Internet for Pharmaceutical and Biotech Communities
| Newsletter | Advertising |
 
 
 

  

Pharm/Biotech
Resources

Outsourcing Guide

Cont. Education

Software/Reports

Training Courses

Web Seminars

Jobs

Buyer's Guide

Home Page

Pharm Patents /
Licensing

Pharm News

Federal Register

Pharm Stocks

FDA Links

FDA Warning Letters

FDA Doc/cGMP

Pharm/Biotech Events

Consultants

Advertiser Info

Newsletter Subscription

Web Links

Suggestions

Site Map
 

 
   

 

  Pharmaceutical Patents  

 

Title:  Use of an agent that restores tissue perfusion and oxygenation
United States Patent:  7,338,670
Issued: 
March 4, 2008

Inventors: 
Dewhirst; Mark W. (Durham, NC), Stamler; Jonathan S. (Chapel Hill, NC), McMahon; Timothy J. (Durham, NC), Sonveaux; Pierre (Ottignies-Louvain-la-Neuve, BE)
Assignee: 
Duke University (Durham, NC)
Appl. No.: 
11/404,494
Filed: 
April 13, 2006


 

Executive MBA in Pharmaceutical Management, U. Colorado


Abstract

The presently disclosed subject matter provides methods for increasing perfusion in hypoxic regions of tissues in subjects. Also provided are methods for treating diseases and/or disorders associated with hypoxia in subjects, methods for increasing sensitivity of tumors to radiation and/or chemotherapy treatments, methods for delaying tumor growth in subjects, and methods for inhibiting tumor blood vessel growth in subjects. In some embodiments, the presently disclosed methods involve administering to subjects in need thereof a first composition selected from the group consisting of a nitrosylated hemoglobin and an agent that induces nitrosylation of endogenous hemoglobin in the subject and a second composition comprising a hyperoxic gas. In some embodiments, the presently disclosed methods also include treating a tumor with radiation therapy, chemotherapy, photodynamic therapy, immunotherapy, or combinations thereof. Also provided are inhalable gases that can be employed in the presently disclosed methods.

Description of the Invention

SUMMARY

The presently disclosed subject matter provides methods of increasing perfusion in a hypoxic region of a tissue in a subject. In some embodiments, the methods comprise administering to the subject (a) a composition selected from the group consisting of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (b) a hyperoxic gas. In some embodiments, the agent that induces nitrosylation of hemoglobin in the subject comprises ethyl nitrite (ENO). In some embodiments, the ethyl nitrite (ENO) is administered to the subject as an inhalable composition comprising about 100 parts per million (ppm) in the hyperoxic gas. In some embodiments, the hemoglobin is present within a red blood cell. In some embodiments, the red blood cell is present within the subject. In some embodiments, the hemoglobin is present within a red blood cell that is administered to the subject. In some embodiments, the hyperoxic gas is selected from the group consisting of pure oxygen and carbogen. In some embodiments, the tissue comprises a tumor cell, a cancer cell, and combinations thereof. In some embodiments, the subject is a mammal. In some embodiments, the mammal is a human. In some embodiments, the administering results increases a pO.sub.2 value in at least a fraction of the hypoxic region of the tissue to at least about 10 mm Hg. In some embodiments, the hypoxic region of the tissue results from a disease or disorder in the subject, and the administering ameliorates at least one symptom associated with the disease or disorder in the subject.

The presently disclosed subject matter also provides methods for treating a disease or disorder associated with hypoxia in a subject. In some embodiments, the methods comprise administering to the subject (a) a composition selected from the group consisting of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (b) a hyperoxic gas. In some embodiments, the agent that induces nitrosylation of endogenous hemoglobin in the subject comprises ethyl nitrite (ENO). In some embodiments, the ethyl nitrite (ENO) is administered to the subject at about 100 parts per million (ppm) in the hyperoxic gas. In some embodiments, the hemoglobin is present within a red blood cell. In some embodiments, the red blood cell is present within the subject. In some embodiments, the hemoglobin is present within a red blood cell that is administered to the subject. In some embodiments, the hyperoxic gas is selected from the group consisting of pure oxygen and carbogen. In some embodiments, the disease or disorder comprises a tumor, a cancer, peripheral vascular disease, diabetes, a disease related to smoking, cirrhosis, rheumatoid arthritis, stroke, myocardial infarction, and combinations thereof. In some embodiments, the disease or disorder comprises a tumor, a cancer, or combinations thereof, and the methods further comprise treating the subject with a second therapy selected from the group consisting of radiotherapy, chemotherapy, immunotherapy, surgery, photodynamic therapy, and combinations thereof. In some embodiments, the treating the subject with a second therapy step is performed concurrently with the administering step. In some embodiments, the subject is a mammal. In some embodiments, the mammal is a human. In some embodiments, the administering results increases a pO.sub.2 value in at least a fraction of the hypoxic region of the tissue to at least about 10 mm Hg.

