Mitoxantrone Combined with Paclitaxel as Salvage Therapy ...TDC) with 0.6 p.g/ml mitoxantrone and 13.6 pg/ml paclitaxel as 100% TDC (14, 24). Each TDC was tested in triplicate. Addi-tionally,

Vol. 3, 1527-1533, September 1997 Clinical Cancer Research 1527

Mitoxantrone Combined with Paclitaxel as Salvage Therapy for

Platinum-refractory Ovarian Cancer: Laboratory Study and

Clinical Pilot Trial1

Christian M. Kurbacher,2 Howard W. Bruckner,

Ian A. Cree, Jutta A. Kurbacher,3

Lucas Wilhelm, Gerald P#{246}ch,Dorit Indefrei,

Peter Mallmann, and Peter E. Andreotti

Department of Gynecology and Obstetrics, University of CologneMedical Center, D-5093l Cologne, Germany [C. M. K., L. W., P. M.];Division of Neoplastic Diseases, Derald H. Ruttenberg Cancer Center,Mount Sinai School of Medicine, New York, New York 10029[H. W. B.]; Department of Pathology, Institute of Ophthalmology,University College London, London EC1V 9EL, United Kingdom

[I. A. C.]; Department of Gynecology and Obstetrics, University ofBonn Medical Center, D-53105 Bonn, Germany [J. A. K., D. I.];Institute of Pharmacology and Toxicology, University of Graz,

A-8020 Gras, Austria [G. P.]; and Atlantic Scientific DevelopmentInc., Boca Raton, florida 33428 [P. E. A.]

ABSTRACT

This report describes preclimcal and early clinical in-

vestigations of the mitoxantrone/paclitaxel combination

(NT) for patients with platinum-refractory ovarian cancer.

The preclinical activity of NT was studied ex vivo, evaluating

native tumor specimens with the ATP tumor chemosensitiv-ity assay. Of 24 tumors tested, 20 (83%) were sensitive to

NT, whereas 7 (29%) responded to mitoxantrone and 8

(33%) responded to paclitaxel. In the majority of tumorsassayed (19 of 24), potentiating or major independent effects

between both agents were found. Subsequently, a clinical

pilot trial of NT was initiated for patients with platinum-

refractory ovarian cancer. Patients had failed one to four

(median, two) prior chemotherapy regimens. In 11 cases, NTwas administered every three weeks with 8 mg/rn2 mito-

xantrone and 180 mg/rn2 paclitaxel (NT-I). Seven patientswere treated biweekly with 6 mg/rn2 mitoxantrone andweekly with 100 mg/rn2 paclitaxel (NT-Il). During 92 NTcourses, myelosuppression with leucopenia, anemia, and

thrombocytopenia was the limiting toxicity, occurring morefrequently with NT-Il. No patient required hospitalization

Received 12/30/96; revised 5/15/97; accepted 5/17/97.The costs of publication of this article were defrayed in part by the

payment of page charges. This article must therefore be hereby markedadvertisement in accordance with 18 U.S.C. Section 1734 solely to

indicate this fact.

‘ Supported in part by DCS Innovative Diagnostik Systeme, Hamburg,Germany.2 To whom requests for reprints should be addressed, at Department ofGynecology and Obstetrics, University of Cologne Medical Center,Kerpener Strasse 34, D-50931 Cologne, Germany. Phone: 49-221-478-4910; Fax: 49-221-478-4929.3 Present address: Department of Obstetrics and Gynecology,Johanniter-Krankenhaus, Johanniterstrasse 3-5, 53 1 1 3 Bonn, Germany.

due to any life-threatening complication. Five complete and

nine partial remissions were observed with both NT-I and

NT-Il, accounting for an overall 78% response rate, with a

median progression-free survival of 40 weeks. One patientshowed early progression during therapy. Currently, three

patients (NT-I, two; NT-H, one) have died due to progressive

relapsed ovarian cancer, so that the median overall survival

is not reached after a median follow-up of 40.5+ weeks.

