TREATMENT FOR EPITHELIAL DISEASES

Abstract: An apparatus and method for treating epithelial hyperproliferative diseases by application of an active composition over the diseased irregular tissue which is in the form of a viscous gel to carry the photosensitizer. The gel's viscosity allows it to adhere to the tissue for a sufficient time to transfer the photosensitizer or for a mechanical device such an expanding balloon to press the gel into the tissue. The photosensitizer within the gel is activated by the corresponding wavelenght of radiation. An extended multi-ballon system limits the area of treatment and localizes the spread of the gel. The apparatus, designed to be used with an endoscope, contains a catheter with at least two balloons, one to block drainage of the gel and one to limit the height of the treatment area and to press the gelinto the tissue.

Description: Treatment for epithelial diseases Inventor(s): Thierry Patrice, Wolfgang Neuberger, Hans-Peter Bode, Ludovic Bourre Assignee: CeramOptec Industries Inc. Background of the Invention 1. Field of the invention The present invention relates to the apparatus and method for necrotizing of epithelial tissue in hyperproliferative epithelial diseases of the interior lining of an organ or of the skin by PhotoDynamic Therapy (PDT). 2. Invention Disclosure Statement Hyperproliferative epithelial diseases comprise pre-cancerous or cancerous states or virally-mediated affections of the mucosa or interior linings of organs or the skin. Examples are Barrett's esophagus, which is a premalignant lesion in which normal squamous epithelium of the esophagus is replaced by a specialized columnar epithelium. Condyloma acuminata is a virally-mediated epithelial overgrowth caused by the human papilloma virus. Its papillary lesion forms are commonly seen in the genital, perineal, and anal areas. Cervix cancer or dysplasia occur at the uterine cervix. A precancerous lesion in the mouth is leukoplakia. The diseases mentioned occur at the mucosa of the different organs or on the skin, and the treatment has to reach irregular tissue structures and a certain depth of the tissue to assure a complete removal of the diseased area. In all of these cases a local treatment is desirable to reduce the side effects of the therapy and to minimize the necessary amount of the therapeutic composition. Nevertheless, locally determined but large areas of the diseased tissue should be treatable at one time to minimize the strain of the patient. Photodynamic therapy (PDT) is a well known method for the treatment of hyperproliferative diseases. The photosensitizer is applied to the patient and is activated by irradiation with (laser) light of the suitable wavelength. Upon activation of the photosensitizer the highly reactive singlet oxygen is generated which oxidizes especially the lipids of the cell membranes thereby destroying the cells and the tissue. Another well known method for photodynamic treatment of malignant and non- malignant hyperproliferative lesions is the application of an effective amount of a precursor of protoporphyrin IX (PpIX) in the biosynthetic pathway for heme so as to induce synthesis of protoporphyrin IX in the lesions, and exposing them to light having a wavelength within the photoactivating action spectrum of PpIX to thereby induce photoactivation in the lesions. An example of such an agent is aminolevulinic acid (ALA) or derivatives thereof, which are not in themselves photosensitizers but which induce the synthesis of protoporphyrin IX (PpLX) in vivo. Protoporphyrin IX (PpIX), a naturally occurring photosensitizer, is the immediate precursor of heme in the heme biosynthetic pathway. All nucleated cells have at least a minimal capacity to synthesize PpLX, since heme is necessary for the synthesis of various essential heme-containing enzymes. However, the usual rate-limiting step in the process, the synthesis of 5-aminolevulinic acid (ALA), can be bypassed by the provision of exogenous ALA, porphobilinogen, or other precursors of PpIX. Certain tissues and organs will then accumulate such a large excess of PpIX that they become both fluorescent and photosensitive. The determination of the areas which become photosensitized is critical to reduce side effects, to reduce applied amounts of the active composition, also reducing possible side effects, and to ensure complete treatment of the afflicted areas in all sizes and in all areas of the body. The current state of the art for the treatment of Barrett's syndrome uses a Nd: YAG laser to treat the afflicted areas. (Ertan et al., Am. J. Gastroenterol. 