WO2015173341A1

WO2015173341A1 - Dosage principle for anti-cancer furazanylbenzimidazoles

Info

Publication number: WO2015173341A1
Application number: PCT/EP2015/060669
Authority: WO
Inventors: Heidi Alexandra Lane; Marc Engelhardt
Original assignee: Basilea Pharmaceutica Ag
Priority date: 2014-05-13
Filing date: 2015-05-13
Publication date: 2015-11-19

Abstract

Disclosed is a novel principle for dosing a specific anti-cancer drug compound of formula (I), a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof as described, wherein said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof is intravenously administered to a cancer patient according to a specific dosage frequency and a specific treatment cycle at a dose being below the maximum tolerated dose (MTD) defined for said dosage frequency and treatment cycle of said drug, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof but providing at least the same exposure of the tissue of the cancer from which said cancer patient is suffering, to said drug as provided by the MTD at the same dosage frequency and treatment cycle.

Description

DOSAGE PRINCIPLE FOR ANTI-CANCER FURAZANYLBENZI I IDAZOLES

The present invention relates to a new dosage principle for anti-cancer drugs, which have a mode of action that includes a partial anti-vascular activity. More particular, the present invention relates to a new dosage regimen for the anti-cancer drug BAL27862 and prodrugs thereof like in particular BALI 01553 and pharmaceutical ly acceptable salts of said drug and prodrugs.

Anti-cancer drugs arc used for chemotherapy, which is the treatment of human cancer, including leukemia, lymphomas and solid mal ignancies with one or more of such

chemotherapy drugs.

Chemotherapy drugs are traditional ly administered to cancer patients using doses near or at the 'ma imum tolerated dose' (MTD) which is a dosage which does not provoke

unacceptable toxicity, i.e. sev ere or even l ife-threatening side effects and/or laboratory abnormalities ( l lanahan et al . J. Clinical Invest. 2000 105(8 ): 1045- 1047). Nevertheless, the use of a chemotherapy drug according to a MTD regimen is often associated w ith toxic effects on healthy tissue which can strongly impair the quality of l ife of the patient.

Conventional MTD therapy is therefore appl ied in treatment cycles, i.e. on a regular schedule including a treatment period followed by a rest period of general ly 2 to 3 w eeks, wherein the patient can recover again from the previous treatment before a further equal treatment cycle is started. An entire chemotherapcutic treatment of said kind consists of a number of such treatment cycles, usually 2 to 6. The response of the patients to such MTD regimens is nevertheless often short-l iv ed, w ith frequent relapses.

As a result, alternative therapeutic approaches are being actively sought.

One approach, which has shown clinical benefits in the treatment of cancers with certain anticancer drugs, is the so-called "dose-dense chemotherapy", wherein the anti-cancer drug is still dosed near or at the MTD but w herein the prolonged breaks of the conventional chemotherapcutic treatment for recovery of the patients are avoided. This approach general ly requires the administration of supportive care l ike growth factors in order to reduce the effects of the chemotherapy on the healthy tissue of the patient ( erbei et al. Nature

Reviews/Cancer, Vol. 4. June 2005; 423-436 ). Dose-dense chemotherapy has also been successfully applied with lower single doses of the anti-cancer drug than those used in a conventional MTD regimen of the same drug. For example 80 mg/m pacl itaxel administered intravenously weekly on days 1 , 8 and 15 of a 21 day treatment cycle and an intravenous dose of carbopiatin to produce a plasma AUC of 6 mg x ml min on day one of each 2 1 -day cycle were used to treat epithelial ovarian cancer (6 cycles) instead of the standard dosage regimen of said drug combination consisting of 175 mg/m paclitaxel and carbopiatin at a dosage to produce a plasma AUC of 5-6 mg ml min every 3 weeks for six cycles (N. Katsumata, Ann. Oncol . (201 1 ) 22 (Suppl. 8), viii29-viii32).

A specific embodiment of a low-dose, dose-dense chemotherapy specifically applicable to anti-cancer drugs that have a mode of action which includes an anti-angiogenic activity is the so-called "metronomic" chemotherapy. Here, said drugs are administered at a very frequent or even continuous schedule with no extended interruptions and at dosages which

substantially have primarily an anti-angiogenic activity which affects the endothelial cells of tumor tissue supplying blood vessels and circulating endothel ial progenitor cells. Metronomic therapy thus targets the grow ing vasculature of the tumors, thereby combating the tumor tissue rather than directly hampering the proliferation of the tumor cel ls, using anti- angiogenic dosages which are often substantially lower than the anti-prol iferation dosages of anti-cancer drugs. Due to these lower dosages, the metronomic dosage regimens cause comparably few and weak adverse effects (Kerbel et al. Nature Reviews/Cancer, Vol. 4, June 2005; 423-436).

Microtubules are one of the components of the cell cytoskclcton and are composed of heterodimers of alpha and beta tubul in. Agents that target microtubules are among the most effective cytotoxic chemotherapeutic agents having a broad spectrum of act iv ity. icrotubule destabilising agents (e.g. the v inca-alkaloids such as v incristine, vinblastine and vinorclbine) are used for example in the treatment of several types of hematologic malignancies, such as lymphoblastic leukemia and lymphoma, as wel l as sol id tumors, such as lung cancer.

M icrotubule stabilising agents (e.g. the taxanes such as paclitaxel, docetaxel ) arc used for example in the treatment of solid tumors, including breast, lung and prostate cancer.

The compounds of formula (I)

wherein

represents

a divalent benzene residue which is unsubstituted or substituted by one or two additional siibstituents independently selected from lower alkyl. halo-lower alkyl. hydro.xy-lower alkyl. lower alkoxy-lower alkyl, acyloxy-lower alkyl, phenyl, hydroxy, lower alkoxy, hydro.xy- lower alko y, lower alkoxy-lower alkoxy, phenyl -lower alkoxy, lower alkylcarbony oxy. amino, mono( lower alkyl )amino, di( low er alkyl )amino. mono( lower alkenyl )amino, di( lower alkenyl )amino, lower a 1 kox yea rbo n y I a m i no , lower a I k y 1 c a rbo n y 1 a m i n o , substituted amino wherein the two siibstituents on nitrogen form together with the nitrogen heterocyclyl, lower alkylcarbonyl, carboxy, lower alkoxyearbonyl, cyano, halogen, and nitro; or wherein two adjacent siibstituents can be methylenedioxy; or

a divalent pyridine residue (Z = N) which is unsubstituted or substituted additionally by lower alkyl, lower alkoxy, lower alkoxy-lower alkoxy, amino, optionally substituted by one or two siibstituents selected from low er alkyl, lower alkenyl and alkylcarbonyl, halo-lower alkyl, lower alkoxy-lower alkyl, or halogen;

R¹ represents hydrogen, lower alkylcarbonyl, hydroxy-lowcr alkyl or cyano-low er alkyl; and R² represents ^NH₂ > or the prodrugs thereof, wherein

R represents a group selected from the groups of formula:

or pharmaceutically acceptable salts of said drug compound or prodrug thereof belong to a recently discovered class of microtubule destabilising agents.

In said formula, and generally in the formulae

of the present application the prefix "lower" refers to residues comprising from 1 to 4 carbon atoms, for example, the term "lower aikyl" refers to CVC ialkyl or the term "lower alkoxy" refers to CVCialkoxy.

These and similar compounds are disclosed in WO2004/ 103994 Al and have been shown to arrest tumor cell proliferation and induce apoptosis.

One compound falling within this class, known as BA 1.27862, and shown in

WO2004 1 03994 A 1 (cf. e.g. Example 58 thereof) has the structure and chemical name given below:

3-(4-{ l-[2-(4-Amino-phenyl)-2-oxo-ethyl]-lH-benzoimidazol-2-yl}-furazan-3-yiamino)- propionitrile WO201 1 012577 discloses the compound having the structure and chemical name given below (cf. e.g. Example 1 of said reference):

(S)-2,6-Diamino-hexanoic acid [4-(2- {2-[4-(2-cyano-ethylamino)-furazan-3-yl]- bcnzoimidazol- l -yl ί -acetyl )-phenyl]-amide

This compound, also known as BAL I 01 553, is a highly water-soluble prodrug of BAL27862 which is thus the pharmaceutically active principle released in vivo by BA L I 01553.

BAL 101553 is particularly advantageously used in the form of a pharmaceutically acceptable acid addition salt, like a hydrochloride salt thereof, in particular in the form of its

dihydrochioride salt.

These compounds have been shown to arrest tumor ceil proliferation and induce apoptosis. BAL27862 has demonstrated antitumor activity across a broad panel of experimental tumor models. Moreover, the prodrug BAL 101553 and its pharmaceutically acceptable acid addition salts have demonstrated anticancer activity in numerous tumor xenograft models, shown to be associated with a dual mechanism of action that involves targeting the tumor ceils themselves as well as the tumor vasculature.