Both schedules were found to be equal in terms of responserate and overall survival. NT is highly active and practical

for salvage treatment of ovarian cancer. NT-Il may be pre-ferred due to both clinical activity and patients’ acceptance.However, NT-I seems to be a less myelotoxic alternative.Both schedules warrant further clinical investigation.

INTRODUCTION

Primary ovarian carcinomas frequently respond to chemo-

therapy. Remission rates of 60-70% have been observed after

platinum-based first-line therapy, reducing the relative risk of

progression and death to 0.7 (1, 2). Nevertheless, the majority of

patients with advanced disease will relapse, resulting in an

overall 5-year survival of only 20% ( 1 , 2). The likelihood of

relapsing patients to respond to either second-line platinum or

nonplatinum regimens strongly depends on the disease-free in-

terval after completion of initial chemotherapy (2-6). The prob-

ability that platinum-refractory patients (i.e., those presenting

with primary progression or recurrence after �6 months) will

benefit from salvage chemotherapy is limited (2, 3, 6, 7). Pa-

clitaxel (Taxol#{174}), ifosfamide, and altretamine are considered to

be the most active single agents in this setting, but at conven-

tional dosages, they produce RRs4 of no more than 30% (2, 6,

7). Unfortunately, higher RRs achieved with dose-escalated

paclitaxel do not translate into improved PFS and OAS, respec-

tively (6, 8, 9). Introduction of paclitaxel into first-line therapy

of ovarian cancer (10) may even create more problems with

recurrent disease. Recently, altretamine and topotecan have

been considered the most effective agents in this setting (1 1,

12), whereas modest activity was demonstrated for gemcitabine

and reinduction with either carboplatin or paclitaxel (13-15).

Therefore, the search for new salvage regimens remains an

important goal to improve treatment for patients with platinum-

refractory ovarian cancer.

Paclitaxel exhibits synergistic cytotoxicity with a number

4 The abbreviations used are: RR, response rate; ATP-TCA, AlP tumorchemosensitivity assay; CR, complete response; G-CSF, granulocyte

colony-stimulating factor; MI, maximum inhibition; NC, no change;NT, mitoxantrone/paclitaxel; OAS, overall survival; PD, progressivedisease; PFS, progression-free survival; PR, partial response; SI, sensi-tivity index; TDC, test drug concentration.

Research. on August 11, 2020. © 1997 American Association for Cancerclincancerres.aacrjournals.org Downloaded from

http://clincancerres.aacrjournals.org/

1528 NT in Refractory Ovarian Cancer

of cytostatics, including platinum and doxorubicin, for a variety

of animal and human tumors (16). Previous preclinical studies

performed in our laboratories used the ATP-TCA (17) to inves-

tigate the activity of the doxorubicin/paclitaxel combination in

native ovarian carcinomas ( 1 8). This method is a valuable

approach for cx vivo testing of clinical tumors and provides

major advantages over classical chemosensitivity assays in

terms of efficacy, reproducibility, robustness, and evaluability

( 17, 19). Clinical correlations are promising for both ovarian

( 17, 20) and breast tumors ( 19). Based on these investigations,

we observed well-tolerated activity of doxorubicin/paclitaxel in

patients with platinum-refractory ovarian cancer who had failed

both single agents (2 1 ). The clinical utility of this combination,

however, may be compromised by the considerable nonhema-

tological side effects of doxorubicin. In particular, cardiotoxic-

ity and mucotoxicity of doxorubicin can be potentiated when

used in combination with paclitaxel (22-24).

The synthetic anthracenedione mitoxantrone (Novantrone)

can often be regarded as a clinical substitute for anthracyclines

(23, 25). It compares favorably to doxorubicin in terms of its

markedly reduced organ toxicity (25, 26). In tests of periopera-

tive breast and ovarian carcinomas, our laboratories have pre-

viously demonstrated that both agents usually have similar

activity, but there seem to be instances of non-cross-resistance

in which mitoxantrone may be superior to doxorubicin (27, 28).

