HK1027049B

HK1027049B - Method and apparatus for using electroporation mediated delivery of drugs and genes

Info

Publication number: HK1027049B
Application number: HK00106147.9A
Authority: HK
Inventors: G‧A‧霍夫曼; S‧B‧德弗; S‧C‧迪姆默; J‧I‧勒瓦特; G‧S‧南达
Original assignee: 基因特朗尼克斯公司
Priority date: 1997-08-01
Filing date: 1998-07-31
Publication date: 2006-04-28

Description

Device and method for delivery of drugs and genes using electroporation route

Background

Technical Field

The present invention relates generally to the use of electrical pulses to increase the permeability of cells, and more specifically to the use of controllable electric fields to deliver drug compounds and genes into cells in vivo by electroporation therapy (EPT), which may also be referred to as Cell Poration Therapy (CPT) or electrochemical therapy (ECT).

Description of the related Art

In the 70's, it was found that it was possible to use an electric field to create pores in cells without causing permanent damage to the cells. This finding makes it possible to introduce macromolecules into the cytoplasm. It is known that genes and other molecules such as pharmaceutical compounds can be introduced into living cells by a route known as electroporation. These genes or other molecules are mixed with living cells in a buffer medium and then a short pulsed high electric field is applied to them. Pores are temporarily formed in the cell membrane, and genes or molecules enter the cells, thereby changing the genome of the cells.

In vivo electroporation is generally limited to application to tissue or cells adjacent to the skin of a living organism where electrodes can be placed. Thus, electrodes used for electroporation are generally inaccessible to tissues such as tumors that can be treated with systemic drug delivery or chemotherapy. In the treatment of certain types of cancer with chemotherapy, it is desirable to use a sufficiently large dose of drug to kill cancer cells without killing too many normal cells. This can be achieved if the chemotherapeutic agent can be injected directly into the cancer cells. Some anticancer drugs, such as bleomycin, are generally unable to effectively penetrate the cell membrane of certain types of cancer cells. However, bleomycin can be injected into cells using electroporation.

The treatment is usually performed by injecting an anti-cancer drug directly into the tumor and then applying an electric field to the tumor between a pair of electrodes. The electric field strength must be adjusted with a suitable degree of precision in order to be able to electroporate tumor cells without damaging, or at least minimally damaging, normal or healthy cells. For tumors on the body surface, electroporation is conveniently performed by applying a pair of electrodes, typically on either side of the tumor, with an electric field generated between the electrodes. In the case of a homogeneous electric field, the distance between the electrodes is measured and then a voltage of suitable magnitude is applied to the electrodes according to the formula E ═ V/d (E ═ field strength in volts/cm; V ═ voltage in volts; d ═ distance in cm). When large or internal tumors are to be treated, it is difficult to properly position the electrodes and measure the distance between the electrodes. In the aforementioned patent application an electrode system for in vivo electroporation is disclosed, wherein the electrodes can be inserted into a tumor. In the related US patent 5273525, injection needles are used in a syringe for the injection of molecules and macromolecules during electroporation, which needles simultaneously function as electrodes. This configuration makes it possible to place the electrodes under the body surface.

Treatment with cell poration therapy provides a method to avoid the side effects normally associated with administration of anticancer drugs or cytotoxic agents. Such therapies allow one to introduce these agents to selectively kill or kill unwanted cells while avoiding killing or killing surrounding healthy cells or tissues.

Summary of The Invention

It is a primary object of the present invention to provide an improved device which can be conveniently and efficiently placed into preselected tissue to generate a predetermined electric field in said tissue.

According to a main aspect of the invention, an electrode device for performing electroporation of a portion of a patient's body comprises a support, needle electrodes mounted on said support at a distance from each other for insertion into tissue from a selected site, and means including a signal generator responsive to said distance signal for applying an electrical signal to said electrodes proportional to the distance between said electrodes, thereby generating an electric field of predetermined intensity.

The present invention includes needles that function both to inject a therapeutic substance into tissue and to act as electrodes to generate an electric field for a portion of the tissue cells.

One embodiment of the present invention includes a system for clinical electroporation therapy that includes a needle array electrode having a "keying" element, such as a resistor or an active circuit, that determines the set point of the therapy voltage pulse and the selectable array switching pattern (a device with such a system is known as MedPulse @)^TM). There are several configurations of electrode applicators available for introduction and treatment of various tissue sites.

Another embodiment of the present invention provides a laparoscopic needle applicator, preferably in combination with an endoscope, to achieve minimally invasive electroporation therapy.

The present invention provides a therapeutic method for treating cells, particularly tumor cells, using a needle array device.

Detailed description of the drawings

FIG. 1 is an assembled view in cross-section of one embodiment of the present invention.

Fig. 2a-2g are schematic illustrations of several alternative electrode embodiments of the present invention.

Fig. 3 is a block diagram of the treatment apparatus of the present invention.

Fig. 4 is a schematic block diagram of the circuitry of the treatment apparatus of fig. 3.

Fig. 5 is a schematic diagram of a selector switch element of the circuit in fig. 4.

Figure 6 schematically illustrates a preferred 4 x 4 layout array of needles forming 9 treatment zones, according to one embodiment of the present invention.

Figure 7a shows a pulse sequence for a 2 x 2 treatment zone according to one embodiment of the present invention.

Fig. 7b-7d are pulse sequences for a 6-pin array according to one embodiment of the present invention.

Fig. 8 is a schematic diagram of a prior art endoscopy apparatus.

Fig. 9a-9b illustrate in more detail an array of retractable needles of the present invention.

Fig. 10 shows the tumor volume up to 120 days after EPT treatment of Panc-3 xenograft nude mice with bleomycin for various control groups (D + E-, D-E +) and treated groups (D ═ drug; E ═ electroporation).

FIGS. 11a and 11b show the effect of EPT treatment of Panc-3 with neocarzinostain up to day 24, with drug injected before and after pulsing, respectively.

FIG. 12 shows tumor volumes 34 days after EPT treatment of non-small cell lung carcinoma cell (NSCLC) xenografted nude mice with bleomycin. The arrow indicates that one mouse was treated again on day 27 (D ═ drug; E ═ electroporation).

FIGS. 13a-13d show the sequence of treatment progression during treatment of xenografted tumors (a) with EPT. The treatment results in the formation of scars (b), which dry out and eventually fall off (c), leaving a clear healing area on the skin (d) free of tumors.

FIGS. 14a-14c show histological images of tumor specimens 35 days after treatment. Tumors that showed only necrosis in the D + E + group were found to be empty of viable and necrotic cells in the D + E-group (a), compared to the cells in the D + E-group (b). Histological studies of samples of the tumor site after 120 days showed that tumor cells were completely absent (c).

FIGS. 15a and 15b show viability of MCF-7 (breast cancer) cells exposed to low and high voltage EPT, respectively.

FIGS. 16a and 16b show the viability of MCF-7 (breast cancer) cells exposed to low and high voltage EPT with bleomycin added.

FIG. 17 shows different bleomycin concentrations and MedPulser without and with pulses^TMThe effect on MCF-7 cells.

Like reference numbers and designations in the various drawings indicate like elements.

Detailed description of the preferred embodiments

The present invention provides devices and methods for performing electroporation therapy. The method comprises the steps of injecting a chemotherapeutic agent or molecule and introducing the agent or molecule into the tumor by electroporation. Specifically, a reagent or molecule is injected into the tissue, and a voltage pulse is applied between "needle" electrodes disposed in the tissue, thereby applying an electric field to the cells of the tissue. The needle electrode assembly, described below, allows one to place the electrodes inside or near a tumor or other tissue beneath the body surface, either in vivo or ex vivo. This method of treatment is known as electroporation therapy (EPT), also known as electrochemotherapy. Although the following description focuses on EPT, the invention is also applicable to other therapeutic techniques, such as gene therapy of certain organs of the body.

For a general discussion of EPT, reference may be made to application 08/537265, co-pending with the present application, having a filing date of 9/29 in 1995, which is a continuation of application 08/467566 filed 6/6 in 1995, which is a continuation of application 08/042039 filed 4/1 in 1993, which has now been abandoned, all of which are incorporated herein by reference.

Electrode assembly

FIG. 1 is a cross-sectional assembly view of a needle assembly 100 according to one embodiment of the present invention. Needle assembly 100 includes an elongated tubular support or needle shaft 112, which may be made of either hollow stainless steel or medical grade plastic (e.g., nylon). If the needle shaft is made of a conductive material, the external device should be provided with electrical insulation to protect the patient and the doctor. Needle shaft 112 includes a plurality of electrode pins 114 at the distal end of the shaft that are respectively connected to different conductors in a multi-conductor cable 116. The electrode needle 114 may be either sharp or blunt, either hollow or solid, and may be of any desired length. The material of the electrode needle 114 must be electrically conductive, but need not be metallic or of the same material (i.e., a composite or layered structure may be used, such as a metal-coated plastic needle or a ceramic needle). One or more hollow electrode needles 114 may be used to inject the therapeutic substance. In different embodiments, the electrode needles 114 may be organized in an array of squares, hexagons, or circles. However, other shapes may be used.

In use, the multi-conductor cable 116 is connected to a high voltage generator. In the illustrated embodiment, a retractable protective shield 118 is provided at the end of the needle shaft, constrained by a friction-type annular washer 120, the shield 118 being capable of sliding back and forth along the needle shaft 112 to cover or uncover the electrode needle 114.

Fig. 2a-2e are schematic illustrations of several alternative electrode embodiments of the present invention. Fig. 2a and 2b show two straight electrodes with needles 200, the distance of the needles 200 being different on the two electrodes. For example, the needles in FIG. 2a constitute an array having a diameter of 0.5 cm, while the needles in FIG. 2b constitute an array having a diameter of 1.4 cm. The size of the electrode body may also vary. For example, the electrode of FIG. 2a has a stepped body configuration with a smaller diameter front portion 202 and a larger diameter rear portion 204. The electrode in fig. 2b has a body 206 with a uniform diameter. The electrodes in fig. 2a and 2b are particularly suitable for treating small surface tumors.

