Conjugate and its use as an imaging agent

Abstract

A compound according to formula (I), wherein A is -As(OH) or an arsenoxide equivalent group; each of R, R, R, and R is independently selected from H, X, OH, NH, CO, SCN, -CHNH, -NHCOCH, -NHCOCHX, or NO; X is a halogen; R is -NHCHCOOH, OH, or OR; and R is C. 1-5 The present invention relates to compounds, or pharmaceutically acceptable salts, esters, prodrugs, or solvates thereof, uses of said compounds, and methods of preparing said compounds, and further relates to diagnostic methods utilizing said compounds.

Description

Technical Field

[0001] The present invention relates to radiolabeled conjugates according to formula (I) defined herein and compounds according to formula (II) defined herein. The present invention further relates to the imaging of cell death, the diagnosis of conditions associated with cell death and the use of such radiolabeled conjugates in therapy, and to methods of making such radiolabeled conjugates.

Background Art

[0002] Cell death plays an essential role in cell turnover. Imbalances in cell death, characterized by a marked increase or decrease in cell death relative to cell regeneration, are often associated with disease. For example, excessive cell death is characteristic of, inter alia, vascular disorders, neurodegenerative diseases, myelodysplastic syndromes, ischemia / reperfusion injury, organ transplant rejection, and neoplastic conditions including tumors and cancer. In particular, cancer results from an imbalance between the rate of cell proliferation and the survival rate of cells within a tissue.

[0003] Therefore, visualization of cell death can be a very useful tool in the diagnosis and treatment of numerous conditions associated with abnormal levels of cell death, as well as in the evaluation and monitoring of cell death during, for example, drug development and tissue toxicity testing of certain substances. For example, in oncology, when successful treatment controls the growth of cancer cells by inhibiting cell proliferation and / or promoting cell death, the ability to directly image cell death would be highly desirable as a means of assessing the response to treatment, but is not available. Currently, in imaging for assessing treatment response in oncology, cell death is indirectly evaluated by a reduction in tumor size (by anatomical methods such as computed tomography (CT) and magnetic resonance imaging (MRI)) or a decrease in metabolic activity (most commonly glucose metabolic activity) by positron emission tomography (PET). These methods are widely used routinely in oncology, but because they indirectly assess cell death, they are affected by both false positive and false negative results. In addition, these techniques do not evaluate cell death in real time and are usually not performed until at least several weeks after the start of treatment (for example, positron emission tomography using 2-fluoro-2-deoxyglucose (FDG PET / CT) is usually not performed until after 2 cycles of chemotherapy - usually up to 6 to 8 weeks after the start of treatment). Furthermore, changes in tumor size measured by CT, such as using Response Evaluation Criteria in Solid Tumours (RECIST 1.1), are often, but not always, related to the response to treatment. Reduction in tumor size occurs slowly after the start of treatment (often taking several months) and in some cases may not occur at all despite the response to treatment. Limited attempts have been made to directly image cell death, such as using derivatives of annexin V and radiolabeled caspase 3 / 7 inhibitors, but these have been hampered by complex and expensive products, poor biodistribution, particularly high physiological uptake in blood and normal tissues / organs, particularly the liver and intestine, low tissue penetration, and the inability to reliably detect tumor cell death in response to treatment. Due to the lack of a method to reliably detect tumor cell death in response to in vivo treatment, the dynamics of cell death are not well understood.

[0004] For these reasons, a method for directly assessing tumor cell death almost in real time (within a few days from the start of treatment) may be very beneficial in clinical and research oncology.

[0005] Particularly advantageous imaging agents will, for example, enable rapid serial imaging commensurate with the time course of cell death following administration of a cancer treatment that causes tumor cell death. Such imaging agents will enable visualization of changes in cell death on a timescale that is biologically and clinically relevant. Thus, it is desirable to provide a convenient and sensitive imaging agent that enables non-invasive, effective, and accurate visualization of cell death in a manner and time frame suitable for use in the diagnosis and treatment of disease. SUMMARY OF THE INVENTION

[0006] According to a first aspect, the present disclosure provides a compound of formula (I),

Chemical formula

[0007] The compounds according to the present disclosure are useful for imaging cell death in vitro and in vivo. The compounds enable accurate, sensitive, and non-invasive detection and measurement of cell death. In particular, such compounds are used in diagnosing, monitoring, and evaluating the treatment of various disorders and conditions where cell death is a relevant factor. The radiolabeled compounds of the present invention are readily synthesizable for in vivo use, exhibit favorable biodistribution, imaging properties, and dosimetry, and enable visualization of cell death on a clinically appropriate time scale due to the half-life of the radioisotope used.

[0008] In some embodiments, each of R1, R2, R3, and R4 is H. In some embodiments, R5 is NHCH2COOH. In some embodiments, the compound is a compound according to formula (Ia),

Chemical formula

[0009] In some embodiments, Z has a half-life of less than 1 day. In some embodiments, Z has a half-life of less than 4 hours. In some embodiments, Z has a half-life of less than 2 hours. In some embodiments, Z is 68 Ga.

[0010] 68 Ga has a half-life of 68 minutes, which means it is particularly useful for visualization of cell death by PET, and using such short-lived positron-emitting radioisotopes enables high-frequency serial and quantitative imaging.

[0011] Particularly preferred compounds are compounds according to formula (I), wherein Z is 68A compound wherein it is Ga, R1-R4 are H, R5 is -NHCH2COOH, and A is As(OH)2. Such embodiments offer the aforementioned advantages of being easily synthesized, readily available from affordable starting materials, having good biodistribution, low uptake in normal organs, favorable imaging properties, preferable dosimetry, and a short half-life suitable for continuous repeated imaging by positron emission tomography.

[0012] The present disclosure provides a compound according to a first aspect for use as an imaging agent, for example, for use as an imaging agent in positron emission tomography. In certain embodiments, the present disclosure provides a compound according to a first aspect for use in visualizing cell death.

[0013] According to a second aspect, the present disclosure provides a pharmaceutical composition comprising a compound according to a first aspect together with a pharmaceutically acceptable carrier, excipient, diluent, vehicle, and / or adjuvant.

[0014] According to a third aspect, the present disclosure provides a compound according to formula (II),

Chemical formula

[0015] In some embodiments, each of R1, R2, R3, and R4 is H. In some embodiments, R5 is NHCH2COOH. In some embodiments, the compound according to formula (II) is a compound according to formula (IIa), [Chemical formula] A is a compound as defined for formula (II), or a pharmaceutically acceptable salt, ester, prodrug, or solvate thereof.

[0016] According to a fourth aspect, the present disclosure provides the use of a compound according to the first aspect as an imaging agent. The imaging agent can be used in positron emission tomography. The imaging agent can be used to visualize cell death.

[0017] According to a fifth aspect, the present disclosure provides a compound of the first aspect for use in a therapy. The compound can be for use in the treatment of conditions associated with changes in cell death and / or for a treatment that results in a change in cell death.

[0018] According to a sixth aspect, the present disclosure provides a compound of the first aspect for use in in vivo diagnosis. This compound can be for use in the diagnosis of conditions associated with changes in cell death and / or for a treatment that results in a change in cell death.

[0019] The compound for use according to the fifth or sixth aspect can be for use in the treatment or diagnosis of a neoplastic condition or an autoimmune condition. The neoplastic condition can be a tumor. The neoplastic condition can be cancer.

[0020] According to a seventh aspect, the present disclosure provides a method for diagnosing or treating a condition in a subject related to a change in cell death and / or a condition whose treatment results in a change in cell death or visualizing cell death in a subject, the method comprising administering an effective amount of a compound according to a first aspect. In some embodiments, the condition is a neoplastic condition or an autoimmune condition. The method may further comprise performing positron emission tomography on the subject after administration of the compound according to the first aspect. After administration of the compound according to the first aspect, a plurality of positron emission tomography images may be collected. In some embodiments, collection of the plurality of images may enable a more accurate and quantifiable assessment of cell death to be performed, since a difference in cell death over a predetermined period rather than an absolute value may be determined.

[0021] The compound according to the first aspect may be administered intravenously.

[0022] In the method according to the seventh aspect, the neoplastic condition may be a tumor. The neoplastic condition may be cancer.

[0023] According to an eighth aspect, the present disclosure provides a method for evaluating a subject's response to a treatment method aimed at causing a change in the level of cell death, the method comprising performing the treatment method, administering a compound according to the first aspect, and visualizing cell death. In some embodiments, cell death is visualized by performing positron emission tomography on the subject. In some embodiments, the treatment method is chemotherapy, radiation therapy, targeted therapy, or immunotherapy, or a combination thereof.

[0024] According to a ninth aspect, the present disclosure provides a process for preparing a compound according to the first aspect wherein Z is 68 Ga, the process comprising eluting 68 Ga onto a strong cation exchange column and eluting the strong cation exchange column with a mixture comprising a compound according to formula (II) and a buffer, the buffer having a pH of about 4.5.

[0025] Exemplary embodiments of the present disclosure will be described herein by way of non-limiting examples only with reference to the following drawings.

Brief Description of the Drawings

[0026]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0027] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, representative methods and materials are described.

[0028] Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated step or element or integer or group of steps or elements or integers but not the exclusion of any other step or element or integer or group of elements or integers. Thus, in the context of this specification, the term "comprising" means "including principally but not necessarily solely".

[0029] In the context of this specification, the terms "a" and "an" denote one or more than one (i.e., at least one) of the grammatical objects of the article. By way of example, "an element" means one element or more than one element.