90:2201-2203[1995]). This method uses a 2.2-mm diameter beam to ablate the afflicted tissue. With such a narrow beam as compared to the size of the area being treated, the treatment procedure becomes time consuming and laborious. Often the patient will have to undergo multiple procedures for a complete treatment. Also to achieve ablation of tissue, a laser with significant power must be used. This increased power creates a larger potential for damage to the healthy tissue underneath. This method does not reveal how to treat a larger area more quickly, efficiently and more safely. One method of treating a larger area is demonstrated in U.S. Pat. No. 6,027,499. This method uses nitrogen gas to quickly freeze the afflicted areas. Gas by its nature expands to fill the volume exposed. This expansion increases the area exposed to treatment. The freezing then kills the cells contacted. However, this method is limited by the lack of depth control in the treating of the tissue. Freezing depth is difficult to control. It would be useful to have fine control on the layer of treatment, so as not to damaged the unaffected non-cancerous cells in the intima of the esophagus. Gels have been used to transfer medicines at a controlled rate or to insure transfer through a tissue of the medicine (e.g. U.S. Pat. No. 4,474,752; 4,474,753; 4.478,822). U.S. Pat. No. 4,474,752 utilizes a thermosetting gel, which gels at body temperature after injection into soft tissue. This liquid is injected into soft tissue where it gels. The gel state releases medication at a measured pace and remains in the injected area until dissolved by the body. The purpose of this invention was to create a slow release subcutaneous mechanism for medication without the discomfort of hard capsules. This invention does not reveal how to deliver medication internally to a site for sole treatment of that site. U.S. Pat. No. 4,474,753, also utilizes a gel which solidifies on contact with the skin. This gel delivers medicine transdermally while it is attached to the skin. This is also a delivery system for medication for general release, not a site specific medication. It would be useful for a gel to release medication for a specific site. U.S. Pat. No. 4,478,822 utilizes another gel system to be injected into body cavities for dose sparing purposes. This again is a general release mechanism designed for a prolonged period of controlled drug release. The medicines released are not meant just for the area where the gel has been injected. It would be useful to have the capability to affect a broad area of treatment during the application of PDT, which will quickly necrotize only the afflicted area and efficiently use the photosensitizer. It would be further useful to have a delivery system for medication to affect one area or system of a body. The present invention addresses these problems. Brief Summary and Objectives of the Invention It is an object of the present invention to provide a treatment for epithelial diseases in pre-cancerous, cancerous or non-cancerous hyperproliferative states using the local application of a therapeutic composition, activating this composition and necrotize the diseased tissue. It is a further object of the invention to use a photosensitizer or aminolevulinic acid or a derivative thereof in the therapeutic composition and to activate the composition by (laser) light of the appropriate wavelength. It is a further object of the invention to apply the active composition in a gel form and thereby increasing the area which can be treated at one time compared to other locally applied compositions, and minimizing the necessary amount of the photosensitizer, although reaching a higher concentration locally than it would have been achieved following a systemic administration. It is another object of the present invention to use a thermosetting gel for the application of the photosensitizer. It is another object of the present invention to treat diseased mucosa which is Barrett's tissue lining a patient's esophagus, esophageal dysplasia or esophageal cancer, condylomata acuminata or other types of condyloma in genital, perineal and anal areas, or other areas of the skin, leukoplakia of the oral cavity and cancer or dysplasia of the uterine cervix. It is another object of the present invention to provide a device to deliver the gel photosensitizer, activate the composition and localize the treatment to just the esophagus. Briefly stated, the present invention provides an apparatus and method for treating epithelial hyperproliferative diseases by local application of the active composition to a determined area of the tissue characterized by complete cover of the diseased, potentially large and irregular structured area. A viscous gel is the medium used to carry the photosensitizer to the treatment site and allow sufficient time to transfer to the tissue. The gel's viscosity allows it to adhere to the tissue for a sufficient amount of time to transfer the photosensitizer or sufficient time for a mechanical device such as an expanding balloon to press the gel into the tissue. The photosensitizer within the gel is activated by the corresponding wavelength of radiation. An extended multi-balloon system limits