Systems and methods for detecting tumor metabolism by HP-mri

Abstract

Provided are methods for characterizing cellular metabolism in a subject through a repeated exposure approach of administering HP pyruvate to a subject. The methods described may be used for determining the efficacy of cancer therapy or for monitoring disease progression in the subject.

Description

SYSTEMS AND METHODS FOR DETECTING TUMOR METABOLISM BY HP-MRICROSS-REFERENCE TO RELATED APPLICATIONS[00011 This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 561,465, filed on March 5, 2024, the contents of which are incorporated herein by reference in their entirety.STATEMENT OF GOVERNMENT SUPPORT

[0002] This invention was made with government support under CA280980, CA274321, and CA211150 awarded by the National Institutes of Health. The government has certain rights in the invention.BACKGROUND

[0003] Early detection of disease, accurate stratification, and early assessment of response to therapeutic treatment improve the likelihood for successful treatment of a disease. The quicker the detection, diagnosis, and treatment of cancer is, the chances of survival will improve. Various methods for the detection of cancer response to treatment focus mainly on changes in tumor size or identifying pathological cancer biomarkers secreted by malignant tissue and / or in the circulatory system. However, such diagnostic methods are problematic because they are effective only at relatively advanced stages of disease, do not provide any spatial information regarding treatment response within the tumor and may not be easily measured multiple times during treatment.

[0004] Magnetic resonance imaging (MRI) is noninvasive and allows for early diagnosis of cancer. However, with the development of individualized therapeutic medicine, such as the development of molecular therapeutics, anatomical imaging diagnosis alone is difficult to determine the therapeutic effect or the prognosis of patient treatment. Metabolic measurement techniques using magnetic resonance imaging are based on nuclear magnetic resonance spectroscopic imaging of substrates and metabolites labeled with13C. However, since there is only 1.1% of13C in nature, the sensitivity is very low and the hyperpolarization technique by DNP (dynamic nuclear polarization) or other hyperpolarization method is used for signal amplification of13C.SUMMARY[0005| According to various aspects of the present disclosure, systems and methods for detecting cellular metabolism in a subject are provided, including but not limited to detecting cellular metabolism relating to cancer therapy based on detecting a doseindependent metric for conversion of HP pyruvate to lactate by the subject.

[0006] In an aspect, provided is a method of characterizing cellular metabolism in a subject, the method comprising: a) administering a first dose of HP pyruvate to the subject and a second dose of HP pyruvate to the subject, wherein the first dose is different from the second dose; b) obtaining, using an MRI scanner, a plurality of MRI scans of the subject; c) outputting, using one or more processors, a first rate of conversion of the HP pyruvate to lactate for the first dose and a second rate of conversion of the HP pyruvate to lactate for the second dose; and d) outputting, by one or more processors, an HP pyruvate conversion metric based at least on the first rate of conversion and the second rate of conversion; where the HP pyruvate conversion metric is used to characterize the cellular metabolism in the subject.

[0007] In an aspect, a method of determining efficacy of cancer therapy in a subject is provided, the method comprising: a) administering a first dose of HP pyruvate (DI) to the subject and a second dose of HP pyruvate (D2) to the subject, wherein DI is different from D2; b) detecting, by one or more processors, a first HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to DI and D2; c) waiting for a period of time; d) repeating administration of the first dose of HP pyruvate (rDl) to the subject and the second dose of HP pyruvate (rD2) to the subject, wherein rDl is different from rD2; and e) detecting, by one or more processors, a second HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to rDl and rD2; where the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are compared to determine the efficacy of cancer therapy in the subject.

[0008] In an aspect, a method of determining disease progression in a subject is provided, the method comprising: a) administering a first dose of HP pyruvate (DI) to the subject and a second dose of HP pyruvate (D2) to the subject, wherein DI is different from D2; b) detecting, by one or more processors, a first HP pyruvate conversion metric based at leaston a plurality of MRI scans of the subject corresponding to DI and D2; c) waiting for a period of time; d) repeating administration of the first dose of HP pyruvate (rDl) to the subject and the second dose of HP pyruvate (rD2) to the subject, wherein rDl is different from rD2; and e) detecting, by one or more processors, a second HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to rDl and rD2; where the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are compared to determine disease progression in the subject.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 depicts an example of a system to detect tumor metabolism using HP -MRI.