[0030] In the context of this specification, the term "about" is understood to denote a range of numbers that a person of ordinary skill in the art would consider equivalent in achieving the same function or result.

[0031] In the context of this specification, references to a range of numbers disclosed herein (e.g., 1 to 10) include references to all rational numbers within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10), and references to any range of rational numbers within that range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7). Thus, all partial ranges of the entire range explicitly disclosed herein are hereby explicitly disclosed in this specification. These are merely examples of what is specifically intended, and all possible combinations of numerical values between the recited minimum and maximum values are considered to be explicitly recited in this application in a similar manner.

[0032] As used herein, the term "and / or" means "and" or "or" or both.

[0033] As used herein, the term "subject" refers to any mammal including, but not limited to, livestock and other farm animals (such as cows, goats, sheep, horses, pigs, and chickens), performance animals (such as racehorses), companion animals (such as cats and dogs), laboratory animals, and humans. Usually, the subject is a human.

[0034] As used herein, the terms "treating", "treatment", "treating", "reduce", "reducing", "prevent", "preventing", and "prevention", etc., include reducing the severity of an infectious disease or disorder, improving an infectious disease or disorder or at least one symptom of an infectious disease or disorder, or otherwise interfering with, delaying, or reversing its progression, and indicate any and all applications. Thus, the terms "treat", "treating", and "treatment" do not necessarily mean that a subject is treated until the infection is completely eliminated or until recovery from the disease. Similarly, the terms "prevent", "preventing", and "prevention", etc., indicate any and all applications that prevent the establishment of an infection or disorder or otherwise delay the onset of an infection or disorder.

[0035] The term "optionally" is used herein to mean that a feature described hereinafter may or may not be present, or an event or situation described hereinafter may or may not occur. Thus, this specification is understood to include and encompass embodiments in which the feature is present, embodiments in which the feature is not present, embodiments in which the event or situation occurs, and embodiments in which it does not occur.

[0036] As used herein, the terms "effective amount" and "effective dose" include, within their meaning, a non-toxic but sufficient amount or dose of a compound to provide the desired effect. The exact amount or dose required varies from subject to subject depending on factors such as the species being treated, the age and general condition of the subject, the severity of the condition being treated, the particular compound being administered, and the mode of administration. Thus, it is not possible to define an exact "effective amount" and "effective dose". However, for any particular case, the appropriate "effective amount" and "effective dose" can be determined by one of ordinary skill in the art using only routine experimentation.

[0037] In the context of this specification, the term "arsenoxide" refers to the -As=O group. Groups written as -As=O and -As(OH)2 should be regarded as synonyms.

[0038] As used herein, the term "arsenoxide equivalent" refers to any dithiol-reactive species that exhibits essentially the same affinity for dithiols as -As=O or As(OH)2. This term includes, for example, transition elements and trivalent arsenic agents that hydrolyze to -As=O or -As(OH)2 when dissolved in an aqueous medium (such as cell culture buffers and liquids contained in the organism being treated). Generally, arsenoxide equivalents include dithiol-reactive species such as As, Ge, Sn, Sb species, etc. Arsenoxide equivalents are expected to exhibit the same or substantially the same activity as the corresponding arsenoxides.

[0039] The term "bifunctional chelating agent" refers to a chemical moiety that includes a chelating moiety capable of binding to a metal or other ion, such as a radionuclide, and a chemically reactive functional group for binding to another chemical substance. In the context of this application, the term "bifunctional chelating agent" refers to both the related compound before chelation with a metal or other ion and / or before reaction at the reactive functional group, and the related compound after chelation with a metal or other ion and / or after binding to another chemical substance by the reactive functional group. The relevant definitions will be readily apparent from the context. When not chelating a metal or other ion, the bifunctional chelating agent is suitable for chelating a metal or other ion.

[0040] Terms such as "C1-C5-alkyl" as used herein refer to saturated, straight-chain, or branched-chain hydrocarbon radicals containing 1 to 3, 1 to 6, or 1 to 12 carbon atoms, respectively. Examples of C1-C5-alkyl radicals include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl.

[0041] The term "pharmaceutically acceptable salt" means a salt that is suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, etc., within the scope of sound medical judgment, and that has a reasonable benefit / risk ratio. References to a compound in this specification are to be understood to include its pharmaceutically acceptable salts, unless otherwise specified or the context otherwise requires.

[0042] In this specification, a compound according to formula (X),

Chemical formula

[0043] In some embodiments, the compound according to formula (X) is a compound according to formula (Xa), or a pharmaceutically acceptable salt, ester, prodrug, or solvate thereof.

Chemical formula

[0044] The present disclosure relates to a compound according to formula (I),

Chemical formula

Chemical formula

[0045] In the compounds suitable for use in the present invention, the arsenoxide group (-As(OH)2) can generally be replaced by an arsenoxide equivalent.

[0046] Such compounds are based on 4-(N-(S-glutathionylacetyl)amino)phenylarsenous acid (GSAO) radiolabeled with a radioactive isotope using a bifunctional chelating agent. In particularly preferred embodiments, the bifunctional chelating agent is 2,2'-(7-(1-carboxy-4((2,5-dioxopyrrolidin-1-yl)oxy)-4-oxobutyl)-1,4,7-triazonane-1,4-diyl)diacetic acid (NODAGA) as shown in formula (I) and formula (Ia).

[0047] GSAO undergoes specific uptake into dead and dying cells. Without wishing to be bound by theory, it is thought that GSAO is retained within the cytosol of dying and dead cells via the formation of a covalent bond between As(III) ions and the thiol groups of proximal cysteine residues. GSAO is a trivalent As(III) peptide and has been found to activate the mitochondrial membrane permeability transition pore. GSAO is toxic to proliferating cells and inhibits angiogenesis in vivo (Don AS, Kisker O, Dilda P et al (2003) A peptide trivalent arsenical inhibits tumor angiogenesis by perturbing mitochondrial function in angiogenic endothelial cells. Cancer Cell 3:497-509), but is non-toxic to quiescent endothelial cells in vitro. The conjugation of a fluorophore or radionuclide to the γ-glutamyl residue of GSAO, as in the present invention, results in the loss of its anti-angiogenic effect and an increased ability to identify dying cells. When the integrity of the plasma membrane is compromised, the GSAO conjugate enters and binds to intracellular proteins, mainly the 90 kDa heat shock protein (Hsp90) (Park D, Don AS, Massamiri T et al (2011) Non-invasive imaging of cell death using an Hsp90 ligand. J Am Chem Soc 133:2832-2835). This protein is very abundant in the cytosol and is only accessible when the cell membrane integrity is compromised during cell death and is upregulated in many malignancies (Hahn JS. The Hsp90 chaperone machinery: from structure to drug development. BMB Rep. 2009;42(10):623-30). The As(III) motif of GSAO cross-links the unpaired thiols of Cys597 and Cys598 of Hsp90 to form a stable cyclic dithioarsenite.

[0048] Accordingly, the compounds according to the present disclosure labeled with a radionuclide moiety are useful for imaging cell death in vitro and in vivo. In particular, the radiolabeled conjugates described herein can be used in the diagnosis, treatment, and monitoring of conditions associated with changes in cell death, such as neoplastic disorders or autoimmune disorders, such as tumors, or cancers, for example. The radiolabeled compounds of the invention are readily synthesizable for in vivo use using readily available and affordable materials, exhibit favorable biodistribution and imaging properties and dosimetry, and provide one or more advantages as a non-invasive means of imaging and measuring cell death. Embodiments of the present disclosure enable imaging of treatment response earlier and in situations that were previously impossible, such as very early stages after initiation of therapy, and enable image-guided personalized therapy that is currently impossible due to insufficient accuracy or speed of existing imaging modalities.

[0049] The use of radioisotopes with a half-life of less than 4 days in the compounds of the present disclosure enables the assessment of cell death on a practical and clinically appropriate time scale. Z can be, for example, 11 C, 64 Cu, 13 N, 15 O, {Al 18 F} 2+ , 68 Ga, 89 Zr, 82 Rb, or 99 mTc. In a preferred embodiment, Z has a half-life of less than 1 day, such as less than 12 hours, such as less than 8 hours, such as less than 6 hours, such as less than 4 hours, or such as less than 2 hours. In a preferred embodiment, the compounds of the present disclosure are suitable for use in positron emission tomography (PET). In a particularly preferred embodiment, Z is 68 Ga. 68The half-life of Ga is 68 minutes, which means it is particularly useful for visualizing cell death by PET. Using such a short-lived positron-emitting radioisotope enables imaging on a practical and clinically appropriate time scale (i.e., a long waiting time after administration is not required to acquire an image). Furthermore, such a short half-life allows for high-frequency serial and quantitative imaging in some cases. That is, repeated imaging can be performed to record the exact changes in cell death over time, for example, before and after administration of a chemotherapeutic agent, or other treatments that induce cell death such as radiation therapy, targeted therapy, or immunotherapy, or combinations thereof. Repeated measurements of the same subject enable a more accurate assessment of cell death compared to a single measurement made with reference to a standard value or image from different subjects. In contrast, using an isotope with a much longer half-life requires waiting several weeks between administration and imaging when visualizing any changes in cell death. In some preferred alternative embodiments, Z is {Al 18 F} 2+ . Such radioisotopes are particularly advantageous because 18 F is widely available, has a half-life (109.7 minutes) short enough to be particularly useful in positron emission tomography as described above, and long enough to facilitate the production and distribution of products containing radioisotopes with substantially no decay.