The presently disclosed subject matter also provides methods for increasing a sensitivity of a tumor in a subject to a treatment. In some embodiments, the methods comprise administering to the subject (a) a composition selected from the group consisting of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (b) a hyperoxic gas, wherein the administering increases pO.sub.2 in a plurality of cells of the tumor to above about 10 mm Hg, thereby increasing sensitivity of the tumor to the treatment. In some embodiments, the treatment is selected from the group consisting of radiotherapy, chemotherapy, photodynamic therapy, immunotherapy, and combinations thereof. In some embodiments, the agent that induces nitrosylation of endogenous hemoglobin in the subject comprises ethyl nitrite (ENO). In some embodiments, the ethyl nitrite (ENO) is administered to the subject as an inhalable composition comprising about 100 parts per million (ppm) in the hyperoxic gas. In some embodiments, the administering comprises administering a minimally therapeutic dose of the first composition and the second composition. In some embodiments, the tumor is resistant to radiation therapy, chemotherapy, or both radiation therapy and chemotherapy. In some embodiments, the hemoglobin is present within a red blood cell. In some embodiments, the red blood cell is present within the subject. In some embodiments, the hemoglobin is present within a red blood cell that is administered to the subject. In some embodiments, the subject is a mammal. In some embodiments, the mammal is a human.

The presently disclosed subject matter also provides methods for delaying tumor growth in a subject. In some embodiments, the methods comprise (a) administering to the subject (i) a composition selected from the group consisting of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (ii) a hyperoxic gas, wherein the administering increases pO.sub.2 in a plurality of cells of the tumor to above about 10 mm Hg; and (b) treating the tumor with radiation therapy, chemotherapy, or both radiation therapy and chemotherapy, whereby tumor growth in the subject is delayed. In some embodiments, the tumor is resistant to radiation therapy, chemotherapy, or both radiation therapy and chemotherapy. In some embodiments, the agent that induces nitrosylation of endogenous hemoglobin in the subject comprises ethyl nitrite (ENO). In some embodiments, the ethyl nitrite (ENO) is administered to the subject as an inhalable composition comprising about 100 parts per million (ppm) in the hyperoxic gas. In some embodiments, the hemoglobin is present within a red blood cell. In some embodiments, the red blood cell is present within the subject. In some embodiments, the hemoglobin is present within a red blood cell that is administered to the subject. In some embodiments, the subject is a mammal. In some embodiments, the mammal is a human. In some embodiments, the treating the tumor with radiation therapy comprises treating the tumor with a subtherapeutic dose of ionizing radiation. In some embodiments, the treating the tumor with chemotherapy comprises administering to the subject a therapeutically effective amount of a chemotherapy agent. In some embodiments, the methods further comprise promoting tumor regression.

The presently disclosed subject matter also provides methods for inhibiting tumor blood vessel growth in a subject. In some embodiments, the methods comprise (a) administering to the subject (i) a composition selected from the group consisting of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (ii) a hyperoxic gas, wherein the administering increases pO2 in a plurality of cells of the tumor to above about 10 mm Hg; and (b) treating the tumor with radiation therapy, chemotherapy, or both radiation therapy and chemotherapy, whereby tumor blood vessel growth in the subject is inhibited. In some embodiments, the agent that induces nitrosylation of hemoglobin in the subject comprises ethyl nitrite (ENO). In some embodiments, the ethyl nitrite (ENO) is administered to the subject as an inhalable composition comprising about 100 parts per million (ppm) in the hyperoxic gas. In some embodiments, the hemoglobin is present within a red blood cell. In some embodiments, the red blood cell is present within the subject. In some embodiments, the hemoglobin is present within a red blood cell that is administered to the subject. In some embodiments, the subject is a mammal. In some embodiments, the mammal is a human. In some embodiments, the methods further comprise delaying tumor growth in the subject. In some embodiments, the methods further comprise promoting tumor regression in the subject.

The presently disclosed subject matter also provides methods of enhancing delivery of a diagnostic, therapeutic, or prognostic agent to a tumor in a subject. In some embodiments, the methods comprise (a) administering to the subject a composition selected from the group consisting of a nitrosylated hemoglobin, a nitrosylating agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and a nitrosylating agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (b) administering a diagnostic, therapeutic, or prognostic agent to the subject, wherein delivery of the diagnostic, therapeutic, or prognostic agent agent to a tumor in the subject is enhanced. In some embodiments, the composition comprises the diagnostic, therapeutic, or prognostic agent. In some embodiments, the diagnostic, therapeutic, or prognostic agent comprises an imaging agent. In some embodiments, the methods further comprise administering to the subject a hyperoxic gas selected from the group consisting of 100% oxygen and carbogen. In some embodiments, the subject is a mammal. In some embodiments, the mammal is a human.