Fig. 2c and 2d show two types of beveled electrodes, each having a set of tips 200 at an angle to the body 206 of the electrode. Figure 2c shows the tip at an angle of approximately 45 degrees to the body 206. Figure 2d shows the needle tip at an angle of approximately 90 degrees to the body 206. The electrodes in fig. 2c and 2d are particularly suitable for treating tumors of the head and neck.

Figure 2e shows a dual angle electrode having a set of tips 200 angled to a smaller diameter front portion 202. The larger diameter rear portion 204 is also angled. The electrode in fig. 2e is particularly suitable for treating tumors of the larynx, but may also be used for tumors in other body cavities.

Figure 2f shows an electrode particularly suitable for treating large tumours. The spacing between the needles 208 may be, for example, about 0.65 centimeters. Figure 2g shows an electrode particularly suitable for treating internal tumours. The spacing between the needles 208 may be, for example, about 1.0 cm.

Any of the individual structural elements shown in fig. 2a-2g (e.g., the size and configuration of the body, the angle of the head and body, etc.) may be combined as desired. Other configurations of electrode assemblies may be used to meet specific size and access requirements.

EPT device

Fig. 3 is a schematic diagram of an EPT treatment device 300 embodying the invention. An electrode applicator 312 is removably attached to the device 300, and the device 300 selectively applies voltage pulses to selected electrode pins 314 on the electrode applicator 312. The pulse duration, the magnitude of the voltage, the addressing of the electrode pins, or the switching pattern output by the device 300 may be controlled by a program.

The display 316 displays the given value of the treatment voltage. A teletherapy activation fitting 318 is provided to receive a foot switch 320, the foot switch 320 being used to activate the pulses delivered to the electrode applicator 312. Foot switch 320 enables the clinician to turn on device 300 while freeing up two hands to place electrode applicator 312 in the patient's tissue.

Indicator lights 322 are provided for convenience to indicate fault detection, power on, and end of treatment phase. Additional indicator lights 324 are provided to indicate specifically that an electrode applicator 312 is connected to the device 300, as well as to indicate the type of array (discussed below). A standby/reset button 326 is provided for "pausing" the device and resetting all functions of the device to a default state. A ready button 328 is provided to prepare the device 300 for entering the treatment phase. A relatively prominent "treatment in progress" indicator light 330 indicates that a voltage pulse has been applied to the electrode needle 314. In addition, the device 300 may also be provided with audible indicators for indicating, for example, a button press, a fault condition, the beginning or end of a treatment session, and indicating that treatment is in progress, etc.

In an alternative embodiment, the device 300 may be coupled to a feedback sensor that detects heart rate. The application of pulses in the vicinity of the heart may be disturbed by a normal heart rhythm. The possibility of such interference can be reduced by pulsing synchronously during the safety period between heart beats.

Fig. 4 is a schematic block diagram of the circuitry 400 of the treatment apparatus 300 of fig. 3. The ac power input module provides power to the entire device 300 in an electrically isolated manner. The dc power input module 402 provides the appropriate power for the control circuitry of the device 300. The high voltage power supply 406 provides the appropriate high voltage (e.g., up to several thousand volts) needed to perform the EPT treatment. The output of the high voltage power supply 406 is connected to a pulse energy assembly 408, and the pulse energy assembly 408 generates pulses of variable width and voltage under the control of a control assembly 410. The output of the pulse energy assembly 408 is connected to a pin array connector 414 through a high voltage switch array 412. The teletherapy activation foot pedal connector 416 can interface with the foot pedal switch 320.

The high voltage switch array 412 enables the high voltages required to implement EPT to be applied to selected subsets of the plurality of electrodes of the needle assembly 100. In previous EPT devices, such voltages are typically applied using a manually-operated rotary "distributor" switch, or such a switch in an electric mode. However, in the present invention, all switching operations are performed by the electrically controlled relay, which enables faster, less noisy switching, longer lifetime, better and more flexible control of the switching pattern.

Fig. 5 is a schematic diagram of one selector switch element 500 of the high voltage switch array 412 of the circuit shown in fig. 4. The number of such switching elements 500 should match at least the maximum number of electrodes in any needle assembly 100 that is mounted. Each switching element 500 controls the high voltage applied to one electrode of the needle assembly 100 and is capable of providing a voltage of either polarity to the associated electrode.

Specifically, when a "negative" control voltage is applied to an inverting input amplifier 502a, an associated normally open relay 504a is closed, thereby establishing a negative return path for the pulse applied to the pair of electrodes connected by electrode connector 506. Similarly, when a "positive" control voltage is applied to a second inverting input amplifier 502b, an associated normally open relay 504b is closed, thereby creating a path for a positive pulse to be applied to a pair of electrodes connected by electrode connector 506.

Needle array addressing

The device 300 shown in fig. 3 is suitable for use with electrode applicators 312 having different numbers of electrode needles 314. Thus, in this preferred embodiment, an addressing scheme is devised that is capable of addressing up to 16 needles, numbered from a to P, that are capable of forming up to 9 square treatment zones and several types of enlarged treatment zones. A treatment zone comprises at least 4 needles, which 4 needles constitute two pairs of opposing needles, which are addressed during a particular pulse. In a particular pulse, the polarity of the two needles in a treatment area is positive and the polarity of the two needles is negative.

Fig. 6 schematically shows a preferred 4 x 4 layout (mapping) array of needles forming 9 square treatment zones, the 9 treatment zones numbered sequentially in a clockwise direction from the center: in the preferred embodiment, this layout array defines 4, 6, 8, 9 and 16 pin electrode configurations. A4-needle electrode consists of needles at positions F, G, K and J (treatment zone 1). A9-needle electrode consists of needles at locations that constitute treatment zones 1-4. A 16-needle array consists of needles in positions that constitute the treatment zones 1-9.

Figure 7a shows a pulse sequence applied to a 2 x 2 treatment area, in accordance with one embodiment of the present invention. As shown, during any one of the four pulses constituting one cycle, two pairs of electrodes are charged positively and negatively, respectively. Such electrode pairs may also have other patterns, such as traveling in a clockwise or counterclockwise manner. For a 9-pin electrode configuration, one preferred cycle includes 16 pulses (4 treatment zones with 4 pulses per treatment zone). For a 16-pin configuration electrode, one preferred cycle includes 36 and one preferred cycle includes 16 pulses (4 treatment zones with 4 pulses per treatment zone). For a 16-pin configuration electrode, a preferred cycle includes 36 pulses (9 treatment zones with 4 pulses per treatment zone).

As shown in fig. 7b-7d, the 6-pin electrode configuration may constitute a circular or hexagonal array. Alternatively, as shown in FIG. 6, the 6-pin electrode configuration may be a small group in a large array. For example, referring to FIG. 6, the 6-pin electrode configuration may be a 2X 3 rectangular array of pins in positions that define treatment zones 1-2 (or any other pair of treatment zones aligned along a line), or a hexagonal configuration of pins B, G, K, N, I, E (or any other set of pins in positions that define a hexagon) that define an enlarged treatment zone (shown in phantom in FIG. 6). Likewise, the 8-pin electrode configuration may constitute either an octagon or a small group of larger arrays as shown in FIG. 6. For example, referring to fig. 6, the 8-pin electrode configuration may be a 2 x 4 array of pins at the locations that make up treatment zones 1, 2, and 6 (or any other three in-line treatment zones), or an octagonal configuration of pins B, C, H, L, O, N, I, E (or any other set of pins at locations that make up an octagon) that define an enlarged treatment zone.

Figures 7b-7d show a hexagonal arrangement and a possible activation sequence. FIG. 7b shows a first sequence in which during the first pulse the polarity of pins G and K is positive and the polarity of pins I and E is negative, and during the next pulse the polarity of these pins is reversed; needles B and N are shown in an inactive state by dashed lines. FIG. 7c shows a second sequence in which the polarity of pins K and N is positive, the polarity of pins E and B is negative during the first pulse, and the polarity of these pins is reversed during the next pulse; needles G and I are in an inactive state. FIG. 7d shows a third sequence in which during the first pulse the polarity of pins N and I is positive, the polarity of pins B and G is negative, and during the next pulse the polarity of these pins is reversed; needles K and E are in an inactive state. A total of 6 pulses are applied in a sequence of one cycle. Similar activation sequences may be used in an octagonal array of clocks.

Regardless of the physical configuration employed, the preferred embodiment of the present invention generally employs at least two pairs of electrodes (e.g., the configuration shown in FIG. 7 a) that are switched relative to one another to create a relatively uniform electric field in the tissue receiving the EPT. The strength of the electric field should be sufficiently large to allow the therapeutic agent to enter, thereby effectively achieving electroporation.

Automatic identification of electrode applicators

The arrangement described above enables different electrode applicators 312 to be connected to the same device 300. Since the number of electrode needles 314 may vary, the present invention includes a means for automatically configuring the device 300 to address the appropriate number of electrode needles 314. In one embodiment, each electrode applicator 312 includes a built-in identification element, such as a "keyed" resistor, which allows the device 300 to determine the number of electrode pins 314 and thereby configure itself to match the addressing scheme. When the electrode applicator 312 is connected to the device 300, the device 300 reads the type-identifying element. The type-identifying element may be installed into one of the connectors for connecting the electrode applicator 12 and read through a shared or designated electrical connection.

As an exemplary embodiment, the following table gives resistance values corresponding to the number of electrode pins 314.

