Abstract:
Mammalian subjects having a neoplasm are treated with a virus and a camptothecin compound, for example irinotecan or topotecan. The virus is selected from the group consisting of a Newcastle disease virus, a measles virus, a vesicular stomatitis virus, an influenza virus, a Sindbis virus, a picornavirus, and a myxoma virus. The treatment can also include administration of a monoclonal antibody against epidermal growth factor receptor, for example cetuximab.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Coadministration of oncolytic viruses with other chemotherapeutic agents is disclosed in WO 00/62735 (pages 35-36). See Kirn D (Cancer Gene Ther 2002; 9:959-960; Virotherapy for cancer: current status, hurdles and future directions) and Bell J C et al. (Cur Gene Ther 2002, 2:243-254; Oncolytic viruses: programmable tumour hunters) for recent reviews on anti-cancer virus therapy. Improvements in efficacy using such virus therapies are important to the field and getting approval and widespread use of the approach. Specifically, a drug which shows supra-additive efficacy with a virus would be most advantageous.  
         [0002]     The use of camptothecins as anticancer agents is reviewed in Garcia-Carbonero, et al., Clin. Cancer Res. (March 2002) 8: 641-661; and in Pizzolato J F and Saltz L B, The camptothecins. Lancet 2003 361:2235-42. Camptothecins have antitumor activity based on their binding to and inhibition of topoisomerase I, a nuclear enzyme which reduces torsional stress during DNA replication and which has an important role in DNA replication. Topotecan and irinotecan are the two camptothecins have been approved for clinical use by the US Food and Drug Administration (FDA). Other camptothecins are in development as cancer therapeutics (Ulukan and Swaan, (Campothecins: a review of their chemotherapeutic potential. Drugs, 2002, 62:2039-57); and Garcia-Carbonero and Supko, 2002).  
         [0003]     The treatment of cancers using certain mutant herpes viruses in combination with any of numerous anticancer agents, including irinotecan and topotecan, is disclosed in U.S. Patent Publication No. 2002/0071832 (Fong, et al.), paragraphs 7 and 40. Methods of treating neoplasias using target cell-specific adenoviral vectors in combination with antineoplastic agents, including irinotecan or topotecan, are disclosed in U.S. Patent Publication No. 2003/0068307 (Yu, et al.) page 13. See also Nemunaitis, et al., Cancer Gene Ther. (2003) 10(5): 341-352; and Meck, et al., Cancer Res. (2001) 61(13): 5083-5089. Combined use of irinotecan and cetuximab was approved in February 2004 by the U.S. FDA to treat colorectal cancer.  
       SUMMARY OF THE INVENTION  
       [0004]     This invention provides a method for treating a mammalian subject having a neoplasm, comprising administering to the subject a virus and a camptothecin compound in a combined amount effective to treat the subject; wherein the virus is selected from the group consisting of a Newcastle disease virus, a measles virus, a vesicular stomatitis virus, an influenza virus, a Sindbis virus, a picornavirus, and a myxoma virus. In an embodiment of this invention the treatment further comprises administering to the subject a monoclonal antibody against epidermal growth factor receptor in an amount effective, in combination with the virus and the camptothecin compound, to treat the subject.  
         [0005]     This invention provides for the use of a virus and/or a camptothecin compound in the manufacture of a medicament for treating, in combination with the other ingredient mentioned, a subject having a neoplasm; wherein the virus is selected from the group consisting of a Newcastle disease virus, a measles virus, a vesicular stomatitis virus, an influenza virus, a Sindbis virus, a picornavirus, and a myxoma virus. This invention also provides the use of a monoclonal antibody against epidermal growth factor receptor in the manufacture of a medicament for treating, in combination with a virus as mentioned above and a camptothecin compound, a subject having a neoplasm.  
         [0006]     This invention is based on the finding that anti-cancer viruses and camptothecins in combination are effective against neoplastic cells. To illustrate, a mesogenic strain of Newcastle disease virus and irinotecan, a camptothecin compound, have demonstrated a greater than additive level of in vivo antitumor activity, as shown in the examples. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0007]     As used herein the transitional term “comprising” is open-ended. A claim utilizing this term can contain elements in addition to those recited in such claim. Thus, for example, the claims can read on treatment regimens that also include other therapeutic agents or therapeutic virus doses not specifically recited therein, as long as the recited elements or their equivalent are present.  
