WO2004091620A1

WO2004091620A1 - Combined therapy comprising an indolopyrrolocarbazole derivative and irinotecan

Info

Publication number: WO2004091620A1
Application number: PCT/EP2004/050351
Authority: WO
Inventors: Dario Ballinari; Marina Ciomei; Enrico Pesenti
Original assignee: Pharmacia Italia S.P.A.
Priority date: 2003-04-18
Filing date: 2004-03-23
Publication date: 2004-10-28

Abstract

The present invention relates to the use of edotecarin in combination with irinotecan or an active metabolite thereof for simultaneous, separate or sequential use for the treatment of cancer and to methods, compositions and kits comprising edotecarin and irinotecan or an active metabolite thereof.

Description

Title

COMBINED THERAPY COMPRISING AN INDOLOPYRROLOCARBAZOLE

DERIVATIVE AND IRINOTECAN

Field of the invention

The present invention pertains to the field of neoplastic diseases therapy. In particular, this invention relates to a method for treating cancer in a subject in need of such a treatment, said method comprising administering to the subject a therapeutically effective amount of an mdolopyrrolocarbazole derivative, namely edotecarin, and irinotecan or an active metabolite thereof. The combination of edotecarin with irinotecan or an active metabolite thereof provides an enhanced effect in treating certain types of cancer patients.

Background of the invention Cancers are a leading cause of death in humans and animals; surgery, radiation and chemotherapy are the useful means to fight cancers.

In particular, combined chemotherapy, designed to treat cancer by using more than one drug in combination or association, is a well-accepted modality of treatment of neoplastic diseases such as cancer. Several efforts have been and are still being undertaken in order to select antitumor combinations more and more active and safe to be administered to a patient suffering from a cancer.

The increase of the antitumor efficacy of a known antitumor compound by administering the same in combination with one or more different antitumor compounds in order to reduce the toxic effects of the individual agents when used alone, and in some instances because the combination has greater efficacy than when either agent is used alone, is a strongly felt need in the field of anti cancer therapy.

The present invention fulfills such a need by providing edotecarin administered in combination with irinotecan or an active metabolite thereof. Among the several advantages found to be achieved by the present invention, therefore, may be noted the provision of an effective method for the treatment of cancer, the provision of such methods that provided beneficial properties that are comparable to or superior to those provided by known and conventional methods of treatment for these conditions, and the provision of compositions, pharmaceutical compositions and kits to effect these methods.

Description of the invention

It is therefore a first object of the present invention combined preparations comprising edotecarin and irinotecan or an active metabolite thereof.

Irinotecan [ 1 ,4'-Bipiperidine]- 1 '-carboxylic acid (4S)-4, 11 -diethyl-3 ,4, 12, 14-tetrahydro-4- hydiOxy-3,14-dioxo-lH-pyrano[3',4':6,7]indolizino[l,2-&]quinolin-9-yl ester is a camptothecin analog and Topoisomerase-I inhibitor derived from a compound, which occurs naturally in the Chinese tree, Camptotheca acvminata. Irinotecan can be prepared following the procedure disclosed in U.S. Pat. No. 4,604,463, European patent No. 835,257, Sawada S. et al., Chem. Pharm. Bull. 39, 1446-1454 (1991) or Ηenegar K. et al., J. Org. Chem. 62, 6588-6597 (1997). Irinotecan hydrochloride, clinically investigated as CPT-11, is a commercially available compound (CAMPTOSAR^® , Pharmacia Corp.).

Irinotecan acts as a prodrug that is converted to 7-ethyl-lO-hydroxy camptothecin (SN-38), active metabolite, in vivo by carboxyl esterase, an enzyme found in the liver, plasma and tumors. The active metabolite of irinotecan, SN-38, is one-hundred to one-thousand-fold more potent inhibitor of Topoisomerase-I than the parent compound. SN-38 is further conjugated to an inactive glucuronide (SN-38G) by uridine diphosphate glucuronosyltransferases. Other irinotecan metabolites identified are the major plasma metabolite 7-ethyl- 10-[4-N-(5-aminopentanoic acid)-l-piperidino]- carbonyloxycamptothecin (APC) and 7-ethyl-10-[4-arnino-l-piperidino]- carbonyloxycamptothecin (NPC), resulting from a ring-opening oxidation of the terminal piperidine ring of irinotecan mediated by cytochrome P450 3A4 enzymes. As used herein, the term "irinotecan" includes, unless otherwise specified, irinotecan and its pharmaceutically acceptable salts, especially the hydrochloride salt.