First interim results of a dose escalating Phase 1 study for determining MTD of BALI 01553 for a 28 days treatment cycle, wherein BA L I 01 553 is intravenously administered on days 1,

2 2 2 2

8 and 15 (evaluated dosage levels 15 mg/m , 30 mg/m , 45 mg/m and 60 mg/m. ) in patients with advanced solid tumors were presented on the 2013 Meeting of the American Society of clinical Oncology from May 3 1 to June 4, 2013 in Chicago ( IL). A maximum tolerated dosage of BAL 101553 for said treatment cycle was not yet determined (Abstract No. 2566 of the A SCO Annual 2013 Meeting). The use of doses below a subsequently defined MTD in said Phase 1 study (as in any other Phase 1 study) is a necessary part of the experimental strategy for determination of the MTD of the drug for use in said treatment cycle. The use of doses in a dose escalating Phase I study which are below the finally defined maximum tolerated dose is thus not considered by those skilled in the art as an actual therapeutic treatment of the participants of a Phase I study, even if this study is not performed in the usual way with healthy volunteers but with actual cancer patients as in present case, but j st represents a means to the end of determining the MTD of the drug. Th e use of sub-MTD doses in the Phase I study can therefore not be considered as a suggestion or

recommendation to use such doses for an actual treatment of solid tumors. First efficacy data in humans also evaluated in said Phase 1 study furthermore suggest a clinical benefit in human patients with advanced solid tumors when BALI 01553 was administered intravenously according to the treatment cycle applied in said Phase 1 study.

An analysis of the levels of BAL27862 after a single intravenous administration of its prodrug BAL 101 553 at two different doses to mice bearing human cancer xenografts has now surprisingly revealed that, although a correspondingly lower exposure of the blood plasma to BAL27862 is unsurprisingly achieved with the lower dose of the prodrug, the exposure of the tumor tissue associated with the low er dose is surprisingly by far higher than that achieved w ith the higher dose of the prodrug.

This suggests that intravenous doses being significantly below the MTD of BALI 01553 or BAL27862 (sub-MTD doses) can nevertheless provide an exposure of the tumor tissue to BAL27862, which is substantially the same or even better than the exposure to BAL27862 achievable by intravenous administration of the TD of BA L 101 553 and BAL27862. The apoptotic effect of BAL27862 on the tumor cel ls should accordingly be larger at sub-MTD doses than at the ma imum tolerated dose. Sub-MTD doses may allow more efficient exposure of tumors to treatment with a compound of general Formula I or pharmaceutically acceptable derivatives thereof, as defined below. It is believed that higher dosages of BA L 101 553 or B A 1.27862 are also associated with a larger cytotox ic effect of the drug on the cells of the growing tumor vasculature and thus reduce the perfusion in the tumor tissue. This results in a reduced transport of the drug to the tumor and a correspondingly reduced absorption of the drug by the tumor tissue. This hypothesis is further supported by clinical findings in BA L 1 01 553-treated cancer patients which show that an intravenous dose representing the BALI 01553 MTD for said dosage frequency and treatment cycle is associated with reduced tumor vascular leakage, indicating less efficient BAL27862 distribution to tumor. Surprisingly, and in contrast, a sub- MTD BALI 01553 dose results in a clear induction of tumor vascular leakage, indicating more efficient BAL27862 perfusion of the tumor. This is despite the MTD dose having higher plasma exposure levcis and greater effects on the normal vasculature as determined by blood pressure changes. Accordingly, the invention relates in a first aspect to an anti-cancer d ug compound o formula ( I )

1

wherein

represents

a divalent benzene residue which is unsubstituted or substituted by one or two additional substituents independently selected from lower alkyl, halo-lower alkyl, hydroxy-lower alkyl, lower aikoxy-iower alkyl, acyioxy-lower alkyl, phenyl, hydroxy, lower alko.xy, hydroxy- lower alkoxy, lower alkoxy-lower alko y, phenyl-lower alkoxy, lower alkylcarbonyloxy, amino, mono( lower alkyl )amino, di( low er alkyl )amino, mono( lower alkenyl)amino, di( lower alkenyl )amino, lower al kox ycarbony lam i no, lower a 1 k y 1 ca rbo n y I a m i n o , substituted amino wherein the two substituents on nitrogen form together with the nitrogen heterocyclyl, lower alkylcarbonyl, carboxy, lower alkoxycarbonyl, cyano, halogen, and nitro; or wherein two adjacent substituents can be methylenedioxy; or

a divalent pyridine residue (Z = N) which is unsubstituted or substituted additionally by lower alkyl, lower alkoxy. lower alkoxy-lower alkoxy, amino, optionally substituted by one or two substituents selected from lower alkyl, lower alkenyl and alkylcarbonyl, halo-lower alkyl, lower aikoxy-low cr alkyl, or halogen;

R ¹ represents hydrogen, lower alkylcarbonyl. hydroxy-lower alkyl or cyano-low er alkyl ; and

R² represents ^NH₂ · or a prodrug thereof wherein

2

R re resents a group selected from the groups of formula:

or a pharmaceutical ly acceptable salt of said drug compound or prodrug thereof

for use for the treatment of a cancer patient, wherein said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof is

(a) intravenously administered to said cancer patient according to a specific dosage

frequency and a specific treatment cycle,

(b) at a dose being below the MTD defined for said dosage frequency and treatment cycle of said drug, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof but prov iding at least the same exposure of the tissue of the cancer from hich said cancer patient is suffering, to said drug as prov ided by the MTD at the same dosage frequency and treatment cycle.

Brief^* Description of Figures and Tables:

Figure 1 : Shows the effect of a single intravenous TD (25 mg/kg) and sub-MTD (10 mg kg) dose of BA L I 01 553 on tumor vascularization in a mouse xenograft model of human lung cancer.

ine mice bearing human H460 non-small cell lung cancer xenografts were treated intrav enously with a single 25 mg/kg or a single 1 0 mg/kg dose of BAL I 01 553. Two days (black symbols), four days (dark grey symbols) and eleven days (light grey symbols ) after administration, three mice per dose were ev aluated for tumor vascular perfusion follow ing fluorescent lectin administration. Mean v essel density in vital tumor regions is shown. Each symbol represents analysis of a single, independent tumor. Figure 2: Shows median plasma C_max and AUC values in cancer patients treated with a single intravenous dose of BAL I 01 553 at MTD (60 mg/m²) and sub-MTD (30 mg/m²).

Plasma pharmacokinetic parameters were determined in treated patients as described in the methods. Box plots of median (interquartile range) plasma C_max (Figure 2A) and AUC

2 2

(Figure 2B) at dose levels of 30 mg/m (n=9) and 60 mg/m (n=18) are shown. · indicates an

2 ^

outlier. In Figure 2 A the mean difference of 60 mg/m minus 30 mg/m^" is -2 1 5 ng/L. In

Figure 2B the mean difference 60 mg/m^" minus 30 mg/m' is -3698 ng x h/L

Figure 3 : Shows the plasma C_max and AUC values in two cancer patients treated with BAL I 01 553 at MTD (60 mg/m²) and sub-MTD (30 mg/m²) doses.

Plasma pharmacokinetic parameters were determined in treated patients as described in the methods. Plasma C_max (Figure 3 A ) and AUC (Figure 3B) for two patients treated initial ly at

2 2

the MTD (60 mg/m ) and subsequently dose-reduced to sub-MTD (30 mg/m ) are shown. Patient 1 was dose-reduced afte completion of the first 28-day cycle of treatment. Patient 2 was dose-reduced from the third dose of cycle 1 onwards. Pharmacokinetic data was obtained

2 2

follow ing the first dose at 60 mg/m and the first dose at 30 mg/m .

Figure 4: Show s median blood pressure changes in cancer patients treated with a single intravenous dose of BAL I 01 553 at MTD (60 mg/m²) and sub-MTD (30 mg/m²).

Systolic (Figure 4A) and diastolic (Figure 4B) blood pressure parameters were determined in treated patients as described in the methods. Box plots of median (interquartile range)

2

changes from baseline at dose levels of 30 mg/m (n=12) and 60 m /m^" (n=20) are show n. ·

2 2

Indicates outliers. In Figure 4 A the mean difference 60 m /m minus 30 mg/m" is -1 1.8 mmHg (95%CI: -23.1 ;-0.5; p < 0.05 ). In Figure 4B the mean difference 60 mg/m² minus 30 mg/m² is -7.9 mmHg (95%CI:-15.8;-0.21 ; p < 0.05 )

Figure 5 : Shows blood pressure changes in two cancer patients treated with BA L I 01 553 at MTD (60 mg/m^' ) and sub-MTD (30 mg/m ) doses.

Blood pressure parameters were determined in treated patients as described in the methods. Systol ic blood pressure changes for two patients treated initially at the MTD (60 mg/m ) and subsequently dose-reduced to sub-MTD (30 mg/m ) are shown. Patient 1 was dose-reduced after completion of the first 28-day cycle of treatment. Patient 2 was dose-reduced from the third dose of cycle 1 onwards. Blood pressure data was obtained following the first dose at 60

2 2

mg/m and the first dose at 30 mg/m . Figure 6: Shows changes in tumor vascular leakage in cancer patients treated with

BAL I 01 553 at MTD (60 mg/m²) and sub-MTD (30 mg/m²) doses.