[0010] FIG. 2 depicts an example of a method of detecting tumor metabolism using HP- MRI.

[0011] FIG. 3 demonstrates the relationship between kpl, the apparent rate constant for the conversion of HP pyruvate to lactate, and the extracellular concentration of spin-labeled (HP) pyruvate ([P*]).[0012| FIG. 4 shows a plot of 1 / kpl as a function of extracellular pyruvate ([P*]). There is a linear dependence of 1 / kpl on extracellular concentration of HP pyruvate ([P*]) in vitro with a slope proportional to 1 / Vpl (inverse of the chemical conversion rate at equilibrium).DETAILED DESCRIPTION

[0013] Various embodiments are described hereinafter. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment s).

[0014] Overview

[0015] Visualization of hyperpolarized (HP) substrates by magnetic resonance (MR) enables interrogation of biological systems with unprecedented spatial resolution and chemical specificity.[0016|13C-pyruvate can be useful to evaluate as an HP substrate, due to its relatively long relaxation time, rapid distribution and uptake, and the central role that pyruvate plays in metabolism. Glucose, the most abundant source of fuel in normal tissue, is catabolized to pyruvate by intracellular enzymes. In normal tissue, most pyruvate is converted into acetyl- CoA by pyruvate dehydrogenase and subsequently oxidized for production of reducing equivalents and generation of ATP. Under anaerobic conditions, or if glycolysis is pathologically upregulated as in many cancers which display the “Warburg” effect, excess pyruvate is rapidly exchanged with lactate via lactate dehydrogenase (LDH) and cofactor nicotinamide adenine dinucleotide (NADH). Pyruvate can also exchange with alanine via alanine aminotransferase in a non-redox dependent fashion. Thus, the chemical conversion of HP13C-pyruvate can provide powerful insight into the metabolic state of tumor tissue and provide an index of metabolic flux changes due to gene expression or response to therapy.

[0017] However, HP13C-pyruvate conversion processes can be affected by various factors, which can make it difficult to efficiently detect a state of a subject (e.g., determining the metabolic state of tumor tissue) using such processes. Confounds such as signal from vasculature and extravasation of HP pyruvate can be addressed in part by pharmacokinetic modeling. However, current pharmacokinetic models do not account for effects of the differences in intracellular pyruvate pool size and may lead to a dose-dependent effect that further confounds accurate measurement of tumor metabolism.[0018[ The present systems and methods can address this confound. Systems and methods in accordance with the present disclosure can allow for more effective assessment of metabolic processes, such as tumor metabolism relating to therapies provided to a subject, including by accounting for dose dependence of pyruvate in connection with how the MRI scan data is evaluated. For example, a dose-independent metabolism metric can be determined according to MRI scans corresponding with multiple doses (e.g., at least two doses). The relationship between the apparent rate constant for the conversion of HP pyruvate to lactate (kpl) and the chemical conversion rate (Vpl, an HP pyruvate conversion metric) at equilibrium and the ability to relate these two values to cellular metabolism can provide a robust method for quantifying tumor metabolism in patients. Since HP pyruvate is not radioactive and because the spin labels within the compound are short-lived (on theorder of a few minutes), measurements can be performed more quickly and more frequently throughout the duration of therapy. Multiple doses of HP pyruvate can also be administered to the patient within one MRI session to allow for cellular metabolic information to be generated within hours or days of the session. This information can determine whether therapy is effective during the early stages of treatment rather than weeks to months after a patient has started therapy.[0019} Definitions[0020| As used herein, “about” will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, “about” will mean up to plus or minus 10% of the particular term.[00211 The use of the terms “a” and “an” and “the” and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0022] As used herein, the “administration” of an agent to a subject includes any route of introducing or delivering to a subject a compound to perform its intended function. Administration can be carried out by any suitable route, including but not limited to, orally, intranasally, intrathecally, parenterally (intravenously, intramuscularly, intraperitoneally, or subcutaneously), rectally, intrathecally, intraocularly, intradermally, transmucosally, iontophoretically, or topically. Administration includes self-administration and the administration by another.[00231 As used herein, the terms “cancer” or “tumor” are used interchangeably and refer to the presence of cells possessing characteristics typical of cancer-causing cells, such as uncontrolled proliferation, immortality, metastatic potential, rapid growth and proliferation rate, and certain characteristic morphological features. Cancer cells are often in the form of a tumor, but such cells can exist alone within an animal, or can be a non-tumorigenic cancer cell. As used herein, the term “cancer cells” includes precancerous (e.g., benign), malignant, pre-metastatic, metastatic, and non-metastatic cells.