In a preferred aspect of the present invention, irinotecan is irinotecan hydrochloride, namely CPT-11. SN-38 can be prepared, for example, following the procedure disclosed in U.S. Pat. No. 4,473,692.

Edotecarin, namely 5H-Indolo[2,3-a]pyπOlo[3,4-c]carbazole-5,7(6H)-dione, 12-β- D- glucopyranosyl-12,13-dihydro-2,10-dihydroxy-6-[[2-hydroxy-l- (hydroxymethyl)ethyljamino is an mdolopyrrolocarbazole derivative also known as ED-749 o J- 107088 having the following formula:

Edotecarin can be prepared, for example, following the procedure described in EP patent No 545,195, EP patent application No. 95917506, PCT/WO 02/079214 or Atsushi A. et al., Tetrahedron (2001) 57, 8917-23.

Edotecarin is a Topoisomerase-I poison that is a cleavable complex-forming inhibitor because it inhibits topoisomerase-1 through stabilization of the DNA-enzyme complex and enhances single-strand DNA cleavage. In this characteristic, resembles camptothecins. However, the potency, the stability of the cleavable complex, and the preferable sequence of cleavage sites are quite different from those of camptothecins.

In a particular aspect, the present invention provides combined preparations comprising edotecarin and 7-ethyl-10-hydroxycamptothecin (SN-38).

As used herein, the term "pharmaceutically acceptable salt" refers to those salts, which retain the biological effectiveness and properties of the parent compound. Such salts include acid addition salts which are obtained by reaction of the free base of the parent compound with inorganic acids such as hydrochloric acid, hydrobromic acid, nitric acid, phosphoric acid, sulfuric acid and perchloric acid and the like, or with organic acids such as acetic acid, maleic acid, methanesulfonic acid, ethanesulfonic acid, tartaric acid, citric acid, succinic acid and the like.

As used herein, the term "metabolite" embraces all derivatives resulted from an enzymatic bio-transformation of each constituent of the combined preparations according to the invention; a particularly preferred metabolite of irinotecan is its active metabolite SN-38.

As used herein, the term "pharmaceutically effective amount" means that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by a researcher or clinician. This amount can be a therapeutically effective amount.

As used herein, the term "therapeutically effective" intends to qualify the amount of each agent for use in the combination therapy, which will achieve the goal of improvement in disease severity and the frequency of incidence over treatment of each agent by itself, and/or of amelioration of adverse side effects typically associated with alternative therapies.

In reference to the treatment of cancer, a therapeutically effective amount refers to that amount which has the effect of: 1. reducing the size of the tumor; 2. inhibiting to some extent (that is slowing to some extent, preferably stopping) tumor growth, and/or

3. relieving to some extent (or, preferably, eliminating) one or more symptoms associated with the cancer.

The combined preparations according to the present invention can be useful for the treatment of cancer.

As used herein, the term "cancer" refers to all forms of cancer including cancers of blood and lymphatic systems comprising Hodgkin's disease, leukemias, lymphomas, multiple myeloma and Waldenstrom's disease; skin cancers comprising malignant melanoma; cancers of digestive tract comprising head and neck, esophageal, stomach, pancreas, liver, colorectal and anal cancer; cancer of genital and urinary systems comprising kidney, bladder, testis and prostate cancer; gynecological cancers comprising cervical, endometrial, ovarian, fallopian tube, vaginal and vulvar cancer; breast cancer, brain cancer, bone cancer, carcinoid tumors, nasopharyngeal cancer, thyroid cancer, retroperitoneal sarcomas and soft tissue tumors.

For example, the combined preparations, according to the invention, are directed to the treatment of colorectal cancer.

As used herein, the terms "treating" or "to treat" mean to alleviate symptoms, eliminate the causation either on a temporary or permanent basis, or to prevent or slow the appearance of symptoms. The term "treatment" includes alleviation, elimination of causation of or prevention of cancer. Besides being useful for human treatment, these combinations are also useful for treatment of mammals, including horses, dogs, cats, rats, mice, sheep, pigs, etc.