         [0008]     As used herein “NDV” is an abbreviation for Newcastle Disease Virus. As used herein “DLT” is an abbreviation for dose limiting toxicity. As used herein the term “plaque-forming unit” (PFU) means one infectious virus particle. As used herein “BPFU” means billion PFUs. As used herein “PP” means plaque-purified. Thus, for example PPMK107 means plaque-purified Newcastle Disease virus strain MK107. As used herein “PFU/m 2 ”, which is a standard unit for expressing dosages, means PFUs per square meter of patient surface area. As used herein the term “replication-competent” virus refers to a virus that produces infectious progeny in cancer cells.  
         [0009]     In an embodiment of this invention the virus is replication-competent.  
         [0010]     In accordance with this invention, when the virus is a Newcastle Disease Virus it can be of low (lentogenic), moderate (mesogenic) or high (velogenic) virulence. The level of virulence is determined in accordance with the Mean Death Time in Eggs (MDT) test. (Alexander, “Chapter 27: Newcastle Disease” in Laboratory Manual for the Isolation and Identification of Avian Pathogens, 3 rd  ed., Purchase, et al. eds. (Kendall/Hunt, Iowa), page 117.) Viruses are classified by the MDT test as lentogenic (MDT&gt;90 hours); mesogenic (MDT from 60-90 hours); and velogenic (MDT&lt;60 hours). Mesogenic NDV is currently preferred.  
         [0011]     In accordance with this invention, any conventional route or technique for administering viruses to a subject can be utilized. For examples of routes of administration refer to WO 00/62735. In one embodiment of this invention, the virus is administered systemically, for example intravenously. For intravenous administration of a therapeutic virus in accordance with this invention, preferably the virus is a mesogenic strain of Newcastle Disease Virus. In a preferred embodiment of this invention, from 12×10 9  to 120×10 9  PFUI/m 2  per dose of a mesogenic strain of Newcastle Disease virus is administered intravenously to a human subject, more preferably from 12×10 9  to 48×10 9  PFU/m 2  per dose. As used herein “mg/m 2 ” means milligrams per square meter of patient surface area.  
         [0012]     In embodiments of this invention the picornavirus is a poliovirus, an echovirus, or a coxsackievirus. Examples of coxsackieviruses that are suitable in accordance with this invention include the following types: A21, A13, A15 and A18. Examples of suitable echoviruses include echovirus type 1.  
         [0013]     As used herein the term “camptothecin compound” means that class of compounds considered to be camptothecins, camptothecin analogs, camptothecin derivatives or camptothecin conjugates. These compounds are based on the characteristic five-ring backbone of camptothecin:  
                         
 
         [0014]     In accordance with this invention any camptothecin compound can be utilized. Examples of camptothecin compounds include irinotecan (CAMPTOSAR; 7-ethyl-10-[4-(1-piperidino)-1-piperidino]-carbonyloxycamptothecin), topotecan (HYCAMPTIN; (S)-9-N;N-dimethylaminoethyl-10-hydroxycamptothecin), 9-aminocamptothecin (9-amino-20(S)-camptothecin), 9-nitrocamptothecin (also called rubitecan), lurtotecan (7-(4-methylpiperazinomethylene)-10,11-ethylenedioxy-20(S)-camptothecin), exatecan, karenitecin, and a homocamptothecin. The structures and clinical information for some camptothecin compounds can be found in Garcia-Carbonero, et al., Clin. Cancer Res. (March 2002) 8: 641-661. Examples of camptothecin compounds can also be found in U.S. Pat. No. 4,604,463, No. 6,403,569, and No. 5,004,758, and in WO 2004/012661, WO 2003/101998, WO 2003/101996, WO 2003/101406, WO 2003/093274, WO 2003/086471, WO 01/76597, WO 01/64194, WO 00/70275, WO 00/53607, WO 99/17805, WO 99/17804, WO 99/05103, WO 98/35969, WO 97/28164, WO 97/25332, WO 97/16454, the contents of all of which are incorporated herein by reference.  
         [0015]     In accordance with the combination therapy of this invention the camptothecin compound can be administered from one month before administration of the virus until one month after administration of the virus. In more specific embodiments the camptothecin compound and the virus are administered to the subject within a single twenty-four hour period; or the camptothecin compound is administered from twenty-four hours to one month, preferably from twenty-four hours to one week, before administration of the virus; or the camptothecin compound is administered to the subject from twenty-four hours to one month, preferably from twenty-four hours to one week, after administration of the virus. The dosing and administration techniques and schedules for camptothecins and anti-cancer viruses are known in the art (See, e.g. Garcia-Carbonero, et al.; WO 00/62735; WO 2004/000209; and Pecora, et al., J. Clin. Oncol. (2002) 20(9): 2251-2266), and their optimization for a specific patient is within the ability of the skilled clinician. Irinotecan is usually administered to human patients in a dosage amount of from 62.5 to 125 mg/m 2  four times per week, or more preferably 80 to 125 mg/m 2  four times per week; or from 300 to 350 mg/m 2  once every three weeks, or more preferably 300 to 350 mg/m 2  once every three weeks.  