Type identification resistance (ohm) of needle array	Needle addressing arrangement
Type identification resistance (ohm) of needle array	Needle addressing arrangement	787	6
453	6	787	6
453	6	232	6
4.32K	9	232	6
4.32K	9	2.21K	16
1.29K	16	2.21K	16

A similar technique may be used to automatically set the treatment voltage of the device 300. That is, each electrode applicator 312 includes a built-in voltage identification element, such as a "keyed" resistor, that enables the device 300 to determine the appropriate voltage level for the treatment pulse for the particular electrode applicator 312. When the electrode applicator 312 is connected to the device 300, the device 300 reads the voltage identification element.

As an exemplary embodiment, the following table gives the resistance values associated with a given voltage value.

Voltage identification resistor (ohm) of pin array	Given voltage value
Voltage identification resistor (ohm) of pin array	Given voltage value	787	560
453	1130	787	560
453	1130	232	1500
4.32K	845	232	1500
4.32K	845	2.21K	845
1.29K	1300	2.21K	845

For type recognition and voltage recognition, the same or different recognition elements can be used. The nature of the identification element may also vary. For example, each electrode applicator 312 may be populated with an electronic circuit that stores digital or analog values of various variables. Examples of information that may be stored in encoded form in the electrode applicator 312 are, for example: needle array type parameters such as the number of needles, the spacing of the needles, the geometry of the needle array, and/or the order of opening and closing the needles; electrical pulse parameters, such as voltage setpoint, pulse length and/or pulse shape; shelf life; and a lifetime. If the electrode applicator 312 employs a writable activation circuit (e.g., NVRAM) capable of storing data, then additional information that can be written in encoded form into an electrode applicator 312 includes: shelf life lock (i.e., one code that disables the electrode applicator 312 upon expiration of the shelf life); usage counting and locking (i.e., one code that disables the electrode applicators 312 when the allowed number of uses is reached; when one electrode applicator 312 is designed to be disposable, contamination from repeated use can be prevented); usage history (e.g., a record of parameters such as the number of applied pulses, date and time of application); and capture of error codes (e.g., to enable one electrode applicator 312 to be returned to the manufacturer and analyzed for failure modes of the applicator or failure modes of the device 300).

The lock-out may be determined by the length of time from initial use of the applicator until the present time, and the number of treatments with the same device. This may be accomplished by writing a time stamp into the disposable activation circuit of the "keying" element of the applicator upon attachment to the device 300, and waiting until a certain time has elapsed before use is terminated. The limit of this length of time may be determined based on the actual maximum time of a surgical procedure.

Further, the use of this "keying" element may include production and quality control information. An example of such information is the production lot number of the instrument. Also, quality control can be facilitated by prohibiting the use of untested materials, for example, by setting the instrument to be usable only after a production test is successfully completed.

Laparoscopic needle applicator

One embodiment of the present invention that is particularly useful for treating tumors inside the body combines a laparoscopic needle array with an endoscopy system for performing EPT that minimizes trauma. Fig. 8 is a schematic diagram of a prior art endoscopy system 800. In a known manner, light from the light source 840 is transmitted through a fiber optic guide 842 to the endoscope 844. Light emitted from the distal end of the endoscope 844 is irradiated on tissue. The reflected light is collected by the tip of the endoscope 844 and transmitted to an eyepiece 846 or, alternatively, to a camera 848 via an optical coupler 850. The signal from the camera 848 may be recorded on a video tape recorder 852 and/or displayed on a video monitor 854.

FIGS. 9a-9b are side views, partially in section, of the distal tip of the endoscope 844 of FIG. 8 with the modifications thereto, and showing in detail a telescopic needle array 960 in accordance with the present invention. A removable sheath 962 encloses an endoscope 944 and needle array 960. FIG. 9a shows the sheath 962 in an extended position, completely covering the endoscope 944 and needle array 960. FIG. 9b shows the sheath 962 in a retracted state, exposing the endoscope 944 and the tip of the needle array 960. (although this preferred embodiment employs a movable sheath 962, all that is required is relative movement between sheath 962 and endoscope 944; thus, endoscope 944 can be considered a movable element.)

In the preferred embodiment, needle array 960 includes at least two needle electrodes 964, each needle electrode 964 being connected to a voltage source (not shown), and at least one of the two electrodes may be hollow and connected to a drug supply (not shown) via tubing 966. It is preferable to extend the tip of the electrode needle 964 beyond the end of the endoscope 944 so that the operator can see the tissue site through the endoscope 944 while inserting the electrode needle 964 into the tissue.

Each electrode needle 964 is connected to a compressible mechanism 968. In the illustrated embodiment, for each electrode needle 964, the compressible mechanism 968 includes a support arm 970, the support arm 970 being rotatably coupled to a slidable base 972 and a first extension arm 974, the slidable base 972 being free to slide along the endoscope 944. Each first extension arm 974 is rotatably connected to a fixed base 976 mounted on the endoscope and also to a corresponding electrode needle 964. The second extension arm 977 is similar in construction to the first extension 974 arm (but without the support arm 970), and functions to increase the stability of the electrode needle 964 when in a deployed configuration as will be described below.

When the sheath 962 is in the extended state, the electrode needles 964 are relatively close to each other. While in some applications this proximity may be appropriate for certain voltages, in other applications, a greater spacing between electrode needles 964 may be desirable.

Thus, in the preferred embodiment, when the sheath 962 is moved to the retracted position, the compression member 978 (e.g., a spring) presses each slidable base 972 away from the fixed base 976 such that each support arm 970 pulls the first extension arm 974 associated therewith. This retraction force causes the extension arms 974, 977 to separate from the endoscope 944 at an angle to a deployed configuration, thereby increasing the distance between the electrode needles 964 as shown in fig. 9 b.

When the sheath 962 is moved to the extended position, the sheath 962 presses the electrode needles 964 together, forcing the extension arms 974, 977 to fold together. This causes each first extension arm 974 to pull on the support arm 970 to which it is attached. This retraction force on each support arm 970 causes each slidable base 972 to move towards fixed base 976, into a sleeve-type configuration, compressing compression member 978, as shown in fig. 9 a.

Other compressible mechanisms 968 may be used to separate the electrode needles 964, such as a wedge (or hollow core cone) made of a compressible, resilient material (e.g., foam or rubber) placed between the endoscope 944 and the electrode needles 964 such that the widest portion of the wedge is at the end of the endoscope 944. When the sheath 962 is in the retracted state, the resilient material at the distal end of the wedge expands more than the resilient material at the proximal end of the wedge, thereby increasing the distance between the electrode needles 964. In addition, it is not necessary that all of the electrode needles 964 be able to be moved by the compressible mechanism 968. For example, if one of the two electrode needles 964 is held in a fixed position relative to the endoscope 944, the other electrode needle 964 can be moved between a compressed position and an extended position, and there can be sufficient space between the two electrode needles 964; when in the deployed state, the two electrode needles 964 are asymmetrically disposed with respect to the endoscope 944.

In either case, compressible mechanism 968 must provide electrical isolation between individual electrode pins 964, and therefore, compressible mechanism 968 is preferably made, in whole or in part, from an insulator, such as a non-conductive plastic.

Although the preferred embodiment of the laparoscopic needle array includes an endoscope, in some embodiments it may be appropriate to use the laparoscopic needle array with a separate endoscope. In such a configuration, the endoscope 944 of FIGS. 15a and 15b may be replaced with a support rod.

Parameters of electric field

The nature of the electric field to be generated is determined by the characteristics of the tissue, the size of the tissue selected and the location in which it is located. The electric field should be as uniform as possible and should have a suitable strength. Too high an electric field can lead to cell lysis, while too low an electric field can lead to reduced efficacy. The manner in which the electrodes are mounted and operated can be varied in many ways, including but not limited to those described in the aforementioned patent applications. The electrodes can be easily manipulated and placed on the site in the body using forceps.

The waveform of the electrical signal provided by the pulse generator may be an exponential decay pulse, a square pulse, a unipolar shaking pulse train, a bipolar shaking pulse train, or any combination of these waveforms. The nominal field strength may be about 10 volts/cm to about 20 kilovolts/cm (nominal field strength is calculated by dividing the voltage between the electrode pins by the distance between the pins). The length of the pulse may be about 10 microseconds to about 100 milliseconds. The number of pulses can be set arbitrarily as required, and is generally 1 to 100 pulses per second. The waiting time between the groups of pulses can also be determined arbitrarily as required, for example 1 second. The waveform, electric field strength and pulse duration may also be determined according to the type of cell and the type of molecule to be electroporated into the cell.

Various parameters including the electric field strength required to electroporate any of the known cells can be obtained generally from a number of research papers reporting this subject matter, or from a database maintained by GENETRONICS corporation, san diego, california, the assignee of the present application. The electric field required for electroporation of cells such as EPT in vivo is generally similar in strength to that required for electroporation of cells in vitro. Recent studies by the inventors have shown that preferred intensities range from 10 volts/cm to about 1300 volts/cm. In vivo experiments by others reported in some scientific publications have confirmed that the upper end of this range exceeds 600 volts/cm.

The rated electric field may be designated as either "high" or "low". Preferably, when a high electric field is used, the nominal field strength can be about 700 v/cm to about 1300 v/cm, and more preferably about 1000 v/cm to about 1300 v/cm. Preferably, when a low electric field is used, the nominal field strength can be from about 10 volts/cm to about 100 volts/cm, and more preferably from about 25 volts/cm to about 75 volts/cm. In a particular embodiment, the pulse length is preferably longer when the electric field is low. For example, when the nominal electric field is about 25-75 volts/cm, the pulse length is preferably about 10 milliseconds.

The method of the present invention is preferably carried out using the apparatus of the present invention which provides an electrode apparatus for use in performing electroporation of a portion of a patient's body, the electrode apparatus comprising a support member, a plurality of spaced apart needle electrodes mounted on said support member for insertion into tissue at a selected site, and means including a signal generator responsive to said distance signal for providing an electrical signal to said electrodes proportional to the distance between said electrodes to generate an electric field of predetermined strength.