Changes in Dynamic Contrast Enhancement (K^trans; tumor vascular leakage) versus baseline were determined by DCE-MRI in treated patients as described in the methods. The median change from baseline in K^!,ans profiles over a seven day period are shown for one patient (with one tumor lesion ) treated at the MTD (60 mg/m ) and two patients (with two tumor lesions) treated with the sub-MTD (30 mg/m ) dose. The median change from baseline in K^!K,n at each measurement time point is averaged across all lesions measured at that time point (if more than one lesion was assessed).

Table 1 : Shows pharmacokinetic parameters after a single intravenous MTD (25 mg/kg) and sub-MTD ( 1 0 mg/kg) dose of BA 1. 101 553 in a mouse xenograft model of human lung cancer.

Thirty mice bearing human H460 non-small cel l l ung cancer xenografts were treated intravenously with a single 25 mg/kg or a single 1 0 mg/kg dose of BA L 101 553. Three mice per sampl ing point were sacri ficed at ten sampl ing points over a 24 hour period. Tumor and plasma were collected and analyzed for active drug (BAL27862) levels.

The MTD of a drug is generally determined in a Phase 1 study. In Phase 1 cancer studies, sequentially increasing the dose of a cytotox ic investigational drug is general ly thought to lead to improved antitumor effect and efficacy. Typical ly a Phase 1 dose escalation study starts at low dosages and dose levels are increased until unacceptable toxicity is observed. To icities are usual ly graded based on the National Cancer Institute^'s ( NCI ) Common Terminology Criteria for Adverse Events (CTCAE ) which defines laboratory ranges.

symptoms, and signs of toxicities or adverse events (AEs) and defines each AE to a severity scale from 1 -5. Based on study protocol-defined rules, definitions are provided for criteria to define "dose limiting toxicities" (DLTs). These are usually severe or life -threatening side effects or laboratory abnormalities. If no DLTs occur in a given dose cohort or if the number of DLTs remain under a predefined threshold (often defined as no more than 1 patient with a DLT out of 6 patients dosed ) new patients can be enrol led in a next higher dose cohort.

The dose escalation continues until a dose level that shows unacceptable toxicity is reached. The MTD is conventionally defined as the dose level just below this toxic dose level. This dose is often used for subsequent Phase 2 studies and is therefore frequently referred to as "recommended Phase 2 dose" (RP2D).

To determine the MTD "Standard" Phase ! trials use what is often called the '3+3 ' design or variations of this design. In this design the dose escalation continues until at least two patients among a cohort of three to six patients experience dose-limiting tox icities (ie, > 33% of patients with a dose-limiting toxicity at that dose level ). Alternative designs and methods include those which use statistical modelling (e.g. continual re-assessment methods or other model l ing approaches).

As already indicated above, the inventors have found that a single sub-MTD dose, as compared to a single MTD dose, is associated with superior tumor drug exposure to com ounds of general formula I, both in a precl inical mouse tumor xenograft model and in cancer patients treated with BA L 101 553 in a Phase l/2a trial. In the mouse tumor xenograft model, this is associated with a less profound effect of the sub-MTD dose on perfusion of the tumor vasculature, as compared to the MTD dose, suggesting that profound vascular disruption may not be preferred for efficient and continued drug deliv ery.

The exposure of the tissue to the drug compound corresponds to the AUC and/or peak concentrations (C_max) of the drug com ound (BAL27862) in the tumor tissue and finds its clinical expression e.g. in the provision of at least the equivalent clinical benefit at the applied sub-MTD dose as provided by administering the drug compound, a prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof at the MTD for said dosage frequency and treatment cycle.

The invention therefore also relates to a drug compound of formula (I), a prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof as described abov e for use for the treatment of a cancer patient, wherein said drug compound, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof is intravenously administered to said cancer patient according to a specific dosage frequency and a specific treatment cycle at a dose being below the MTD defined for said dosage frequency and treatment cycle of said drug, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof, but at a dose which prov ides an ex osure of the tissue of the cancer from which said cancer patient is suffering, to said drug compound to provide at least the clinical benefit provided by the MTD of said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof at the same dosage frequency and treatment cycle. The a fore-mentioned clinical benefit can advantageously be e.g. evaluated in clinical studies, so that clinical benefit provided by the MTD of said drug compound corresponds preferably to the clinical benefit obtained in at least one clinical study with the MTD of said drug com ound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof at the same dosage frequency and treatment cycle.

The clinical benefit may be e.g. expressed as the objective overall response rate to the administered drug substances, which is defined as the portion of patients evaluated in said at least one clinical study with a stabilisation or reduction of the size of the cancer tissue in said patients.

In a specific embodiment of the present invention, the sub-MTD doses of the drug compound of formula (I), prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof are therefore chosen thus, that they are associated with superior or at least equivalent anti-cancer response to BAL I 01553 or BAL27862 as compared to MTD doses.

Response is in general terms the reaction of the subject, or more preferabiy of the disease in a subject, to the activity, preferably therapeutic activity, of a compound of general formula I or a pharmaceutically acceptable derivative thereof. The response data may for example be monitored in terms of clinical benefit, including but not restricted to objective response rates, time to disease progression (time on study), progression free survival and overall survival. The response of a cancerous disease (anticancer response) may be evaluated by using criteria well known to a person in the field of cancer treatment, for example but not restricted to: Response Evaluation Criteria in Solid Tumors (RECIST) Guidelines, Source: Eisenhauer EA, Therasse P, Bogaerts J, Schwartz LH, Sargent D, Ford R, Dancey J, Arbuck S, Gwyther S, Mooney M, Rubinstein L, Shankar L, Dodd L, Kaplan R, Lacombe D, Verweij J. New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1). Eur J Cancer.2009 ;45:228-47;

RANO Criteria for High-Grade Gliomas, Source: W en PY, Macdonald DR, Reardon DA,

Cloughesy TF, Sorensen AG, Gal an is E, Degroot J, Wick W, Gilbert MR, Lassman AB, Tsien C, ikkelsen T, Wong ET, Chamberlain MC, Stupp R, Lamborn KR, Vogelbaum MA, van den Bent MJ, Chang SM. Updated response assessment criteria for high-grade gliomas: response assessment in neuro-oncoiogy working group. J Clin Oncol . 2010;28(1 1): 1963-72; CA- 1 25 Rust in Criteria for Ovarian Cancer Response, Source: Rustin GJ, Quinn M, Thigpen T, du Bo is A. Pujade-Lauraine E, Jakobsen A, Eisenhauer E, Sagae S, Greven K, Vergote 1, Cervantes A. Vermorken J. Re: New guidelines to evaluate the response to treatment in sol id tumors (ovarian cancer). J Natl Cancer Inst. 2004;96(6):487-8; and

PSA Working Group 2 Criteria for Prostate Cancer Response, Source: Scher HI, Haiabi S, Tannock I, Morris M, Sternberg CN, Carducci MA, Eisenberger MA, Higano C, Bubley GJ, Dreicer R, Petrylak D, Kantoff P, Basch E, Kelly WK, Figg WD, Small EJ, Beer TM,

Wilding G, Martin A, Hussain M; Prostate Cancer Clinical Trials Working Group. Design and end points of clinical trials for patients with progressive prostate cancer and castrate levels of testosterone: recommendations of the Prostate Cancer Clinical Trials Working Group. J Clin Oncol. 2008:26( 7 ): 1 148-59.

The response of a cancerous disease may also be evaluated by using biochemical, molecular or functional imaging criteria wel l known to a person in the field of cancer treatment, for example but not restricted to: 1) Direct evaluation of the effects of treatment with a compound of general formula I or a pharmaceutically acceptable derivative thereof on tumor biology, including but not restricted to:

Evaluation of tumor tissue before and after treatment, wherein post-treatment changes in tumor biology parameters indicate tumor response to compound treatment. The methods for removal of the tumor tissue sample are well known in the art. It may for example be removed from the subject by tumor biopsy, for example by punch biopsy, core biopsy or aspiration fine needle biopsy, endoscopic biopsy, or surface biopsy. The tumor biopsy may be preserved in an appropriate manner, for example by formalin fixation and paraffin embedding or by freezing. Subsequent analysis may include evaluation of the fol lowing parameters: tumor cell proliferation levels, for example by i m m u noh i s toe hem i ca I (IHC) staining for nuclear Ki67; tumor blood vessel density, for example by IHC staining for CD34; tumor cel l v iability, for example by IHC staining for active caspase 3 or evaluation of necrotic areas after

hematoxylin and cosin staining: or tumor cell expression of proteins involved in the mechanism of action of the drug, for example cell cycle regulators such as cyclin-dependent kinase inhibitor 1 (p21/WAFl/CIPl) and the mitotic checkpoint seri ne/th reon i ne-protei n kinase BubR l .