the area of treatment and localizes the spread of the gel. An endoscope with fiber optics may be used to view the operation. A preferred embodiment of the apparatus contains a catheter with at least two balloons, one to block drainage of the photosensitizer into the stomach and one to limit the height of the treatment area and to press the gel into the tissue. Included in this embodiment is a tube for the delivery of the gel, a tube for cooling purposes or aspiration, an image bundle and a diffuse light source. The apparatus and method may be used to treat Barrett's tissue by removal of the mucosa through PhotoDynamic Therapy (PDT) as well as various other diseases involving diseased mucosa of the gastrointestinal tract, the genital, perineal, and anal area, the oral cavity like leukoplakia, or the skin like basalioma. The most salient feature of this invention with regard to pre-cancerous or cancerous diseases of the esophagus is the multi-balloon system used to limit the area of treatment but affect the entire desired area at one time. The above, and other, objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawing. Brief Description of Figures Fig. 1 - Double Ballooned Catheter With Various Endoscopic Devices Detailed Description of Preferred Embodiments It is an object of the present invention to locally apply an active composition to a selected area of a diseased epithelium area, confining said active composition to said areas, allowing time for sufficient uptake and activating the composition to necrotize the diseased tissue. In a preferred embodiment, aminolevulinic acid (ALA) or derivatives thereof are used as active compositions from which clinically useful amounts of PpIX can be synthesized within the tissues, and the provision of ALA is only beneficial if the tissue affected is at a site that can be reached by photoactivating light. ALA is water soluble and can be administered orally, topically or by injection. The advantages of ALA are first, that the biosynthesized PpIX has a much shorter half-life in normal tissues than does HpIX, HpD or Photofrin II. This greatly reduces the danger of accidental photo toxic skin reactions in the days following treatment. Second, the topical application of ALA to certain types of lesions can induce PpIX within those lesions, but nowhere else. This improves the specificity of the treatment, reduces the danger of accidental photo toxic reactions to a very low level, and greatly reduces the amount of both ALA and PpIX to which the entire body would be exposed if an equally effective dose of ALA were to be given systemically. Both ALA and PpIX are normal products of metabolism, and are handled quite readily by the biochemical machinery of the body. However, since very large doses of ALA (like large doses of HpIX or HpD) are associated with a transient decrease in motor nerve conduction velocity, it is desirable to reduce the dose of ALA to the minimum that is still effective. Topical application requires much less ALA than systemic administration. Third, PpIX is rapidly inactivated by the photoactivating light. Following exposure of tissues containing PpIX to a therapeutic dose of photoactivating light, there is a substantial decrease in photosensitization of the tissues within the treatment volume. Consequently, if PpIX is induced by the topical application of ALA to specific lesions, the patient can be exposed to sunlight immediately post-treatment without danger of serious photo toxicity. However, to reach also deeper parts of the afflicted tissues, it might be useful to apply photo sensitizers that are activated by longer wavelengths than PpIX is, because of the deeper penetration of longer wavelengths into the tissue. Therefore, in another preferred embodiment the use of "second generation photosensitizers" including porphyrins, chlorins, pheophorbides, bacteriopheophorbides and derivatives thereof are used for the determined application on the diseased epithelial areas. The local treatment of determined epithelial areas, preferably large areas is achieved by the application of a highly viscous fluid, a gel or a thermosetting gel. It has been shown that the uptake of ALA into the tissue out of a thermosetting gel is significantly enhanced compared to application of watery ALA solutions (see example 1). The viscosity of the gel allows it to adhere to the tissue for a sufficient amount of time to transfer the photosensitizer, further, a determined application to large areas that are to be treated, and also limits the further distribution of the active composition. The mechanism for the delivery of the job must perform a few basic functions. First, the gel must be delivered to the treatment site. In case of easily accessible treatment sites the gel can be applied directly. In case of the interior lining of inner organs the gel can be applied through a catheter as a pre-mixed gel or through a double lumen catheter