         [0016]     In accordance with this invention any antibody against epidermal growth factor receptor can be utilized. Chimeric and humanized monoclonal antibodies are preferred. Examples of suitable anti-EGF antibodies include cetuximab (tradename: ERBITUX), ABX-EGF, MDX-447, h-R3, and EMD-7200 (see Mendelsohn J and Baselga J, “Status of epidermal growth factor receptor antagonists in the biology and treatment of cancer”, 2004 J Clin Oncol 21:2787-2799). Cetuximab is preferably administered to human patients intravenously, and is usually administered in an initial intravenous infusion of from 200 to 400 mg/m 2 , followed approximately weekly thereafter by subsequent infusions of from 125 to 250 mg/m 2 .  
         [0017]     The subject that is treated in accordance with this invention can be either a human subject or a non-human mammalian subject. In accordance with this invention, any neoplasm can be treated, including but not limited to the following: rectal cancer, pelvic cancer, colon cancer, lung cancer, breast cancer, prostate cancer, glioblastoma, renal cancer, pancreatic cancer, head and neck cancer, endometrial cancer, neuroblastoma, carcinoid, melanoma, ovarian cancer, sarcoma, cancer of the gastro-esophageal junction, gastric cancer, esophageal cancer, liver cancer, and cervical cancer.  
         [0018]     Although monitoring the treatment is not an essential aspect of the invention, there are techniques for measuring the therapeutic effects of the treatment. These include, measuring the size of the tumor after administration of the virus, and a decrease in tumor size is a positive result.  
         [0019]     The invention will be better understood by reference to the following examples, which illustrate but do not limit the invention described herein. In the following examples 1 to 6, the NDV is a triple-plaque purified MK107, which is an attenuated (mesogenic) version of Newcastle Disease Virus, described more fully in International Patent Publication WO 00/62735, published Oct. 26, 2000 (Pro-Virus, Inc.). The entire content of WO 00/62735 is hereby incorporated herein by reference.  
       EXAMPLES  
     Example 1  
     NDV in Combination with Irinotecan  
       [0020]     Athymic mice were injected subcutaneously with 10 million human HT1080 fibrosarcoma cells. Five days later when the subcutaneous tumors were approximately 100 mm 3  in size, groups of animals were treated intraperitoneally with irinotecan (25 mg/kg) or vehicle. Two days later animals were treated intravenously with either NDV (6×10 6  plaque forming units, PFU) or vehicle. The incidence of complete tumor regression (CR, 100% tumor reduction) was much higher in the group receiving both irinotecan and NDV (60%) than either irinotecan alone (30%) or NDV alone (0%); see Table 1.  
                                 TABLE 1                           Treatment of tumor-bearing mice with irinotecan 2       days before treatment with NDV yields greater complete       tumor responses than either agent alone.                Treatment   Number of Mice   CR, %                       Irinotecan   10   30%           NDV   10    0%           Both Irinotecan   10   60%           and NDV           Vehicle Control   10    0%                      
 
       Example 2  
     NDV in Combination with Irinotecan  
       [0021]     Athymic mice were injected subcutaneously with 10 million human HT1080 fibrosarcoma cells. Seven days later when the subcutaneous tumors were approximately 125 mm 3  in size, groups of animals were treated intraperitoneally with irinotecan (25 mg/kg) or vehicle and then approximately one hour later they were treated intravenously with either NDV (6×10 6  plaque forming units, PFU) or vehicle. The incidence of complete tumor regression (CR, 100% tumor reduction) was much higher in the group receiving both irinotecan and NDV (90%) than either irinotecan alone (50%) or NDV alone (0%), see Table 2.  
                                 TABLE 2                           Treatment of tumor bearing mice with irinotecan the       same day as treatment with NDV yields greater complete       tumor responses than either agent alone.                Treatment   Number of Mice   CR, %                       Irinotecan   10   50%           NDV   10    0%           Both Irinotecan   10   90%           and NDV           Vehicle Control   10    0%                      
 
       Example 3  
     NDV in Combination with Irinotecan  
       [0022]     Athymic mice were injected subcutaneously with 10 million human HT1080 fibrosarcoma cells. Seven days later when the subcutaneous tumors were approximately 387 mm 3  in size, groups of animals were intravenously with either NDV (6×10 6  plaque forming units, PFU) or vehicle. Two days later, the mice were then treated with treated intraperitoneally with irinotecan (25 mg/kg) or vehicle. The incidence of complete tumor regression (CR, 100% tumor reduction) was much higher in the group receiving both irinotecan and NDV (70%) than either irinotecan alone (10%) or NDV alone (0%), see Table 3.  