[0024] Cancers of virtually every tissue are known to those of skill in the art, including solid tumors such as carcinomas, sarcomas, glioblastomas, melanomas, etc., and circulating cancers such as leukemias. Examples of cancer include, but are not limited to, ovarian cancer, breast cancer, colon cancer, lung cancer, prostate cancer, gastric cancer, pancreatic cancer, cervical cancer, ovarian cancer, liver cancer, bladder cancer, cancer of the urinary tract, thyroid cancer, renal cancer, carcinoma, melanoma, head and neck cancer, and brain cancer. The phrase “cancer burden” or “tumor burden” refers to the quantity of cancer cells or tumor volume in a subject. Reducing cancer burden accordingly may refer to reducing the number of cancer cells, or the tumor volume in a subject. The term “cancer cell” refers to a cell that exhibits cancer-like properties, e.g., uncontrollable reproduction, resistance to anti- growth signals, ability to metastasize, and loss of ability to undergo programmed cell death (e.g., apoptosis) or a cell that is derived from a cancer cell, e.g., clone of a cancer cell.

[0025] As used herein, the terms “subject”, “patient”, or “individual” can be an individual organism, a vertebrate, a mammal, or a human. In some embodiments, the subject, patient or individual is a human.

[0026] “Treating” or “treatment” as used herein covers the treatment of a disease or disorder described herein, in a subject, such as a human, and includes: (i) inhibiting a disease or disorder, i.e., arresting its development; (ii) relieving a disease or disorder, i.e., causing regression of the disorder; (iii) slowing progression of the disorder; and / or (iv) inhibiting, relieving, or slowing progression of one or more symptoms of the disease or disorder. In some embodiments, treatment means that the symptoms associated with the disease are, e.g., alleviated, reduced, cured, or placed in a state of remission.

[0027] The term “hyperpolarized” is hereinafter used interchangeably with the term “polarized” and denotes a nuclear polarization level in excess of 0.1%, more preferred in excess of 1% and most preferred in excess of 10%.

[0028] The terms “hyperpolarized13C-pyruvate”, “13C-pyruvate”, “HP pyruvate”, and “[1-13C] pyruvate” are hereinafter used interchangeably, unless specified otherwise. In the same way, the terms “hyperpolarized13C-lactate”, “13C-lactate”, “HP lactate”, and “[ 1 -13C] lactate” are hereinafter used interchangeably, unless specified otherwise. In some embodiments, at least one carbon on HP pyruvate is labeled. In some embodiments, the present methods use hyperpolarized [ 1 -13C] pyruvate.

[0029] Systems and Methods for Characterizing Cellular Metabolism

[0030] System and methods described herein can enable measurement of tumor metabolism in vivo by magnetic resonance imaging. Dynamic spectroscopic MRI after administration of HP pyruvate permits visualization of the distribution of HP pyruvate and of HP lactate after the chemical conversion of HP pyruvate into HP lactate, providing a direct window for assessing altered metabolism that is observed in many tumors and referred to as aerobic glycolysis or the “Warburg effect.” The conversion of HP pyruvate to HP lactate can be estimated using the MR imaging or spectroscopic data.

[0031] HP pyruvate is not radioactive, and the spin labels are only visible for a few minutes, permitting repeated exposure within a single MRI slot and frequent measurements throughout the course of therapy. The repeated measure approach can be used to estimate the pool-size independent equilibrium reaction velocity. This would be achieved by administering different doses of HP pyruvate to a subject and calculating the inverse of the slope of 1 / kpl versus dose (FIG. 4). This measurement can be made with as few as two doses of HP pyruvate. In some embodiments, this measurement is made with two doses of HP pyruvate. In some embodiments, this measurement is made with at least two doses of HP pyruvate. In some embodiments, this measurement is made with more than two doses of HP pyruvate.