The presently disclosed subject matter also provides inhalable compositions. In some embodiments, the inhalable compositions comprise (a) a composition selected from the group consisting of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (b) a hyperoxic gas. In some embodiments, the inhalable composition comprises at least about 100 parts per million (ppm) ethyl nitrite (ENO). In some embodiments, the hyperoxic gas is selected from the group consisting of pure oxygen and carbogen.

Accordingly, it is an object of the presently disclosed subject matter to provide methods and compositions for increasing perfusion in a hypoxic region of a tissue in a subject. This and other objects are achieved in whole or in part by the presently disclosed subject matter.

An object of the presently disclosed subject matter having been stated above, other objects and advantages of the presently disclosed subject matter will become apparent to those of ordinary skill in the art after a study of the following description and non-limiting Examples.

DETAILED DESCRIPTION

The most powerful sensitizer for radiotherapy is oxygen, and an agent with similar radiosensitizing properties is nitric oxide. As disclosed herein, a vasodilating agent is used to increase perfusion and maintain oxygenation of tumors during high oxygen content gas breathing. The vasodilating agent is capable of carrying NO to the tumor site and releases NO in a form that can increase radiosensitivity and/or chemosensitivity of the tumor at least in part by reducing tumor hypoxia and by providing NO in sufficient quantities to mimic oxygen in fixation of sublethal radiation or chemotherapy damage.

The steal effect arises as a consequence of the non tumor-selective vasoresponses to vasodilators. It prevents the clinical use of these agents for sensitizing tumors to radiation therapy and chemotherapy (Feron, 2004). Ethyl nitrite (ENO; also referred to as O-nitrosoethanol) has not been previously tested in this regard. ENO is a gas that can be delivered through airways to subjects and it does not reduce blood pressure. As such, it can react with fully-oxygenated hemoglobin (Hb) within red blood cells that transit through the lung vasculature, leading to the formation of S-nitrosylated Hb (SNO-Hb).

SNO-Hb is used to maintain perfusion and improve oxygenation of tumors during high oxygen content gas breathing. During hyperoxic gas breathing, nitrosohemoglobin releases NO in the distal arterioles, thereby opposing the vasoconstricting effects of hyperoxia. This effect improves delivery of oxygen and perfusion to tumor regions that might otherwise be hypoxic. Additionally, this vasodilating agent is capable of releasing NO in tumor regions in a form that can increase radiosensitivity and/or chemosensitivity of hypoxic regions by providing NO in sufficient quantities to mimic oxygen in fixation of sublethal radiation or chemotherapy damage, following exposure. Thus, the presently disclosed subject matter includes the combination of improved oxygen delivery and NO delivery to increase tumor radiosensitivity and/or chemosensitivity.

SNO-Hb is delivered to the tumor via red blood cells. The delivery occurs by having a tumor-bearing subject breathe a NO donor gas (such as ethyl nitrite) that is mixed with a hyperoxic gas, such as pure oxygen or carbogen (95% oxygen, 5% CO.sub.2). The addition of hyperoxic gas breathing maintains Hb in the R-state, which prevents unloading of O.sub.2 and SNO until the Hb enters into tumor regions, which are relatively hypoxic as compared to normal tissues. This approach maintains or improves perfusion and oxygen delivery to relatively hypoxic tumor regions.

Compositions

The presently disclosed subject matter provides in some embodiments compositions comprising one or more of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof. As such, the compositions disclosed herein are designed in some embodiments to deliver to, or produce in, a subject a nitrosylated hemoglobin.

Thus, in some embodiments the compositions disclosed herein comprise a hemoglobin that has been nitrosylated prior to administration to a subject. Any nitrosylation methods can be used to nitrosylate the hemoglobin to be administered, and include, but are not limited to the methods disclosed in the Materials and Methods used in EXAMPLES 1-5 presented hereinbelow. Thus, a hemoglobin or hemoglobin substitute can be modified in vitro or in vivo prior to administration to a subject. In some embodiments, the hemoglobin is present within a red blood cell.

Additionally, in some embodiments the compositions disclosed herein comprise an agent that induces nitrosylation of hemoglobin in the subject. As used herein, the phrase "an agent that induces nitrosylation of hemoglobin in a subject" refers to any agent that when administered to a subject results in a higher level of hemoglobin nitrosylation in the subject than would have been present in the subject in the absence of the agent. A representative agent that induces nitrosylation of hemoglobin in a subject comprises a nitric oxide donor.