[0050] In a particularly preferred embodiment, the compound according to formula I is 68 Ga-NODAGA-GSAO (i.e., Z is 68 Ga, R1-R4 are H, R5 is -NHCH2COOH, and A is As(OH)2 in the compound of formula I). Such an embodiment is easily synthesized, is synthesized from readily available and affordable starting materials, exhibits good biodistribution, low uptake in normal organs, favorable imaging characteristics, and favorable dosimetry, is non-invasive in use, and provides the advantage of a short half-life suitable for serial repeated imaging by positron emission tomography and imaging on a clinically appropriate and practical time scale.

[0051] According to another aspect, the present disclosure further provides a compound according to formula (Y), wherein [Chemical formula] A is -As(OH)2 or an arsenoxide equivalent group, each of R1, R2, R3, and R4 is independently selected from H, X, OH, NH2, CO, SCN, -CH2NH, -NHCOCH3, -NHCOCH2X, or NO, X is a halogen, R5 is -NHCH2COOH, OH, or OR6, and R6 is C 1-5 a straight-chain or branched alkyl group, and L is a compound that is a bifunctional chelating agent, or a pharmaceutically acceptable salt, ester, prodrug, or solvate thereof.

[0052] In some preferred embodiments, the compound according to formula (Y) is a compound according to formula (Ya). [Chemical formula]

[0053] The present disclosure provides a compound according to formula (Y) that is a compound according to formula II, wherein [Chemical formula] A is -As(OH)2 or an arsenoxide equivalent group, each of R1, R2, R3, and R4 is independently selected from H, X, OH, NH2, CO, SCN, -CH2NH, -NHCOCH3, -NHCOCH2X, or NO, X is a halogen, R5 is -NHCH2COOH, OH, or OR6, and R6 is C 1-5 a straight-chain or branched alkyl group, or a pharmaceutically acceptable salt, ester, prodrug, or solvate thereof.

[0054] The compounds of formula (Y) are useful in the synthesis of compounds of formula (X). In particular, the compounds according to formula (II) are useful in the synthesis of compounds according to formula I by radiolabeling of the NODAGA group. Such synthesis uses NODAGA-GSAO as a starting material.68 Ga is exemplified as the radioisotope and is schematically represented in the following Scheme 1. [Chemistry]

[0055] In a preferred embodiment, each of R1, R2, R3, and R4 is H. In a more preferred embodiment, R5 is -NHCH2COOH. In a particularly preferred embodiment, the compound is a compound according to formula (IIa), [Chemistry] A is a compound as defined for formula (II), or a pharmaceutically acceptable salt, ester, prodrug, or solvate thereof.

[0056] In a preferred embodiment, A is the arsenoxide group As(OH)2.

[0057] In compounds suitable for use in the present invention, the arsenoxide group (-As(OH)2) can generally be replaced by arsenoxide equivalents.

[0058] The present disclosure provides a process for preparing a compound according to formula (I) comprising mixing a radioisotope having a half-life of less than 4 days with a compound according to formula (II), wherein the compound of formula (I) or formula (II) can be any of those described above. In a preferred embodiment, the mixing is carried out at room temperature, i.e., without heating. The present disclosure relates to a process for preparing a compound according to formula (I) wherein Z is 68 Ga and comprising 68Eluting Ga onto a strong cation exchange column and eluting the strong cation exchange column with a mixture containing the compound of formula (II) and a buffer, the buffer having a pH of about 4.5, provides a process. In some embodiments, the mixing is carried out at room temperature, i.e., without heating. In some embodiments, the compounds of formula (I) and formula (II) are the compounds of formula (Ia) and formula (IIa), respectively. The present disclosure further provides a process for preparing a compound of formula (X), which comprises mixing a radioisotope having a half-life of less than 4 days with a compound of formula (Y), wherein the compound of formula (X) or formula (Y) can be any of those described above. In preferred embodiments, the mixing is carried out at room temperature, i.e., without heating. The present disclosure, where Z is 68 A process for preparing a compound of formula (X) wherein Z is 68 Ga, which comprises eluting Ga onto a strong cation exchange column and eluting the strong cation exchange column with a mixture containing a compound of formula (Y) and a buffer, the buffer having a pH of about 4.5, provides a process. In some embodiments, the mixing is carried out at room temperature, i.e., without heating.

[0059] The present disclosure further provides a pharmaceutical composition and / or therapeutic formulation, i.e., a compound of the present disclosure in the presence of a pharmaceutically acceptable carrier, excipient, diluent, and / or vehicle.

[0060] For medical use, salts of the compounds according to the present disclosure may be used, and the salts include pharmaceutically acceptable salts, but other salts may also be used in the preparation of the compound or its pharmaceutically acceptable salts. Pharmaceutically acceptable salts mean salts that are suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic reaction, etc., within the scope of sound medical judgment, and that exhibit a reasonable benefit / risk ratio.

[0061] Pharmaceutically acceptable salts are well known in the art.

[0062] For example, suitable pharmaceutically acceptable salts of the compounds of the present disclosure can be prepared by mixing a pharmaceutically acceptable acid such as hydrochloric acid, sulfuric acid, methanesulfonic acid, succinic acid, fumaric acid, maleic acid, benzoic acid, phosphoric acid, acetic acid, oxalic acid, carbonic acid, tartaric acid, or citric acid with the compounds of the present invention. Accordingly, suitable pharmaceutically acceptable salts of the compounds of the present disclosure include acid addition salts.

[0063] For example, S. M. Berge et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66: 1-19. The salts can be prepared in vivo in situ during the final isolation and purification of the compounds of the present disclosure or separately by reacting the free base functional groups with suitable organic acids. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecyl sulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxyethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate, etc. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, etc., and non-toxic ammonium, quaternary ammonium, and amine cations, including, but not limited to, ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, etc.

[0064] In addition, the present disclosure provides prodrugs. Generally, a prodrug is a functional derivative of a compound of the present disclosure that is readily convertible in vivo to the required (active) compound of the present disclosure, such as an imaging agent, a therapeutic agent, and / or a diagnostic agent.

[0065] General procedures for the selection and preparation of prodrugs are known to those skilled in the art and are described, for example, in H. Bundgaard (Ed), Design of Prodrugs, Elsevier, 1985.

[0066] Intermediates and final products can be worked up and / or purified by standard methods, for example, using chromatography, partitioning, (re)crystallization, etc. Compounds including their salts can also be obtained in the form of solvates, especially hydrates. In the context of the present invention, a solvate refers to a form of a compound according to the present disclosure that forms a complex by coordination with solvent molecules in the solid or liquid state. A hydrate is a specific form of a solvate by coordination with water. The crystals of the present compound may include, for example, the solvent used for crystallization. Different crystal forms may exist.

[0067] The present disclosure also relates to a form of a process for preparing a compound according to the present disclosure, in which a compound obtained as an intermediate at any stage of the process is used as a starting material and the remaining process steps are carried out, or the starting material is formed under reaction conditions or is used in the form of a derivative, for example, a protected form or a salt form, or a compound obtained by the method according to the present invention is produced under process conditions and further processed in situ in vivo.

[0068] Single or multiple administrations of the compound or pharmaceutical composition can be carried out at dosage levels and patterns selected by the treating physician. However, the compound or pharmaceutical composition of the present disclosure should provide a sufficient amount of the compound to effectively treat or diagnose a patient or to visualize cell death in a subject.

[0069] One of ordinary skill in the art can determine, through routine experimentation, an effective and non-toxic amount of the compounds or pharmaceutical compositions used in the present invention that is required for the detection of cells undergoing cell death and / or the treatment or prevention of the disorders and diseases disclosed herein.

[0070] The compounds of the present disclosure can be administered at a dosage of, for example, up to 300 μg, for example up to 250 μg, for example up to 200 μg, for example up to 150 μg, for example up to 100 μg, for example up to 50 μg. In some embodiments, the compounds of the present disclosure are administered at a dosage of less than 50 μg, for example, at a dosage of 10 to 50 μg.

[0071] The compounds of the present disclosure can be administered alone, but it is generally preferred to administer the compounds as a pharmaceutical composition / formulation. Generally, the pharmaceutical formulations of the compounds of the present disclosure can be prepared according to methods known to those of ordinary skill in the art, and thus may contain pharmaceutically acceptable carriers, excipients, diluents, vehicles, and / or adjuvants.

[0072] Carriers, excipients, diluents, vehicles, and adjuvants need to be "acceptable" in that they are compatible with the other components of the formulation and not harmful to its recipient.

[0073] In some embodiments, the pharmaceutical compositions of the present disclosure contain a compound according to the present disclosure and one or more other components selected from ascorbic acid, sodium, phosphate, acetate, and chloride. In some embodiments, the pharmaceutical composition contains all such components. In a preferred form, the pharmaceutical composition of the compound of the present disclosure contains an effective amount of the compound according to the present disclosure together with a pharmaceutically acceptable carrier, diluent, and / or adjuvant, as shown in Example 3.

[0074] The pharmaceutical compositions of the present disclosure can be administered by standard routes.

[0075] In a particularly preferred embodiment, the compounds or pharmaceutical compositions of the present disclosure are administered intravenously. For administration as an injectable solution or suspension, non-toxic parenterally acceptable diluents or carriers can include Ringer's solution, isotonic saline, phosphate buffered saline, ethanol, and 1,2-propylene glycol.