It will be appreciated that other systems may be used in the treatment methods of the present invention (e.g., at low voltage, long pulse treatments), for example, a square wave pulse electroporation system may be used. For example, an electrosquarereporator (T820) available from GENETRONICS corporation of san diego, california, usa may be used. Square wave electroporation systems emit controllable electrical pulses that can rise rapidly to a set voltage level for a set time (pulse length) and then fall rapidly to zero. Such systems produce better transformation efficiencies than exponentially decaying systems in electroporation of plant protoplasts and mammalian cell lines.

ElectroSquarePorator (T820) was the first commercially available square wave electroporation system capable of generating voltages as high as 3000 volts. The pulse length may be adjusted between 5 microseconds and 99 milliseconds. Square wave electroporation pulses produce a more gentle effect on the cells, resulting in higher viability of the cells.

The T820 ElectroSquarePorator can start in both High Voltage Mode (HVM) (100-3000 volts) and Low Voltage Mode (LVM) (10-500 volts). The pulse length at LVM is about 0.3 to 99 milliseconds and at HVM is about 5 to 99 microseconds. T820 has the ability to generate multiple pulses, and can generate about 1 to 99 pulses.

Method of treatment

The therapeutic methods of the present invention include electrotherapy, also referred to herein as electroporation therapy (EPT), which utilizes the devices of the present invention to deliver macromolecules into cells or tissues. As previously mentioned, the term "macromolecule" or "molecule" herein refers to drugs (e.g., chemotherapeutic agents), nucleic acids (e.g., polynucleotides), peptides and polypeptides, including antibodies. Polynucleotides include DNA, cDNA, and RNA sequences.

The drugs intended for use in the method of the invention are generally chemotherapeutic agents having an anti-tumor or cytotoxic effect. These drugs or agents include bleomycin, neocarzinostain, suramin, doxorubicin, carboplatin, taxol, mitomycin C and cisplatin. Other chemotherapeutic agents are well known to those skilled in The art (see, e.g., The Merck Index). In addition, "membrane-acting" formulations may also be used in the methods of the invention. These agents may also be those mentioned above, or those which act primarily in a manner to damage the cell membrane. Examples of agents acting on the membrane include N-alkyl melamines and p-chloromercuribenzoic acid. The chemical composition of the formulation will determine the optimal timing of application of the formulation in relation to the application of the electrical pulse. For example, while not wishing to be bound by a particular theory, it is believed that a drug with a lower isoelectric point (e.g., neocarzinostatin, IEP 3.78) will produce better results if the drug is applied after electroporation in order to avoid electrostatic interactions between the highly charged drugs in the electric field. Also, drugs like bleomycin with a relatively large negative logP value (P is the partition coefficient between octanal and water) are large in molecular weight (MW 1400) and hydrophilic and therefore bind tightly to the membrane of lipids, diffuse very slowly into tumor cells, and are usually applied before or almost simultaneously with the electrical pulse. In addition, certain agents may need to be modified in order to allow more efficient entry of the drug into the cell. For example, formulations such as taxol may be modified to increase their solubility in water, which will allow them to be more efficiently incorporated into cells. Electroporation causes perforation of the cell membrane, thereby facilitating the entry of bleomycin or other similar drug into the tumor cells.

In one embodiment, the present invention provides a method for administering electroporation therapy to a tissue of a subject for introducing molecules into cells of the tissue, the method comprising the steps of: providing an array of electrodes, at least one of the electrodes having a needle configuration for penetrating tissue; inserting a needle electrode into the selected tissue to introduce molecules into the tissue; placing a second electrode of the electrode array in electrical communication with the selected tissue; high amplitude electrical signal pulses are applied to the electrodes to electroporate tissue, the signal amplitude being proportional to the distance between the electrodes. It is understood that electroporation of tissue can be performed in vitro or in vivo or ex vivo. Electroporation can also be performed using single cells, for example using single cell suspensions or in vitro or ex vivo cell cultures.

It may be desirable to introduce molecules to modulate gene expression in cells using the methods of the invention. The term "modulation" predicts that expression of a gene is suppressed when it is overexpressed and enhanced when it is underexpressed. Where the cell proliferative disorder is associated with expression of a gene, a series of nucleic acids that interfere with gene expression at the translational level may be employed. This method uses, for example, antisense nucleic acids, ribozymes or triple helix reagents to block transcription or translation of a specific mRNA, either by using an antisense nucleic acid or triple helix reagent to mask that mRNA, or by nuclease degradation. .

Antisense nucleic acids are DNA or RNA molecules that are at least partially complementary to a specific mRNA molecule (Weintraub, Scientific American),262: 40, 1990). In a cell, antisense nucleic acids hybridize with the corresponding mRNA to form a double-stranded molecule. Antisense nucleic acids interfere with the translation of mRNA because the cell does not translate double-stranded mRNA. Oligomers of about 15 nucleotides are preferred because they are easier to synthesize and less likely to cause problems than macromolecules when introduced into a target cell. The use of antisense methods to inhibit in vitro translation of genes is well known in the art (Marcus-Sakura, analytical biochemistry (anal. biochem.),172：289，1988)。

the use of oligonucleotides to prevent transcription is known as triple helix strategy because the oligomers wind around the DNA of the double helix, forming a triple helix. Thus, the triple helix combination can be designated to identify a unique point in a selected gene (Maher, et al, Antisense Res.and Dev., 1 (3): 227, 1991; Helence, C., anticancer drug design, 6 (6): 569, 1991)

Ribozymes are RNA molecules that have the ability to specifically degrade other single-stranded RNA in a manner similar to DNA restriction endonucleases. By modifying the order of the nucleotides encoding these RNAs, molecules can be designed that recognize and degrade specific nucleotide sequences on one RNA molecule (Cech, j.amer.med.assn.,260: 3030, 1988). One major advantage of such protocols is that, because they are sequence specific, only mRNAs with a specific sequence are inactivated.

There are two basic types of ribozymes, the tetrahymena type (Hasselhoff, Nature, 334: 585, 1988) and the "hammerhead" type. Tetrahymena-type ribozymes recognize sequences of four bases in length, while "hammerhead" -type ribozymes recognize sequences of 11-18 bases in length. The longer the recognition sequence, the greater the likelihood that the sequence will appear exclusively in the target mRNA species. Therefore, hammerhead type ribozymes are more preferable than tetrahymena type ribozymes for inactivating specific mRNA species, and 18-base recognition sequences are more preferable than short recognition sequences.

The invention also provides gene therapy methods for treating cell proliferative disorders or immunological disorders caused by a particular gene, or by the absence of a particular gene. Such therapies achieve their therapeutic effect by introducing polynucleotides of particular interest or antisense into cells having the disorder. Delivery of the polynucleotide may be accomplished using a recombinant expression vector, such as a chimeric virus, or may be delivered, for example, as "naked" DNA.

Various viral vectors described herein that can be used in gene therapy include adenovirus, herpes virus, vaccinia virus, or, preferably, RNA viruses such as retroviruses. The retroviral vector is preferably a derivative of a murine or avian retrovirus. Examples of retroviral vectors into which a single foreign gene can be inserted include, but are not limited to: moloney murine leukemia virus (MoMuLV), Harvey murine sarcoma virus (HaMuSV), murine mammary tumor virus (MuMTV), and Rose Sarcoma Virus (RSV). When the subject is a human, a vector such as gibbon ape leukemia virus (GalV) can be used. Many additional retroviral vectors can be inserted into multiple genes. All of these vectors are capable of transferring or integrating a gene selectable marker so that transduced cells can be identified and generated.

Therapeutic peptides or polypeptides may also be used in the therapeutic methods of the invention. For example, immunomodulators and other biological response modifiers can be administered for cellular incorporation. "biological response modifiers" include substances which are involved in the modulation of an immune response. Examples of immune response modifiers include complexes such as lymphokines. Lymphokines include tumor necrosis factor, interleukins 1, 2 and 3, lymphotoxins, macrophage activating factor, migration inhibitory factor, colony stimulating factor, and alpha, beta, and gamma interferons and their subtypes.

Also included are polynucleotides encoding metabolic enzymes and proteins, including anti-angiogenic complexes, such as factor eight or factor ninth. Macromolecules of the invention also include antibody molecules. "antibodies" as used herein include intact molecules as well as fragments thereof, such as Fab and F (ab')₂。

The drug, polynucleotide or polypeptide acid in the methods of the invention may be administered by parenteral routes such as injection, rapid infusion, nasopharyngeal absorption, dermal absorption, or may be administered orally. For example, in the case of tumors, chemotherapeutic or other agents may be administered locally or systemically, or directly injected into the tumor. For example, when the drug is injected directly into the tumor, it is desirable to inject the drug in a "fanning" fashion. By "fan-shaped" is meant that the drug is administered by changing the direction of the needle as the drug is injected, or by injecting the drug multiple times in multiple directions, such as in an open palm, rather than injecting the drug as a bolus, to achieve a broader distribution of the drug throughout the tumor. When administering (e.g., injecting) a drug within a tumor, it is desirable to increase the amount of the drug-containing solution compared to the amount typically employed in the art to ensure proper distribution of the drug throughout the tumor. For example, in the examples presented herein using mice, one skilled in the art would typically inject 50 microliters of medicated solution, but increasing the amount of medicated solution to 150 microliters provided a significant improvement. In human clinical studies, approximately 20 ml of solution was injected to ensure adequate perfusion of the tumor. Preferably, the injection is performed very slowly around the bottom in a fan-like manner. Although the interstitial pressure in the center of the tumor is very high, this site is often also a tumor necrosis zone.

It is preferred to administer the molecule substantially simultaneously with the electroporation therapy. By "substantially simultaneously" is meant that the molecules are administered at a time very close to the time at which the electroporation treatment is performed. The molecule or therapeutic agent may be administered over any period of time depending on such factors as the nature of the tumor, the condition of the patient, the size and chemical characteristics of the molecule, and the half-life of the molecule.