and mixed at the treatment site. In place of a straight gel, a liquid which gels after contact with the afflicted surface can serve the same purpose in delivering the photosensitizer to the treatment site. The conventional application of the photosensitizer through spraying results in a loss of material and in unwanted side effects. The spraying of the photosensitizer to the treatment area is an inefficient method of saturating the tissue in that the liquid will drip off the mucosa into organs of the body that are not to be treated. This liquid nature of the photosensitizer also creates a problem in controlling the treatment area. Dripping or over spray may cause areas of the same organ to receive unwanted treatment. Next after delivery to the site, the gel is prevented from moving beyond the treatment site by its viscosity. In case of the esophagus, the described multi-balloon application device further prevents distribution of gel away from the treatment site. The gel is prevented from dripping into the stomach. Not preventing dripping into the stomach can result in waste of the photosensitizer and severe side effects due to the systemic distribution of the sensitizer. Delimiting the treatment areas can be done in a number of ways. Regarding the esophagus, one way is to use the described or a similar multi-balloon catheter, which define the upper and lower limits of the treatment area. Upper and lower limits of treatments could also be delimited with expanding diaphragm devices through which a catheter could poke through and form a seal. After delimiting the treatment site and delivering the gel, the gel can then be pressed into the esophageal mucosa to insure that there is an even distribution of medication. A balloon catheter could be used here to press the gel. Such a balloon can also serve as reservoir from which the gel is applied, through perforations of the balloon. Several forms of the balloon could be used depending on the viscosity of the gel being used. Balloons may have grooves to allow easier flow through thick gels, have a swirling or vibrating motion to insure more complete even distribution or have ridges to remove excess gel. Alternatively, the gel could be allowed to sit and spread on its own. A diffuse radiation source is then applied to the areas covered by the gel to activate the photosensitizer. This radiation source may be obtained in many different ways including, for example, laser endoscope with diffusers, chemiluminescence, and radio frequency devices. Electrical and magnetic fields could also serve to improve the transfer of active molecules through the electrical field. Excess or spent gel can be removed through a vacuum or spent gel may also be allowed to slide into the stomach and be excreted. The procedure can be viewed through fiber optic bundles passed through the catheter. The present invention is further illustrated by the following examples, but is not limited thereby. Example 1: Improved uptake of ALA into murine stomach mucosa from thermosetting gel preparations ALA was incorporated into Noveon® and Pluronic® F-127 gels at concentrations varying from 2.5 to 40 mg/mL to obtain ALA-Noveon®, ALA- Pluronic®. One milliliter of gel was instilled directly through an 18 -gauge needle into the stomach lumen of mice after abdominal incision, pylorus ligature and washing stomach mucosa with NaCl aqueous solution (0.9%, 37°C). After a period of 30 min to 4 h of instillation, the gel was removed and the stomach was washed with NaCl aqueous solution. The fluorescence of Protoporphyrin IX synthesized by cells of stomach mucosa, was detected by laser fiber spectrofluorimetry. Measurements were performed through the optic fiber placed in direct contact with the stomach wall. A control of the optical properties of the different gels had previously been performed using the same excitation wavelength. Results were expressed in counts per second. At 2.5 mg/mL concentration of ALA, a better uptake has been measured at any time for ALA-Pluronic® gel compared to ALA-Noveon® or ALA only. For example, after 4 hours of contact between the gel and gastric mucosa, the PpIX signal after incubation with ALA-Pluronic® was 15% increased compared to ALA-Noveon®, and 65%> increased compared to the watery solution of ALA. Example 2, treatment of esophageal disease: In a preferred embodiment catheter (106) having multiple lumen through wliich are fed a double balloon system. Also fed through these lumen, is a vacuum tube (104) for removal of excess or spent gel, a lumen for the delivery of the gel (105), a diffuse light source (103) between the balloons for activation of the gel and possibly a lumen for an image bundle (107). The lower balloon (102) will project beyond the lower esophageal sphincter, inflate and then be retracted to prevent leakage of the gel into the stomach. The gel is delivered to the treatment area through a delivery tube and the