In some embodiments, a nitric oxide donor comprises ethyl nitrite (ENO). It is understood, however, that other NO donors can be employed in the practice of the presently disclosed subject matter, with the proviso that the NO donor is capable of nitrosylating hemoglobin in vitro and/or in vivo, optionally endogenous hemoglobin present within a red blood cell. Other NO donors include, but are not limited to S-nitrosoglutathione (GSNO) and ethyl nitrate (ENO.sub.2).

Additionally, the route of administration of the agent (e.g., a NO donor) is not to be viewed as a limitation of the presently disclosed subject matter. Therefore, while in some embodiments an NO donor is provided in a breathable gas, NO donors can also be administered for example in an oral form, in the form of intravenous, intra-arterial, intramuscular, subcutaneous, or other injectable form, provided that the administration of the NO donor results in an increased level of nitrosylation of hemoglobin in the subject (e.g., the subject's own hemoglobin and/or an administered hemoglobin or hemoglobin product).

In some embodiments, the agent that induces nitrosylation of hemoglobin in the subject is capable of nitrosylating hemoglobin present within a red blood cell that is already in the subject. The red blood cell can be one of the subject's own red blood cells or can be a red blood cell that was administered to the subject.

In some embodiments, the compositions further comprise a hyperoxic gas. As used herein, the phrase "hyperoxic gas" refers to a gas that comprises an oxygen content that is greater than that found in normal room air (i.e., about 21%). Thus, a "hyperoxic gas" is a gas that includes, for example, about 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, or 25% oxygen. In some embodiments, a hyperoxic gas is 100% oxygen, and in some embodiments a hyperoxic gas is carbogen (about 95% oxygen, about 5% carbon dioxide).

Breathing hyperoxic gas can lead to vasoconstriction, which can negatively impact the ability of the hyperoxic gas to deliver increased oxygen to a target tissue (e.g., a region of hypoxia). Accordingly, the hyperoxic gas is mixed in some embodiments with a vasodilation agent such as nitric oxide and/or a nitric oxide donor including, but not limited to an alkyl nitrite such as C1-C6 straight chain, branched, or substituted alkyl nitrite (e.g., ethyl nitrite). While applicants do not wish to be bound by any particular theory of operation, a nitric oxide donor is chosen that is capable of nitrosylating hemoglobin either in vitro or in vivo, including hemoglobin that is within a red blood cell or not within a red blood cell.

II Methods of Treatment

III.A. Methods for Increasing Perfusion

The presently disclosed subject matter provides in some embodiments methods for treating conditions associated with hypoxia. As used herein, the phrase "condition associated with hypoxia" refers to any disease and/or disorder, and/or any symptom thereof, which results from and/or is exacerbated or aggravated by hypoxia. Exemplary conditions associated with hypoxia include, but are not limited to tumors, cancers, peripheral vascular diseases, diabetes, diseases related to smoking, cirrhosis, rheumatoid arthritis, stroke, myocardial infarction, and combinations thereof. Accordingly, the methods and compositions disclosed herein can be employed to treat and/or ameliorate at least one symptom of these conditions.

As disclosed herein, certain diseases and/or disorders associated with hypoxia, and/or one or more symptoms thereof, can be treated by reducing hypoxic regions of relevant tissues in a subject. This can be accomplished in any manner including, but not limited to delivering more oxygen to the tissue such as by increasing perfusion in a hypoxic region of the tissue.

Accordingly, the presently disclosed subject matter provides in some embodiments methods for increasing perfusion in a hypoxic region of a tissue in a subject. In some embodiments, the methods comprise administering to the subject an inhalable composition comprising ethyl nitrite (ENO) and optionally a hyperoxic gas.

Increasing perfusion can also lead to other beneficial outcomes. For example, it is also expected that the distribution of other agents delivered by the blood to a tumor would be enhanced using the methods and compositions disclosed herein. Exemplary, non-limiting agents include diagnostic, therapeutic, and/or prognostic agents such as contrast agents using for functional imaging of tumors.

III.B. Methods for Treating Tumors and/or Cancers

The presently disclosed subject matter also provides methods for treating subjects with particular conditions associated with hypoxia. In some embodiments, a condition associated with hypoxia is a tumor and/or a cancer. In some embodiments, the methods and compositions disclosed herein are part of a combination therapy as discussed in more detail hereinbelow.