Formulations for parenteral administration include sterile solutions or aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of water insoluble solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. In addition to inert diluents, such compositions can also include adjuvants, wetting agents, emulsifying and suspending agents. In addition, vasoconstrictors may be used to retain the therapeutic agent at a site prior to pulsing.

Any cell can be treated with the methods of the invention. Several examples are presented herein to demonstrate the utility of the methods of the invention in the treatment of tumor cells, such as pancreatic cancer, lung cancer, head and neck cancer, skin cancer, and subcutaneous cancer. Other cell proliferative disorders can also be treated with the electroporation methods of the invention. "cell proliferative disorder" refers to malignant as well as non-malignant cell populations that differ from the surrounding tissue in both morphology and genotype. Malignant cells (i.e., tumors or cancers) evolve from multiple stages. The methods of the invention are useful for treating malignant or other types of disorders of various organ systems. In particular, it can be used for the treatment of cells of, for example, the pancreas, the head and neck (e.g., larynx, nasopharynx, oropharynx, laryngopharynx, lips, throat) and the lungs, but also cells of the heart, kidney, muscle, breast, colon, prostate, thymus, testis and ovary. In addition, malignant lesions of the skin, such as basal cell carcinoma or melanoma, may also be treated using the methods of the present invention (see example 2). The subject is preferably a human, however, it will be appreciated that the invention may also be used in the veterinary field for the treatment of non-human animals or mammals.

In another embodiment, the invention provides a method of applying electroporation therapy to a tissue of a subject to damage or kill cells in the tissue.

The method comprises providing an array of electrodes; placing a second electrode of the electrode array in electrically conductive relation to the selected tissue; high amplitude electrical signal pulses proportional to the distance between the electrodes are applied to the electrodes to electroporate the tissue. It is desirable to use low voltage, long pulses in this method, eliminating the need for additional cytotoxic or chemotherapeutic agents. For example, the nominal electric field strength is preferably from about 25 volts/cm to 75 volts/cm, with a pulse length of from about 5 microseconds to 99 milliseconds.

The following examples are intended to illustrate the invention but are not intended to limit it. Although they are the more typical of the many methods that may be employed, other therapies known to those skilled in the art may be employed as well.

Several embodiments

The following examples describe the use of EPT in cell lines, animals and humans. Example 1 illustrates the case of performing EPT in a poorly differentiated human pancreatic tumor (Panc-3) transplanted to the flank of a nude mouse by way of subcutaneous xenograft. Example 2 describes the results of clinical trials using EPT to treat basal cell carcinoma and melanoma in humans. Example 3 describes the results of a clinical trial using EPT to treat head and neck tumors in humans. Example 4 provides in vitro data for EPT using low voltage (electric field) and long pulses. The parameters used for performing EPT are described in these examples; for example 1 and for clinical trials of head and neck tumors, the nominal electric field strength was 1300 volts/cm, 6 pulses of 99-100 microseconds, with 1 second interval. The clinical trial (of example 2) used similar parameters but the electric field strength was 1130 volts/cm. These examples show that the use of EPT can effectively kill unwanted cell populations (e.g., tumors) in vitro as well as in vivo.

Example 1 in vivo treatment of tumors Using EPT

One course of treatment includes the following steps: bleomycin (0.5 units in 0.15 ml saline) was injected into the tumor in a fan-like manner as described herein and 10 minutes later 6 square wave electrical pulses were applied using needle array electrodes as described herein, which were placed along a circumference of 1 cm in diameter. Needle arrays with variable diameters (e.g., 0.5 cm, 0.75 cm, and 1.5 cm) are also used to accommodate tumors of different sizes. Stoppers of different heights can be inserted in the center of the array so that the depth of penetration of the needles into the tumor can be varied. There is a built-in mechanism to switch the electrodes so that the pulsed field can cover the tumor to the maximum extent. The electrical parameters are: the central field strength was 780 v/cm, 6 x 99 microsecond pulses, with 1 second intervals.

The results showed that severe necrosis and edema occurred at the treatment site in almost all mice. The tumor volume in mice in the treated group (D + E +; D ═ drug, E ═ electric field) decreased significantly (slightly increased initially due to edema), while the tumor volume in mice in the control group (D + E-) increased significantly. Histological analysis of the tumor samples showed only empty cells of necrotic tumor cells in the D + E + group, and a mixed image of live and necrotic cells in the D + E-group. Preliminary studies on human non-small cell carcinoma (NSCLS) tumors xenografted in nude mice also showed encouraging results with EPT plus bleomycin treatment.

The tumor cell line Panc-3, a poorly differentiated adenocarcinoma cell line of the pancreas, was provided by Anticancer corporation of san Diego. For the EPT experiment, tissues were removed from tumor-bearing mice maintained with tumor cell lines, the tissues were thawed and cut into very small pieces, each of about 1 mm, 8 to 10 such small pieces of xenografts were surgically placed in a subcutaneous pouch cut on the left flank of nude mice, and the pouches were sutured with 6.0 surgical sutures. After the average tumor size reached approximately 5 mm, mice bearing palpable tumors were randomly grouped, 10 mice were assigned to a control group (D + E-; D ═ drug, E ═ electric field), and 10 mice were used for EPT treatment, i.e., bleomycin was injected first, followed by pulsing with a BTX square wave T820 generator (D + E +). The size of the tumor was measured and the volume of the tumor was calculated using the following formula:

(II/6). times.a.times.b.times.c wherein, a, b and c are the length, width and thickness of the tumor, respectively. 0.5 units of bleomycin (supplied by Sigma Chemicals) was dissolved in 0.15 ml of 0.9% sodium chloride and this solution was injected in a fan-shaped manner into the tumor of each mouse in the control group (D + E-) and the treatment group (D + E +). 10 minutes after injection, each mouse in the D + E + group was pulsed with a BTX T820 square wave punch using the needle array electrodes described in the present invention. The electrical parameters used were as follows: the electric field strength was 1300 v/cm, 6 pulses of 99 microseconds each, with 1 second pulse interval.

Mice were monitored daily for mortality and noted for any signs of morbidity. The size of the tumor was determined at regular intervals and tumor regression/progression was monitored.

Figure 10 shows the treatment of animals bearing Panc-3 in the control and treatment groups with and without drugs and/or with or without pulses with bleomycin. EPT results were obtained. There was a clear difference in tumor volume between the untreated and treated animals. After approximately 24 days of treatment, there were essentially no detectable tumors. Table 1 below also summarizes the results in fig. 10 from day 0 to day 43. FIGS. 13a-13d show the actual regression of the tumor in sequence, and FIGS. 14a-14d show the corresponding histological images.

TABLE 1

Electrochemical treatment of PANC-3 tumors in nude mice

Days after treatment	Tumor volume (mm)³)C1	Tumor volume (mm)³)C2	Tumor volume (mm)³)T1	Tumor volume (mm)³)T2
Days after treatment	Tumor volume (mm)³)C1	Tumor volume (mm)³)C2	Tumor volume (mm)³)T1	Tumor volume (mm)³)T2	0	138.746	148.940	123.110	178.370
1	206.979	179.820	210.950	252.720	0	138.746	148.940	123.110	178.370
1	206.979	179.820	210.950	252.720	8	394.786	451.787	104.550	211.110
15	557.349	798.919	113.210	226.966	8	394.786	451.787	104.550	211.110
15	557.349	798.919	113.210	226.966	18	939.582	881.752	161.730	246.910
24	1391.057	1406.980	41.560	47.223	18	939.582	881.752	161.730	246.910
24	1391.057	1406.980	41.560	47.223	28	1628.631	1474.210	0	0
35	2619.765	2330.310	0	0	28	1628.631	1474.210	0	0
35	2619.765	2330.310	0	0	38	2908.912	2333.967	0	0
43	3708.571	5381.759	0	0	38	2908.912	2333.967	0	0

Cell line: human pancreatic tumor with poor differentiation (Panc-3)

Mouse model: nude mouse

Transplanting: subcutaneous xenografts

Mice in the control group: c1 and C2

Mice of the treatment groups: t1 and T2

Panc-3 experiments were performed in duplicate using a non-small cell lung cancer cell line (NSCLC), 177 (AntiCanaer, san Diego, Calif.). The results obtained were similar to those shown in FIG. 10 using bleomycin and Panc-3. In one example, a recurrent tumor was treated again at day 27 (fig. 12), and after 7 more days, no evidence of tumor was seen.

The test was performed using the Panc-3 and NSCLC models, using the drug Neocarzinostatin (NCS) according to the same procedure as above. As shown in FIG. 11a, when NSC was administered before the pulse, the effect of reducing the size of the tumor was not achieved at all when the same method as that used when studying bleomycin. It is believed that this is due to the lower isoelectric point of the NSCs, and the electrostatic effect prevents the drug from entering the tumor cells. Thus, this experiment was repeated by pulsing first and then injecting NSC after pulsing.

FIG. 11b shows the results of comparing initial tumor volume (I) and final tumor volume (F) at day 13 for 7 mice in the treatment group (mice numbered 1-7). An increase in tumor volume was observed in several of the mice (numbered 1, 2, 4, and 7), but apparently due to edema. However, as shown in figure 20d, when tested on an independent panel of 5 mice at day 23, all mice showed a significant reduction in tumor volume.

A comparison of fig. 11a and 11b shows that adding NSC after a pulse works much better than adding NSC before a pulse.

This example demonstrates that pancreatic cancer (Panc-3) and non-small cell lung cancer (NSCLC), which are poorly differentiated by being xenografted subcutaneously in nude mice, can be effectively treated using bleomycin or NSC and a needle array electrode according to the EPT method of the present invention. Other similar chemotherapeutic agents may also achieve good therapeutic efficacy using the methods of the present invention.