Evaluation of circulating tumor cells (CTC) before and after treatment, wherein post- treatment changes in CTC cell number and other biological parameters indicate tumor response to compound treatment. The methods for isolation of the CTC are well known in the art. A blood sample may be collected by venipuncture and further processed according to standard techniques. CTC may be obtained from blood based on, for example, size (e.g. ISET - Isolation by Size of Epithelial Tumor cells), dieiectrophoresis (e.g. ApoStream®, ApoCeii, Houston, TX ) or immunomagnetic cell enrichment, (e.g. CeliSearch®, Veridex, Raritan, NJ ). Subsequent analysis may include evaluation of the fol lowing parameters: CTC numbers in a fixed amount of blood, for example by flow cytometry; or tumor cel l expression of proteins involved in the mechanism of action of the drug, for example cell cycle regulators such as cycl in-dependcnt kinase inhibitor 1 (p21/WAFl/CIPl) and the mitotic checkpoint seri ne/th eon i ne-protei n. kinase BubR l .

Enumeration of circulating endothelial cells (CECs) and circulating endothelial progenitor cells (CEPs) before and after treatment, wherein post-treatment changes in CEC or CEP cel l numbers indicate tumor anti-vascular response to compound treatment. The methods for isolation of the CEC and CEPs are know n in the art. A blood sample may be col lected by venipuncture and further processed according to standard techniques. CECs and CEPs may then be enumerated for example by flow cytometry fol low ing staining for specific markers (Taylor M, Bil l iot F, Marty V, Rouffiac V, Cohen P, To urn ay E, Opolon. P, Louache F, Vassal G, Laplace-Builhe C, Vielh P, Soria JC, Farace F. Reversing resistance to vascular- disrupting agents by blocking late mobilization of circulating endothelial progenitor cells. Cancer Discov. 2012;2:434-49).

2) Functional evaluation of the effects of treatment with a compound of general formula I or a pharmaceutically acceptable derivative thereof on tumor metabolism or tumor vascularization, including but not restricted to:

Evaluation of tumor metabolic status before and after treatment using functional imaging techniques including but not restricted to for exam le Fi uoroDeoxyG I ucose (FDG) Positron Emission Tomography ( PET). FDG is an analogue of glucose which acts as a tracer indicating tumor tissue metabol ic activity. The administration of FDG to cancer patients is well known in the art, and post-treatment reductions in tracer uptake, indicative of reduced tumor glucose metabol ism, are considered an early surrogate of clinical benefit to compound treatment ( elloff GJ 1 , Hoffman JM, Johnson B, Scher H I, Siege! BA, Cheng EY, Cheson BD, O'shaughnessy J, Guy ton KZ, Mankoff DA, Shankar L, Larson SM, Sigman CC, Schilsky RL, Sul livan DC. Progress and promise of FDG-PET imaging for cancer patient management and oncologic drug development. C lin. Cancer Res. 2005; 1 1 :2785-808).

Evaluation of tumor vascularization (vascular perfusion) before and after treatment using functional imaging techniques including but not restricted to for example Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) and Diffusion-Weighted Imaging ( DWI ). Suitable contrast agents used for MRI contrast enhancement include for example gadolinium-based agents, and administration of such agents to cancer patients is well known in the art. Post-treatment changes in tumor contrast enhancement are associated with response to compound treatment and often precede morphologic alterations ( Li S 1 , Padhani AR. Tumor response assessments with diffusion and perfusion MRI. J. agn. Reson. Imaging. 2012;35 :745-63).

The cl inical benefit can also be measured and defined, including in particular a definition in terms of one or more of the following parameters

(1) reduction of tumor size evaluated in said at least one clinical study at the same dosage frequency and treatment cycle;

(2) reduction of tumor vascularization evaluated in said at least one clinical study at the same dosage frequency and treatment cycle;

(3) reduction of tumor proliferation evaluated in said at least one clinical study at the same dosage frequency and treatment cycle;

(4) reduction of tumor metabolism evaluated in said at least one clinical study at the same dosage frequency and treatment cycle; or

(5) reduction of tumor vitality evaluated in said at least one clinical study at the same dosage frequency and treatment cycle. In another aspect, the present invention relates furthermore to a drug compound of formula (I), a prodrug thereof or a pharmaceutically acceptable salt of said drug com ound or prodrug thereof, wherein said d ug com ound, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof is administered at a dose, which provides less anti- vascular (vascular disrupting) efficacy than the anti-vascular efficacy of said drug compound. prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof at its MTD for the same dosage frequency and treatment cycle.

Said anti-vascular efficacies can e.g. be obtained in at least one cl inical study using said doses of said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof at identical dosage frequency and treatment cycle.

In a still independent further aspect, preferably however in a preferred aspect of the aforementioned embodiments of the invention, the present invention relates furthermore to a drug compound of formula (I), a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof; wherein said drug compound, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof is administered at a dose of 75 or less percent, preferably of 25 to 75 percent, more preferably at a dose of 60 percent and less, especially of 25 to 60 percent, more specifical ly of 40 to 60 percent of the MTD defined for said compound, when used according to the dosage frequency and treatment cycle.

Preferred drug compounds of formula ( I ) and prodrugs thereof for use according to the present invention include such compounds, wherein

in formula (I) re resents 1 .4-phenylene or a group of formula

in particular, when R¹ represents hydrogen or cyano-Ci -Ci alkyl, especial ly cyano-ethyl. and pharmaceutical ly acceptable salts of said drug compounds or prodrugs.

Especial ly preferred are the following drug compounds of formula ( I ) and prodrugs of such compounds: 

n particular the following drug compound and prodrugs

as well as their pharmaceutically acceptable salts.

Most preferred for use according to the invention is the following compound :

( BA L I 0 1 553 ) and pharmaceutical ly acceptable salts thereof, preferably hydrochloride salts, in particular the dihydrochloride salt. In one embodiment this compound is administered at a dose of less than 75 percent, preferably at a dose of less than 60 percent of the MTD defined for said compound for use according to the same dosage frequency and treatment cycle. In other embodiment this compound is administered at 25 to 75 percent, more preferably 25 to 60 per cent, even more preferably 40 to 60 percent of the MTD defined for said compound for use according to the same dosage frequency and treatment cycle.

In one embodiment BALI 01553 can be administered to a human patient at a dose of about 50 percent of the MTD defined for said compound for use according to the same dosage frequency and treatment cycle. In a further embodiment BA L I 0 1 553 can be administered to a human patient at a dose of about 75 percent of the MTD defined for said compound for use according to the same dosage frequency and treatment cycle.

BAL101553 can e.g. advantageously be administered to a human patient at a dose of 45

2 2

mg/m maximum, preferably of 15 to 45 mg/m .

In one embodiment BAL I 01553 can be administered to a human patient at a dose of about 30

2

mg/m , preferably with an infusion period of about 2 hours. In a further embodiment

BA L I 0 1 553 can be administered to a human patient at a dose of about 45 mg/m , preferably with an infusion period of about 2 hours. In a preferred embodiment of the invention, the sub-MTD doses applied are therefore chosen thus, that they are associated with superior or at least equivalent anti-cancer response to

BAL101553 as compared to MTD doses. Although the present invention is general ly also useful for the treatment of cancer in animals, in particular mammals, the cancer patient is preferably a human.

Humans are preferably treated according to the invention according to treatment cycles wherein the dosage frequency is below tw ice per week and preferably about once per week.

Preferred treatment cycles furthermore include intermission of the drug dosage, preferably after 1 to 5, more preferably 2 to 3 dosages of the drug compound, the prodrug thereof or the pharmaceutical ly acceptable salt of said drug compound or prodrug thereof. Preferably, the mentioned intermissions last for 0.5 to 4 weeks, more preferably 1 to 2 weeks, in particular about 1 week.

The MTD of drug compounds of formula (I) of the present invention, prodrugs thereof or pharmaceutical ly acceptable salts of said drug compounds or prodrugs thereof can vary to a certain extent. It depends, for example, on the specific drug substance of formula ( I ) which is administered, the infusion time, the specific treatment cycle and the dosage frequency and also from the severity of the cancer disease. Patients suffering from a cancer with bad prognosis generally accept more and stronger side effects and thus usual ly tolerate higher dosages of the anti-cancer medication. The MTD of the drug compounds of formula (I), prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof, when appl ied to humans, range for example from about 1 5 to about 500 mg/m ,

2 2

including from about 1 5 to about 400 mg/m , from about 1 5 to about 300 mg/m preferably

2 2

from about 1 5 to about 200 mg/m , more preferably from about 1 5 to 100 mg/m , e.g. from about 60 to 80 mg/m , wherein the indicated surface area represents the outer surface area of the human, which can be determined by methods generally known in the art.

The MTD of said drug compounds, prodrugs thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof is part icularly preferably about 60 mg/m , in particular for BA L 101 553, especial ly when used to treat humans in a 28 days treatment cycle. wherein BALI 01553 is intravenously administered preferably using a 2 hour infusion on days 1 , 8 and 15 or a similar treatment cycle.