[0076] The present disclosure provides compounds and compositions according to the present disclosure for use in detecting, imaging, and / or visualizing cell death. Such use can be in a therapeutic method or in vivo diagnosis, or the use can be in a subject otherwise healthy. For example, the compounds according to the present disclosure can be used to visualize cell death of a subject by positron emission tomography (PET). When administered intravenously, the compounds of the present disclosure can target dying cells and visualize them by their radiolabeling, thus providing information regarding the level of cell death in different parts of the subject. The compounds according to the present disclosure can be used to provide a measurement of cell death at a single point in time, i.e., by performing a single PET scan. In some embodiments, multiple administrations and / or scans can be performed before and after applying a stimulus that induces cell death (e.g., chemotherapy drugs, radiotherapy, targeted therapy or immunotherapy, or combinations thereof) to evaluate the change in the level of cell death before and after the application of the stimulus.

[0077] Such visualization of cell death can be used, for example, in evaluating the normal tissue toxicity of a substance, environmental conditions or activity, such as an experimental therapy. Thus, such compounds are used in research and pharmaceutical development. The compounds can be used to evaluate cell death in drug screening in animal models of cancer and other conditions. These compounds may also be used, for example, to evaluate cell death in human tissues during clinical trials, which is beneficial for patient safety and potentially enables a more rapid dose escalation regimen by providing accurate feedback on the level of cell death at a particular dose. This enables an individualized risk-adapted approach during the trial, which is useful for all patients, particularly those with altered renal or hepatic function, or patients of extreme age. The compounds of the present disclosure have specific uses in late-stage tumor clinical trials and are potentially useful for understanding overall and temporal treatment responses, such as the administration and duration of a drug. For example, when the overall response rate is relatively modest, use of the compounds can identify subpopulations that respond and enable optimization of future studies. Such use of the compounds can be useful in demonstrating to regulatory authorities a subpopulation with a superior response to increase the potential for potential regulatory and reimbursement approval.

[0078] The present specification provides compounds according to the present disclosure for use in a treatment method and for use, for example, in in vivo diagnosis by PET imaging. The use in treatment and in vivo diagnosis can be directed to any condition associated with a change in the level of cell death or a condition in which treatment results in a change in the level of cell death. A change in cell death is a change (increase or decrease) in the level of cell death expected in the area of concern in a healthy subject. For example, the compounds of the present disclosure can be used for the diagnosis of neoplastic conditions, such as tumors, such as solid tumors, and / or, for example, cancer. For example, tumors may contain high levels of cell death and can thus be visualized by using the compounds of the present disclosure. The compounds of the present disclosure can further be used in the treatment of such conditions to determine whether a treatment has been successful by enabling visualization of cell death and changes in its level in response to administration of the treatment. For example, the success of treatment of a neoplastic condition, such as a tumor or cancer, after implementation of a treatment method aimed at treating such a condition can be determined by visualization of an increase in the level of cell death at the site of the neoplastic condition by use of the compounds of the present disclosure. Similarly, the compounds of the present disclosure can be used for the diagnosis or treatment of autoimmune conditions in which autoimmunity causes cell death. Examples of autoimmune conditions include, but are not limited to, rheumatoid arthritis, systemic lupus erythematosus (SLE), multiple sclerosis, type 1 diabetes, Crohn's disease, vasculitis, and seronegative arthropathies. The compounds according to the present disclosure can be used to diagnose and / or monitor a condition and to evaluate the success of any treatment administered.

[0079] Even if a diagnosis has already been made and no treatment method has been implemented, but the condition is associated with a change in the level of cell death, the compounds of the present disclosure are used for monitoring the condition.

[0080] In the treatment of a condition associated with cell death, or a condition whose treatment causes a change in cell death, the compounds of the present disclosure can be used to adjust or modify the treatment administered, such as the intensity, type, or duration of the treatment. Measurement of cell death can indicate whether a particular treatment method is effective, and if not, another dosage or another treatment method can be employed. If effective, the treatment can be continued as needed or reduced / discontinued as needed. For example, the compounds of the present disclosure are used to visualize cell death in response to the administered treatment, and the treatment dosage can be adjusted according to the level of cell death. For example, the identification of patients with little or no tumor cell death after treatment indicates the need to increase (escalate) the dosage or duration of the current treatment or change to a more intensive or multimodal treatment in order to maximize the chance of cure or disease control. Conversely, by accurately evaluating the response early in the treatment process, it is possible to reduce either the treatment duration or the treatment intensity of responsive cancer patients in order to avoid treatment-related morbidity and death without compromising the chance of cure or disease control (de-escalation). If the measurement of cell death after the initial treatment means indicates that the initial means has not been successful, the evaluation of cell death may be a factor in adopting a new treatment method.

[0081] The present disclosure further provides a method of treating or diagnosing the above-described condition, or a method of visualizing cell death, or a method of monitoring such a condition by administration of the compounds described herein. The present disclosure further provides the use of the compounds described herein in such methods, and their use in the manufacture of a medicament for the treatment of such a condition. For example, the use of the compounds described herein as imaging agents in PET and for visualizing cell death is also provided herein.

[0082] The use of the compounds of the present disclosure and the methods of treatment or diagnosis provided herein, such as those described above, involve administering to a subject an effective amount of a compound described herein. The method may further include performing a PET on the subject after administration of a compound described herein, for example, immediately after administration of a compound described herein. In alternative embodiments, any suitable imaging method other than PET may be used to image the compounds described herein.

[0083] In some embodiments, the PET scan is performed at least 10 minutes, for example, at least 20 minutes, at least 30 minutes, at least 40 minutes, at least 50 minutes, or at least 1 hour after administration of a compound according to the present disclosure. In some embodiments, multiple PET scans may be performed at various time points after administration. For example, a compound of the present disclosure may be administered and PET scans may be performed immediately after administration and at about 30 minutes, about 1 hour, about 2 hours, and about 3 hours after administration. In some embodiments, the method of diagnosis or treatment involves, in the treatment of a tumor, administration of an agent that induces cell death, such as a chemotherapeutic agent, radiation therapy, targeted therapy, or immunotherapy, or a combination thereof, and the compound of the present disclosure may be administered to visualize the effectiveness of the agent in inducing cell death. For example, a chemotherapeutic agent, radiation therapy, targeted therapy, or immunotherapy, or a combination thereof, may be administered to the subject before, together with, or after administration of a compound of the present disclosure. A PET scan may be performed after administration of the compound to visualize the cell death-inducing activity of the chemotherapeutic, radiation therapy, targeted therapy, or immunotherapy, or a combination thereof.

[0084] In some embodiments, the administered agent, such as a drug, may have an effect of reducing cell death, and thus visualization of cell death after administration of such an agent may show a decrease in cell death in the target region.

[0085] Some administered species, such as drugs, may take time for their effects to be shown. Therefore, visualization of cell death by, for example, PET scan may be performed after a long time has elapsed since the administration of the species, for example, 1 day, 3 days, 5 days, 1 week, 2 weeks, or 1 month after administration. In such cases, the compounds according to the present disclosure may be administered before the scan, in addition to or instead of before the administration of the drug or other species.

[0086] In some particular embodiments, the present disclosure provides a method for evaluating the response of a subject to a therapy aimed at causing a change in the level of cell death, the method comprising performing the therapy, administering a compound according to the present disclosure, and visualizing cell death. In one particular embodiment, cell death is visualized by performing positron emission tomography on the subject. In one particular embodiment, the therapy aimed at causing a change in the level of cell death is chemotherapy, radiotherapy, targeted therapy, or immunotherapy, or a combination thereof. In a therapy aimed at causing an increase in the level of cell death, such as chemotherapy, radiotherapy, targeted therapy, or immunotherapy, or a combination thereof, in a specific part of the subject, when a high level of cell death is visualized at the desired location, an evaluation indicating the success of the therapy is made. In some embodiments, the compound according to the present disclosure is administered and / or cell death is also visualized before the implementation of the therapy, enabling a comparison between the levels of cell death before and after the implementation of the therapy. In such cases, an increase in the level of cell death between the two visualizations may indicate the success of the treatment. Conversely, a low level of cell death or a decrease in cell death may indicate the failure of the therapy or that the therapy is not optimal. In some alternative embodiments, the therapy is aimed at reducing the level of cell death in a specific part of the subject, and in such embodiments, a low level of cell death or a decrease in the level of cell death in the target area indicates the success of the therapy, while a high level of cell death or an increase in cell death indicates the failure of the therapy or that the therapy is not optimal.

[0087] In the above method, the administration of the compounds of the present disclosure and the visualization of cell death can be carried out, for example, about 1 day, about 2 days, about 3 days, about 1 week, about 2 weeks, about 3 weeks, about 4 weeks, about 5 weeks, and / or about 6 weeks after the implementation of the treatment method. In some embodiments, the administration of the compounds of the present disclosure and the visualization of cell death are carried out within 7 days after the implementation of the treatment method. In some embodiments, the administration of the compounds of the present disclosure and the visualization of cell death are carried out at least 4 weeks after the implementation of the treatment method. In some embodiments, the administration of the compounds of the present disclosure and the visualization of cell death are carried out more than once after the implementation of the treatment method. For example, in some embodiments, the administration of the compounds of the present disclosure and the visualization of cell death are carried out both within 7 days and at least 4 weeks after the implementation of the treatment method.