[0032] The apparent rate of conversion of HP pyruvate into lactate (kpl) is inversely proportional to the extracellular concentration of HP pyruvate in vitro (FIG. 3). Without wishing to limit the present disclosure by any theory or mechanism, a higher extracellularpyruvate leads to higher intracellular pyruvate, which causes a reduced rate constant as described in the first equation below. This apparent rate constant can be written as a function of the velocity of the chemical conversion rate at equilibrium and the intracellular pool size for pyruvate.

[0033] The relationship between kpl, the equilibrium velocity of the conversion of pyruvate to lactate, and intracellular pyruvate concentration can be written as: k =v”‘[P] + [P »]

[0034] Plotting 1 / kpl as a function of extracellular [P*] shows a linear dependence on [P]+[P*] with a slope equal to 1 / Vpl. If transport across the cell membrane is not a rate limiting factor for HP pyruvate, then the slope of that line can be determined by repeated exposure to HP pyruvate. Given a dose DI and a second dose D2=cDl :

[0035] In an aspect, a method of characterizing cellular metabolism in a subject comprises: administering a first dose of HP pyruvate to the subject and a second dose of HP pyruvate to the subject, wherein the first dose is different from the second dose; obtaining, using an MRI system 104 (FIG. 1), MRI data comprising a plurality of MRI scans of the subject; and outputting, using a therapy evaluator 108, a therapy evaluation. The therapy evaluation may include information related to the subject’s response to cancer therapy, or a measure of disease progression in response to cancer therapy.

[0036] Various aspects of the present disclosure can be implemented by a system 100. The system 100 can be used to monitor parameters of a subject, such as conversion of HP pyruvate to lactate. For example, the system 100 can include at least one MRI system 104. The MRI system 104 can be or include one or more MRI machines that can detect MRI data regarding the subject during one or more sessions. The MRI system 104 can be tuned to detect MRI data relating to HP pyruvate conversion. The MRI system 104 can output the MRI data as an image data structure, such as a two-dimensional and / or three-dimensional image data structure representing parameters of the subject (e.g., parameters indicative ofHP pyruvate conversion). The image data structure may be a dynamic (i.e., time-lapsed) image of the HP pyruvate and HP lactate.[0037| The system 100 can include at least one therapy evaluator 108 coupled with the MRI system 104. The therapy evaluator 108 can process the MRI data outputted by the MRI system 104 to determine parameters relating to HP pyruvate metabolism, including to determine a dose-independent metric of HP pyruvate metabolism (which can be used to determine efficacy of therapy applied to the subject). The therapy evaluator 108 may analyze the images using a pharmacokinetic model to generate parameters that reflect the state of the subject, such as kpl.

[0038] The therapy evaluator 108 can include one or more processors 112 and a memory 116. The processor 112 may be a general purpose or specific purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable processing components. The processor 112 may be configured to execute computer code or instructions stored in memory (e.g., fuzzy logic, etc.) or received from other computer readable media (e.g., CDROM, network storage, a remote server, etc.) to perform one or more of the processes described herein. The memory 116 may include one or more data storage devices (e.g., memory units, memory devices, computer-readable storage media, etc.) configured to store data, computer code, executable instructions, or other forms of computer-readable information. The memory 116 may include random access memory (RAM), read-only memory (ROM), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and / or computer instructions. The therapy evaluator 108 can be implemented as a hardware processor including a Central Processing Unit (CPU), an Application-Specific Integrated Circuit (ASIC), an Application-Specific Instruction-Set Processor (ASIP), a Graphics Processing Unit (GPU), a Physics Processing Unit (PPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a Controller, a Microcontroller unit, a Processor, a Microprocessor, an ARM, or the like, or any combination thereof. The memory may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. Thern emory 116 may be communicably connected to the processor 112 via the processing circuit and may include computer code for executing (e.g., by processor) one or more of the processes described herein. The memory can include various modules (e.g., circuits, engines) for completing processes described herein. The therapy evaluator 108 can include one or more input and / or output ports for electronic communication with various components of the MRI system 104. The therapy evaluator 108 can be implemented using one or more computing devices that can include various communications and / or user interfaces for communicating data and presenting outputs and / or receiving inputs (e.g., user inputs).

