly suppress the bone marrow.

10 While not wishing to be bound by theory, it is believed that the advantageous results of the present invention are obtained because of the uneven deposition of the present complex over the surface of the bone, particularly the midshaft of the long bones appears spared [see Appelbaum, F. R. et al., Antibody, !mmunoconjugates, and Radiop harm. 263-270 (1988)].

Such uneven deposition of the present complex allows areas of the marrow to survive the radiation treatment 20 at the present higher dose levels. In contrast, other known calcific tumor agents appear, to deposit relatively evenly over the surface of the bone.

A furl her concern when admuinistering 25 radioactive dr,,gs is the drug's therapeutic index.

Therapeutic index means a measure of the relative desirability of a drug for the attaining of a particular medical end that is usually expressed as the ratio of the largest dose producing no toxic symptoms to the smallest dose routinely producing cures. Thus the higher the ratio or therapeutic index, the better the drug regarding toxicity to the patient. It is known that many cancer drugs work quite well against the intended tumor or cancer site, but are too toxic for use in the patient. The saying that the drug worked well

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-6but the patient died has some relevance in the field of cancer drugs. Many drugs presently available on the market for cancer treatment (such as methotrexcate, fluorouracil and various cytotoxins) have a therapeutic index of For example, methotrexate, having the chemical name N-(4-{[(2,4-diamino-6-pteridinyl)methyl]methylamino}benzoyl)-L-glutamic acid, has a therapeutic index of from about 1.1 to about 1.0. Clearly, this low Io*" a therapeutic index poses problems in any flexibility of "10 the dose administered. In contrast, the present 1 10 complex, 153 Sm-EDTMP, has a therapeutic index of about o- 10. Clearly, the advantage for therapy of having the Shigher therapeutic index for the present complex is *apparent to one skilled in the art.

The term 153 Sm-EDTMP" or 153 Sm-EDTMP complex" includes a physiologically acceptable salt thereof in any form suitable for administration for the treatment of calcific tumors. "Calcific tumors" includes primary tumors where the skeletal system is the first site of involvement, invasive tumors where the primary tumor I, invades the skeletal system or other tissue tumors which calcify, and metastatic bone cancer where the neoplasm spreads from other primary sites, e.g. prostate and 25 25* breast, into the skeletal system. An "animal" means a mammal, including a human.

For the purpose of the present invention, the complex described herein and physiologically ^-ir

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''i .i 4 i i t:i i "i r g r ii 1 i: t _U acceptable salts thereof are considered equivalent in the therapeutically effective compositions.

Physiologically acceptable salts refer to the acid addition salts of those bases which will form a salt with at least one acid group of EDTMP and which will not cause a significant adverse physiological effect C-38,249 -7when administered to an animal at dosages consistent with good pharmacological practice. Suitable bases include, for example, the alkali metal and alkaline earth metal hydroxides, carbonates, and bicarbonates 3uch as sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, sodium bicarbonate, magnesium-carbonate and the like, ammonia, primary, secondary and tertiary amines and the like.

Physiologically acceptable salts may be prepared by treating the 153 Sm-EDTMP with an appropriate base.

U The fdrmulations of the present invention are in the solid or liquid form, preferably the liquid form, containing the 153 Sm-EDTMP. These formulations may be in kit form such that the two components are m;xed at the appropriate time prior to use. Whether premixed or as a kit, the formulations usually require a pharmaceutically acceptable carrier. Frequently, it is desirable to have a buffer present in the formulation.

2 0 S 0 Injectable compositions of the present y. invention may be either in suspension or solution form.

In the preparation of suitable formulations it will be S recognized that, in general, the water solubility of the S 25 salt is greater than the free acid. In solution f'-rm the complex (or when desired the separate components) is dissolved in a pharmaceutically acceptable carrier.