                                 TABLE 3                           Treatment of tumor bearing mice with irinotecan two       days after treatment with NDV yields greater complete       tumor responses than either agent alone.                Treatment   Number of Mice   CR, %                       Irinotecan   10   10%           NDV   10    0%           Both Irinotecan   10   70%           and NDV           Vehicle Control   10    0%                      
 
       Example 4  
     NDV in Combination with Weekly Dosing of Irinotecan.  
       [0023]     Cancer patients are treated with NDV followed by treatment with irinotecan. In each 3 week portion of the 6 week cycle, NDV treatment consist of six total intravenous treatments given at three times per week for two weeks followed by a one week rest period (see Table 4 below). The first dose of each cycle consists of 12 to 24 billion PFU/m 2  (administered over 3 hours for course 1 and over 1 hour for all other courses) followed by additional doses of between 24 to 48 billion PFU/m 2  (each dose administered over 1 hour). Irinotecan is given for four consecutive weeks on a weekly basis beginning during week 3 or 4 of cycle 1 followed by two weeks without irinotecan therapy (As an example, see Table 4 below). Additional 6 week courses (also termed cycles) of both NDV and irinotecan are given to the patients.  
                                 TABLE 4                           Combination of treatment of NDV using irinotecan       (80 to 125 mg/m 2 )given weekly ×4. Cycles       of treatment are repeated every 6 weeks.            Cycle   Week   NDV?   Irinotecan?               1   1   3 doses/wk for two   No           2   weeks followed by 1   No           3   week off   Yes, one dose over 90 minutes           4   3 doses/wk for two   Yes, one dose over 90 minutes           5   weeks followed by 1   Yes, one dose over 90 minutes           6   week off   Yes, one dose over 90 minutes       2   1   3 doses/wk for two   No           2   weeks followed by 1   No           3   week off   Yes, one dose over 90 minutes           4   3 doses/wk for two   Yes, one dose over 90 minutes           5   weeks followed by 1   Yes, one dose over 90 minutes           6   week off   Yes, one dose over 90 minutes                  
 
       Example 5  
     NDV in Combination Irinotecan Given Once Every 3 Weeks.  
       [0024]     Cancer patients are treated with NDV followed by treatment with irinotecan. NDV treatment consist of six total intravenous treatments given at three times per week for two weeks followed by a one week rest period (see Table 5 below). The first dose of six consists of 12 to 24 billion PFU/m 2  (administered over 3 hours for course 1 and over 1 hour for all other courses) followed by a additional doses of 24 to 48 billion PFU/m 2  (each dose administered over 1 hour). Patients begin their irinotecan therapy during week 3 and are given one dose every 3 weeks (See Table 5 below). Additional 3 week courses of both NDV and irinotecan are given to the patients.  
                                 TABLE 5                           Combination of treatment of NDV using irinotecan given once       every 3 wks. Cycles of treatment are repeated every 3 weeks.            Cycle   Week   NDV?   Irinotecan?               1   1   3 doses/wk for two   No           2   weeks followed by   No           3   1 week off   Yes, one dose at 300 to 350                   mg/m 2  over 30 minute                   intravenous infusion       2   4   3 doses/wk for two   No           5   weeks followed by   No           6   1 week off   Yes, one dose at 300 to 350                   mg/m 2  over 30 minute                   intravenous infusion                  
 
       Example 6  
     NDV in Combination with Irinotecan and Cetuximab.  
       [0025]     Cancer patients are treated with both NDV and irinotecan as in examples 4 and 5, except that they additionally receive treatment with cetuximab [ERBITUX, a monoclonal antibody (mAb) against the epidermal growth factor receptor (EGFR)]. Cetuximab dosing begins on week 3 or week 4. The cetuximab dose is 200 to 400 mg/m 2  for the first intravenous (IV) infusion [administered as a 120 minute IV infusion (with a maximal infusion rate of 5 mL/min)] then 125 to 250 mg/m 2  [infused IV over 60 minutes] administered weekly thereafter. Some patients may also receive an initial test dose of cetuximab of 20 mg. Diphendydramine (50 mg IV) is commonly given to help lessen any infusion reactions due to cetuximab.