In a variety of human cancer cell lines and some perioperative

tumors, we and others have found NT to be highly synergistic

and, therefore, possibly the best combination (28, 29).

Doxorubicin/paclitaxel is at the forefront of clinical inves-

tigation for breast cancer (30) and exhibits preclinical and

clinical activity against recurrent ovarian cancer as well (21,

3 1 ). NT represents a logical next step that may be less toxic.

This article describes new evidence that NT has high preclinical

activity against tumor cells taken directly from patients with

platinum-refractory ovarian carcinoma. Based on these ex vivo

results, we have initiated a pilot study of NT at two different

schedules in heavily pretreated ovarian cancer patients. All had

previously failed platinum-based chemotherapy. This report

summarizes the first results of this clinical trial.

MATERIALS AND METHODS

Preclinical Studies

Tumor Samples. The preclinical evaluation of NT used

tumor samples taken directly from 24 patients with platinum-

refractory recurrent ovarian cancer, 17 solid tumors and 7 ma-

lignant ascitic fluids. Tumor material was sampled under sterile

conditions and immediately transferred to the laboratory. Sur-

gical specimens were transported in HBSS (Life Technologies,

Inc., Paisley, United Kingdom) supplemented with 300 units/ml

penicillin and 300 p.g/ml streptomycin. Malignant effusions

were stored natively after adding preservative-free sodium

heparin (Vetren 200; Promonta, Hamburg, Germany) at 25-50

units/ml.

Chemosensitivity Testing. Chemosensitivity was as-

sessed using the ATP-TCA. This assay uses commercially avail-

able test kits (TCA-IO0; DCS Innovative Diagnostik Systeme,

Hamburg, Germany) that include all required material not oth-

erwise identified. ATP-TCA methodology has been described in

detail (17, 19, 27).

Briefly, tumor cells were isolated by mechanical and en-

zymatic dissociation and subsequent Ficoll gradient centrifuga-

tion (Lymphoprep; ICN Flow, Meckenheim, Germany). Viabil-

ity and quality of cell suspensions were determined by trypan

blue dye exclusion (0.2%; Merck, Darmstadt, Germany) and

cytological examination, respectively. Approximately 10,000-

20,000 cells were then seeded into each well of a 96-well

polypropylene microplate. Commercial formulations of mito-

xantrone (Novantron; Cyanamid-Lederle, Wolfratshausen, Ger-

many) and paclitaxel (Taxol#{174}, Bristol-Myers Squibb, Munich,

Germany) were used for this investigation. Single agents and the

combination were tested at six different TDCs (i.e., 6.25-200%

TDC) with 0.6 p.g/ml mitoxantrone and 13.6 p�g/ml paclitaxel as

100% TDC (14, 24). Each TDC was tested in triplicate. Addi-

tionally, both no inhibition (MO) and MI controls were set up for

each microplate.

Assay Evaluation. After 5-7 days of culture at 37#{176}Cin

a humidified 5% CO,. 95% air atmosphere, ATP was extracted

from the cells and subsequently measured luminometncally

using the luciferin-luciferase firefly reaction. Comparing treated

cells with both controls, individual tumor growth inhibition

(TGI) was calculated as:

TGI(%) = [1 - (TDC - MI)/(MO - MI)] x 100 (1)

Individual dose-response curves were constructed for both drugs

and the combination, respectively. IC50 and IC90 were deter-

mined by linear interpolation. Four categories of ex vivo sensi-

tivity were defined as (27): (a) strong sensitivity, IC90 � 100%

TDC and IC50 �25% TDC; (b) partial sensitivity, IC90 >100%

TDC and IC50 �25% TDC; (c) weak sensitivity, IC90 � 100%

TDC and IC50 >25% TDC; and (6) resistance, IC90 >100%

TDC and IC50 >25% TDC.