[0088] In the above method, for example, the visualization of cell death by positron emission tomography is carried out, for example, at least 10 minutes, at least 20 minutes, at least 30 minutes, at least 40 minutes, at least 50 minutes, at least 1 hour, or at least 90 minutes after the administration of the compounds according to the present disclosure. For example, after administering the compounds of the present disclosure, the visualization can be carried out, for example, immediately after administration, or about 30 minutes, about 1 hour, about 90 minutes, about 2 hours, or about 3 hours after the administration of the compounds according to the present disclosure.

[0089] The present disclosure relates to the above method, the compounds according to the present disclosure for use in such a method, the use of the compounds of the present disclosure in such a method, and the use of the compounds according to the present disclosure in the manufacture of a drug for use in such a method.

[0090] Furthermore, the present invention may be broadly said to exist in the parts, elements, and features individually or collectively mentioned or shown in the present specification, and in any or all combinations of any two or more of the above-mentioned parts, elements, or features. When specific integers having equivalents known in the technical field related to the present invention are described in this specification, such known equivalents are considered to be incorporated into this specification as if they were individually described.

[0091] Any reference in this specification to any prior publication (or information derived therefrom) or known matter shall not be construed as an admission or acknowledgment or any way suggesting that the prior publication (or information derived therefrom) or known matter forms part of the common general knowledge within the scope of the attempts relevant to this specification.

[0092] The present disclosure will be described below with reference to the following specific examples, which should not be construed as limiting the scope of the invention in any way.

Example

[0093] Example 1

[0094] Synthesis of NODAGA-GSAO

[0095] a) GSAO was prepared using the process described in Park D, Don AS, Massamiri T et al (2011) Non-invasive imaging of cell death using an Hsp90 ligand. J Am Chem Soc 133:2932 - 3835. 4-(N-(Bromoacetyl)amino)phenylarsonic acid (BRAA) was synthesized from p-arsanilic acid and bromoacetyl bromide, and BRAA was reduced to 4-(N-(bromoacetyl)amino)phenylarsenous acid (BRAO). BRAO was conjugated with glutathione (GSH) to generate GSAO. GSAO was separated from unreacted BRAO and GSH by C18 chromatography.

[0096] b) Sodium bicarbonate and ultrapure water were purged with nitrogen for 30 minutes before use. The reaction setup and purification were carried out under an inert atmosphere of nitrogen. The GSAO (20.0 mg, 36.5 μmol) obtained in step a) was dissolved in 0.1 N sodium bicarbonate (7.4 mL) at 4 °C and stirred for 10 minutes.

[0097] c) NODAGA-NHS (2,2’-(7-(1-carboxy-4-((2,5-dioxopyrrolidin-1-yl)oxy)-4-oxobutyl)-1,4,7-triazonane-1,4-diyl)diacetic acid mono-N-hydroxysuccinimide ester) (34.5 mg, 47.0 μmol) obtained from CheMatech (Dijon, France) was dissolved in anhydrous dimethylformamide (DMF) (1 mL) and added dropwise to the reaction mixture obtained in step b) over 1 hour.

[0098] d) The reaction mixture was stirred for 4 hours, acidified by the addition of 1 M hydrochloric acid (1 mL), shock frozen in liquid nitrogen, and lyophilized.

[0099] Purification of NODAGA-GSAO

[0100] e) The residue resulting from step d) was redissolved in degassed water (4 mL), filtered (0.45 μm), and purified by reverse-phase high-performance liquid chromatography (RP-HPLC). A gradient of 2 - 20% mobile phase B (0.2% trifluoroacetic acid (TFA) in acetonitrile) in mobile phase A (0.2% TFA in ultrapure water) was applied within 0 to 25 minutes. NODAGA-GSAO eluted at 20.6 minutes. Samples were collected manually and each fraction was immediately purged with nitrogen.

[0101] HPLC was performed on a Shimadzu LC-20 series LC system (System A) equipped with two LC-20AP pumps, a SIL-10AP autosampler, an SPD-20A UV / VIS detector, and a Shimadzu ShimPak GIS-C18 column (150 × 10.0 mm i.d., 5 μm, 4 mL / min 1 )). Shimadzu LabSolutions software (Ver. 5.73) was used for data acquisition and processing.

[0102] f) The pooled fractions were frozen at -20 °C and lyophilized to obtain 7.3 mg of a white powder (yield 21.6%).

[0103] g) NODAGA-GSAO was aliquoted at 54 μg per 100 μL of water and stored at 20 °C.

[0104] h) The purity of the compound (>95%) was verified by injecting a solution of NODAGA-GSAO (5 μL; approximately 17 mM in water) into 2–2–50% mobile phase B (0.1% formic acid (FA) in acetonitrile) in mobile phase A (0.1% FA in mass spectrometry grade water) over 0–5–45 min by liquid chromatography mass spectrometry (LC-MS). NODAGA-GSAO eluted at 19.4 min.

[0105] LC-MS was performed using an Agilent system (Santa Clara, California, USA) consisting of a 1260 series quaternary pump with in-built degasser, a 1200 series autosampler, a column compartment with thermostat, a diode array detector, a fraction collector, a 6120 series single quadrupole mass spectrometer, and an Agilent Zorbax Eclipse XDB-C18 column (150 × 4.6 mm i.d., 5 μm) at 30 °C (System B). The flow rate, temperature, and nebulizer of the drying gas were set at 12 L / min, 350 °C, and 35 psi, respectively. Agilent OpenLAB Chromatography Data System (CDS) ChemStation Edition (C.01.05) was used for data acquisition and processing. An aliquot (5 μL) was analyzed in positive ion mode at a capillary voltage of 3500 V using electrospray ionization (ESI). Nuclear magnetic resonance (NMR) spectroscopy ( 1 H and 13 C) spectra were obtained in a 5 mm Pyrex tube (Wilmad, USA) using a Varian 400-MR NMR spectrometer (Lexington, Massachusetts, USA) at frequencies of 399.73 MHz ( 1 H) or 100.51 MHz ( 13C) Recorded at 24 °C using VnmrJ 3.1 software (Agilent Technologies, Santa Clara, CA, USA). Spectral data are reported in ppm (δ) and referenced to residual solvent (deuterated dimethyl sulfoxide [DMSO-d6] at 2.50 / 39.52 ppm).

[0106] i) Absorbance was measured at 210 and 254 nm, and compound purity was determined as the percentage of total AUC compared to background using the respective area under the curve (AUC).

[0107] Example 2

[0108] Radiolabeling of NODAGA-GSAO with 68 Ga

[0109] a) The barrel of the BondElute SCX column was cut such that upon insertion, the serrated female Luer thread sits directly above the column media to form a cartridge (hereinafter referred to as the SCX cartridge). The serrated female Luer thread should fit tightly and firmly into the cut barrel of the BondElute SCX column to create a gas-tight and liquid-tight sealed cartridge.

[0110] b) The SCX cartridge was primed with 1 mL of 5.5 M HCl and then washed with 10 mL of water.

[0111] c) The SCX cartridge was purged with air.

[0112] d) 44 mg of ascorbic acid was dissolved in 1 mL of water (Water Ultrapur, Merck) to obtain an ascorbic acid solution (0.25 M).

[0113] e) By dissolving 10.21 g of CH3COONa·3H2O in water (Water Ultrapur, Merck), a sodium acetate buffer solution (1.5 M CH3COONa·3H2O, pH 4.5) was obtained. The pH was adjusted to 4.5 with glacial acetic acid, and water was added to make the total volume 50 mL.

[0114] f) One vial of 54 μg of NODAGA-GSAO obtained in Example 1 was thawed and mixed with 100 μL of ascorbic acid solution (used as a free radical scavenger since GSAO is sensitive to radiolysis and oxidation), 250 μL of sodium acetate buffer solution, and 3.5 mL of water, and the mixture was transferred to a 10 mL vacuum glass reaction vial.

[0115] g) 68 Ge / 68 Ga was eluted onto a primed SCX cartridge according to the supplier's instructions.

[0116] h) The SCX cartridge was purged with air.

[0117] i) To minimize the leaching of metal ions from the needle, the contents of the SCX cartridge were eluted into the reaction vial with 500 μL of NaCl / HCl elution mixture, followed by 0.5 mL of air using a B.Braun Sterican needle. The contents of the reaction vial were mixed briefly and reacted at room temperature for 10 minutes.

[0118] j) 3 mL of phosphate buffer was added to the reaction vial. The contents of the reaction vial were taken out with a 10 mL syringe, passed through a 0.22 μm filter and put into a new sterile vial to obtain the final injectable product. 68 Ga-NODAGA-GSAO was not significantly retained on a C-18 cartridge and no post-purification of the product was performed since no suitable biocompatible post-purification cartridge / solvent system was identified. Nevertheless, by the described method, 68 a high radiochemical purity and specific activity exceeding the current release requirements of Ga radiopharmaceuticals 68Ga-NODAGA-GSAO was generated.

[0119] k) Since it is suitable for preparations used by humans and for minimizing the risk of radioactive contamination to the operator and the environment, a sterile closed radiolabeling system is used in the above procedure (Figure 2). This can also be automated using a radiochemical synthesis module.