In some embodiments, the presently disclosed subject matter relates to methods for delaying tumor growth in a subject. In some embodiments, the methods comprise administering to the subject a composition selected from the group consisting of a nitrosylated hemoglobin, an agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and an agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof, optionally in combination with a hyperoxic gas. In some embodiments, the administering increases pO.sub.2 in a plurality of cells of the tumor to above about 10 mm Hg, whereby tumor growth in the subject is delayed. In some embodiments, the hyperoxic gas is selected from the group consisting of pure oxygen and carbogen. In some embodiments, the administering step increases pO.sub.2 in a plurality of cells of the tumor to above about 10 mm Hg. In some embodiments, pO.sub.2 is monitored in the tumor in real time to ensure that it is at least about 10 mm Hg. In some embodiments, the methods also comprise treating the tumor with radiation therapy, chemotherapy, or both radiation therapy and chemotherapy.

Additionally, the presently disclosed subject matter relates in some embodiments to methods for inhibiting tumor blood vessel growth in a subject. In some embodiments, the methods comprise administering to the subject an inhalable composition comprising ethyl nitrite (ENO) and optionally a hyperoxic gas (for example, a hyperoxic gas selected from the group consisting of pure oxygen and carbogen). In some embodiments, the administering step increases pO.sub.2 in a plurality of cells of the tumor to above about 10 mm Hg. In some embodiments, the methods further comprise and (b) treating the tumor with radiation therapy, chemotherapy, or both radiation therapy and chemotherapy. As used herein, such an inhibition need not be absolute, but can include a decrease in a rate and/or extent of tumor angiogenesis that results from employing the methods and/or compositions disclosed herein.

IV. Methods for Enhancing Delivery of Diagnostic, Therapeutic, and/or Prognostic Agents

The presently disclosed subject matter also provides methods for enhancing delivery of a diagnostic, therapeutic, or prognostic agent to a target tissue including, but not limited to a tumor, in a subject. In some embodiments, the methods comprise (a) administering to the subject a composition selected from the group consisting of a nitrosylated hemoglobin, a nitrosylation agent that induces nitrosylation of hemoglobin in the subject, a hemoglobin and a nitrosylation agent that induces nitrosylation of hemoglobin in the subject, and combinations thereof; and (b) administering the diagnostic, therapeutic, or prognostic agent to the subject, wherein delivery of the diagnostic, therapeutic, or prognostic agent to a tumor in the subject is enhanced. The compositions and methods disclosed herein can be employed to increase perfusion and/or blood flow in target tissues including, but not limited to hypoxic regions of tumors. In some embodiments, the methods further comprise administering to the subject a hyperoxic gas selected from the group consisting of 100% oxygen and carbogen.

Accordingly, the compositions and methods disclosed herein can be employed to enhance delivery of diagnostic, therapeutic, and prognostic agents that are carried via the bloodstream (e.g., agents that are injected intravenously) by enhancing blood flow in the target tissue. The delivery of any such agent can be enhanced, including but not limited to therapeutic agents such as drugs and diagnostic and/or prognostic agents such as imaging agents. Particularly with respect to imaging agents that cannot be conveniently administered directly to a target tissue, the ability to increase the delivery of the imaging agent by employing the compositions and methods disclosed herein can result in greater capacity to image the target tissue, less time the subject must spend in the imaging apparatus, a lower dose of imaging agent that is required for acceptable imaging, and combinations thereof. Particularly with respect to imaging agents that have known toxicity associated with their use, the ability to use less of the agent can be a considerable advantage.

V. Combination Therapies

Tumors and/or cancers can be treated using combination therapies comprising combinations of surgery, radiotherapy, and/or chemotherapy, and/or other therapies include, but not limited to photodynamic therapy (PDT) and immunotherapy (IT). Thus, the presently disclosed subject matter can be employed as a part of a combination therapy. As used herein, the phrase "combination therapy" refers to any treatment wherein the methods and compositions disclosed herein are used in combination with another therapy including, but not limited to radiation therapy (radiotherapy), chemotherapy, surgical therapy (e.g., resection), PDT, IT, and combinations thereof.

As disclosed herein, various therapies that are employed to treat neoplastic disease can be relatively ineffective if the tumor and/or cancer includes localized regions of hypoxia. This is based at least in part on the requirement for the therapy to generate free radicals from oxygen, which does not occur in hypoxic sites.

As a result, the methods and/or compositions disclosed herein can be employed to enhance the effectiveness of a second treatment such as radiotherapy, chemotherapy, photodynamic therapy, immunotherapy, and combinations thereof. In these embodiments, the methods relate to increasing the sensitivity of a tumor and/or a tumor cell in a subject to a treatment, and in some embodiments the methods comprise administering to the subject an inhalable composition comprising ethyl nitrite (ENO) and optionally a hyperoxic gas, which further optionally can be selected from the group consisting of pure oxygen and carbogen, whereby pO.sub.2 in a plurality of cells of the tumor is increased to above about 10 mm Hg, thereby increasing sensitivity of the tumor to the second treatment (e.g., a treatment selected from the group consisting of radiotherapy, chemotherapy, photodynamic therapy, immunotherapy, and combinations thereof.