[0039] The therapy evaluator 108 can process the MRI data to determine metrics regarding HP pyruvate in the subject relating to one or more respective doses of HP pyruvate administered to the subject, such as at least one of intracellular concentration or extracellular concentration of HP pyruvate. The therapy evaluator 108 can determine a conversion rate of HP pyruvate to lactate based on the concentrations for the respective doses and / or the factor c indicative of a ratio of doses. For example, the therapy evaluator 108 can provide the concentrations for the respective doses as input to a function (e.g., a function based on one or more equations described herein) to convert the concentrations into an equilibrium velocity of the conversion of HP pyruvate to lactate (e.g., V L). Responsive to determining the equilibrium velocity, the therapy evaluator 108 can characterize a treatment administered to the subject. For example, the therapy evaluator 108 can compare the conversion to a threshold indicate of efficacy of the treatment, and output an indication of the treatment being effective according to the comparison.

[0040] FIG. 2 depicts an example of a method of characterizing cellular metabolism in a subject. The method can be implemented using various systems and devices described herein, such as the therapy evaluator 108 and / or system 100. The method 200 can include administering a first dose of HP pyruvate to the subject and a second dose of HP pyruvate to the subject (205). The first dose can be different from the second dose, which can facilitate determining dose-independent metrics relating to the HP pyruvate conversion.

[0041] The method 200 can include detecting MRI data that includes a plurality of MRI scans of the subject (210). For example, the MRI system can start scanning the subject, a first dose of HP pyruvate can then be administered to the subject, an MRI scan can bedetected while the first dose of HP pyruvate is present in the subject, a second dose of HP pyruvate can be administered to the subject, and an MRI scan can be detected while the second dose of HP pyruvate is present in the subject.

[0042] The method 200 can include determining a first rate of conversion corresponding to the first dose and a second rate of conversion corresponding to the second dose (215). The rates of conversion can be determined based on concentrations of HP pyruvate (e.g., intracellular and / or extracellular) represented by the MRI scans.

[0043] The method 200 can include determining an HP pyruvate conversion metric based at least on the first rate of conversion and the second rate of conversion (220). The HP pyruvate conversion metric is used to characterize the cellular metabolism in the subject, such as to compare the metric with a threshold indicative of effectiveness of the therapy.

[0044] In some embodiments, the HP pyruvate conversion metric comprises a rate of conversion of the HP pyruvate versus dose of HP pyruvate.[00451 In some embodiments, a slope of the plot of the inverse of the rate of conversion versus concentration is proportional to the inverse of an equilibrium velocity of a reaction that mediates the chemical conversion of HP pyruvate to lactate.

[0046] In some embodiments, the first dose and second dose of HP pyruvate are each up to about 0.43 mL / kg of a 250 mM solution.

[0047] In some embodiments, measuring the first rate of conversion and the second rate of conversion occurs over a period from about 5 seconds to 5 minutes.

[0048] In some embodiments, a period of time between administration of the first dose and the second dose is from 5 minutes to 1 hour.

[0049] In some embodiments, the subject is assigned a diagnosis of cancer.

[0050] In some embodiments, the subject is assigned a diagnosis of an aggressive or a latestage cancer.

[0051] In another aspect, a method of estimating cellular metabolism in a subject comprises: administering a first dose of HP pyruvate to the subject and a second dose of HPpyruvate to the subject, wherein the first dose is different from the second dose; measuring, using an MRI scanner, a first rate of conversion of the HP pyruvate to lactate for the first dose and a second rate of conversion of the HP pyruvate to lactate for the second dose; generating an HP pyruvate conversion metric based at least on the first rate of conversion and the second rate of conversion; wherein the HP pyruvate conversion metric is used to estimate the cellular metabolism in the subject. In some embodiments, the first rate of conversion of the HP pyruvate to lactate for the first dose and the second rate of conversion of the HP pyruvate to lactate for the second dose are each measured from images of the HP pyruvate and the HP lactate obtained from the MRI scanner.

[0052] Methods for Determining Efficacy of Cancer Therapy

[0053] The methods described herein may be used to provide early indications of response to therapy to provide feedback on therapeutic efficacy that will benefit the patient and reduce costs of therapy. For example, if induction or front-line therapy is determined to be ineffective, then the treatment schedule can be altered before the disease progresses and becomes more difficult to manage. The early indications of response to therapy can be determined in hours to days, for example, rather than weeks to months.