Such carriers comprise a suitable solvent, preservatives .c such as benzyl alcohol, if needed, and buffers. Useful solvents include, for example, water, aqueous alcohols, glycols, and phosphonate or carbonate esters. Such i aqueous solution3 preferably contain no more than 50% of the organic solvent by volume.

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Injectable suspensions as compositions of the present invention require a liquid suspending medium, with or without adjuvants, as a carrier. The suspending medium can be, for example, aqueous polyvinylpyrrolidone, inert oils such as vegetable oils or highly refined mineral oils, or aqueous carboxymethlycellulose.

Suitable physiologically acceptable adjuvants, if necessary to keep the complex in suspension, may be chosen from among thickners such as carboxymethyl- 10 cellulose, polyvinylpyrrolidone, gelatin, and the alginates. Many surfactants are also useful as suspending agents, for example, lecithin, alkylphenol, polyethylene oxide adducts, naphthalenesulfonates, alkylbenzenesulfonates, and the polyoxyethylene sorbitan esters. Many substances which effect the hydrophibicity, density, and surface tension of the liquid suspension medium can assist in making injectable suspensions in individual cases. For example, silcone antifoams, sorbitol, and sugars are all useful suspending agents.

The complex of the present invention is administered at an effective amount. An "effective amount" is a therapeutic dose level for the treatment of 2 calcific tumors. In order to attain the therapeutic dose desired, the complex is usually administered from at least 2 mCi/kg of body weight of an animal, preferably in a mCi range of from at least 2 to about mCi/kg of body weight of an animal, preferably from at least 2 to about 3 mCi/kg of body weight of an animal, more preferably from about 2.1 to about 2.7 mCi/kg of body weight of an animal, most preferably from about 2.3 to about 2.5 mCi/kg of body weight of an animal. The effective amount used to treat calcific tumors will C"-38,249 -8- 1-: -9 typically be administered, generally by administration into the bloodstream, in a single dose or multiple doses.

It may be possible to achieve the same beneficial results of high delivery of the 153 Sm to the area of the tumor, but with little soft 153 tissue damage, by administering the EDTMP and the Sm in a manner which 153 allows formulation of the Sm-EDTMP complex in situ such as by simultaneous or near simultaneous administration of the 153 Sm and an appropriate amount of EDTMP. The composition or formulation may be administered as a single dose or as multiple doses over a longer period of time.

The 153 Sm and EDTMP may be combined under any conditions which allow the two to form a complex. Generally, mixing in water at a controlled pH is all that is required. The complex formed is by a chemical O bond and results in a relatively stable 153 Sm-EDTMP complex, e.g. stable 5 to the disassociation of 1Sm from EDTMP. The preparation of the S 153 Sm-EDTMP complex is given in Australian Patent No 563 671, the disclosure of which is hereby incorporated by reference.

The ratio of EDTMP to Sm (total metal both cold and radioactive) is a .oO result of two competing considerations. The EDTMP and Sm are believed to 0 6 be in equilibrium with the complex. As appreciated by one skilled in the art of radiochemistry, only a portion of the Sm which is irradiated will be S radioactive. In the practice of this invention it is preferred that an amount of EDTMP be employed that is sufficient to insure that all of the radioactive Sm present is complexed GSA/14 4 S GSA/1554W o ^1 i: ii F~ since any uncomplexed radioactive Sm may localize in the soft tissue. To insure complexation of the radioactive Sm it is preferred that the amount of EDTMP used be in excess of the total amount of metal present, i.e.