Table 2 shows the reaction of Panc-3 on EPT plus bleomycin. After 28 days of treatment, 68% (17/25) of the treated mice had complete regression of the tumor, 20% (5/25) partial (> 80%) regression, 8% (2/25) no response, and 4% (1/25) died after 20 days of treatment. No palpable tumors were observed in 64% (16/25) of the mice even at 120 days post-treatment. No tumors were observed in the typical animals (2/17) in this group after 243 days of observation, after which the animals were euthanized by the experimenter. However, in 8% of these mice tumor regrowth occurred 35 days after treatment, but the growth rate was significantly slower.

Histological studies clearly showed that in the group receiving EPT treatment, there was a sharp necrosis of the tumor zone, whereas in the control group there was no significant necrosis. This method is very effective when the drug injection is performed in a fan-like fashion with a larger dose of bleomycin to maximize the even distribution of the drug throughout the tumor as compared to the conventional mode of injecting the drug prior to pulsing.

TABLE 2

Electrochemical treatment of Panc-3 with bleomycin

Number of mice receiving treatment on days post-treatment: 25	28	35	57	84	94	120
	28	35	57	84	94	120	Complete regression (100%)	17	16	16	16	16	16
Partial regression (80% or more)	5	3	3	3	3	3c	Complete regression (100%)	17	16	16	16	16	16
Partial regression (80% or more)	5	3	3	3	3	3c	No reaction	2	2	1^a	1	1^c
Death was caused by death	1			2^b			No reaction	2	2	1^a	1	1^c
Death was caused by death	1			2^b			Regrowth of tumor			2		1^d
Retreatment of			2				Regrowth of tumor			2		1^d
Retreatment of			2				Histological study		1

a, c: mice died as tumor burden increased

b: 1 mouse died after treatment; 1 mouse died without palpable tumor after 64 days of survival

d: metastatic tumor of second stage

e: fibrous tissue

Using MedPulser^TMResults of in vivo experiments

Using MedPulser^TMPreliminary studies on the treatment of tumors grown in nude mice by means of subcutaneous xenografts (device of the invention) achieved encouraging results. When using MedPulser^TMAnd bleomycin EPT treatment of human pancreatic xenograft tumors (Panc-4) it was observed that at 39 days, approximately 75% of treated mice had complete tumor regression. Treatment of human prostate xenograft tumors (PC-3) also showed complete regression of approximately 66% of the tumors. (inNo tumor was observed at 60 days post treatment). Both the 4-needle array and the 6-needle array were effective for treating tumors with EPT.

MedPulser was compared by experiments performed on PC-3 in vitro^TM4-and 6-needle arrays

By MedPulser^TMExperiments were performed in vitro on PC-3 (human prostate cell line) to compare the effect of the 4-needle array and the 6-needle array. Cells were suspended in RPMI medium and seeded uniformly at a concentration of 200,000 cells/ml. 2 x 10 to^-5M bleomycin was added to wells (well) (only for D + E-and D + E +). Cells placed in 24-well plates (wellplates) were electroporated with 6-and 4-pin array electrodes connected to a MedPulser. The parameters of the electric pulse when 6-pin electrodes are adopted are as follows: 6 × 99 microseconds, 1129 volts; the parameters of the electric pulse when the 4-pin electrode is adopted are as follows: 4 x 99 microseconds, 848 volts. These cells were transferred to 96-well plates and cultured at 37 ℃ for 20 hours. Cell viability was determined using the XTT assay based on the metabolic conversion of XTT to trimethyl * and spectrophotometric analysis at a wavelength of 450 nm. Only living cells were able to convert XTT to trimethyl *. The percentage cell viability values are relative values calculated from the O.D. values of the samples, the control for 100% cell viability (D-E-) and the control for 0% cell viability (D-E-plus SDS, which lyses all cells). Cell viability data were as follows:

TABLE 3

Treatment of	Percent mean survival	SE
Treatment of	Percent mean survival	SE	D-E-	100	3.65(n＝6)
D+E-	27.71	1.05(n＝6)	D-E-	100	3.65(n＝6)
D+E-	27.71	1.05(n＝6)	D-E+(4N)	101.15	4.32(n＝12)
D-E+(6N)	97.72	4.33(n＝12)	D-E+(4N)	101.15	4.32(n＝12)
D-E+(6N)	97.72	4.33(n＝12)	D+E+(4N)	4.78	7.53(n＝12)
D+E+(6N)	-4.12	0.59(n＝12)	D+E+(4N)	4.78	7.53(n＝12)

From preliminary data obtained from experiments, it can be concluded that: statistically, 4 needles and 6 needles have the same effect on killing tumor cells in vitro.

Example 2 clinical trials for basal cell carcinoma and melanoma

The efficacy of bleomycin-EPT on tumours was not assessed over 8 weeks using the same tumour response criteria as in example 1.

The concentration of bleomycin administered was 5U/1 ml. The dosage of bleomycin was as follows:

TABLE 4

Tumor size	Dosage of bleomycin
Tumor size	Dosage of bleomycin	＜100mm³	0.5U
100-150mm³	.75U	＜100mm³	0.5U
100-150mm³	.75U	150-500mm³	1.0U
500-1000mm³	1.5U	150-500mm³	1.0U
500-1000mm³	1.5U	1000-2000mm³	2.0U
2000-3000mm³	2.5U	1000-2000mm³	2.0U
2000-3000mm³	2.5U	3000-4000mm³	3.0U
≥5000mm³	4.0U	3000-4000mm³	3.0U

Table 5 below shows the results of the response to treatment

NE is invalid; the tumor volume decreased by less than 50%.

PR ═ partial reaction; the reduction in tumor volume is equal to or greater than 50%.

CR is complete reaction; tumors were determined to have disappeared when examined by physical examination and/or biopsy.

TABLE 5

Subject response to treatment

		Tumor response												Percentage of reaction (%)
		Tumor response												Percentage of reaction (%)														NE				PR				CR				NE				PR				CR
Tumor type	Total number of mass	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-			NE				PR				CR				NE				PR				CR
Tumor type	Total number of mass	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	D⁺E⁺	D⁺D^-	D^-E⁺	D^-E^-	BCC	67	0/44	5/6	3/15	2/2	1/44	1/6	4/15	0/2	43/44	0/6	0/15	0/2	0	83	20	100	2	17	27	0	98	0	0	0
Mel	97	1/58	5/6	4/30	4/4	4/58	0/6	4/30	0/4	53/58	0/6	0/30	0/4	2	100	13	100	7	0	13	0	91	0	0	0	BCC	67	0/44	5/6	3/15	2/2	1/44	1/6	4/15	0/2	43/44	0/6	0/15	0/2	0	83	20	100	2	17	27	0	98	0	0	0
Mel	97	1/58	5/6	4/30	4/4	4/58	0/6	4/30	0/4	53/58	0/6	0/30	0/4	2	100	13	100	7	0	13	0	91	0	0	0	Others	8	0/5	3/3	0/0	0/0	1/5	0/3	0/0	0/0	4/5	0/3	0/0	0/0	0	100	0	0	20	0	0	0	80	0	0	0
Sum of	172	1/107	13/14	7/45	6/6	6/107	1/14	8/45	0/6	100/107	0/14	0/45	0/6	1	93	16	100	6	7	18	0	93	0	0	0	Others	8	0/5	3/3	0/0	0/0	1/5	0/3	0/0	0/0	4/5	0/3	0/0	0/0	0	100	0	0	20	0	0	0	80	0	0	0

EXAMPLE 3 treatment of head and neck cancer with EPT

All patients below were treated with intratumoral bleomycin injection and with needle arrays of different diameters consisting of 6 needles. The length of the pulse is 100 microseconds by setting the voltage to achieve a nominal electric field strength of 1300 volts/cm (multiplying the diameter of the needle array by 1300 to give the set voltage for the generator).

Research method

This study is called a single-center feasibility clinical study in which the effects of EPT techniques combined with damaging bleomycin are compared to the effects of conventional surgical therapy, radiation therapy and/or systemic chemotherapy. 50 study subjects were enrolled in the study. All study subjects were assessed by physical examination and biopsy prior to treatment. Study subjects were evaluated postoperative once a week for 4-6 weeks, after which they were evaluated monthly for a total of 12 months. A biopsy of the tumor site was performed approximately 8 to 12 weeks after treatment. CT or magnetic resonance imaging techniques were utilized in accordance with standard medical follow-up assessment methods for HNC subjects.

The assessment of the tumor involves determining the diameter of the tumor (in centimeters) and estimating its volume (in cubic centimeters). Prior to the injection of bleomycin sulphate into the tumour, the tumour site was anaesthetised with 1% lidocaine (xylocaine) and 1: 100,000 epinephrine. The concentration of bleomycin sulphate injected is 4 units per ml, with the highest dose of 5 units per tumour. If more than one tumor per subject is to be treated, the total dose per subject should not exceed 20 units. The dose of bleomycin administered should be 1 unit per cubic centimeter of calculated tumor volume. Approximately 10 minutes after the bleomycin sulfate injection, the applicator was placed onto the tumor and the electrical pulse was initiated. Each application or firing of an electrical pulse is referred to as a sequence. The use of EPT is not contraindicated for any subsequent palliative treatment required by the subject.

In this study, the definition of success was: within 16 weeks or less, tumors regress significantly without some of the major side effects of traditional therapies. There are three possible reaction outcomes:

complete Reaction (CR): tumors were determined to have disappeared when examined by physical examination and/or biopsy.

Partial Reaction (PR): the reduction in tumor volume is equal to or greater than 50%.

No Reaction (NR): the tumor volume decreased by less than 50%.

If the size of the tumor increases (25% of the tumor volume), additional treatment regimens can be tailored to the needs of each subject, if necessary.