[0054] In an aspect, a method of determining efficacy of cancer therapy in a subject comprises: administering a first dose of HP pyruvate (DI) to the subject and a second dose of HP pyruvate (D2) to the subject, wherein DI is different from D2; detecting, by one or more processors, a first HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to DI and D2; waiting for a period of time; repeating administration of the first dose of HP pyruvate (rDl) to the subject and the second dose of HP pyruvate (rD2) to the subject, wherein rDl is different from rD2; and detecting, by one or more processors, a second HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to rDl and rD2; wherein the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are compared to determine the efficacy of cancer therapy in the subject.

[0055] In some embodiments, the period of time is from 30 minutes after a therapy session to up to 6 months after completion of therapy.[0056| In some embodiments, the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are each reflective of a velocity of the chemical conversion rate of HP pyruvate to lactate.

[0057] In some embodiments, cancer therapy is effective when the second HP pyruvate conversion metric is less than the first HP pyruvate conversion metric. In some embodiments, cancer therapy is effective when the second HP pyruvate conversion metric is greater than the first HP pyruvate conversion metric. In some embodiments, cancer therapy is effective when the second HP pyruvate conversion metric changes in relation to the first HP pyruvate conversion metric.

[0058] In some embodiments, cancer therapy is ineffective when the second HP pyruvate conversion metric is greater than or equal to the first HP pyruvate conversion metric. In some embodiments, cancer therapy is ineffective when the second HP pyruvate conversion metric is less than the first HP pyruvate conversion metric. In some embodiments, cancer therapy is ineffective when the second HP pyruvate conversion metric does not change in relation to the first HP pyruvate conversion metric.

[0059] Methods for Determining Disease Progression

[0060] The methods described herein may be used to monitor or determine disease progression in a subject.

[0061] In an aspect, a method of determining disease progression in a subject comprises: administering a first dose of HP pyruvate (DI) to the subject and a second dose of HP pyruvate (D2) to the subject, wherein DI is different from D2; detecting, by one or more processors, a first HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to DI and D2; waiting for a period of time; repeating administration of the first dose of HP pyruvate (rDl) to the subject and the second dose of HP pyruvate (rD2) to the subject, wherein rDl is different from rD2; and detecting, by one or more processors, a second HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to rDl and rD2; wherein the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are compared to determine disease progression in the subject.[00621 In some embodiments, the period of time is from about 30 minutes after a session of therapy to about 6 months after the completion of therapy.

[0063] In some embodiments, the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are each a velocity of the chemical conversion rate of HP pyruvate to lactate.

[0064] In some embodiments, the disease progression is worsening when the second HP pyruvate conversion metric is greater than the first HP pyruvate conversion metric.

[0065] In some embodiments, the disease progression is improving when the second HP pyruvate conversion metric is less than the first HP pyruvate conversion metric.[0066| The methods of the present disclosure may also be used in patient stratification and in further determining whether the patient may respond to a given treatment.EXAMPLES

[0067] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects as defined in the following claims.

[0068] Example 1.

[0069] Experimental

[0070] The apparent rate constant (kpl) for the conversion of pyruvate to lactate was measured in Hth83 anaplastic thyroid cancer cells in vitro.

[0071] Results

[0072] The relationship between kpl, the apparent rate constant for conversion of pyruvate to lactate, the equilibrium velocity of the pyruvate to lactate reaction, and intracellular pyruvate concentration can be written as:Vpl

[0073] kpl[p] + [p*][0074| Here, P and P* reflect intracellular endogeneous pyruvate and exogeneous, spin- labeled (HP) pyruvate, respectively.[0075| Plotting 1 / kpl as a function of the local HP pyruvate concentration [P*] shows a linear dependence. If transport across the cell membrane is not a rate limiting factor for HP pyruvate, then intracellular [P*] will be proportional to extracellular [P*], and the slope of that line can be written as an function of the inverse of equilibrium velocity of the exchange reaction and determined by repeated exposure to HP pyruvate. Given a dose DI and a second dose D2=cD 1 :Solving for the reaction velocity:[0076| Therefore the inverse of the slope of this line (1 / m) is proportional to Vpl. The ratio of [P*] / D1 (the fraction of the dose of HP pyruvate that is delivered to a given tumor voxel) depends on vascular function, the HP MRI injection, tumor location and cardiac function, and other factors.

[0077] The embodiments, illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising,” “including,” “containing,” etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase “consisting essentially of’ will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase “consisting of’ excludes any element not specified.[0078| The present disclosure is not to be limited in terms of the particular embodiments described in this application. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and compositions within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, or compositions, which can of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0079] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0080] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range comprises each individual member.