radioactive metal plus non-radioactive metal plus any other metals present that can complex with EDTMP. Thus, in"the practice of this invention it is desirable to employ the complexed nuclide in the presence of excess EDTMP. Such excess should provide an amount sufficient 10 to inhibit significant uptake of the radionuclide by ,j J soft tissue. The excess ligand is usually EDTMP but could also be a different ligand which is suitable for o this purpose. However, too much excess ligand may have adverse effects, e.g. it may be toxic to the patient or o* 15 result in less favorable biolocalization of the radionuclide. Generally, in light of these above concerns, the 15 3 Sm-EDTMP complex is administered at a ligand to metal molar ratio of at least about 5:1, 6 preferably from about 5:1 to about 5,000:1, :ore 20 preferably from 50:1 to 3,000:1, most preferably from S50:1 to 500:1, and especially about 300:1. These ligand to metal fmolar ratios give biodistributions that are consistent with excellent skeletal agents. By contrast, S 25 certain other aminophosphonic acid complexes result in 25 some localization in soft tissue liver) if excess o: amounts of ligand are not used. A large excess of ligand is undesirable since uncomplexed ligand may be toxic to the patient or may result in cardiac arrest or hypocalcemic convulsions.

ii 15 3 Sm can be produced in several ways. In a nuclear reactor, a nuclide is bombarded with neutrons to i' obtain a radionuclide, e.g.

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1 23 J I -11- Sm-152 neutron Sm-153 gamma.

aoo 0a *o 6 .0: 0*I *L Another process for obtaining 15 3 Sm is by bombarding nuclides with linear accelerator or cyclotron-produced particles. Yet another way of obtaining 153 Sm is to isolate it from fission product mixtures. The process for obtaining 153 Sm is not 10 critical to the present invention.

For example, to irradiate Sm203 for production of Sm-153, the desired amount of target was first weighed into a quartz vial, the vial was flame sealed under vacuum and welded into an aluminum can. The can was irradiated for the desired length of time, cooled for several hours and opened remotely in a hot cell.

The quartz vial was removed and transferred to a glove box, crushed into a glass vial which was then sealed with a rubber septum and an aluminum crimp cap. One milliliter of 1 to 4M HC1 was then added to the vial via syringe to dissolve the Sm203. Once dissolved, the solution was diluted to the appropriate vo.ume by addition of water. The solution was removed from the original dissolution vial which contains chards of the crushed quartz vial and transferred via syringe to a clean glass serum vial. This solution was then used for complex preparation.

Ethylenediaminetetramethylenephosphonic acid (EDTMP) is prepared from its amine precursor containing at least one reactive amine hydrogen with a carbonyl compound (aldehyde or ketone) and phosphorous acid or derivative thereof under conditions well known a *r 0 0. *0 i:I 31: t--i i I i: ii k-: B::iM C-38,249 -11- 0 0 q 0 6 0 a a O 00 0 0 *0 0 S00 009~ 0 0 S BO aa 0 0 00 6 6 60 0 06o O 0 00 00< 0 0 e 0 0 0 0 0 *0 0> 06 -12in the art. (See for example U.S. Patents 3,726,912 and 3,398,198 and U.S. Application Serial No. 050,263, filed May 14, 1987, now allowed, the disclosure of which is hereby incorporated by referernce.) The amine precursor, e.g. ethylenediaminetetraacetic acid (EDTA), is a commercially available compound.

The toxicity of the 153 Sm-EDTMP complex of the present invention were studied in dogs [Appelbaum, F. R.

et al., Antibody, Immunoconjugates, andRadiopharm. 263- 10 270 (1988)]. Following intravenous injection, 153 Sm- EDTMP rapidly localized to bone. When administered by slow intravenous infusion, myelosuppression was the only toxicity observed. Although increasing myelosuppression was seen with increasing dose, even at 30 mCi/kg, which was estimated to deliver 3000 rad to red marrow, spontaneous marrow recovery without marrow transplantation was observed. This result is in clear contrast to results using external beam total body 20 irradiation in which doses in excess of 400 rad were invariably fatal due to the development of prolonged and profound marrow aplasia.