The skilled person will understand that the MTD may vary depending upon the infusion time. A human MTD of about 60 mg/m corresponds e.g. to an infusion time of about 2 hours, a longer in fusion time may however result in a higher MTD, whereas shorter infusion times may result in a lower MTD.

As already indicated, the compounds of general formula (I) have been shown to arrest cell proliferation and induce apoptosis.

Deregulation of cell proliferation, or lack of appropriate cell death, has wide ranging clinical implications. A number of diseases associated with such deregulation involve

hyperproliferation, inflammation, tissue remodeling and repair. Famil iar indications in this category include cancers, restenosis, neointimal hyperplasia, angiogenesis, endometriosis, iymphoproliferative disorders, transplantation related pathologies (graft rejection ), polyposis, loss of neural function in the case of tissue remodeling and the like.

Cancer is associated with abnormal cell proliferation and ceil death rates. As apoptosis is inhibited or delayed in most types of proliferative, neoplastic diseases, induction of apoptosis is an option for treatment of cancer, especial ly in cancer types which show resistance to classic chemotherapy, radiation and immunotherapy (Apoptosis and Cancer Chemotherapy, Hickman and Dive, eds., Blackwell Publishing, 1999). The compounds according to formula (I) may accordingly be used for the prophylactic or especially therapeutic treatment of the human or animal body, in particular for treating a neoplastic disease. Examples of such neoplastic diseases include, but are not limited to, epithelial neoplasms, squamous cel l neoplasms, basal cell neoplasms, transitional cell papillomas and carcinomas, adenomas and adenocarcinomas, adnexal and skin appendage neoplasms, mucoepidermoid neoplasms, cystic neoplasms, mucinous and serous neoplasms, ducal-, lobular and medul lary neoplasms, acinar cell neoplasms, complex epithelial

neoplasms, specialized gonadal neoplasms, paragangliomas and glomus tumors, naevi and melanomas, soft tissue tumors and sarcomas, fibromatous neoplasms, myxomatous neoplasms, lipomatous neoplasms, myomatous neoplasms, complex mixed and stromal neoplasms, fibroepithelial neoplasms, synovial like neoplasms, mesothelial neoplasms, germ cell neoplasms, trophoblastic neoplasms, mesonephromas, blood vessel tumors, lymphatic vessel tumors, osseous and chondromatous neoplasms, giant cell tumors, miscellaneous bone tumors, odontogenic tumors, gliomas, neuroepitheliomatous neoplasms, meningiomas, nerve sheath tumors, granular cell tumors and alveolar soft part sarcomas, Hodgkin's and non- Hodgkin's lymphomas, other lymphoreticular neoplasms, plasma cell tumors, mast cell tumors, immunoproliferative diseases, ieukemias, miscellaneous myeloproliferative disorders, iymphoproliferative disorders and myelodysplastic syndromes. In an especially preferred embodiment the disease is cancer. Examples of cancers in terms of the organs and parts of the body affected include, but are not limited to, the breast, cervix, ovaries, colon, rectum, (including colon and rectum i.e. colorectal cancer), lung, (including small cell lung cancer, non-small cell lung cancer, large ceil lung cancer and mesothelioma), endocrine system, bone, adrenal gland, thymus, liver, stomach, intestine, (including gastric cancer), pancreas, bone marrow, hematological malignancies, (such as lymphoma, leukemia, myeloma or lymphoid malignancies), bladder, urinary tract, kidneys, skin, thyroid, brain, head, neck, prostate and testis.

Preferably the cancer is selected from the group consisting of breast cancer, prostate cancer, cervical cancer, ovarian cancer, gastric cancer, colorectal cancer, pancreatic cancer, liver cancer, brain cancer, neuroendocrine cancer, lung cancer, kidney cancer, hematological malignancies, melanoma and sarcomas.

Especially preferably the cancer is selected from the group consisting of colorectal cancer, gastric cancer and cancers of the gastro-oesophageal junction, non-small ceil lung cancer, ovarian and primary peritoneal cancer, pancreatic cancer (including ampullary cancer) and triple negative breast cancer.

In one embodiment the cancer to be treated is a tumor, preferably a solid tumor.

The drug compounds of present formula (I), prodrug thereof or a pharmaceutically acceptabl e salt of said drug compound or prodrug thereof can according to the invention also be used in combination with other drugs, in particular other anti-cancer drugs, which are administered on the same days of the treatment cycle like the drug compounds of present fomula (I), prodrugs thereof or pharmaceutically acceptable salts of said drug compounds or prodrugs thereof or on different days. Appropriate dosages of said further drugs can be evaluated easily by those skilled in the art starting e.g. from the dosages at which said ot!ier drugs are conventionally used alone. Preferably, said other drugs are also used at sub-MTD doses.

In a further aspect, the present invention relates to a use of a drug compound of formula (I), a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof as described above for the manufacture of a medicament for the treatment of cancer in a patient in need of such treatment, wherein said medicament is designed for a treatment, wherein said drug compound, prodrug thereof or pharmaceutical ly acceptable salt of said d ug compound or prodrug thereof is intravenously administered to said cancer patient according to a specific dosage frequency and a specific treatment cycle at a dose being below the MTD defined for said dosage frequency and treatment cycle of said drug, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof but providing at least the same exposure of the tissue of the cancer from which said cancer patient is suffering, to said drug as provided by the MTD at the same dosage frequency and treatment cycle.

In yet another aspect, the invention relates to a method for the treatment of a cancer patient in need of such treatment, which comprises intrav enously administering to said pat ient an effective dose of a drug compound of formula (I), a prodrug thereof or a pharmaceutical ly acceptable salt of said drug compound or prodrug thereof as described above according to a specific dosage frequency and a specific treatment cycle and said dose is below the MTD defined for said dosage frequency and treatment cycle of said drug, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof but prov ides at least the same exposure of the tissue of the cancer from which said cancer patient is suffering, to said drug as prov ided by the MTD at the same dosage frequency and treatment cycle.

The methods of the invention may include the steps of

i. choosing a dosage frequency and treatment cycle,

ii. identifying the MTD associated with the dosage frequency and treatment cycle, and iii. administering the drug, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof. Identification of the MTD associated with said dosage frequency maybe performed by reference to clinical data. Methodology of Examples:

E validation of Functional Tumor Vasculature and Plasma and Tumor Drug Concentrations in Xeno grafted Mice:

NCI-H460 NSCLC cells (ATTC: HTB- 1 77) were expanded in vitro using conventional cel l culture techniques and subcutaneously injected into the flank of 6-8 week old NMRI:nu/nu female mice under aseptic conditions. Each mouse received 1 0⁷ cells. Tumor Vascularization Analysis:

When the tumors reached a mean size of 220+/-90 mm , animals were treated with a single intravenous dose of BAL I 01 553 at 1 0 or 25 mg ^'kg (formulated in 0.9% NaCl vehicle - pH adjusted to pH 5 ) or with vehicle control alone (5 mL/kg). Nine mice were treated per group, and tumors from three mice were analyzed at the time-points indicated. Tumors were excised 1 5 minutes after intravenous administration of 0.2 m L F I TC- lectin solution (1 mg/mL in phosphate buffered saline)(Vector Labs: FL-1081). Excised tumors together with cryo- embedding compound OCT (Sakura: Cat. No. 4583) were snap frozen and cryosections of 2 iim thickness were prepared and embedded in Fluore Care anti-fade mountant (Biocare Medical). FITC-iabeied vessels were visualized using fluorescence microscopy. Vascular quantification was restricted to v ital tumor areas and calculated per mm .

Pharmacokinetic Analyses:

When tumors reached a size of 275+/- 135 mm , animals were treated with a single intravenous dose of BAL I 01 553 at 10 or 25 mg kg ( formulated in 0.9% NaCl vehicle - pH adjusted to pH 5 ). Thirty mice were treated per group, and tumors and plasma from three mice were analyzed after 5, 1 5, 30, 45, 60 and 90 minutes and 2, 4. 6 and 24 hours. For plasma, blood was taken from the orbital venous into a chilled EDTA/ 3 tube and mixed with 10 μ L 2 citric acid per m L of blood, incubated on ice for 1 5 minutes and then centrifuged at 1 ^' 200.x g for 10 minutes at 4°C. The resulting plasma samples were transferred into new vials and stored at -80°C until analysis. Excised tumors were quickly rinsed in ice cold phosphate buffered saline and then snap-frozen and stored until analysis at -80 C.

Analysis of mouse plasma samples: Plasma concentrations of BAL27862 were determ ined with a specific LC-MS/MS method: 40 ill . to 50 μ I , plasma was treated with 1 20 μ L to 150 u L of acetonitrile containing stable label led internal standards ( IS ). After vortex in g. the samples were centrifuged for 1 0 minutes at 50Ό00 g and 8°C. 10 μ L supernatant was injected on the LC column. The extract was separated by l iquid chromatography, performed using water (1 % formic acid ) as mobile phase A and acetonitrile :methanol (50:50; v:v) (1% formic acid ) as mobile phase B. The column used was a Maisch Stability Amid C 1 2, 2.1 x 100 mm, 3 iim (Dr. Maisch GmbH, Ammerbuch, Germany).