Subject response to treatment

Table 6 shows the subject's response to treatment. Three subjects had complete responses (subjects No. 1, 3 and 4); four subjects had partial responses (subjects No. 2, 6, 8 and 9); two subjects did not respond to treatment (subjects No. 5 and 7). Three subjects died before reaching week 12 due to progressive disease or complications unrelated to investigational treatment (subjects No. 2, 5 and 7). One of these three subjects reached PR at week 4 (subject No. 2). Two subjects had not received early-stage clinical cancer treatment before being enrolled in the study (subjects No. 4 and 8). The tumors suffered by the three subjects were not fully accessible by the applicator part of the instrument and therefore received only fractionated treatments (subjects 5, 7 and 9).

TABLE 7 Pair of MedPulse Using bleomycin sulfate and the apparatus according to the invention^TMClinical studies in which EPT was performed were summarized.

TABLE 6

Reaction with bleomycin sulphate/EPT

Subject number/first letter of last and first name	Early treatment	Week of treatment	Time of reaction (week)	Reaction state	Last visit (week)
Subject number/first letter of last and first name	Early treatment	Week of treatment	Time of reaction (week)	Reaction state	Last visit (week)	1/J-S	S	0	2，8	PR，CR	22
2/G-C	R	0，4	4	PR	4	1/J-S	S	0	2，8	PR，CR	22
2/G-C	R	0，4	4	PR	4	3/L-O	R	0	3	CR	16
4/G-R	None	0，4	4，9	PR，CR	9	3/L-O	R	0	3	CR	16
4/G-R	None	0，4	4，9	PR，CR	9	5/R-H	R	0，4	na	NR^**	4
6/C-B	R	0，12	2	PR	12	5/R-H	R	0，4	na	NR^**	4
6/C-B	R	0，12	2	PR	12	7/C-J	S，R，C	0	na	NR^**	1
8/L-J	None	0，6	4	PR	9	7/C-J	S，R，C	0	na	NR^**	1
8/L-J	None	0，6	4	PR	9	9/J-T	S，R，C	0，7	7	PR^**	7

(S) surgery, (R) radiation therapy, (C) chemotherapy; PR-partial reaction; CR-complete reaction; NR-no reaction;^**segmental treatment

TABLE 7

Summary of clinical studies using bleomycin sulfate and electroporation therapy

Site/p.i.	Status of state	Number of patients	History record	Tumor volume	Number of lesions	Bleomycin (Unit) IT IV	Total number of EPT (sequences)	CR(n) ％		PR(n) ％		NR(n) ％		NE(n)
Site/p.i.	Status of state	Number of patients	History record	Tumor volume	Number of lesions	Bleomycin (Unit) IT IV	Total number of EPT (sequences)	CR(n) ％		PR(n) ％		NR(n) ％		NE(n)	Head and neck cancer	Start of registration: 08/14/96 terminating: 12/18/96 State: follow-up visit of patient	7	Squamous cell	0.52-25.12cm³	7	1-16	1-14	3	43	2	29	2	29	2
		2	Adenocarcinoma	4.12-12.56cm³	2	2-8	2-8	0	0	2	100	0	100		Head and neck cancer		7	Squamous cell	0.52-25.12cm³	7	1-16	1-14	3	43	2	29	2	29	2
		2	Adenocarcinoma	4.12-12.56cm³	2	2-8	2-8	0	0	2	100	0	100			In total	9			9			3	33％	4	44％	2	22％
Skin and subcutaneous cancer	Start of registration: 08/01/96 terminating: 01/27/97 State: follow-up visit of 5 patients, 2 patients to be evaluated	7	Basal cell	0.07-0.63cm³	8	0.8-0.64	1	4	67	2	33	0	0	2		In total	9			9			3	33％	4	44％	2	22％
Skin and subcutaneous cancer		7	Basal cell	0.07-0.63cm³	8	0.8-0.64	1	4	67	2	33	0	0	2		In total	7			8			4	67％	2	33％	0	0％	2
Skin and subcutaneous cancer	Start of registration: 01/20/95 terminating: 11/05/96	18	Basal cell	0.019-2.023cm³	54	0.5-3	1-5	51	94	5	9	0	0			In total	7			8			4	67％	2	33％	0	0％	2

Table 7 (continuation)

The state is as follows: complete the process
The state is as follows: complete the process																10	Met melanoma	0.007-5.376cm³	84	0.2-2		1-8	75	91	8	9	2	2
	1	Kaposi sarcoma	0.014-7.472cm³	4	1-2		1-2	4	100	0	0	0	0			10	Met melanoma	0.007-5.376cm³	84	0.2-2		1-8	75	91	8	9	2	2
	1	Kaposi sarcoma	0.014-7.472cm³	4	1-2		1-2	4	100	0	0	0	0			1	Squamous cell	0.453cm³	1	1.5		1-4	0	0	1	100	0	0
In total	30			146				130	89％	14	10％	2	1％			1	Squamous cell	0.453cm³	1	1.5		1-4	0	0	1	100	0	0
In total	30			146				130	89％	14	10％	2	1％	Skin and subcutaneous cancer	Start of registration: 02/18/94 terminating: 05/04/94 State: complete the process	2	Basal cell	0.078-0.782cm³	6		22-23	1	1	17	5	83	0	0
	3	Met melanoma	0.038-1.786cm³	10		19-23	1	3	30	2	20	5	50	Skin and subcutaneous cancer		2	Basal cell	0.078-0.782cm³	6		22-23	1	1	17	5	83	0	0
	3	Met melanoma	0.038-1.786cm³	10		19-23	1	3	30	2	20	5	50			1	Met breast cancer	0.285-0.454cm³	2		17	1

Complete reaction PR, partial reaction NR, no reaction NE and evaluation of the reaction

Example 4 EPT with Low Voltage Long pulse Length (LVLP)

Conventional electrochemotherapy uses high voltage short pulses to treat tumors. It has been found that 1200-1300 v/cm and 100 μ s electric field conditions in combination with anti-cancer drugs such as bleomycin, cisplatin, pelamycin, mitomycin C and carboplatin are very effective in vitro and in vivo. These results relate to work in vitro and in vivo. While patients in clinical settings are fully tolerant of such electrical conditions, such treatments often cause the patient's muscle twitching and occasional discomfort. It can often be found that the feeling of discomfort is related to the pain sensation of the individual patient. Patients often respond quite differently under the same experimental conditions. Some of these problems can be effectively solved by means of electrochemical therapy with low voltage long pulses. The lowest electric field strength that has been reported for gene transfer in vivo is 600 volts/cm (T. Nishi et al cancer research 56: 1050- & 1055, 1996). The maximum electric field strength for the in vitro EPT experiments is shown in Table 8, where the electric field strength required to kill 50% of the cells is 50V/cm or less.

The following in vitro experiments on various tumor cell lines, e.g., MCF-7 (human breast cancer), PC-3 (human prostate cancer) and C6 (rat glioma), showed that low voltage long pulses are higher than high voltage long pulses for killing tumor cellsThe press burst pulse has the same or better effect. These results are made for example for MCF-7. Titration of the pulse length indicated that it could be in the range of 4-15 milliseconds. After 70 hours, the electric pulse reaction assay of MCF-7 was performed under both high voltage/short pulse length (HVSP) and low voltage/long pulse length (LVLP) conditions using the XTT assay based on the metabolic conversion of XTT to formazan * and spectrophotometric assay at a wavelength of 450 nm. (M.W.Roehm et al: an improved colorimetric assay for cell proliferation and activity using tetrazolium salt XTT, journal of immunological methods: (M.W.Roehm et al)J.Immunol.Methods) 142: 2,257-265, 1991. ) XTT is a tetrazolium reagent, i.e. 2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl) -5- [ (aniline) carbonyl]-2H-tetrazolyl hydroxide (XTT), a water-soluble formazan * product that is metabolically reduced in living cells. Thus, only living cells are able to convert XTT to a formazan *. The percentage of cell viability value is a relative value calculated from the o.d. value of the sample using a formula. (control with 100% cell viability (D-E-) and control with 0% cell viability (D-E-plus SDS)). In order to directly compare with EPT of the recently developed LVLP mode, some experiments were performed using HVSP.

TABLE 8

Cell lines	Cell type	HVSPLD₅₀(volt/cm)	LVLPLD₅₀(volt/cm)
Cell lines	Cell type	HVSPLD₅₀(volt/cm)	LVLPLD₅₀(volt/cm)	MCF-7	Breast cancer (human)	1800	50

(LD₅₀Is the pulse lethal dose required to kill 50% of the cells)

Voltages as low as 25 v/cm induce significant cytotoxicity to the cells. The increase in the electric field strength results in complete killing of the cells. Some cell lines, such as C6 glioma, were not significantly affected by the high voltage pulse, but were completely killed by the low voltage of 20-30 volts/cm. The results of these in vitro experiments clearly demonstrate the potential of EPT therapy with low voltage long pulse patterns.

Cytotoxicity of drugs and EPT in vitro

The results of EPT experiments using MCF-7 under both high and low voltage conditions using different drugs applied in vitro are described below. Cells were obtained from the ATCC (American Type tissue Collection, Rockville, Md., USA) and cultured as suggested by the ATCC. Cells were suspended in a suitable medium and seeded evenly in 24/96 well plates. One of these drugs is administered at about 1X 10^-4(1E-4) to 1.3X 10^-9(1.3E-9) the final concentration was added directly to the cell suspension: these drugs are bleomycin, cisplatin, mitomycin C, doxorubicin and taxol. Using the BTX needle array electrodes described herein, electrical pulses generated by a BTX T820 electro-square wave punch were applied to the cell suspension located in the microplate. According to the experiments performed, 6 pulses of 100 microseconds or 10 milliseconds were applied between two opposing pairs of electrodes in a 6-pin array at different high or low voltage ratings using the EPT-196 pin array switch. The microplate was cultured for 20 hours or 70 hours, and the cell viability was measured by the XTT assay. Some of these results are shown in FIGS. 15(a), 15(b), 16(a), 16(b) and 17In (1).

Using MedPulser^TMA curve corresponding to fig. 17 was obtained.