153 Sm-EDTMP is known as a potential agent for the therapy of calcific tumors either primary bone malignancies or malignancies metastatic to bone [see, for example, Ketring, A. Nucl. Med.Biol. 14, 223-232 (1987), Goeckler, W. F. et al., J.Nucl.Med. 28, 495-504 (1987) and our copending U.S. Patent Application Serial No. 050,263, filed May 14, 1987, now allowed, -he disclosure of which is hereby incorporated by reference]. A number of features of 153 Sm-EDTMP make it an attractive agent for this purpose, namely: 153 Sm primarily emits medium energy P particles with 810 710 and 640 keV energies which 0

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y^ a 0 *o 00 or a 9 0 *0 o 0 *6 0 0 6 penetrate over a relatively short distance, thereby allowing for selective therapy; 153 Sm also emits a 103 ke' y ray (abundance= 28%) which 153 allows for high quality scintigraphic scanning; and Sm has a half-life of about 46.8 hours which allows for flexibility in dose regimens.

Another feature of concern when using drugs for treatment of calcific bone tumors is the clearance time after administration. Biodistribution studies in rats showed that after intravenous injection, 153 Sm-EDTMP was rapidly cleared from the blood, about 50% of the injected dose localized to the skeleton, while the rest was rapidly excreted in the urine [see 10 Goeckler, N. F. et al., J.Nucl. Med. 28, 495-504 (1987), Logan, K. W. et al., J. Nucl. Med. 28, 505-509 (1987) and Australian Patent No. 563 671, the disclosure of which is hereby incorporated by reference]. Within the Sskeleton, differential uptake of 153 Sm-EDTMP was demonstrated in bone S lesions using a drill-hole technique as well as in osseous metastatic T5 lesions and primary osteosarcomas. Lesion to normal bone ratios of between Sfrom about 4:1 to 15:1 have been reported [see Goeckler, W. F. et al., J.

Nucl. Med. 28, 495-504 (1987) and Corwin, L. A. et al., J. Nucl.Med. 27, 986-987 (1986)]. This pattern of distribution is very different from that 153 of unchelated ionic 153 Sm which localizes to liver, lung and spleen after 20 Intravenous injection [see Goeckler, N. F. et al., J. Nucl. Med. 28, 495-504 (1987)]. Thus the physical characteristics of the radionuclide and 153 the invivo behavior of the chelate suggest that 1 Sm-EDTMP could be quite effective to treat calcific tumors either primary bone malignancies S or malignancies metastatic to bone.

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t' A possible potential limitation of 153 Sm-EDTMP therapy for calcific tumors is bone marrow toxicity. Bone marrow is contiguous with bone and therefore could receive a substantial dose of rediation following therapy.

Logan et al. [J.Nucl.Med. 28, 505-509 (1987)] predicted that an average adult would receive 3.82 rad per millicurie 'mCi) to red marrow following injection of 153 Sm-EDTMP. If accurate, this amount of radiation would substantially limit the dose of 153 Sm-EDTMP that could be used therapeutically. Therefore, the following examples show the results of 153 Sm-EDTMP on hemapoiesis in dogs.

10 The possible additional use of 1 53 Sm-EDTMP to deliver radiotherapy

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relatively specifically to bone marrow prior to bone marrow transplantation for marrow based diseases such as thalassemia, preleukemia and acute and chronic leukemia, has been discussed by Appelbaum, F. R. et al., Antibody, S Immunoconjugates, and Radiopharmaceuticals 263-270 (1988) and 15 Australian Patent No. 563 671.

The invention will be further clarified by a consideration of the following examples, which are intended to be purely exemplary of the present invention.

The complexes employed in the examples are prepared as described in Australian Patent No. 563 671.

26 In the following examples, Beagles or Harriers, raised at the Fred Hutchinson Cancer Research Center or bought from commercial kennels, were Sdewormed, vaccinated against distemper, hepatitis, leptospirosis, and Parvovirus, and observed for disease for at least two months. The dogs weighed 7-12 kg and were 7-18 months of age at the time of treatment.

25 Research was conducted according to the principles enunciated in

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9- ~11 "Guide for Laboratory Animal Facilities and Care" prepared by the Nat' .nal Academy of Sciences-National Research Council. ine research protocol was approved by the Internal Animal Care and Use Committee of the Fred Hutchinson Cancer Research Center.