[0120] 68 Purity of Ga-NODAGA-GSAO

[0121] l) 68 The radiochemical purity of Ga-NODAGA-GSAO (a sample of approximately 100 μL of the final product obtained in step h above) was evaluated by HPLC system C using radiometric detection over 0 - 6 - 10 minutes in mobile phase A (0.1% TFA in ultrapure water) with 9 - 9 - 60% mobile phase B (acetonitrile). The AUC of the Ga-NODAGA-GSAO peak relative to the sum of all radiometric peaks exceeding three times the background was used to determine the radiochemical purity. Absorbance was also measured at 210 and 280 nm, but since the molar amount was below the limit of reliable absorbance detection, it was not used for purity evaluation. 68 Ga-NODAGA-GSAO was eluted with a retention time of approximately 3 minutes and 55 seconds. As shown in the radio-HPLC chromatogram of the final product in Figure 3, region 1 corresponds to 68 Ga, region 2 corresponds to the oxidation product, and region 3 corresponds to 68 Ga-NODAGA-GSAO. The release criterion for the radiochemical purity of 68 Ga-NODAGA-GSAO in the final product is 91% or more (European Pharmacopeia (2016) 01 / 2013:2482 Gallium (68Ga) Edotreotide injection correct 8.6. European Pharmacopeia, 9th edn, pp 1150 - 1152). 68

[0122] m) 68Further evaluation of the radiochemical purity of Ga-NODAGA-GSAO was performed by reacting 200 μL of the final product with 5 μL of a DMP / DMSO solution for 10 minutes at room temperature with occasional stirring. Approximately 100 μL of this mixture was evaluated using a radiometric detection by HPLC system C in mobile phase A (0.1% TFA in ultrapure water) with 9 - 9 - 60% mobile phase B (acetonitrile) over 0 - 6 - 10 minutes. The sum of all radiometric peaks exceeding three times the background for the DMP - 68 The Ga-NODAGA-GSAO peak (retention time is approximately 9 minutes 30 seconds) should be 91% or more, which is because DMP 68 binds to the phenylarsone moiety of Ga-NODAGA-GSAO with a very high affinity, thereby eliminating the normal 68 Ga-NODAGA-GSAO peak with a retention time of about 3 minutes 55 seconds and generating a new peak with a retention time of about 9 minutes 30 seconds. This provides specific information regarding the radiochemical purity of the active GSAO and 68 allows differentiation between Ga-NODAGA-GSAO and other products such as the oxidative degradation products of GSAO. However, this is not included in the release criteria necessary to minimize product loss due to spoilage. The obtained radiometric HPLC chromatogram is shown in Figure 4, where region 1 corresponds to unchelated 68 Ga, region 2 corresponds to the oxidation products, and region 3 corresponds to DMP - 68 Ga-NODAGA-GSAO.

[0123] n) Evaluation of colloidal contaminants was performed by instant thin layer chromatography developed in 0.9% NaCl. The colloidal contaminants remained at the origin, while 68 Ga-NODAGA-GSAO had an Rf > 0.5. A release criterion of 90% or more was used for colloidal contaminants with a total radioactivity having an Rf of 0.5 or more.

[0124] o) The half-life was determined by at least four measurements over 10 minutes performed in the dose calibrator. A calculated half-life of 64 to 72 minutes was used for the release criteria (determination of the half-life was necessary to confirm the absence of significant 68 Ge breakthrough).

[0125] Sterility and pyrogen tests

[0126] p) Sterility and pyrogenicity were first tested in three consecutive syntheses in a duly authorized laboratory, and for the process, it was confirmed that sterility and pyrogenicity were within the pharmacopoeial guidelines (European Pharmacopeia (2016) 01 / 2013:2482 Gallium 68Ga Edotreotide injection correct 8.6. European Pharmacopeia, 9th edn, pp 1150 - 1152). Random testing of subsequent preparations is carried out regularly.

[0127] Example 3

[0128] 68 Formulation of Ga - NODAGA - GSAO

[0129] A composition containing the amounts of components described in Table 1 below was prepared.

Table 1

[0130] Example 4

[0131] 68 In vivo distribution of Ga - NODAGA - GSAO

[0132] The in vivo distribution was investigated in 10 healthy male rats (Lewis, Liverpool Hospital Animal Facility) aged 6 to 8 weeks. Five rats received 68Ga-NODAGA-GSAO was administered. The rats were housed individually in cages equipped with impermeable absorbent mats and, 1 hour after administration, 5 rats were sacrificed by lethal carbon dioxide overdose. Blood was collected by cardiac puncture immediately after death. Next, 2 out of the 5 rats were imaged by PET CT (GE Discovery 710). The PET CT scan consisted of a CT scan (80 kVp, 20 mA, helical mode, reconstructed slice thickness 0.625 mm) followed by a PET scan (2 bed positions, 7.5 minutes / bed position, 256×256 reconstruction matrix, slice thickness 3.27 mm).

[0133] Thereafter, all the rats were dissected, organs were sampled, weighed, counted in a gamma counter, and the cpm values were converted to MBq using known standards. The activity in the remaining carcasses was measured with a dose calibrator.

[0134] The biodistribution study was further performed in 5 rats 68 2 hours after Ga-NODAGA GSAO administration.

[0135] The injected activity was corrected by measuring the residual activity remaining in the syringe after injection in a dose calibrator. To correct for the dose spilled at the injection site, the tail was collected and the activity in the tail was subtracted from the administered activity. All calculations were decay corrected using the injection time as a reference.

[0136] The biodistribution was expressed as %ID / g and %ID / organ. The retained activity % was the sum of all the activities of all the individually collected organs and the activity in the remaining carcasses, expressed as a percentage of the injected dose. The recovered activity % was the sum of all the activities of all the individually collected organs and the activity of the remaining carcasses and the excreted activity of the impermeable mat, expressed as a percentage of the injected dose.

[0137] Results

[0138] The body weight of the rats was 170 g on average (range 120 to 229 g, standard deviation 32.2 g). The average injected activity was 27.3 MBq (range 18.9 to 38.6 MBq, standard deviation 7.4 MBq).

[0139] In the in vivo distribution group at 1 hour, the average uptake time was 62.6 (range 60 to 65) minutes, and in the in vivo distribution group at 2 hours, the average uptake time was 122.2 (range 120 to 126) minutes.

[0140] Figure 5 shows 68 the in vivo organ distribution (%ID / g) of 68 Ga-NODAGA-GSAO in healthy male rats 1 hour and 2 hours after administration of Ga-NODAGA-GSAO.

[0141] As seen in Figure 5, 68 Ga-NODAGA-GSAO reached the highest concentration in the kidneys, 68 and the organs with the highest uptake of Ga-NODAGA-GSAO were the kidneys, liver, and small intestine. The high uptake in the kidneys and liver is consistent with renal excretion and hepatic metabolism, while the uptake in the small intestine is likely to reflect uptake into dead and dying cells of the small intestinal epithelium.

[0142] At 1 hour, 32.4% (range 24.9 to 38.2%, SD 5.6%) of the injected activity was retained, and at 2 hours, 21.4% (range 11.2 to 32.1%, SD 7.5%) of the injected activity was retained in the animals. The overall average total recovered activity at 1 hour was 84.9% (range 55.3 to 107.9%, SD 19.0%), and the total recovered activity at 2 hours was 75.3% (range 50.0 to 120.9%, SD 27.2%) of the injected activity.

[0143] Imaging

[0144] PET CT images showed findings consistent with the quantitative in vivo distribution data. Figure 6 shows the 68 PET CT images performed a) 1 hour and b) 2 hours after administration of the tracer (68 The maximum intensity projection of a Ga-NODAGA-GSAO PET CT scan is shown. Images taken 1 hour after tracer administration show high tracer concentration in the kidneys (arrows i) in a) and b) of Fig. 6) and low uptake levels in the liver (arrow ii)). In the mediastinum, there is residual blood pool activity similar to that of the liver (arrow iii)). Images taken 2 hours after administration (Fig. 6b) also show high tracer concentration in the kidneys and low uptake levels in the liver. In the mediastinum, visible blood pool activity has disappeared. In both sets of images, uptake is present in the small intestine (arrow iv)) and epiphyseal cartilage (arrow v)), which is likely due to specific uptake at sites of high physiological cell death.

[0145] Example 5

[0146] Dosimetry

[0147] Using the biodistribution data obtained above, human dosimetry was estimated for a standard adult male using the method described by Stabin (Stabin and Siegel 2003). The %ID / g in specific standard male organs was estimated from the rat biodistribution data using the following equation.

Equation

[0148] Single exponential clearance curves for each organ and total remaining tissue were fitted using the tools of the OLINDA / EXM software. 68 Taking into account the rapid excretion of Ga-NODAGA-GSAO, all excretion was assumed to be via urine (i.e., the urinary half-clearance time was calculated using single exponential fitting and assumed to be 1 - total retention activity % at each time point). In the voiding bladder model, the patient was assumed to void at 1 hour after administration.

[0149] The effective whole-body dose was estimated to be 2.13E-02 mSv / MBq. Assuming an injection activity of 150 MBq, this results in an effective whole-body dose of 3.2 mSv, which is lower than that of a diagnostic CT scan of the abdomen and lower than the dose of FDG-PET CT. The estimated doses to individual human organs are shown in Table 2 below (ULI = upper large intestine, LLI = lower large intestine).