[0081] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained intext incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

Claims

WHAT IS CLAIMED IS:

1. A method of characterizing cellular metabolism in a subject, comprising: administering a first dose of HP pyruvate to the subject and a second dose of HP pyruvate to the subject, wherein the first dose is different from the second dose; obtaining, using an MRI scanner, a plurality of MRI scans of the subject; outputting, using one or more processors, a first rate of conversion of the HP pyruvate to lactate for the first dose and a second rate of conversion of the HP pyruvate to lactate for the second dose; outputting, by one or more processors, an HP pyruvate conversion metric based at least on the first rate of conversion and the second rate of conversion; wherein the HP pyruvate conversion metric is used to characterize the cellular metabolism in the subject.

2. The method of claim 1, wherein the HP pyruvate conversion metric comprises a plot of the inverse of the rate of conversion of the HP pyruvate versus dose of HP pyruvate.

3. The method of claim 2, wherein the slope of the plot is inversely proportional to an equilibrium velocity of a reaction that mediates the chemical conversion of HP pyruvate to lactate, and wherein the reaction velocity is calculated from the slope of this line as a doseindependent measure of tumor metabolism.

4. The method of any one of claims 1-3, wherein the first dose and second dose of HP pyruvate are each up to about 0.43 mL / kg of a 250 mM solution.

5. The method of any one of claims 1-4, wherein measuring the first rate of conversion and the second rate of conversion occurs over a period from about 1 minute to 5 minutes.

6. The method of any one of claims 1-5, wherein a period of time between administration of the first dose and the second dose is from 5 minutes to 1 hour.

7. The method of any one of claims 1-6, wherein the subject is assigned a diagnosis of cancer.

8. The method of any one of claims 1-7, wherein the subject is assigned a diagnosis of an aggressive or a late-stage cancer.

9. A method of determining efficacy of cancer therapy in a subject, the method comprising:administering a first dose of HP pyruvate (DI) to the subject and a second dose of HP pyruvate (D2) to the subject, wherein DI is different from D2; detecting, by one or more processors, a first HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to DI and D2; waiting for a period of time; repeating administration of the first dose of HP pyruvate (rDl) to the subject and the second dose of HP pyruvate (rD2) to the subject, wherein rDl is different from rD2; and detecting, by one or more processors, a second HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to rDl and rD2; wherein the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are compared to determine the efficacy of cancer therapy in the subject.

10. The method of claim 9, wherein the period of time is from about 30 minutes after a therapy session to up to about 6 months after completion of therapy.

11. The method of claim 9 or claim 10, wherein the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are each a velocity of the chemical conversion rate of HP pyruvate to lactate.

12. The method of any one of claims 9-11, wherein cancer therapy is effective when the second HP pyruvate conversion metric is less than the first HP pyruvate conversion metric.

13. The method of any one of claims 9-11, wherein cancer therapy is ineffective when the second HP pyruvate conversion metric is greater than or equal to the first HP pyruvate conversion metric.

14. A method of determining disease progression in a subject, the method comprising: administering a first dose of HP pyruvate (DI) to the subject and a second dose ofHP pyruvate (D2) to the subject, wherein DI is different from D2; detecting, by one or more processors, a first HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to DI and D2; waiting for a period of time; repeating administration of the first dose of HP pyruvate (rDl) to the subject and the second dose of HP pyruvate (rD2) to the subject, wherein rDl is different from rD2; and detecting, by one or more processors, a second HP pyruvate conversion metric based at least on a plurality of MRI scans of the subject corresponding to rDl and rD2;wherein the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are compared to determine disease progression in the subject.

15. The method of claim 14, wherein the period of time is from 45 minutes after a therapy session to up to 6 months after completion of therapy.

16. The method of claim 14 or claim 15, wherein the first HP pyruvate conversion metric and the second HP pyruvate conversion metric are each a velocity of the chemical conversion rate of HP pyruvate to lactate.

17. The method of any one of claims 14-16, wherein the disease progression is worsening when the second HP pyruvate conversion metric is greater than the first HP pyruvate conversion metric.

18. The method of any one of claims 14-16, wherein the disease progression is improving when the second HP pyruvate conversion metric is less than the first HP pyruvate conversion metric.

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