Ex vivo RR was defined as:

- (all tumors tested - resistant tumors)RRen,,v(, (all tumors tested) (2)

Additionally, a SI represented by the area under the inhibition

curve was calculated by trapezoidal transformation, with high

values indicating high sensitivity, and low values evidencing

resistance ex vivo (1 7, 27). Drug interactions were analyzed by

the sigmoid model described by P#{246}ch(32). Assuming that both

single agents act independently on tumor cells, a theoretical

dose-response curve for the combination was constructed for

each tumor. Drug interactions were defined as independent if the

experimental dose-response curve was equal to the theoretical

one. Potentiation was assumed if NT produced a significantly

higher cell kill, as could be expected theoretically. In tumors

showing an experimental dose-response curve inferior to the

theoretical one, drug interactions were regarded as relative an-

tagonism (if NT was superior to the best single agent) or

absolute antagonism (if the best single agent was superior to

NT).

Clinical Trial

Patients. Since November 1994, 15 patients with histo-

logically confirmed platinum-refractory ovarian carcinoma



DODD

o�g8 �9

o�g -D�DD- 2DD�

0 0

O�O

0

00 0�0

Clinical Cancer Research 1529

)( 15000a,�0C

.�.

I5000

U Mitoxantrone Paclitaxel Combination

Fig. I. Distribution of SIs for mitoxantrone (0), paclitaxel (G), and

the combination NT (�) in 24 platinum-refractory ovarian cancers testedex vivo with the ATP-TCA. Horizontal lines, mean values.

(characterized by either progression during initial platinum-

based chemotherapy or relapse after a disease-free interval of

�6 months after a minimum of four courses of platinum drugs)

were enrolled. All patients recruited were distinct from those

who had sent tumors for the preceding ex vivo study. Written

informed consent was obtained from all patients. Two patients

underwent reinduction, resulting in a total of 1 8 NT treatments.

Patients had one to four prior chemotherapies (median, two).

Prior second-line regimens included alkylators, topoisomerase II

inhibitors, paclitaxel, doxorubicin/paclitaxel, and high-dose

chemotherapy with autologous stem cell support. Cytoreductive

surgery was unsuccessfully attempted for eight patients before

NT; none of these operations reduced the tumor to less than 2

cm in diameter.

Eligibility criteria included: (a) bidimensionally measur-

able tumor before starting NT therapy; (b) leukocytes �3,000/

pA, neutrophils �1,500/pA, serum hemoglobin �8 g/dl, and

platelets � 100,000/pA; (c) absence of other severe serum chem-

istry abnormalities; (d) Karnofsky performance status �60%;

(e) an anticipated life span of � 12 weeks; and (f) complete

recovery from surgery.

Before starting NT, patients underwent complete tumor

staging including serum marker measurements (CA 125, CEA,

or CA 19-9), transvaginal and abdominal ultrasound, thoracic

X-ray scans, and computed or magnetic resonance tomography

of both chest and abdomen, if indicated.

Chemotherapy. In 1 1 cases, NT was administered every

three weeks with iv. bolus injections of 4 mg/m2 mitoxantrone

on days 1 and 2 followed by a 24-h infusion of 180 mg/m2

paclitaxel (NT-I). Routine supportive treatment included both

antiemesis and delivery of corticosteroids, clemastine, and ra-

nitidine for prevention of hypersensitivity-like reactions. En-

couraging preliminary experiences with weekly fractionated pa-

clitaxel evidenced both considerable clinical activity and well-

tolerated toxicity that might be particularly important for

combination chemotherapy (33-35). The regimen was thus mod-

ified in the remainder to provide an optimized protocol for

future Phase Il/Ill trials. This schedule used a 6 mg/m2 bolus

injection of mitoxantrone on day 1 followed by a I -h infusion of

100 mg/m2 paclitaxel on days I and 8 (NT-Il). The whole course

was repeated on day 15. Between courses 3 and 4, treatment was

Table I Patterns of chemosensitivity cx viva exhibited by 24perioperative ovarian cancer specimens”