Detection was carried out using a triple-stage quadrupole MS/MS (Micromass Quattro Premier XE, Waters, M il ford USA or QTrap 2000, AB Sciex, Toronto, Canada) in the selected reaction monitoring mode.

The following cal ibration range was applied:

5 or 10 to 10000 ng/mL for BAL27862 in mouse plasma (K3-EDTA, citric acid) Analysis of xeno grafted tumor samples: Tumor concentrations of BA 1.27862 were determined with a specific LC-MS/MS method: One equivalent of mouse tumor was homogenized w ith five or nine equivalents of water by using glass homogenizers. To 30 or 50 μΐ . of this tumor/water solution 90 or 1 50 μΐ, of acetonitrile containing stable labelled internal standards ( IS ) was added. Samples were vortexed, centrifuged and 1 0 μΤ, of the supernatant was injected into the LC-MS/MS. The extract was separated by liquid chromatography, performed using water (1% formic acid ) as mobile phase A and acetonitrile methanol (50:50; v:v) (1% formic acid ) as mobile phase B. The column used was a Maisch Stability Amid C12, 2. 1 x 100 mm. 3 μπι ( Dr. Maisch GmbH, Ammerbuch, Germany).

Detection was carried out using a triple-stage quadrupole MS/MS ( Micromass Quattro Premier XE, Waters, M ilford USA or QTrap 2000, AB Sciex, Toronto, Canada) in the selected reaction monitoring mode.

The following cal ibration range was applied:

5 or 10 to 10000 ng/mL for BAL27862 in mouse tumor homogenate BAL101553 Phase 1/2A Trial Design:

A single-agent, open-label Phase 1 trial was carried out in adult patients w ith solid tumors who had failed standard anticancer therapy or for whom no effective standard therapy was available (ClinicalTrials.gov identifier: NCTO 1397929). The primary objective of the trial was to determine the ma imum tolerated dose (MTD) of BALI 01553 when given as 2 hour infusions on days 1 , 8, and 1 5 of each 28-day cycle. The MTD was defined as the highest dose that could be administered in cycle I without the occurrence of dose-limiting toxicity (DLT) in 2 or more patients in a dosing cohort of 3 to 6 patients. Detailed DLT definitions were provided in the study protocol and general ly included drug-related hematological adverse effect of Grade 4 or non-hematological adverse effect of Grade 3 or higher according to the Common Toxicity Criteria for Adverse Events Version 4.0 (CTCAEv4, found in nih.gov) with a separate definition of DLTs relating to hypertension.

Dose escalation used a modified accelerated titration design. The starting weekly dose of BAL I 01 553 was 1 5 mg/m based on Good Laboratory Practice (GLP) toxicology studies. The first dose cohorts comprised 1 patient per cohort and dose increments were 100 % between dose cohorts until a drug-related > CTCAE grade 2 toxicity was observed in the first patient administered 30 mg/m . Thereafter, doses were escalated by approx imately 33 % utilizing a 3+3 titration design. Patients without progressive disea.se, who completed two treatment cycles, were also evaluated for antitumor efficacy at the end of the second cycle and every two cycles thereafter. Best objective response in evaiuabie patients was evaluated using computed tomography (CT) based on criteria in the Response Evaluation Criteria in Solid Tumors ( R EC I ST) guidel ines, version 1. 1 ( Eur J Cancer. 2009 ;45 :228-47).

Following MTD determination, a Phase 2 A expansion phase was initiated in predetermined tumor types with patients randomized to two dosing a ms (MTD and sub-MTD). Antitumor efficacy was evaluated as described above.

As of 3 1 December 201 3. 24 patients had received BA L I 01 553 given at 1 5 mg/m (one

^ 2 2

patient ), 30 mg/m^" (three patients), 45 mg/m (three patients), 60 mg/m (ten patients), and 80

2

mg m (seven patients). Evaluation of Plasma Drug Concentrations in Patients Treated with BALI 01 53 :

On day 1 of cycle 1 blood samples were collected at pre-dose and 0.5, 1 , 2, 3, 4, 6, 8 and 24 hours after dosing. Venous blood samples were collected into chilled 2 mL plastic tubes containing K2-EDTA as an anticoagulant, mixed with 20 iiL 2 M citric acid and kept on ice for 1 5 minutes. Approximately 1 .0 m L plasma was prepared by centrifugation at l '500^xg for 10- 1 5 minutes at 4°C, transferred into new v ials and stored at -80°C unt il analysis. Plasma concentrations of BA 1.27862 were determined with a fully validated LC-MS/MS method:

50 LIL of acetonitrile was added to 25 ill . plasma containing stable label led internal standards ( IS ). After vortexing, the samples were eentrifugcd for 1 0 minutes at 50Ό00 g and 8°C and 50 μΐ, of the supernatant was transferred to an empty autosampler vial. The extract was separated by l iquid chromatography, performed using water (0.1% formic acid ) as mobile phase A and acetonitrile (0.1% formic acid) as mobile phase B. The column used was a YMC Hydroshere C 1 8. 2. 1 x 33 mm, 3 iim (YMC Co, Kyoto, Japan ). The injection volume was set to 2 μ L (lull loop).

Detection was carried out using a triple-stage quadrupole MS/MS (TSQ Vantage. Thermo

Fisher Scientific, San Jose, CA, USA) in the selected reaction monitoring mode.

The following calibration range was applied:

1 to 1000 ng/m L for BAL27862 in human plasma (K3-EDTA, citric acid )

Calculation of^* Pharmacokinetic Parameters (exposure I Area Under the Curve - AUC I and

AUG and C_max were calculated by non-compartmental analysis (NCA) using Phoeni Win No n Lin 6.3 software from Certara.

Blood Pressure Measurements in Patients Treated with BAL 101 553 :

Blood pressure measurements were performed on seated patients using val idated monitoring devices according to standard clinical practice, i.e. either an automatic device or a manually calibrated device ( Dougherty and Lister 201 5. The Royal Marsden Manual of Clinical Nursing Procedures. 9th edition. Chichester, Wiley Blackw el l ). Whenever possible, the same staff member, patient arm and monitoring device were used for any given patient visit. Screening and pre-dose measurements were obtained from both arms in triplicate. For blood pressure measurements during study drug infusion, the arm used was contralateral to the arm of study drug infusion. During treatment, single measurements were taken every 30 minutes during and for at least 1 hour after the end of the infusion. Any systolic blood pressures (SBP) > 160 mmtlg or diastolic blood pressures (DBP) > 1 00 mmHg were confirmed in triplicate. In addition, if SBP > 160 mmHg or DBP > 1 00 mmHg occurred, the patient was monitored every 10 - 15 minutes until a return to SBP < 160 and DBP < 100 mmHg. Antihypertensive medication was administered, if required, prior to or during study drug administration. Patients were el igible for the study if any of the following appl ied at screening:

- The average blood pressure of the first triplicate reading was SBP < 140 mmHg and DBP <

90 mmHg;

- The average blood pressure of the first triplicate reading is SBP > 140 mmHg or DBP > 90 mmHg, but two subsequent triplicate measurements on the same screening day were performed with SBP < 140 mmHg and DBP < 90 mmHg at both readings;

- The average of either triplicate reading is SBP > 140 or DBP > 90 mmHg, but a subsequent, technically adequate ambulatory blood pressure monitoring (ABPM) is performed, and the daytime average from the ABPM is SBP < 130 mmHg and DBP < 85 mmHg.

Patients were not eligible for the study if they were treated with a calcium channel blocker, or if they required a combination of more than two antihypertensive medications to control blood pressure.

Statistical analysis was performed on the difference in the mean change from baseline blood pressures to the 3 -hour post baseline blood pressures (systolic blood pressure and diastolic

2 2 blood pressure) in patients treated at a dose level of 0 mg/m versus 60 mg/m of BA L I 01 553, using a two-sample t-test.

Dynamic Contrast-enhanced Magnetic Resonance Imaging (DCE-MRI) in Patients Treated with BA L K) 1 553 :

DCE-MRI depicts the function of the tumor vasculature. MRI imaging uses gadolinium chelate contrast agents to provide a time-resolved enhancement pattern and/or a quantitative pharmacologic model-based assessment. Pharmacodynamic parameters such as K^!iai!s (transfer constant ), k_ep (rate constant ), and v_e (extra-vascular extra-cellular space) and IAUGC ( initial area under the gadol inium curve ) may be extracted. A detailed background of the method is described in Leach et al. Eur Radiol . 2012;22: 1451-64. DCE-MRI is performed after administration of extracellular gadolinium based contrast agents and evaluates the contrast enhancement of tumors, compared to normal tissue, allowing evaluation of tumor vascular response to therapy. Drugs that target tumor vasculature often lead to a decrease in tumor-vascular permeabil ity (Galbraith et al. J Clin Oncol 2003;21(15):2831-42).