For the LVLP mode, the method showed that the survival of cells was much less than 50% even when the cells were pulsed without drug; this percentage is further reduced when combined with a drug. It is more desirable to be able to indicate the effect of the drug rather than the pulse, so it is desirable to select an initial survival rate of about 80% for a pulse only. FIG. 15(a) shows a typical cell killing curve in LVLP mode.

Although the invention has been described with reference to this preferred embodiment, it will be understood that various modifications may be made without departing from the spirit of the invention. Accordingly, the scope of the invention is to be limited only by the following claims.

Claims

1. A laparoscopic needle applicator for electroporation therapy, comprising:

(a) a support rod;

(b) a sheath surrounding the support shaft, said sheath being movable relative to the support shaft between an extended position covering the distal end of the support shaft and a retracted position exposing the distal end of the support shaft;

(c) at least two electrode needles adapted for electroporation therapy and disposed between the support shaft and the sheath;

(d) a compressible mechanism secured to at least one of the needles for moving the needle electrode associated therewith from a sheathed state, in which the sheath is in the extended position, to an extended state, in which the sheath is in the retracted position, and in which the distance between the needle electrodes is greater than in the sheathed state.

2. The laparoscopic needle applicator of claim 1, wherein the support shaft comprises an endoscope.

3. Method for selectively addressing a plurality of electrode needle configurations, each electrode needle configuration comprising at least 4 electrode needles for performing an electroporation treatment, the method comprising the steps of:

(a) arranging each electrode needle in one of the plurality of electrode needle structures into an array of locations to define treatment zones having at least 4 sides;

(b) pulses of alternating voltage polarity are applied to opposing pairs of needle electrodes defining each treatment zone.

4. A method as claimed in claim 3, wherein an electrode needle structure comprises 4 needles defining a treatment zone.

5. A method as claimed in claim 3, wherein one electrode needle configuration comprises 9 needles defining 4 treatment zones.

6. A method as claimed in claim 3, wherein one electrode needle configuration comprises 16 needles defining 9 treatment zones.

7. The method of claim 3, wherein one electrode needle configuration comprises 6 needles defining a hexagonal treatment zone.

8. The method of claim 3, wherein one electrode needle configuration comprises 8 needles defining an octagonal treatment zone.

9. A method for automatically setting an electrode needle addressing scheme for an electroporation therapy apparatus, the apparatus capable of receiving a plurality of electrode applicators having different numbers of electrode needles, the method comprising the steps of:

(a) providing a type recognition element in an electrode applicator having a plurality of electrode needles, the type recognition element representing at least the number of the electrode needles;

(b) connecting an electrode applicator to an electroporation therapy device;

(c) determining the number of electrode needles by the type recognition element;

(d) the electroporation therapy apparatus is set to address a determined number of electrode needles.

10. The method of claim 9, further comprising the steps of: the electroporation therapy apparatus is set to address a determined number of electrode needles in a selected mode.

11. A method for automatically setting electrotherapy parameters of an electroporation therapy device, said device capable of receiving a plurality of different electrode applicators, said method comprising the steps of:

(a) providing a type identification element in an electrode applicator, the type identification element being representative of at least one of the following electrical treatment parameters for the electrode applicator: needle voltage setpoint, pulse length or pulse shape;

(b) connecting an electrode applicator to an electroporation therapy device;

(c) determining an electrical therapy parameter by the type identification element;

(d) the electroporation therapy apparatus is configured to have the determined electroporation therapy parameters.

12. A system for automatically setting an electrode needle addressing scheme for an electroporation therapy device capable of receiving a plurality of electrode applicators having different numbers of electrode needles, the system comprising:

(a) an electrode applicator having a plurality of electrode needles and a type recognition element representing at least the number of the electrode needles;

(b) a circuit in the electroporation therapy apparatus for determining the number of electrode needles by the type recognition element when the electrode adapter is connected to the electroporation therapy apparatus;

(c) the electroporation therapy apparatus is configured as a circuit that addresses a determined number of electrode needles.

13. A system for automatically setting electrotherapy parameters of an electroporation therapy device, said electroporation therapy device capable of receiving a plurality of different electrode applicators, said system comprising:

(a) an electrode applicator having a type-identifying element that represents at least one of the following electrical treatment parameters for the electrode applicator: needle voltage setpoint, pulse length or pulse shape;

(b) a circuit in the electroporation therapy apparatus for determining the electrical therapy parameters via the type identification element when the electrode adapter is connected to the electroporation therapy apparatus;

(c) and a circuit configured to set the electroporation therapy device to have the determined electrical therapy parameters.

14. An electrode applicator for automatically setting an electrode needle addressing scheme in an electroporation therapy apparatus capable of receiving a plurality of electrode applicators having different numbers of electrode needles, the electrode applicator comprising:

(a) some electrode needles for performing electroporation therapy; and

(b) a type recognition element capable of being electrically connected to the electroporation therapy apparatus, the type recognition element representing at least the number of the electrode needles;

wherein the type identification element is provided to the electroporation therapy apparatus when the electrode adapter is connected to the electroporation therapy apparatus, enabling the electroporation therapy apparatus to automatically set itself to address a determined number of electrode needles.

15. An electrode applicator for automatically setting electrotherapy parameters of an electroporation therapy device, said electroporation therapy device capable of receiving a plurality of different electrode applicators, said electrode applicator comprising:

(a) some electrode needles for performing electroporation therapy; and

(b) a type identification element capable of being electrically connected to the electroporation therapy device, the type identification element representing at least one of the following electrical therapy parameters for the electrode applicator: needle voltage setpoint, pulse length or pulse shape;

wherein the type identification element is provided to the electroporation therapy apparatus when the electrode applicator is connected to the electroporation therapy apparatus, enabling the electroporation therapy apparatus to automatically set itself to have the determined electroporation therapy parameters.

16. An electroporation therapy apparatus, comprising:

(a) a power supply for generating voltage pulses;

(b) a connector for connecting to one of a plurality of electrode applicators having different numbers of electrodes, each electrode applicator including a type recognition element representing at least the number of the electrode needles;

(c) a circuit for determining the number of the determined number of electrode pins by the type recognition element when the electrode adapter is connected to the connector;

(d) an electrical circuit for setting the electroporation therapy apparatus to address a determined number of electrode needles and to apply the generated voltage pulses to the addressed electrodes.

17. The electroporation therapy apparatus of claim 16, further comprising a teletherapy activation device for controlling the generation of the voltage pulses.

18. The electroporation therapy apparatus of claim 17, wherein the remote therapy activation device comprises a foot pedal switch.

19. An electroporation therapy apparatus, comprising:

(a) a power supply for generating voltage pulses, said power supply having programmable electrical therapy parameters including at least one of: needle voltage setpoint, pulse length, or pulse shape;

(b) a connector for connection to one of a plurality of electrode applicators having an electrode needle, each electrode applicator being required to have selected electrical treatment parameters, each electrode applicator including a type identification element representative of the particular electrical treatment parameters to be used in conjunction with the electrode applicator;

(c) a circuit for determining specific electrical therapy parameters by the type identification element when the electrode adapter is connected to the connector;

(d) a circuit for programming the electrical treatment parameters of the electroporation therapy apparatus to equal the determined specific electrical treatment parameters.

20. The electroporation therapy apparatus of claim 19, further comprising a teletherapy activation device for controlling the generation of the voltage pulses.

21. The electroporation therapy apparatus of claim 20, wherein the remote therapy activation device comprises a foot pedal switch.

22. An electrode applicator for providing applicator-specific parameters for an electroporation therapy apparatus capable of receiving a plurality of different electrode applicators, the electrode applicator comprising:

(a) some electrode needles for performing electroporation therapy; and

(b) a type identification element capable of being electrically connected to the electroporation therapy device, the type identification element providing an indication of at least one applicator-specific parameter;

wherein the type-identifying element is provided to the electroporation therapy apparatus when the electrode adapter is coupled to the electroporation therapy apparatus, such that the electroporation therapy apparatus is responsive to the determined applicator-specific parameter.

23. The electrode applicator of claim 22, wherein the type-identifying element represents at least one of the following needle array type parameters: the number of needles, the needle spacing, or the switching order of the needles.

24. The electrode applicator of claim 22, wherein the at least one applicator-specific parameter is the number of needles in the electrode applicator.

25. The electrode applicator of claim 22, wherein the at least one applicator-specific parameter is the spacing of the needles in the electrode applicator.

26. The electrode applicator of claim 22, wherein the at least one applicator specific parameter is a needle switching sequence of the electrode applicator.

27. The electrode applicator of claim 22, wherein the at least one applicator specific parameter is a given value of a voltage to be applied to a needle in the electrode applicator.

28. The electrode applicator of claim 22, wherein the at least one applicator-specific parameter is a pulse length to be applied to a needle in the electrode applicator.

29. The electrode applicator of claim 22, wherein the at least one applicator-specific parameter is a pulse shape to be applied to a needle in the electrode applicator.

30. The electrode applicator of claim 22, wherein the at least one applicator-specific parameter is the shelf life of the electrode applicator.

31. The electrode applicator of claim 22, wherein the at least one applicator-specific parameter is the life of the electrode applicator.

32. The electrode applicator of claim 22, further comprising a writable drive circuit capable of storing data specific to the electrode applicator.

33. The electrode applicator of claim 22, wherein the at least one applicator specific parameter is a shelf life of the electrode applicator, and a shelf life lock code is stored in the writable drive circuit when the shelf life is exceeded.

34. The electrode applicator of claim 33, wherein the at least one applicator specific parameter is the life of the electrode applicator, and a life lock code is stored in the writable drive circuit when the life is exceeded.

35. The electrode applicator of claim 33, wherein a history of use of the electrodes is stored in a writable drive circuit.

36. The electrode applicator of claim 33, wherein the captured error code is stored in a writable drive circuit.