V.A Radiation Treatment

In some embodiments, the methods and compositions disclosed herein are employed in a combination therapy with radiation treatment. For such treatment of a tumor, the tumor is irradiated concurrent with, or subsequent to, administration of an inhalable composition as disclosed herein. One of skill in the medical art can design, upon consideration of the instant disclosure, an appropriate dosing schedule for treating a subject with radiation in conjunction with the compositions and methods disclosed herein. For example, tumors can be irradiated with brachytherapy utilizing high dose rate or low dose rate brachytherapy internal emitters.

In order to enhance the benefit gained from administration of the compositions disclosed herein, the timing of administration of the composition and the radiation treatment should be adjusted such that the pO.sub.2 in the tumor to be treated is at least about 10 mm Hg during at least a portion of the entire period when the radiation is being administered (optionally, during the entire period). Accordingly, the composition can be administered beginning, for example, 5, 10, 15, 20, 30, 45, or 60 minutes before the radiation treatment is administered. Additionally, the subject can continue to breathe the composition while the radiation treatment is being administered. Upon cessation of the radiation treatment, the administration of the composition can also be terminated.

It is understood that since radiotherapy typically is repeated several times in order to affect a maximal response, the administration of the composition can likewise be repeated each time radiotherapy is given. Thus, the time course over which a inhalable composition as disclosed herein is administered can comprise in some embodiments a period of several weeks to several months coincident with radiotherapy, but in some embodiments can extend to a period of 1 year to 3 years as needed to effect tumor control. Alternatively, a composition can be administered prior to an initial radiation treatment and then at desired intervals during the course of radiation treatment (e.g., weekly, monthly, or as required).

Subtherapeutic or therapeutic doses of radiation can be used for treatment of a tumor and/or a cancer as disclosed herein. In some embodiments, a subtherapeutic or minimally therapeutic dose (when administered alone) of ionizing radiation is used. For example, the dose of radiation can comprise in some embodiments at least about 2 Gy ionizing radiation, in some embodiments about 2 Gy to about 6 Gy ionizing radiation, and in some embodiments about 2 Gy to about 3 Gy ionizing radiation. When radiosurgery is used, representative doses of radiation include about 10 Gy to about 20 Gy administered as a single dose during radiosurgery or about 7 Gy administered daily for 3 days (about 21 Gy total). When high dose rate brachytherapy is used, a representative radiation dose comprises about 7 Gy daily for 3 days (about 21 Gy total). For low dose rate brachytherapy, radiation doses typically comprise about 12 Gy administered twice over the course of 1 month. .sup.1251I seeds can be implanted into a tumor can be used to deliver very high doses of about 110 Gy to about 140 Gy in a single administration.

Radiation can be localized to a tumor using conformal irradiation, brachytherapy, stereotactic irradiation, intensity modulated radiation therapy (IMRT), and/or can be localized to a tumor by employing vectors that comprise, but are not limited to, proteins, antibodies, liposomes, lipids, nanoparticles, and combinations thereof. The threshold dose for treatment can thereby be exceeded in the target tissue but avoided in surrounding normal tissues. For treatment of a subject having two or more tumors, local irradiation enables differential drug administration and/or radiotherapy at each of the two or more tumors. Alternatively, whole body irradiation can be used, as permitted by the low doses of radiation required following radiosensitization of the tumor.

Radiation can also comprise administration of internal emitters, for example .sup.131I for treatment of thyroid cancer, NETASTRON.TM. and QUADRAGEN.RTM. pharmaceutical compositions (Cytogen Corp., Princeton, N.J., United States of America) for treatment of bone metastases, .sup.32P for treatment of ovarian cancer. Other internal emitters include .sup.125I, iridium, and cesium. Internal emitters can be encapsulated for administration or can be loaded into a brachytherapy device.

Radiotherapy methods suitable for use in the practice of presently disclosed subject matter can be found in Leibel & Phillips, 1998, among other sources.

V.B. Chemotherapy Treatment

In some embodiments, the methods and compositions disclosed herein are employed in a combination therapy with chemotherapy. Particular chemotherapeutic agents are generally chosen based upon the type of tumor to be treated, and such selection is within the skill of the medical professional.

Chemotherapeutic agents are generally grouped into several categories including, but not limited to DNA-interactive agents, anti-metabolites, tubulin-interactive agents, hormonal agents, and others such as asparaginase or hydroxyurea. Each of the groups of chemotherapeutic agents can be further divided by type of activity or compound. For a detailed discussion of various chemotherapeutic agents and their methods for administration, see Dorr et al., 1994, herein incorporated by reference in its entirety.