The term "subject" for purposes of treatment includes any human or animal subject who is in need of the prevention of, or who has a cancer. The subject is typically a mammal. "Mammal", as that term is used herein, refers to any animal classified as a mammal, including humans, domestic and farm animals, and zoo, sports, or pet animals, such as dogs, horses, cats, cattle, etc., Preferably, the mammal is a human.

As used herein, the term "administer" or "administration" refers to the delivery of irinotecan in combination with edotecarin.

The administration of the constituents of the combined preparations of the present invention can be made simultaneously, separately or sequentially in any order. Namely, the present invention intends to embrace administration of edotecarin and irinotecan or an active metabolite thereof in a sequential manner in a regimen that will provide beneficial effects of the drug combination, and intends as well to embrace co-administration of these agents in a substantially simultaneous manner, such as in a single dosage device having a fixed ratio of these active agents or in multiple, separate dosage devices for each agent, where the separate dosage devices can be taken together contemporaneously, or taken within a period of time sufficient to receive a beneficial effect from both of the constituent agents of the combination.

It is therefore another object of the present invention the use of edotecarin for the preparation of a medicament in association with irinotecan or an active metabolite thereof for simultaneous, separate or sequential use for the treatment of cancer.

In another aspect the present invention provides a method for the treatment of cancer in a subject in need of such a treatment, said method comprising administering to said subject a therapeutically effective amount of edotecarin in combination with irinotecan or an active metabolite thereof, in amounts effective to produce a synergistic anticancer effect.

It is a still another aspect the present invention provides a method for the treatment of cancer in a subject in need of such a treatment, said method comprising administering to said subject a therapeutically effective amount of edotecarin and irinotecan or an active metabolite thereof, wherein edotecarin and irinotecan or an active metabolite thereof are administered simultaneously, separately or sequentially in amounts effective to produce a synergistic anticancer effect, and wherein the cancer is sensitive to the synergistic combination.

The constituents of the combined preparations according to the invention can be administered to a patient in any acceptable manner that is medically acceptable including orally, parenterally, or with local therapeutic approaches such as, e.g., implants. Oral administration includes administering the constituents of the combined preparation in a suitable oral form such as, e.g., tablets, capsules, lozenges, suspensions, solutions, emulsions, powders, syrups and the like. Parenteral administration includes administering the constituents of the combined preparation by subcutaneous, intravenous or intramuscular injections. Local therapeutic approaches include implants, for example intra-arterial implants. Typically, edotecarin is administered parenterally, typically irinotecan is administered parenterally or orally.

The actual preferred dosage, method, order and time of administration of the constituents of the combined preparations of the invention may vary according to, inter alia, the particular pharmaceutical formulation of edotecarin being utilized, the particular pharmaceutical formulation of irinotecan or an active metabolite thereof being utilized, the particular cancer being treated, the age, condition, sex and extent of the disease treated and can be determined by one of skill in the art.

The dosage regimen must therefore be tailored to the particular of the patient's conditions, response and associate treatments, in a manner, which is conventional for any therapy, and may need to be adjusted in response to changes in conditions and/or in light of other clinical conditions.

In the method of the subject invention, for the administration of edotecarin according to the invention, the course of therapy generally employed is from about 0.1 mg/m² to about 100 mg/m² of body surface area. More preferably, the course of therapy employed is from about 5 mg m² to about 50 mg/m² of body surface area. In the method of the subject invention, for the administration of irinotecan the course of therapy generally employed is within a range of is from about 10 mg/m² to about 1000 mg/m² of body surface area. More preferably, the course of therapy employed is from about 50 mg/m² to about 500 mg/m² of body surface area, most preferably from about 100 mg/m² to about 400 mg/m".

When the active constituents of the combined preparation according to the invention are supplied along with a pharmaceutically acceptable carrier or excipient, a pharmaceutical composition is formed.