Table 2

[0150] Discussion

[0151] As shown in the experiment described above, 68 Ga-NODAGA-GSAO has advantageous imaging characteristics with relatively little interference from physiological kidney and liver activity. Furthermore, the rapid clearance suggests that imaging can be performed 1 to 2 hours after injection, and thus 68 is suitable for the use of Ga (clinically, 68 for Ga-based somatostatin receptor expression imaging, imaging is performed 45 to 90 minutes after injection). 68 Notable from the Ga-NODAGA-GSAO PET / CT images (Figure 6) is the visualization of uptake in the small and large intestines and the epiphyseal cartilage of long bones, which may represent uptake in regions with a high rate of physiological cell death. The appearance of the images is confirmed by the measured distribution, and suggests that, in contrast to some other organs (especially the liver and kidneys), uptake is higher at 2 hours than at 1 hour after injection, and that uptake in the intestine may represent specific binding rather than non-specific tracer diffusion.

[0152] Estimated human radiation dose measurements are favorable, with an estimated effective whole-body dose of 0.021 mSv / MBq, which results in a total effective whole-body dose of 3.2 mSv assuming a standard injection dose of 150 MBq. The dose-limiting organ is the bladder wall with a dose of 0.32 mSv / MBq.

[0153] The combination of these results 68Ga-NODAGA-GSAO may be a promising agent for in vivo imaging of dead and dying cells, suggesting that a first-in-human trial is warranted.

[0154] Example 6

[0155] Testing in humans

[0156] The following patients were administered 200 MBq of 68 Ga-NODAGA-GSAO between 200 and 207 MBq: 1. A 66-year-old male patient with esophageal squamous cell carcinoma 2. A 73-year-old female with metastatic ovarian cancer 3. A 66-year-old male with metastatic cutaneous squamous cell carcinoma 4. An 81-year-old female with invasive ductal carcinoma of the breast.

[0157] All subjects tolerated the study well without any related or unrelated serious adverse events or adverse events. There were no significant changes in any of the clinical, laboratory, or electrocardiogram parameters.

[0158] Biodistribution

[0159] Biodistribution data demonstrate rapid intravascular distribution of 68 Ga-NODAGA-GSAO, with a second, slower phase of clearance from the blood pool after rapid initial clearance. Rapid renal uptake and excretion are present.

[0160] For patient 1), the percentage of the injected dose excreted in urine at 2 hours was on average 30% (range 19 to 38%), and at 3 hours it was on average 48% (range 21 to 71%). In Figure 7 showing the imaging findings of this subject, at eight time points 68The anterior maximum intensity projection of Ga-NODAGA-GSAO PET is shown. For comparison, the anterior maximum intensity projection of FDG PET is shown below. The location of the tumor is marked with an arrow at each time point. Low-level tracer uptake is seen in the remaining organs and gradually decreases over time (except for the testes and the large intestine). Biliary excretion is not evident. There is little activity in the brain, suggesting that it does not cross the blood-brain barrier at all. The imaging findings of Patients 2 to 4 are also shown in Figs. 8 (Patient 2), 9 (Patient 3), and 10 (Patient 4), respectively.

[0161] Fig. 11 shows in the normal organs of Patient 1 68 the in-vivo distribution of Ga-NODAGA-GSAO over time. In the blood, after an initial rapid decrease in concentration, there is a second, slower phase of clearance. Most organs show a gradual decrease similar to the second phase of blood clearance after the initial peak, except for the large intestine and the testes, which show an initial increase in concentration up to approximately 40 minutes after administration and then slowly decrease. This may be due to the high physiological rate of cell death in these two organs. Note that the bladder wall was evaluated separately.

[0162] The pattern of in-vivo distribution in the organs and tissues was consistent among Subjects 1 to 4 (as shown in Fig. 16). All showed a rapid distribution of 68 Ga NODAGA GSAO via the blood pool after injection, along with rapid renal uptake and excretion. One hour after injection, the kidneys had 68 the highest concentration of Ga NODAGA GSAO (4.85 ± 0.70, mean SUV ± SD, SUV = standardized uptake value), and in the other tissues and organs, 68 Ga NODAGA GSAO was at a relatively low level and disappeared over time. The large intestine had 68 the next highest concentration of GaNODAGA GSAO (3.00 ± 0.62), followed by the blood pool (2.31 ± 0.37) and the stomach (2.05 ± 1.34).

[0163] Figs. 12 to 15 show, respectively, in the selected normal tissues and tumors of Patients 1 to 4 68It shows the biodistribution of Ga NODAGA GSAO. Note that Tumor 2 is only applicable to Patients 3 and 4, so it is blank in Figures 12 and 13. Figure 16 shows the biodistribution (mean SUV ± SD) in the selected normal tissues of Subjects 1 to 4.

[0164] Radiation dose measurement

[0165] The effective whole-body dose was estimated by drawing representative spheres of interest within the organs, estimating the %ID / g for each organ, and then calculating the %ID / organ using the organ weights from the standard adult phantom.

[0166] For Subjects 1 to 4 68 The effective whole-body dose from Ga NODAGA GSAO was 2.16×10 -2 to 3.38×10 -2 mSv / MBq, and the estimated effective whole-body dose was in the range of 13.5 to 15.9 mSv for the protocol used in the first-in-human study. 68 Detailed organ dose measurements of Ga NODAGA GSAO are shown for four subjects (Tables 5 to 8). In all cases, the bladder was the dose-limiting organ. In subsequent human studies, the number of required time points is reduced, the need for low-dose CT is decreased, and the overall radiation dose is reduced. The dose is at a level corresponding to many normal medical imaging procedures using ionizing radiation, including X-ray computed tomography (CT), SPECT / CT, and PET / CT scans.

[0167] For Subjects 1 to 4, the radiation dose measurements were calculated using OLINDA / EXM based on the above-described organ biodistribution. Urinary excretion was modeled based on the measurement of the activity in the collected urine samples, and the urine volume was measured from the images.

[0168] Tables 3 to 6 show the 68The estimated values of radiation dose measurements for subjects 1 to 4 of Ga NODAGA GSAO are shown in mSv / MBq for individual organs and the whole body (EDE cont. = effective dose equivalent contribution, ED cont. = effective dose contribution). The whole-body dose estimated from one low-dose CT and two ultra-low-dose CTs was 9.2 mSv.

[0169] Table 3 shows the estimated values of radiation dose measurements for subject 1. The overall estimated radiation dose for subject 1 was 14.5 mSv.

Table 3

[0170] Table 4 shows the estimated values of radiation dose measurements for subject 2. The overall estimated radiation dose for subject 2 was 13.9 mSv.

Table 4

[0171] Table 5 shows the estimated values of radiation dose measurements for subject 3. The overall estimated radiation dose for subject 3 was 13.5 mSv.

Table 5

[0172] Table 6 shows the estimated values of radiation dose measurements for subject 4. The overall estimated radiation dose for subject 4 was 15.9 mSv.

Table 6

[0173] Tumor uptake

[0174] Figure 17 shows the blood pool activity and tumor deposits for subjects 1 to 4 68Shows the uptake of Ga NODAGA GSAO (Note: Patients 3 and 4 had two tumor deposits, which were analyzed separately). Blood pool and clearance are reproducible, but tumor uptake and clearance vary depending on the type of tumor.

[0175] Overall in Subjects 1 to 4, tumor uptake varied according to tumor histology, with high levels of uptake seen in esophageal squamous cell carcinoma (SUVmean 3.8) and metastatic cutaneous squamous cell carcinoma (SUVmean 4.1), and low uptake seen in metastatic ovarian cancer (SUVmean 1.9) and breast cancer (SUVmean 1.8). Note that Subjects 3 and 4 had two tumor deposits, which were analyzed separately. It is not unexpected that the proportion of denovo cell death would also differ if the tumor histology differed. To confirm this, the histological correlation between tumor cell death and 68 the tumor uptake of Ga NODAGA GSAO was performed on the two tumor deposits of Patient 3 (one had 68 a high uptake of Ga NODAGA GSAO SUVmean 4.1 in the right axilla, and the other had 68 a low uptake of Ga NODAGA GSAO SUVmean 2.7 in the right anterior cervical triangle) (Figure 18).

[0176] The dissected tumors were fixed with formalin, embedded in paraffin, and 4-μm thick sections were cut. The apoptotic cells were stained using TUNEL (Abcam, Cat#206386), or the morphology was stained using hematoxylin and eosin. For TUNEL staining, the sections were deparaffinized with xylene, rehydrated by decreasing the ethanol concentration, and permeabilized with proteinase K at room temperature for 20 minutes. The endogenous peroxidase activity was quenched with 3% H2O2 for 5 minutes. The apoptotic cells were labeled with biotinylated terminal deoxynucleotidyl transferase at 37°C for 2 hours in a humidified chamber, and then incubated with streptavidin-HRP conjugate for 30 minutes. The HRP-positive cells were developed using diaminobenzidine, and the sections were counterstained with methyl green (Sigma). The entire section was imaged by scanning at a magnification of 10 times using Power Mosaic on a Leica DM6000D microscope.

[0177] Figure 18 shows the anterior maximum intensity projections of FDG-PET (Figure 18A), performed 60 minutes after administration of 256 MBq of FDG (fluorodeoxyglucose), and CDI-PET (Figure 18B), performed 60 minutes after administration of 205 MBq of CDI( 68 Ga NODAGA GSAO), in a 66-year-old male (patient 3) with metastatic cutaneous squamous cell carcinoma. FDG-PET shows two very metabolically active lymph node metastases, one in the right axilla and the other in the right anterior jugular triangle. These are thought to represent synchronous lymph node metastases from two different cutaneous squamous cell carcinomas (previously resected). CDI-PET( 68 Ga NODAGA GSAO) shows strong uptake (SUVmean = 4.1) in the right axillary lymph node metastasis and mild uptake (SUVmean = 1.7) in the right anterior jugular triangle lymph node metastasis. The tumor was surgically resected, fixed, and adjacent sections were stained for apoptotic cells (Figure 18C, brown TUNEL staining, a and b) or for morphology using hematoxylin and eosin (Figure 18C, c and d). The arrows in the TUNEL staining indicate areas of extensive apoptosis.