Example 1 i "Ova aa 6 0, o 9 *e 9,, 04 0*00 a *c S 94 0 0 a 9 a 49 9 *9 4D Sa 4 Sa 9e The biodistribution of 153 Sm-EDTMP was determined by injecting normal beagles with 10 approximately 4 mCi of 153 Sm-EDTMP. The animals were imaged over the first three hours and again at 24 hours.

Immediately after the 24 hour imaging the animals were sacrificed. Excised tissues were washed with normal saline, blotted, and weighed prior to counting. The samples were counted using a gamma scintillation counter, using the 103 keV gamma photon of 153 Sm-EDTMP and comparing it to a known standard.

When the images of a dog given 153 Sm-EDTMP were 20 observed 10 minutes after injection, the cardiac blood pool and kidneys were quite visible. Over the next minutes, there was progressive clearing of the cardiac and renal activity as seen by anterior gamma camera 25 images at 10, 20, 30, 40, 60 and 90 minutes, so that minutes after injection most activity was localized to the skeleton and bladder. Quantitative biodistribution at 24 hours, as determined by actual measurement of separate tissues in 2 dogs, is presented in the following Table I.

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J it r -16- TABLE I Uptake of 15 3 Sm-EDTMP 24 hours after injection Organ Injected Bone/Tissue Organ Activity/gmil

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Bone 0.27 1 Kidney 0.0032 84 Liver 0.0028 96 Colon 0.00055 490 Spleen 0.00045 600 Bladdet 0.00041 658 Lung 0.00036 750 Lymph node 0.00025 1080 Heart 0.00018 1500 Ad r rial 0.000095 2842 Pancreas 0.000053 5094 Muscle 0.000027 10000 Blood 0.000013 20769 1 values represMntthe mean of the injected dose per g of tissue; 2 animals were studied with 4 samples per animal As shown, bone had 84 times more activity than liver, and even higher ratios to all other organs.

Example 2 n

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Macroscopic autoradiography was performed using standard techniques. Briefly, bone was sectioned with an Alsomet"' low-speed saw and exposed to Kodax X- OMATAR'" film and routinely developed. It was observed that 153 Sm-EDTMP distributed throughout the trabecular bone of the femoral head. A cross section of the femoral neck also showed deposition of 153 Sm-EDTMP in C-38,249 -16i: I t -17trabecular bone, while a cross section of femoral midshaft, a location devoid of trabecular bone, showed activity along the nutrient arteries and along the inner surface of the cancellous bone but no activity in the lumen of the midshaft.

Example 3 Normal dogs were given varying activities of 153 Sm-EDTMP via a leg vein by intravenous infusion over 10 minutes using an Isoned infusion pump. Starting on the day of infusion, all dogs were placed on oral p* nonabsorbable antibiotics (polymyxin and neomycin) and intravenous antibiotics (ampicillin and Amikacin), using the procedure described by Appelbaum, F. R. et al, 15 Transplantation (1989). Complete blood counts including hematocrit, white blood cell count, differential, and platelet counts were obtained daily until recovery of blood counts. Jamshidi needle biopsies of marrow were obtained on days 7, 14, 21 and 28 following therapy.

20 4 Six animals were given 4, 6, 8, 10, 15 and SmCi/kg of 153 Sm-EDTMP. As shown in Table II following, Sincreasing myelosuppression was seen with increasing dose. But even at 30 mCi, a dose calculated to deliver over 3000 rad to red marrow, both leukocytes and S° platelets began recovering from the postradiotherapy nadir within 14 days of therapy.