Pharmaceutically acceptable carriers and excipients are chosen such that side effects from the pharmaceutical compound are minimized and the performance of the compound is not canceled or inhibited to such an extent that treatment is ineffective. Pharmaceutically acceptable carriers or excipients to be utilized in the preparation of a pharmaceutical composition according to the invention are well known to people skill in the art of formulating compounds in a form of pharmaceutical compositions. For example, "pharmaceutically acceptable carrier" refers to one or more compatible solid or liquid filler, diluent or encapsulating substances which are suitable for administration to mammals including humans. For example, "pharmaceutically acceptable excipient" refers to any inert substance used as a diluent or vehicle for an active substance(s) that is intentionally added to the formulation of a dosage form. The term includes binders, fillers, disintegrants, and lubricants.

Techniques for formulation and administration of drugs can be found in "Remington's Pharmacological Sciences"; Mack Publishing Co., Easton, PA., latest edition. Pharmaceutical compositions suitable for parenteral administration are formulated in a sterile form.

The sterile composition thus may be a sterile solution or suspension in a non-toxic parenterally acceptable diluent or solvent. The amount of an active ingredient contained in the pharmaceutical composition according to the invention may vary quite widely depending upon many factors such as, for axample, the administration route and the vehicle.

As an example, the pharmaceutical compositions of the invention may contain from 0.5 mg to 500 mg of edotecarin; and from 5 mg to 1000 mg of irinotecan.

It is a further object of the present invention a pharmaceutical composition comprising a pharmaceutically acceptable carrier or excipient and, as an active ingredient, edotecarin and irinotecan or an active metabolite thereof.

Pharmaceutical compositions according to the invention are useful in anticancer therapy.

The present invention also provides a therapeutic kit comprising, in suitable container means, a pharmaceutical composition comprising edotecarin and a pharmaceutical compositio comprising irinotecan or an active metabolite thereof In a kit according to the invention edotecarin and irinotecan or an active metabolite thereof are present within a single container means or within distinct container means.

As a particular example, a kit comprises a pharmaceutical formulation of edotecarin and a pharmaceutical formulation of irinotecan or an active metabolite thereof, within distinct container means.

Kits according to the invention are intended for use in anticancer therapy as defined above.

Not only edotecarin but also edotecarin analogous compounds belonging to the broad class of mdolopyrrolocarbazole derivatives known to be active as anticancer agents may be combined with irinotecan or an active metabolite thereof, with the expectation of obtaining synergistic anticancer effect.

As stated above, the effect of the combined administration of edotecarin and irinotecan or an active metabolite thereof, is significantly increased (synergic effect) with respect to the effect obtained administering each drug as single agent. The superadditive antitumor effect of the combined preparation s of the present invention can be shown, for instance, by the following examples.

EXAMPLE 1 In vitro antitumor efficacy

HCT-116 human colon carcinoma cells are seeded at the density of 5000 cells/cm²

(1600/well) in 96-well plates in DMEM culture medium added with 10 % fetal calf serum.

24-h after seeding the cells are treated with different doses of edotecarin or SN-38 for 24 hours. Medium is then removed, cells are washed and left in fresh medium for 16-24 h, when the second compound (SN-38 or edotecarin) is added for 24 h. Cell growth is determined by a method measuring the amount of ATP present in the cells (CellTiter-

GloTM Cell viability assay, Promega Corporation).

The combination effect of the two drugs in terms of synergy, additivity or antagonism is determined by the Combination Index (CI) value:

CI= p)ι/(Dx)₁ + (D)₂/(Dx)₂

where (Dx)ι and(Dx)₂ in the denominators are the doses for edotecarin and SN-38 alone that gives x% inhibition, whereas (D)ι and (D)₂ in the numerators are the doses of edotecarin and SN-38 in combination that also inhibit x%.

We apply this formula from T-C. Chou and P.Talalay (Adv. Enzyme Regul. 22: 27 - 55,

1984) because we know that the drugs are mutually exclusive (i.e. with similar mode of action). Data are evaluated by taking the means of the CIs at 50%, 70% and 90% growth inhibition. When CI =1 the interaction is considered additive, when CI < 1 synergy is indicated and when CI >1 antagonism is indicated.

When we test 0.6 nM and 2 nM of edotecarin in the first 24 h followed by SN-38 in the range of 15- 600 nM CI results to be 0.79.

When we test 0.6 and 2 nM of SN-38 in the first 24 h followed by edotecarin in the range 15 - 600 nM CI results to be 0.77. The above-reported data, demonstrating that a synergistic interaction between the two active substances can be reached, provide an indication that a therapeutic advantage of the combination can be achieved over the administration of each active substance administered alone.