An MRI scanner, with a magnetic field strength of 1.5 Tesla was used for the DCE-MRI scanning using 3D high-resolution imaging protocols. A DCE-MRI scanning protocol, optimized for the 1 .5 T Siemens Avanto scanner, was used according to establ ished procedures at the cl inical site and manufacturer^'s instructions.

Target lesions were ideally of a size > 2 cm (preferably in all planes) and representative of the primary tumor (if present ) and similar to other metastases, based on computed tomography imaging features. Necrotic lesions or lesions with signs of hemorrhage were avoided. Scans were preferentially taken in the coronal plane. The axial plane was only used for the pelvic region or for a particular lesion shape as determined by an experienced radiologist. A gadol inium chelate contrast of at least 2-5 mL/s was used, with approximately the same contrast flow rate used for all MRI examinations. Each tumor lesion measured at baseline was measured throughout the study by the same method of assessment (e.g. consistent use of CT with the same anatomic coverage, contrast administration, slice thickness and reconstruction interval) to allow for consistent assessments and comparisons. Endpoints included: change versus baseline in DCE quantitative biomarkers, including K^trans which represents the volume transfer constant between the blood pool and the extravascular- extracellular space, reporting on perfusion and microvascular permeabil ity. Endpoints can be derived by appropriate software such as MRI workbench (MRIW1) and/or Analysis Appl ication for Medical Imaging (AAMI) software (dArcy et al. Radiographics 2006:26:62 1 32; Yap et al, Clin Cancer Res 2013; 19(4):909-19). Up to five DCE-MRI imaging sessions were performed for each patient, including two baseline assessments and three on-treatment assessments. Depending on the results, this imaging schedule was modified as appropriate.

Patients were eligible for the study if ail of the following applied at screening:

- Informed consent for the Functional Imaging Protocol provided.

- No contraindications for the administration of gado!ini u m -con ta i n i n g RI contrast agents. - Peripheral venous access or an implanted venous access dev ice that permits a contrast flow rate of at least 2-5 mL/s. Example 1 : Single Sub-MTD Doses of BAL I 01 553 Result in Reduced Tumor Vascular Disruption and Enhanced Tumor Drug Exposure in a Mouse Xenograft Model of Human Lung Cancer

Intravenous treatment of H460 tumor-bearing mice with a single VI^' I^'D (25 mg/kg) and sub- MTD ( 10 mg/kg) dose of BA L I 01 553 induced a dose-dependent, tumor vascular disruption as compared to controls, as determined by measurement of tumor vascular perfusion

following intravenous administration of fl uorcscent I y-l abel I ed FITC-iectin and microscopic evaluation (Figure 1). The most profound effect on tumor vascularization was observed with the ID dose (25 mg/kg), with complete inhibition of tumor perfusion observed up until 1 1 days after administration. In contrast, intermediate vascular disruption was observed for the sub-MTD dose (10 mg/kg) at all time-points measured (Figure 1). Surprisingly, analysis of drug levels after a single administration of 10 or 25 mg/kg

BALI 01553 indicated that the MTD dose achieved a higher plasma exposure (C_max and

AUC) to the active drug BAL27862. However, in tumors higher B A 1.27862 exposures (C_max and AUC) were measured with the sub-MTD dose (Table 1). Table 1 :

These data demonstrate that a single BALI 01553 administration has dose-dependent effects on tumor vascularization. Moreover, higher MTD doses do not result in proportionally higher tumor drug levels. The latter observation may be related to more profound anti-vascular effects at higher MTD drug doses, resulting in less efficient drug distribution to tumor. Example 2: Definition of MTD BA L I 01 553 Dose in Advanced Cancer Patients Treated in a

Phase 1 Dose-escalation Trial

A Phase 1 dose-escalation trial in advanced cancer patients, to determine the MTD of intravenous BAL I 01 553 when administered on days 1 , 8 and 1 5 of a 28 day treatment cycle. has been completed. The dose levels evaluated included 1 5 mg/m^", 30 mg/m , 45 mg/m , 60 mg/m and 80 mg/m , with 60 mg/m being defined as the MTD.

Example 3 : Pharmacokinetic Evaluation of Pla.sma Samples Obtained from Advanced Cancer

Patients Treated with sub-MTD and MTD BA L I 01 553 Doses Indicates Dose Proportionality Related to Blood Pressure Changes

In the Phase l/2a trial, plasma samples obtained from patients administered a single

2 ^ intravenous dose of BAL I 01 553 at 30 mg/m (n=9; defined as a sub-MTD dose) or 60 mg/m^' (n=18; defined as the MTD dose) were analyzed for levels of the active drug BAL27862 ( Figure 2). Derived pharmacokinetic data indicated that the 60 mg/m MTD dose achieved an appro imately 2-fold higher pla.sma exposure (C_max and AUG) to the active drug than the 30 mg/m sub-MTD dose. Moreover, if the analysis was performed in the same patient (i.e. a

2 2 patient who had received 60 mg m and was subsequently dose-reduced to 30 mg/m ) a similar dose-proportionality was observed (Figure 3).

As a measure of drug effect on the normal vasculature of patients, average changes in both systol ic and diastolic blood pressure from baseline were calculated on day 1 of cycle 1 (n=32 patients) 1 hour after completion of the 2 hour infu ion (defined as the time of maximal drug exposure: T_max). Strikingly, increases in both systolic and diastolic blood pressure were

2 2

higher (p- 0.05 ) at 60 mg/m than at 30 mg/m , suggesting that the MTD dose had more profound effects on the normal vasculature of patients consistent with higher pla.sma exposure levels (Figure 4 ). Moreover, analysis of systolic blood pressure by dose level in the

2 2 patients who had received 60 mg/m and were subsequently dose-reduced to 30 mg m confirmed the higher blood pressure changes associated with MTD doses ( Figure 5; same patients as exempl i fied in Figure 3 ). Taking these data together, the 60 mg/m MTD dose is associated with more profound increases in blood pressure as compared to the 30 mg/m sub- MTD dose, suggesting that this adverse event is related to the higher plasma drug levels associated w ith MTD dosing. Example 4: A Single Sub-MTD Dose of BALI 01553 Results in More Pronounced Tumor Vascular Leakage than the MTD Dose

In order to further evaluate the effect of the MTD ( 60 mg/m^") and sub-MTD (30 mg/m ) dose on tumor vascular leakage (permeability) (as a surrogate for tumor drug exposure) changes in Dynamic Contrast Enhancement (K^tmns) versus baseline were analyzed at the fol lowing three time points after the first dose in cycle 1 day 1 : 1 to 6 hours; 1 to 2 days; 7 days. The median change from basel ine in K"^'"^ls at each measurement time point over the seven day period is shown in Figure 6. The MTD dose of the drug was associated with reduced vascular leakage in the tumor. However, surprisingly and in contrast, a clear induction of vascular leakage was observed with the sub-MTD dose of 30 mg/m indicating more efficient drug perfusion of the tumor. These data are consistent with the findings in the tumor xenograft model (Example 1); clinically supporting that BA L I 01 553 administration has dose-dependent effects on tumor vascularization, with MTD doses resulting in less efficient drug distribution to tumor despite higher plasma exposure levels and greater effects on the normal vasculature.

Claims

Claims:

1 . A prodrug ha ing the formula:

or a pharmaceutically acceptable salt thereof,

for use for the treatment of cancer in a human patient, wherein said prodrug or

pharmaceutically acceptable salt of said prodrug thereof is intravenously administered to said cancer patient according to a specific dosage frequency and a specific treatment cycle at a dose being below the ma imum tolerated dose defined for said dosage frequency and treatment cycle of said prodrug or pharmaceutical ly acceptable salt thereof but providing at least the same exposure of the tissue of the cancer from which said cancer patient is suffering, to said drug as provided by the ma imum tolerated dose at the same dosage frequency and treatment cycle;

wherein the maximum tolerated dose of said prodrug or pharmaceutically acceptable salt thereof is about 60 mg'm ;

and wherein said treatment is not a dose escalating Phase 1 study for determining MTD of the prodrug for a 28 days treatment cycle, wherein the prodrug is intravenously administered on

2 2 2

days 1 , 8 and 1 5 with evaluated dosage levels 15 mg cm , 30 mg/cm , 45 mg/cm and 60 mg/cm². 2. A prodrug according to claim 1 o a pharmaceutically acceptable salt of said prodrug thereof, for use for the treatment of a cancer in a human pat ient , wherein said prodrug or pharmaceutically acceptable salt of said prodrug thereof is intravenously administered to the cancer patient as a 2-hour infusion on days 1 , 8 and 1 5 of a 28-day cycle.