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C-38,249 -17- 4 -18- TABLE II Myelosuppression Associated with 15 3 Sm-EDTMP Dog mCi/kg tl/2 in Estimated WBC PLT Dog 153Sm marrow rad toVVBC

PLT

No. 1 P (Sm- marrow ra to red nadir/day2 nadir/day 2 EDTMP (hrs.)I marrow 1 4.1 42 422 2000/9 7000/19 2 6.0 41 646 1300/6 25000/14 3 8.0 42 859 1100/8 8200/19 4 10.5 48 1081 130/9 4200/20 15.3 41 1579 970/9 4200/11 6 29.3 ND 3024 600/8 1000/16 Ct t C tt CC I t t 1 Half-life of 153Sm in marrow as determined by sequential marrow biopsies; ND not determined ml) Ii 33 Li rer C I f

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4 9** 20 2 Nadir of white blood cells (WBC) and platelets (PLT) per mm 3 and the day post treatment in which the nadir was seen Jamshidi needle biopsies of marrow in the region of the 25 humeral head were performed weekly on these animals.

The results in Table III following show that the marrow in this region became aplastic by day 7 in all animals receiving 6 mCi or more.

C-38,249 -18- -19- TABLE III Marrow Biopsy Results Following Administration of 1 5 3 Sm-EDTMP V t# I t 0 o @5 S* o f @5 I @51« I a* 0 ?i: 15 1 5 3 Sm- Marrow cellularityl Dog EDTMP No mCi/kg 7 14 21 28 1 4.1 75 0 0 2 6.0 0 10 50 3 8.0 0 0 4 10.5 0 0 10 5 15.3 0 0 0 0 6 293 0 S% of normal cellularity on the given days post injection Interestingly, in the animals receiving the higher doses 20 of 153 Sm-EDTMP, the marrow biopsy from the humeral head remained aplastic by day 28 even though peripheral blood counts recovered to normal by this time. This finding led to the following test to determine whether the marrow function was recovering in areas of nontrabecular 25 bone.

Three animals were given 15 mCi/kg of 153 Sm- EDTMP and then sacrificed at 1, 2 and 3 weeks after treatment, respectively. At days 7, 14 and 21, the marrow space surrounding trabecular bone was essentially aplastic. However, the marrow space in the midshaft, an area which normally supports little marrow function, by day 14 showed modest hematopoiesis and by day 21 displayed abundant hematopoiesis.

C-38,249 -19i-, with at least one acid group of EDTMPadhihwl not cause a significant adverse physiological effect C-38,249 1 Example 14 "S"1 factor for 153 Sm in an adult human have been previously determined [Logan, W. et al, J. Nucl.

Med. 28, 505-509 (1987)1. These volumes were adapted for use in a 9.4 kg infant using known organ geometry and organ mass. In addition,--it-was assumed that the activity was localized to bone surfaces only, rather than uniformly distributed in bone tissue. Based on these estimates, 153 Sm-EDTMP should deliver to red 10marrow 11 rad/mCi injected dose in a 9.14 kg infant.

Beagles of varying weights were assumed to receive a 4: linearly proportionate dose based on weight.

9 00 0 aa V'0 Example 15 Twenty patients with hormone-refractory, bonedominant prostate carcinomas were treated with 13m 'FDTMP in a single dose, escalating approach with 14 patients entered in each dose level until grade 3 tor-icity was observed in 2 of 14 patients. Patients with pathologic bone fractures, spinal cord compression, obvious soft tissue metastasis, more than one prior regimen of chemotherapy or maximum tolerated radiation to the spine were not 1,iligible for this study. All a radiation and chemotherapy must have been completed 14 weeks prior to entry in this study. Clinical monitoring included serial evaluation of complete blood counts, prostrate specific antigen (PSA), bone scans, performance status and pain. Pain was assessed by a daily diary and by the treating physician. Dose levels studied were 1.0, 1.5, 2.0, 2.5, and 3.0 mCi/kg, with all patients hospitalized until residual radioactivity met safety standards for discharge (about 1-2 nights). All patients had indwelling catheters and .a J _4U_

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a a p4 0 I a -21 bladder irrigation to minimize dose to the bladder as 153 Srri-EDTMP is renally excreted.