EXAMPLE 2

In vivo antitumor efficacy

Balb Nu Nu, male mice, from Harlan, Italy, are maintained in cages with paper filter covers, food and bedding sterilized and water acidified. HCT116 colon carcinoma (from American Type Culture Collection) is maintained by subcutaneous (SG) transplantation in athymic mice using 20 - 30 mg of tumor brei. For the experiment, tumors are excised and fragments are implanted SC into the left flank. The treatments start when the tumors are measurable (advanced protocol): tumor weight mean for all the groups is 0.15 g: All drugs are prepared immediately before use. Treatments are administered IN in a volume of 10 ml /kg. The dose of CPT-11 is 45 mg/kg and the doses for edotecarin are: 1.5, 3, 10 and 30 mg/kg. Treatments are repeated every four days for four treatments. The daigs are administered alone as single agent and in combination. In the combination groups, CPT-11 is administered 1 h before edotecarin.

Eveiy 3 days the tumor growth and the net body weight are evaluated. Tumor growth is assessed by caliper. The two diameters are recorded, and the tumor weight is calculated according to the following formula: length (mm) x width ^~ (mm)/2.

Toxicity is evaluated on the basis of the body weight reduction.

No toxicity is observed in any treatment group.

All the groups treated with the combination of the two drugs show a significant increase (P<0.005) in the time (in days) required for tumors to reach a predetermined weight (1 g) in comparison with the groups treated with edotecarin or CPT-11 as single agents. In addition, in the group treated with CPT-1 1 45 mg/kg and edotecarin 30 mg/kg one tumor-free mouse was observed out of eight mice after 90 days of treatment, whilst no tumor-free mouse was observed in the groups treated with the corresponding dosage of edotecarin and CPT-11 administered as single agents for the same period of time.

Claims

1 A combined preparation comprising edotecarin administered in combination with mnotecan or an active metabolite thereof

2 A combined preparation according to claim 1, wherein irinotecan is in the form of its hydrochloride salt

3 A combined preparation according to claim 1, wherein the active metabolite is SN-38

4 A combined preparation according to claim 1, for use m the treatment of cancer

5 A combined piepaiation accoidmg to claim 1, foi use in the treatment of coloiectal cancel

6 The use of edotecarin foi the piepaiation of a medicament in association with ninotecan oi an active metabolite theieof foi simultaneous, sepaiate oi sequential use foi the treatment of cancel

7 The use according to claim 6, wherein irinotecan is m the foim of its hydrochloride salt

8 The use accoidmg to claim 6, wheiem the active metabolite is SN-38

9 The use according to claim 6, wheiem the cancer is colorectal cancel

10 A method for the treatment of cancer in a subject in need of such a treatment, said method comprising administering to said subject a theiapeutically effective amount of edotecarin in combination with irinotecan or an active metabolite thereof, in amounts effective to produce a synergistic anticancer effect

11. A method of claim 10, wherein irinotecan is in the form of its hydrochloride salt.

12. A method of claim 10, wherein the active metabolite is SN-38.

13. A method of claim 10, wherein the cancer is colorectal cancer.

14. A method for the treatment of cancer in a subject in need of such a treatment, said method comprising administering to said subject a therapeutically effective amount of edotecarin and irinotecan or an active metabolite thereof, wherein edotecarin and irinotecan or an active metabolite thereof are administered simultaneously, separately or sequentially in amounts effective to produce a synergistic anticancer effect, and wherein the cancer is sensitive to the synergistic combination.

15. A method of claim 14, wherein irinotecan is in the form of its hydrochloride salt.

16. A method of claim 14, wherein the active metabolite is SN-38.

17. A method of claim 14, wherein the cancer is colorectal cancer.

18. A therapeutic kit comprising, in suitable container means, a pharmaceutical formulation comprising edotecarin and a pharmaceutical formulation comprising irinotecan or an active metabolite thereof.

19. A kit of claim 18, wherein edotecarin and irinotecan or an active metabolite thereof are present within a single container means.

20. A kit of claim 18, wherein edotecarin and irinotecan or an active metabolite thereof are present within distinct container means.