upper balloon (101) is used either to press the gel into the mucosa or to prevent any regurgitation of the gel that could be of adverse effect for the patient . The diffuse light source (103) activates the photosensitizer. Example 3, treatment of diseased epithelia at the uterine cervix: In the case of epithelial disease at the uterine cervix, additional measures are employed to enhance the tendency of the gel to remain localized. These measures can be, for example, a rubber cup similar to a cervix diaphragm as it is used for contraception, or a moist dressing especially designed for mucosal surfaces. Having described preferred embodiments of the invention, with reference to the accompanying drawing, it is to be understood that the invention is not limited to these precise embodiments, and that changes and modifications may be effected therein by skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims: What is claimed is: 1. A method for treatment of diseased epithelium comprising the steps of : locally applying an active composition to a selected area of said diseased epithelium; confining said active composition to said areas; allowing time for sufficient uptake of said active composition into said diseased epithelium; activating said composition; and necrotizing said diseased epithelium. 2. A method for treatment of diseased epithelium according to claim 1, wherein said active composition is selected from the group consisting of: singlet oxygen producing photo sensitizers, aminolevulinic acid (ALA) and derivatives of ALA. 3. A method for treatment of diseased epithelium according to claim 1, wherein said activating step consists of irradiation of said composition with an appropriate wavelength to activate said composition, representing Photodynamic Therapy (PDT). 4. A method for treatment of diseased epithelium according to claim 1, wherein said active composition is applied as a highly viscous fluid . 5. A method for treatment of diseased epithelium according to claim 1, wherein said active composition is applied as a gel. 6. A method for treatment of diseased epithelium according to claim 1, wherein said active composition is applied as a thermosetting gel. 7. A method for treatment of diseased epithelium according to claim 1, wherein said diseased epithelium is Barrett's tissue lining a patients' esophagus. 8. A method for treatment of diseased epithelium according to claim 1, wherein said disease is one selected from the group consisting of: condylomata acuminata, other types of condyloma in genital, perineal, and anal areas, or other areas of skin. 9. A method for treatment of diseased epithelium according to claim 1, wherein said disease is leukoplakia of the oral cavity. 10. A method for treatment of diseased epithelium according to claim 1, wherein said disease is cancer of a uterine cervix. 11. A method for treatment of diseased epithelium according to claim 1, wherein said disease is dysplasia of a uterine cervix. 12. A method for treatment of diseased epithelium according to claims 1, wherein a basalioma of a patient's skin is treated. 13. An endoscopic method for treatment of diseased epithelium according to claim 7, wherein said allowing time for sufficient uptake is shortened by adding, as part of said application step, a further step of: pressing said composition \against said diseased epithelium by means of a component of said endoscope, preferably a balloon, to enable an even distribution of gel by unfolding of the esophageal mucosa and to enhance uptake into said diseased epithelium. 14. An endoscopic method for treatment of diseased epithelium according to claim 13, wherein said balloon can also serve as a reservoir from which the gel is applied. 15. An endoscopic device/apparatus, having a distal end and a proximal end, for controlled treatment of diseased epithelium in an organ including, the esophagus, comprising: at least a first balloon, positioned at said distal end of said device; an applicator assembly to deliver said highly viscous fluid composition; viewing means to monitor application and treatment; irradiating means; and a multi-lumen catheter with channels for said aforementioned components. 16. An endoscopic device/apparatus according to claim 15, further comprising: a second balloon positioned above said first balloon; and wherein said second balloon functions to define an upper limit to a treatment area. 17. An endoscopic device/apparatus according to claim 15, further comprising: a second balloon which is moveable; and wherein said balloon has means for applying and pressing a viscous fluid against said diseased mucosa. l l

Inventors: BODE HANS-PETER, BOURRE LUDOVIC, NEUBERGER WOLFGANG, PATRICE THIERRY, BODE, HANS-PETER, BOURRE, LUDOVIC, NEUBERGER, WOLFGANG, PATRICE, THIERRY
Applicants: CERAMOPTEC IND INC, CERAMOPTEC INDUSTRIES, INC.
Application year: 2001
Main classification: A61B18
IPC codes: A61B17, A61B18, A61N5