Only hematologic toxicity has been observed.

At 1.0 to 2.0 mCi/kg, 6 of 12 patients had a nadir absolute poly count (APC) of 1,500, and 3 of 12 patients had a nadir APC of <1,000, with 1 of 12 patients who had nadir platelets-of <50,000. At 2.5 to mCi /kg, 7 of 8 patients had a nadir APC of 1,500, and 3 of-8 patients had a nadir APC of <1,000, with 2 10 of 8 who had nadir platelets of <50,000. No infectious or bleeding complications occurred, and blood count recovery has been complete for all patients at 6 weeks.

Median age of patients treated was 69 (range 57 to 84).

15 PS was 0-1 in 14 patients, and 2-3 in 6 patients. Of 19 patients evaluative for pain response, 10 had complete relief and 7 partial relief, with pain response seen at all dose levels. Serial PSA decreased in 7 patients was stable in 4 patients and 20 demonstrated progressive elevation in 9 patients over the period of study. Remaining on the study at 3 to 9+ months are 9 patients, and 11 patients are now off study with symptomatic progressions. The median time to progression is 3+ months (range 1 to 6+ months).

Other embodiments of the invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. It is intended that the 30 specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

21 c~

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C-38,249 -1 -21-

Claims (32)

1. A sterile composition suitable for administration to an animal comprising 1) a complex which comprises Sm-153 and ethylenediaminetetra- methylenephosphonic acid or a physiologically acceptable salt thereof and 2) ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof, in excess of that required to make the complex, and wherein the resulting composition is therapeutically effective, having a high therapeutic index and wherein the Sm-153 in dosage form is present in an amount containing greater than 2 mCi per kilogram of body weight of said animal.

2. The composition of Claim 1 wherein a physiologically acceptable liquid carrier is present.

3. The composition of Claim 2 wherein the physiologically acceptable liquid carrier is water and the resulting solution is adjusted to have a pH of about 7 to about 8.

4. The composition of any one of Claims 1 to 3 wherein the therapeutic index is greater than The composition of any one of Claims 1 to 4 wherein the cog* 04 00 a 0 0 Ce C OI 600 t o Cn C( 0 C 9 C therapeutic index is greater than 8.

6. The composition of any one of Claims 1 Co o therapeutic index is greater than 9.

7. The composition of any one of Claims 1 therapeutic index is about

8. The composition of any one of Claims 1 in dosage form is present in an amount containing 30 mCi/kg of body weight of an animal. to 5 wherein the to 6 wherein the to 7 wherein greater than to 8 wherein from greater the Sm-153 2 to about the Sm-153 than 2 to a $o 9. The in dosage form about 3 mCi/kg The in dosage form 2.7 mCi/kg of

11. The in dosage form composition of is present in of body weight composition of is present in body weight of composition of is present in any one of Claims 1 an amount containing of an animal. any one of Claims 1 an amount containing an animal. any one of Claims 1 an amount containing to 9 wherein the Sm-153 from about 2.1 to about to 10 wherein the Sm-153 from about 2.3 to about of an animal having one mCi/kg of body weight of an animal.

12. A method for the therapeutic treatment or more calcific tumors which comprises administering to said animal a GSA/1554W 1 ii r Y i ii;, i. I 23 therapeutically effective amount of a composition comprising 1) a complex which comprises Sm-153 and ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof and 2) ethylenediaminetetra- methylenephosphonic acid or a physiologically acceptable salt thereof, in excess of that required to make the complex, and wherein the resulting composition is therapeutically effective, having a high therapeutic index and wherein the Sm-153 in dosage form is present in an amount containing greater than 2 mCi per kilogram of body weight of said animal.

13. The method of Claim 12 wherein the animal is a human.

14. The method of Claim 12 or Claim 13 wherein a physiologically acceptable liquid carrier is present.

15. The method of Claim 14 wherein the physiologically acceptable liquid carrier is water and the resulting solution is adjusted to have a pH 8 9 49 4 994 4 c9 C'l 4 9 9 9 04 49~ 9 4 44 o 4. *s 9 of about 7 to about 8.