In order to reduce the mass of the tumor and/or stop the growth of the cancer cells, a chemotherapeutic agent should prevent the cells from replicating and/or should interfere with the cell's ability to maintain itself. Exemplary agents that accomplish this are primarily the DNA-interactive agents such as Cisplatin, and tubulin interactive agents.

DNA-interactive agents include, for example, alkylating agents (e.g., Cisplatin, Cyclophosphamide, Altretamine); DNA strand-breakage agents (e.g., Bleomycin); intercalating topoisomerase II inhibitors (e.g., Dactinomycin and Doxorubicin); non-intercalating topoisomerase II inhibitors (e.g., Etoposide and Teniposide); and the DNA minor groove binder Plicamycin.

Generally, alkylating agents form covalent chemical adducts with cellular DNA, RNA, and/or protein molecules, and with smaller amino acids, glutathione, and/or similar biomolecules. These alkylating agents typically react with a nucleophilic atom in a cellular constituent, such as an amino, carboxyl, phosphate, or sulfhydryl group in nucleic acids, proteins, amino acids, or glutathione.

Anti-metabolites interfere with the production of nucleic acids by either of two major mechanisms. Some of the drugs inhibit production of deoxyribonucleoside triphosphates that are the immediate precursors for DNA synthesis, thus inhibiting DNA replication. Some of the compounds are sufficiently like purines or pyrimidines to be able to substitute for them in the anabolic nucleotide pathways. These analogs can then be substituted into the DNA and RNA instead of their normal counterparts.

Hydroxyurea appears to act primarily through inhibition of the enzyme ribonucleotide reductase.

Asparaginase is an enzyme which converts asparagine to nonfunctional aspartic acid and thus blocks protein synthesis in the tumor.

Tubulin interactive agents act by binding to specific sites on tubulin, a protein that polymerizes to form cellular microtubules. Microtubules are critical cell structure units. When the interactive agents bind on the protein, the cell can not form microtubules. Tubulin interactive agents include Vincristine and Vinblastine, both alkaloids and Paclitaxel.

Adrenal corticosteroids are derived from natural adrenal cortisol or hydrocortisone. They are used because of their anti-inflammatory benefits as well as the ability of some to inhibit mitotic divisions and to halt DNA synthesis. These compounds include Prednisone, Dexamethasone, Methylprednisolone, and Prednisolone.

The hormonal agents and leutinizing hormones are not usually used to substantially reduce the tumor mass. However, they can be used in conjunction with the chemotherapeutic agents. Hormonal blocking agents are also useful in the treatment of cancers and tumors. They are used in hormonally susceptible tumors and are usually derived from natural sources. These include, but are not limited to estrogens and conjugated estrogens, progestins, and androgens. Leutinizing hormone releasing hormone agents or gonadotropin-releasing hormone antagonists are used primarily the treatment of prostate cancer. These include leuprolide acetate and goserelin acetate. They prevent the biosynthesis of steroids in the testes. Other anti-hormonal agents include anti-estrogenic agents, anti-androgen agents, and anti-adrenal agents such as Mitotane and Aminoglutethimide.

VI. Other Oxygen-Dependent Treatments

Various other oxygen-dependent therapies can be employed that would be expected to benefit from the presently disclosed compositions and methods. Examples of therapies that could benefit from a combined treatment regimen employing the methods and/or compositions disclosed herein include any antitumor therapies wherein an active agent reaches the tumor from the systemic circulation. Such therapies include, but are not limited to, photodynamic therapy, hormone therapy, immunotherapy, gene therapy, antivascular therapy, antiangiogenic therapy, cell therapy (based on injection or mobilization of cells with an antitumor activity), and combinations thereof, including any of these therapies further in combination with radiotherapy and/or chemotherapy. Circulating antitumor agents for which therapeutic efficacy can be increased through administration of the compounds disclosed herein include ions, small molecules, macromolecules, peptides, proteins, nucleotides, virus, liposomes, emulsions, bacteria, immune cells, stem cells, and combination(s) thereof.

One further therapy that can benefit from the methods and compositions disclosed herein is photodynamic therapy (PDT). The therapeutic effect of PDT is highly dependent upon oxygen availability. PDT involves two individual inactive components that are combined to induce cellular and tissue effects in an O.sub.2-dependent manner (Dolmans et al., 2003). The first component is the photosensitizer (e.g., porphirins), which localizes to the tumor. The second component involves the administration of light of a specific wavelength that activates the photosensitizer. In situ, the activated photosensitizer transfers energy from light to O.sub.2 to generate reactive oxygen species, which then mediate cellular toxicity. The biological responses are activated only in the particular areas of tissue that have been exposed to light and contain sufficient amounts of O.sub.2. The toxic species formed with PDT is singlet oxygen. Thus, the cytotoxic effects of PDT drugs are entirely O.sub.2-dependent and photosensitization typically does not occur in hypoxic tumor areas. As a result, increasing the local concentration of oxygen in a tissue targeted for PDT (e.g., a hypoxic region of a tumor) can be expected to enhance the efficacy of the PDT in that target tissue.