3. A drug compound of formula (I)

wherein

represents

a divalent benzene residue which is unsubstituted or substituted by one or two additional substituents independently selected from lower alkyl, halo-lower alkyl, hydroxy-lower alkyl, lower alkoxy-iower alkyl, acy oxy-lower alkyl, phenyl, hydroxy, lower alko y, hydroxy- lower alkoxy, lower alkoxy-lower alkoxy, phenyl-iower alkoxy, lower alky!carbonyloxy, amino, mono( lower alkyl )amino, di( low er alkyl )amino. mono( low er alkenyl )amino, di( lower alkenyl )amino, lower a I kox yea rbo n y I a m i no , lower al kylcarbonylam ino, substituted amino wherein the two substituents on nitrogen form together with the nitrogen heterocyciyi, lower alkylcarbonyl, carboxy. lower alkoxycarbony , cyano, halogen, and nitro; or wherein two adjacent substituents can be methyienedioxy; or

a divalent pyridine residue (Z = N) which is unsubstituted or substituted additionally by lower alkyl, lower alkoxy, lower alkoxy-lower alkoxy, amino, optionally substituted by one or two substituents selected from lower alkyl, lower alkenyl and alkylcarbonyl, halo-lower alkyl, lower alkoxy-low er alkyl, or halogen;

R ' represents hydrogen, lower alkylcarbonyl, hydroxy-lower alkyl or cyano-lower alkyl ; and

R² represents ^NH₂ , or a prodrug thereof, wherein

R represents a group selected from the groups of formula:

or a pharmaceutically acceptable salt of said drug compound, prodrug thereof for use for the treatment of a cancer in a human patient, wherein said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof is

intravenously administered to the cancer patient according to a dosage frequency and a treatment cycle, for which a maximum tolerated dose has been determined in a clinical study,

at a dose being below said ma imum tolerated dose and providing at least the same exposure of the tissue of said cancer to said drug compound as prov ided by the maximum tolerated dose at the same dosage frequency and treatment cycle.

4. A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use for the treatment of a cancer in a human patient according to claim 3, wherein a treatment of patients in a cl inical study for establishing the maximum tolerated dose of said drug compound, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof is excluded.

5. A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 4, w herein the maximum tolerated dose is determined in the Phase 1 Study of said drug compound, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof.

6. A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 5, wherein the exposure of the tissue of the cancer corresponds to the Area under the Curve (AUC) and/or peak concentrations (C_max) of the drug compound of formula (I) in said tumor tissue.

7. A drug com ound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 6, w herein the administered dose of said drug compound, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof prov ides an exposure of the tissue of said cancer to said drug compound which provides at least the same clinical benefit as provided by the maximum tolerated dose for said dosage frequency and treatment cycle.

8. A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to claim 7, wherein said clinical benefit corresponds to the clinical benefit obtained in at least one clinical study with the maximum tolerated dose of said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof at the same dosage frequency and treatment cycle.

9. A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to claim 7 or 8, wherein said clinical benefit is the objective overall response rate, which is defined as the portion of patients evaluated in said at least one clinical study showing a stabilisation or reduction of the size of the cancer tissue in said patient.

10. A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 9, wherein the dose, at which the drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof is administered, is selected thus that it provides less ant i- vascular efficacy (vascular disruption) than provided by said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof at its maximum tolerated dose at the same dosage frequency and treatment cycle.

1 1 . A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to claim 10, wherein the anti-v ascular efficacy is determined by evaluating tumour vascular perf usion and/or tumour vascular permeability.

12. A drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 11, wherein said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof is administered at a dosage of 75 or less percent, preferably of 25 to 75 percent, of the MTD defined for said compound, when used according to the dosage frequency and treatment cycle.

1 . A drug compound, a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 3 to 12, wherein

in formula (I) re resents 1 ,4-pheny enc or a group of formula

preferably, w herein R represents hydrogen or cyano-lovver alkyl;

more preferably, wherein the drug compound or prodrug thereof arc selected from the compounds of formulae:

and pharmaceutically acceptable salts thereof;

still more preferably, wherein the drug compound or prodrug thereof are selected from the compounds of formulae:

and pharmaceutically acceptable salts thereof.

14. A prodrug f r use according to any one of claims 1 to 13 having the formula:

or a pharmaceutically acceptable salt thereof, preferably a hydrochloride salt, in particular a dihydrochloride salt.

1 5. A d ug compound, a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 14 and in part icular according to claim 14, wherein said drug compound, prodrug thereof or pharmaceutical ly acceptable salt of said drug compound or prodrug thereof is administered at a dose of less than 60 percent, preferably of 25 to 60 percent, more preferably of 40 to 60 percent of the maximum tolerated dose defined for said compound for use according to the same dosage frequency and treatment cycle.

16. A drug compound, a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 1 5, wherein the d ug compound, a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof is administered at a dosage frequency which is below a frequency of twice per week, preferably about once per week.

1 7. A drug compound, a prodrug thereof or a pharmaceutically acceptable salt of said d ug compound or prodrug thereof for use according to any one of claims 1 to 16, wherein said d ug compound, prodrug thereof or pharmaceutically acceptable salt of said d ug compound or prodrug thereof is appl ied in a treatment cycle, which includes an intermission of the drug dosage after 1 to 5, preferably 2 to 3, dosages of the drug compound, the prodrug thereof or the pharmaceutically acceptable salt of said drug compound or prodrug thereof.

18. A drug compound, a prodrug thereof or a pharmaceutical ly acceptable salt of said d ug compound or prodrug thereof for use according to claim 17, wherein the intermission lasts for 0.5 to 4 weeks, preferably 1 to 2 weeks, more preferably for about 1 week.

1 9. A drug compound, a prodrug thereof or a pharmaceutically acceptable salt of said d ug compound or prodrug thereof for use according to any one of claims 3 to 18, wherein the maximum tolerated dose of said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof is about 1 5 to about 500mg m , in

2 ^

particular about 1 5 to about 200 mg m , preferably about 1 5 to 100 m 'm^" , more preferably about 60 to 80 mg'm^" , wherein the indicated surface area represents the body skin area ( BSA ) of the human.

20. A drug compound, a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to claim 1 9, wherein the max imum tolerated dose of said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof is about 60 mg/m .

21. A drug compound, a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 20, wherein the cancer, from which said human patient is suffering, is selected from the group consisting of breast cancer, prostate cancer, cervical cancer, ovarian cancer, gastric cancer, colorectal cancer, pancreatic cancer, l iver cancer, brain cancer, neuroendocrine cancer, lung cancer, kidney cancer, hematological mal ignancies, melanoma and sarcomas, and is preferably selected from the group consisting of colorectal cancer, gastric cancer and cancers of the gastro-oesophageai junction, non-small cell lung cancer, ovarian and primary peritoneal cancer, pancreatic cancer ( including ampul lary cancer) and triple negative breast cancer.

22. A drug compound, a prodrug thereof or a pharmaceutical ly acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 20, wherein the cancer, from which said human patient is suffering, is selected from the group consisting of breast cancer, prostate cancer, cervical cancer, ovarian cancer, gastric cancer, colorectal cancer, pancreatic cancer, l iver cancer, brain cancer, neuroendocrine cancer, lung cancer, kidney cancer, hematological malignancies, melanoma and sarcomas.

23. A drug compound, a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof for use according to any one of claims 1 to 20, wherein the cancer, from which said human patient is suffering, is selected from the group consisting of colorectal cancer, gastric cancer and cancers of the gastro-oesophageai junction, non-small cel l lung cancer, ovarian and primary peritoneal cancer, pancreatic cancer ( including ampul lary cancer) and triple negative breast cancer.

24. A prodrug hav ing the formula

or a pharmaceutical ly acceptable salt of said prodrug for use for the treatment of a cancer in a human patient according to any one of claims 1 to 23, wherein said prodrug is administered

2 2

to said patient at a dose of 45 mg/m maximum, preferably of 1 5 to 45 mg/m , more preferably of about 0 mg/m^".

25. The use of a drug compound of formula (I), a prodrug thereof or a pharmaceutical ly acceptable salt of said drug compound or prodrug thereof as claimed in claim 1 or claim 3 for the manufacture of a medicament for the treatment of cancer in a human pat ient in need of such treatment, w herein said medicament is designed for a treatment, wherein said drug compound, prodrug thereof or pharmaceutically acceptable salt of said drug com ound or prodrug thereof is intravenously administered to said cancer patient according to a dosage frequency and a treatment cycle at a dose being below the maximum tolerated dose determined for said dosage frequency and treatment cycle of said drug, prodrug thereof or pharmaceutically acceptable salt of said drug compound or prodrug thereof in a cl inical study and providing at least the same exposure of the tissue of the cancer from w hich said cancer patient is suffering, to said drug compound as prov ided by the maximum tolerated dose at the same dosage frequency and treatment cycle.

26. A method for the treatment of a human cancer patient in need of such treatment, w hich comprises intravenously administering to said patient a dose of a drug compound of formula (I), a prodrug thereof or a pharmaceutically acceptable salt of said drug compound or prodrug thereof as claimed in claim 1 or claim 3 according to a dosage frequency and a treatment cycle, for which a ma imum tolerated dose for human patients has been determ ined in a clinical study, and the administered dose is below said maximum tolerated dose and provides at least the same exposure of the tissue of the cancer from which said cancer patient is suffering, to said drug com ound as provided by the ma imum tolerated dose at the same dosage frequency and treatment cycle.