Pattern of

Drug(s)

chemosensitivity

Partial Weaktested Sensitivity sensitivity sensitivity Resistance

Mitoxantrone 3 - 4 17Paclitaxel 2 3 3 16

NT 13 - 7 4a Response rate ex vivo: mitoxantrone. 7 of 24 (29%): paclitaxel. 8

of 24 (33%); NT, 20 of 24 (83%).

interrupted for 1 week. G-CSF was used if leukocytes were

<2,000/pA or the neutrophils were < 1,000/pA. Delayed hema-

tological recovery in spite of G-CSF or any severe organ tox-

icity required both dose reduction or interval prolongation until

recovery of bone marrow or any other involved organ. In re-

sponding patients, a maximum of six NT courses was adminis-

tered. Therapy was discontinued in patients with evidence of

either progression or unresolved life-threatening toxicities.

Evaluation of Toxicity. Patients enrolled in this trial

were regarded as eligible for toxicity if they received at least one

course of NT. All adverse effects were monitored and recorded

using the WHO score. Toxicity was assessable for all 18 NT

therapies.

Evaluation of Response. Therapy was monitored by

measurements of the appropriate serum marker preceding each

NT course. Tumor evaluation was performed every 6 weeks by

transvaginal ultrasound, X-ray scan or computed tomography of

the chest, and computed or magnetic resonance tomography of

the abdomen, respectively. Additional tumor imaging was per-

formed at any time when progression was suspected. A mini-

mum of two NT cycles was required to classify a patient as

evaluable for response. Responses were assessed using standard

criteria: (a) CR, complete disappearance of all measurable tu-

mor and normalization of elevated serum markers for a mini-

mum of 4 weeks; (b) PR, a �50% decrease in the sum of the

products of two diameters of all measurable lesions (or clinical

CR with elevated tumor markers) for at least 4 weeks; (c) NC,

any condition distinct from CR, PR, or PD; and (d) PD, a �25%

increase in the sum of two diameters of all measurable lesions or

the appearance of new metastases.

Follow-Up. All patients entered a follow-up program

including gynecological checks, transvaginal ultrasound, and

measurements of tumor markers every 3 months. Tumor imag-

ing was performed as appropriate. OAS and PFS were measured

from the start of the first NT course. All causes of death were

used to calculate OAS. PFS was defined as the minimal interval

between commencing NT therapy and evidence of progression,

death, or loss to follow-up.

Statistics. Statistical calculations were performed using

GraphPAD software (San Diego, CA). SI values for mitox-

antrone, paclitaxel, and NT were analyzed by repeated measure

ANOVA. Differences in ex vivo RRs were analyzed by extended

x2 tests. Survival analyses were performed using Kaplan-Meierprocedures. For all statistical calculations, P �O.05 indicated

significance.



Patient(initials)

Age(yrs)

Priorchemotherapy” Metastatic site”

NTschedulec

No. ofNT courses

Quality ofresponse

TPP”(wks)

C. B. 43 aCP, EPI, aCC Pelvis, abdomen I 6 CR 88+M. C. 48 CC, CP Pelvis, abdomen I 6 CR 76+M. E. 55 CP, VP-l6 Pelvic, paraaortic LNS I 3 NC 65+B. F. 67 CP Pelvis, abdomen, lung I 2 PD - (alive)P. F. 63 CC Abdomen, abdominal wall, subhepatic LNS I 6 NC 55 (dead)K. 0. (a) 45 CP Pelvis, subhepatic LNS I 6 PR 50 (alive)

K. 0. (b) 46 CP, NT-I, Pelvis, liver, spleen capsule II 6 PR 28K. G. (c) 46 CP, NT-I, NT-Il Pelvis, spleen II 6 PR 16E. K. 63 CC Pelvis, abdomen II 4 NC 10+