Another approach to tumor and/or cancer treatment is immunotherapy. Immunotherapy generally relates to strategies designed to augment the ability of the subject's immune system to recognize tumor cells and eliminate them. Typically, these strategies are intended to boost and/or to activate antitumor lympocytes. A non-limiting example of immunotherapy relates to the use of therapeutic vaccines. Naked peptides, peptides loaded on protein carriers, and/or antigen presenting cells loaded with peptide can also elicit an antitumor response in vivo in subjects. Responses generally involve the activation of antitumor T lymphocytes, but also can include activation of other immunomodulatory cells including, but not limited to memory lymphocytes, natural killer cells, and B lymphocytes.

Heterologous or autologous immune transfer can also be a part of an antitumor treatment strategy, and all these approaches are expected to benefit from the presently disclosed subject matter because immune cells enter the tumor through the systemic circulation and need oxygen to live, to multiply, and to act in a hypoxic environment. See e.g., U.S. Pat. No. 5,405,940 and progeny thereof (including, but not limited to U.S. Pat. Nos. 5,462,871; 5,695,994; 6,034,214; 6,222,012; 6,379,901; and 6,488,932); PCT International Patent Application Publications WO 94/05304; WO 94/16713; WO 95/25530; WO 95/33855; WO 96/29409; WO 98/32855; and WO 98/58956; van Baren et al. 2005; Godelaine et al., 2003; Chaux et al., 1999; Van den Eynde et al., 1995; van der Bruggen et al., 1994; Gaugler et al., 1994; Boon et al., 1994; Traversari et al., 1992; and other patents, published patent applications, and scientific publications from Dr. Thierry Boon and co-workers (each of which is incorporated by reference herein in its entirety) for discussion of MAGE and MAGE-related approaches to antitumor therapy, several of which are currently in clinical trials.

Other immunotherapeutic strategies are designed to affect the anti-tumor activities of the subject's macrophages, which are frequently found in close association with tumors (e.g., so-called "tumor-associated macrophages (TAMs); see Lewis & Murdoch, 2005 for a review). In some cases, macrophages can comprise up to 80% of the cell mass in certain tumors (see Bingle et al., 2002).

Macrophage recruitment to tumors results in alterations in the tumor microenvironment, and is a strongly negative predictive factor for outcome. For example, it has been shown that hypoxic areas of tumors attract macrophages and macrophage precursors (Murdoch et al., 2004), and that the macrophage response to hypoxia can actually increase the ability of the tumor cells to proliferate and/or metastasize (see Lewis & Murdoch, 2005, and references therein). Macrophage responses to hypoxia include the production of various growth factors relevant to tumor cell proliferation and angiogenesis (e.g., epidermal growth factor, vascular endothelial growth factor) as well as the production of immunomodulatory factors such as prostaglandin E.sub.2 and IL-10 that can downregulate the anti-tumor response of various immune effector cells.

Additionally, hypoxia inhibits the phagocytosis of tumor cells and other necrotic cells by macrophages. Taken together, therefore, it is clear that hypoxia alters macrophage biological activities in ways that alone or in combination can severely negatively impact the ability of the subject's immune system to respond to the presence of tumor and/or cancer cells.
 

Claim 1 of 10 Claims

1. A method of increasing perfusion in a hypoxic region of a cancer tissue or tumor in a subject, the method comprising administering to the subject: (a) a composition comprising an agent that induces nitrosylation of hemoglobin in the subject; and (b) a hyperoxic gas.

____________________________________________
If you want to learn more about this patent, please go directly to the U.S. Patent and Trademark Office Web site to access the full patent.

 

 

     
[ Outsourcing Guide ] [ Cont. Education ] [ Software/Reports ] [ Training Courses ]
[ Web Seminars ] [ Jobs ] [ Consultants ] [ Buyer's Guide ] [ Advertiser Info ]

[ Home ] [ Pharm Patents / Licensing ] [ Pharm News ] [ Federal Register ]
[ Pharm Stocks ] [ FDA Links ] [ FDA Warning Letters ] [ FDA Doc/cGMP ]
[ Pharm/Biotech Events ] [ Newsletter Subscription ] [ Web Links ] [ Suggestions ]
[ Site Map ]