16. The method of any one of index is greater than

17. The method of any one of index is greater than 8.

18. The method of any one of index is greater than 9.

19. The method of any one of index is about Claims 12 to 15 wherein the therapeutic Claims 12 to 15 wherein the therapeutic Claims 12 to 15 wherein the therapeutic Claims 12 to 15 wherein the therapeutic 99 8* 4a 9. s I 's 4 8i 89 9 88I 4 4. The method of any one of Cidlms 12 to 19 dosage form is present in an amount containing greal mCi/kg of body weight of an animal.

21. The method of any one of Claims 12 to 19 dosage form is present in an amount containing from 3 mCi/kg of body weight of an animal.

22. The method of any one of Claims 12 to 19 dosage form is present in an amount containing from mCl/kg of body weight of an animal.

23. The method of any one of Claims 12 to 19 dosage form is present in an amount containing from mCi/kg of body weight of an animal.

24. The method of any one of Claims 12 to 23 Is administered in a single dose. wherr n :er than wherein greater the Sm-153 in 2 to about the Sm-153 in than 2 to about wherein the Sm-153 in about 2.1 to about 2.7 wherein the Sm-153 in about 2.3 to about wherein the composition GSA/1554W L a 8 8t o a. r a 24 The method of any one of Claims 12 to 23 wherein the composition is administered in multiple doses.

26. A method for the therapeutic treatment of an animal having bone pain which comprises administering to said animal a therapeutically effective amount of a composition comprising 1) a complex which comprises Sm-153 and ethylenediaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof and 2) ethylenedlaminetetramethylenephosphonic acid or a physiologically acceptable salt thereof, in excess of that required to make the complex, and wherein the resulting composition is therapeutically effective, having a high therapeutic index and wherein the Sm-153 in dosageform s present in an amount containing greater than 2 mCi per kilogram of body weight of said animal.

27. The method of Claim 26 wherein a physiologically acceptable liquid carrier is present.

28. The method of Claim 27 wherein the physiologically acceptable liquid carrier is water and the resulting solution is adjusted to have a pH of about 7 to about 8.

29. The method of any one of index is greater than

30. The method of any one of index is greater than 8.

31. The method of any one of index is greater than 9. Claims 26 to 28 wherein the therapeutic Claims 26 to 28 wherein the therapeutic Claims 26 to 28 wherein the therapeutic Claims 26 to 28 wherein the therapeutic 32. The index is about

33. The method of any one of method of any one of Claims 26 to 32 wherein t dosage form is present in an amount containing greater than mCi/kg of body weight of an animal.

34. The method of any one of Claims 26 to 32 wherein dosage form is present in an amount containing from greater 3 mCi/kg of body weight of an animal. The method of any one of Claims 26 to 32 wherein dosage form is present in an amount containing from about 2 of body weight of an animal.

36. The method of any one of Claims 26 to 32 wherein dosage form is present in an amount containing from about 2 the Sm-153 in 2 to about the Sm-153 in than 2 to about the Sm-153 in .1 co 2.7 mCi/kg the Sm-153 in .3 to about GSA/1554W L i-i V l 25 mCi/kg of body weight of an animal.

37. The method of any one of Claims 26 to 36 wherein the composition is administered in a single dose.

38. The method of any one of Claims 26 to 36 wherein the composition Is administered in multiple doses.

39. A sterile composition suitable for administration to an animal, as defined in claim 1 and substantially as hereinbefore described with reference to any one of the Examples. 0 0 a3 a)0 DATED this NINETEENTH day of DECEMBER 1990 The Dow Chemical Company Patent Attorneys for the Applicant SPRUSON FERGUSON 0 0 o 0 8 4 4I 0 a s 0I A 0 41 *1 K I,' GSA/1554W I' i