[0178] Tumors with these high uptakes have uptakes that are up to two times greater than the blood pool and are noted to be greater than the uptake in all other organs except the renal tubules, which are the excretory pathway. The combination of the high levels of uptake within some of these tumors and the low levels of activity within normal tissues and organs 68 demonstrates the potential of Ga NODAGA GSAO to be used as an effective imaging agent.

[0179] Discussion

[0180] This 68 Interim analysis of four patients in the first-in-human trial of Ga NODAGA GSAO has shown it to be safe, well tolerated, and without adverse effects. The biodistribution and imaging characteristics are favorable, with low levels of activity in most normal organs. The urinary tract is the only excretory pathway. Uptake into dead and dying cells within tumors is seen, 68 and the tumor uptake variable of Ga NODAGA GSAO is consistent with various tumor tissues and has been histopathologically demonstrated to correlate with the proportion of dead and dying cells within the tumor. 68 The effective whole-body dose of Ga NODAGA GSAO is in the range of 2.16×10 -2 to 3.38×10 -2 mSv / MBq, and the estimated effective whole-body dose is in the range of 4.3 to 6.8 mSv for an administered activity of 200 MBq. This is comparable to the effective whole-body doses from many other diagnostic radiopharmaceuticals used in PET / CT and SPECT / CT, and other radiation procedures such as x-ray computed tomography (CT).

Explanation of Symbols

[0181] [Figure 2] PO4 Buffer: PO4 buffer Legend: Legend 68 Ga generator: 68 Ga generator Three way tap: Three-way tap SCX cartridge: SCX Cartridge Syringe: Syringe 0.22μm filter: 0.22μm Filter Waste: Waste Reaction: Reaction Product: Product [Figure 3, 4] Counts: Counts Region 1: Region 1 Region 2: Region 2 Region 3: Region 3 [Figure 5] Heart: Heart Testes: Testes Lungs: Lungs Liver: Liver Thymus: Thymus Kidneys: Kidneys Spleen: Spleen Stomach: Stomach Pancreas: Pancreas Small Bowel: Small Intestine Large Bowel: Large Intestine Brain: Brain Organ: Organ [Figure 11] Activity: Activity LV Blood Pool: LV Blood Pool Aortic Arch Blood Pool: Aortic Arch Blood Pool Tumour: Tumor Heart: Heart Testes: Testes Lungs: Lungs Liver: Liver Kidney-mean: Kidney - Mean Spleen: Spleen Stomach: Stomach Pancreas: Pancreas Small intestine: Small Intestine Large bowel: Large intestine Muscle: Muscle Bone / Marrow: Bone / Marrow Brain: Brain Thyroid: Thyroid Adrenals: Adrenals Prostate: Prostate Parotid: Parotid Gallbladder: Gallbladder Scan Start PI (min): Scan Start PI (min) [Figure 12, 13, 14, 15] Tumour: Tumour Tumour 2: Tumour 2 Blood Pool: Blood Pool Kidney: Kidney Liver: Liver Spleen: Spleen Stomach: Stomach Small intestine: Small intestine Large Bowel: Large intestine Muscle: Muscle Bone marrow: Bone marrow Brain: Brain Mean SUV: Mean SUV Uptake (min): Uptake (min) [Figure 16] Blood Pool: Blood Pool Kidney: Kidney Liver: Liver Spleen: Spleen Stomach: Stomach Pancreas: Pancreas Small intestine: Small intestine Large Bowel: Large intestine Muscle: Muscle Bone marrow: Bone marrow Thyroid: Thyroid Brain: Brain Mean SUV: Mean SUV Uptake (min): Uptake (min) Patient: Patient [Figure 17] Blood Pool: Blood Pool Tumour: Tumour Tumour 2: Tumour 2 Mean SUV: Mean SUV Uptake (min): Uptake (min) Patient: Patient [Figure 18] cervical: cervical axillary: axillary

Claims

1. A compound according to formula (I), 【Chemical Formula 1】 A is -As(OH)2, R 1 、R 2 、R 3 、and R 4 each is independently selected from H, X, OH, NH 2 、CO、SCN、-CH 2 NH、-NHCOCH 3 、-NHCOCH 2 X, or NO, where X is halogen, R 5 is -NHCH 2 COOH, OH, or OR 6 and R 6 is a C 1-5 straight-chain or branched alkyl group, Z is, 64 Cu, {Al 18 F} 2+ 、 68 Ga, or 99m Tc, a compound, or a pharmaceutically acceptable salt, ester, or solvate thereof.

2. R 1 、R 2 、R 3 、and R 4 each is H, the compound according to Claim 1.

3. R 5 is NHCH 2 COOH, the compound according to Claim 1 or 2.

4. A compound according to any one of Claims 1 to 3, according to formula (Ia), 【Chemical Formula 2】 A and Z are as defined in Claim 1, a compound, or a pharmaceutically acceptable salt, ester, or solvate thereof, a compound.

5. Z is, 68 Ga or {Al 18 F} 2+ The compound according to any one of claims 1 to 4, wherein it is

6. Z is 68 Ga. The compound according to any one of claims 1 to 3, wherein it is

7. Z is {Al 18 F} 2+ The compound according to any one of claims 1 to 4, wherein it is

8. The compound according to claim 1, having the following structure 【Chemical formula 3】 Or a pharmaceutically acceptable salt, ester, or solvate thereof.

9. The compound according to any one of claims 1 to 8, for use as an imaging agent.

10. The compound according to claim 9, for use as an imaging agent in positron emission tomography.

11. The compound according to claim 9 or 10, for use in visualizing cell death.

12. A pharmaceutical composition comprising the compound according to any one of claims 1 to 11 together with a pharmaceutically acceptable carrier, excipient, diluent, vehicle, and / or adjuvant.

13. A compound according to formula (II), wherein 【Chemical formula 4】 A is -As(OH)2, R 1 、R 2 、R 3 、and R 4 Each of is independently selected from H, X, OH, NH 2 、CO、SCN、-CH 2 NH、-NHCOCH 3 、-NHCOCH 2 X, or NO, and X is a halogen. R 5 is -NHCH 2 COOH, OH, or OR 6 and R 6 is a C 1-5 compound that is a straight-chain or branched alkyl group, compound, or a pharmaceutically acceptable salt, ester, or solvate thereof. **Claim 14** R 1 , R 2 , R 3 , and R 4 each of which is H, the compound according to claim 13. **Claim 15** R 5 is NHCH 2 COOH, the compound according to claim 13 or 14. **Claim 16** The compound according to any one of claims 13 to 15, having the following structure, **Chemical Formula 5** or a pharmaceutically acceptable salt, ester, or solvate thereof. **Claim 17** Use of the compound according to any one of claims 1 to 11 as an imaging agent. **Claim 18** The use according to claim 17, wherein the imaging agent is used in positron emission tomography. **Claim 19** The use according to claim 17 or 18, wherein the imaging agent is used to visualize cell death. **Claim 20** The compound according to any one of claims 1 to 11 for use in a therapeutic method. **Claim 21** The compound according to any one of claims 1 to 11 for use in in vivo diagnosis. **Claim 22** A compound for use in the diagnosis or treatment of a condition associated with a change in cell death, or a condition in which treatment results in a change in cell death, according to claim 20 or 21.

23. A compound for use in the treatment or diagnosis of a neoplastic condition or an autoimmune condition according to claim 22.

24. A compound for use according to claim 23, wherein the neoplastic condition is a tumor.

25. A compound for use according to claim 23 or 24, wherein the neoplastic condition is cancer.

26. A process for preparing the compound according to claim 8, comprising 68 eluting Ga on a strong cation exchange column and eluting the strong cation exchange column with a mixture comprising the compound according to claim 16 and a buffer, wherein the buffer has a pH of about 4.

5.

27. A medicament comprising an effective amount of the compound according to any one of claims 1 to 11 for diagnosing or treating a condition associated with a change in cell death in a subject and / or a condition in which treatment thereof results in a change in cell death, or for visualizing cell death in a subject.

28. The medicament according to claim 27, wherein the condition is a neoplastic condition or an autoimmune condition.

29. The medicament according to claim 27 or 28, wherein positron emission tomography is performed on the subject after administration of the compound.

30. The medicament according to any one of claims 27 to 29, wherein a plurality of positron emission tomography images of the subject are collected after administration of the compound.

31. The medicament according to any one of claims 27 to 30, wherein the compound is administered intravenously.

32. The medicament according to any one of claims 27 to 31, wherein the neoplastic condition is a tumor.

33. The pharmaceutical according to any one of claims 27 to 32, wherein the neoplastic state is cancer.

34. A radiopharmaceutical comprising a compound according to any one of claims 1 to 11 for evaluating the response of a subject to a therapy aimed at causing a change in the level of cell death.

35. The cell death is visualized by performing positron emission tomography on the subject, The radiopharmaceutical according to claim 34.

36. The therapy is chemotherapy, radiotherapy, targeted therapy, or immunotherapy, or a combination thereof, The radiopharmaceutical according to claim 34 or 35.

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