M. J. (a) 67 CC, PTX Subhepatic and paraaortic LNS II 4 PR 28

M. J. (b) 68 CC, PTX, NT Subhepatic, retroperitoneal, sigma II 6 PR 20+

R. R. 64 CC, PTX, CP Subhepatic and paraaortic LNS II 6 PR 15+B. R. 35 CC, CI, ICE (high dose) Pelvis, pelvic and paraaortic LNS, bursa omentalis I 6 CR 40 (alive)U. R. 55 CP, TREO Pelvis, abdomen, paraaortic LNS I 2 PR 36+

T. S. 49 CC Pelvis, abdomen I 6 CR 20+M. S. 55 CP Pelvis, paraaortic LNS I 6 CR 23 (dead)R. T. 58 CP, CC, VP-l6, P1 Pelvis, pelvic LNS I 6 PR 20+P. U. 40 CC, aCP, CPA, AT Pelvis, perihepatic and paraaortic LNS, spleen II 4 PR 22 (dead)

a The abbreviations used are: aCC, cytosine arabinoside/carboplatin; aCP, cytosine arabinoside/cisplatin; AT, doxorubicin-paclitaxel; CC,

cyclophosphamide/carboplatin; CI, carboplatin/ifosfamide; CP, cyclophosphamide/cisplatin; CPA, cyclophosphamide; EPI, epirubicin; ICE, ifosf-amide/carboplatin/etoposide; P1, cisplatin/ifosfamide; PTX, paclitaxel; TREO, treosulfan; VP-l6, etoposide.

b LNS, lymph nodes.Cl NT-I; II, NT-Il.d y�’p time to progression. + , patients still on response.


Table 2 Patients’ characteristics and therapeutic outcome

RESULTS

Preclinical Studies

All 24 drug assays were evaluable. Mean SI values for all

three regimens are presented in Fig. 1. NT was significantly

more active compared to both mitoxantrone (P < 0.01) and

paclitaxel (P < 0.001). Patterns of preclinical chemosensitivity

are summarized in Table 1. Ex vivo RRs for mitoxantrone (29%)

and paclitaxel (33%) did not differ significantly, whereas NT

produced a significantly higher ex vivo RR of 83% (P <0.0001).

Strong sensitivity was observed in 13 of 20 tumors responding

to NT. Seven tumors resistant to both single agents exhibited

sensitivity to the combination. In 10 tumors, drug interactions

showed potentiation according to the P#{246}chmodel (32). In an

additional nine samples, both agents were found to act inde-

pendently. In only five tumors, relative or absolute antagonism

was obvious.

Clinical TrialToxicity. A total of 92 NT courses were administered

(NT-I, 56 courses; NT-Il, 36 courses); all were evaluable for

toxicity. The predominant adverse effect was myelosuppression

with grade 3-4 leukopenia, grade 3 thrombocytopenia, and grade

3-4 anemia occurring during 59, 7 and 9% of cycles. Myelo-

toxicity was seen more frequently in patients receiving NT-Il,

with 75% of cycles complicated by grade 3-4 leukopenia. In

comparison, grade 3-4 leukopenia was observed during 48% of

NT-I cycles. Severe thrombocytopenia and anemia were seen in

4 and 7% of NT-I cycles and in I 1 and 1 1 % of NT-Il cycles,

respectively. However, bone marrow function recovered spon-

taneously in most cases within 3-5 days or was successfully

supported by G-CSF required during 10 of 18 treatments (56%).

There were no febrile episodes seen with NT at either schedule.

In patient P. U., the last two NT-Il cycles were administered

with 4 mg/m2 mitoxantrone and 70 mg/m2 paclitaxel due to both

persistent grade 3 thrombocytopenia and grade 4 anemia requir-

ing erythrocyte transfusion. In patients P. F. and M. E., NT-I

treatment was delayed for 7-11 days due to leukopenia in spite

of G-CSF support. As expected, all patients experienced grade

2-3 alopecia. With the exception of grade 3 nausea/vomiting

occurring during one cycle of NT-I and grade 3 malaise/fatigue

observed during five courses of NT-Il, nonhematological side

effects such as peripheral neuropathy, myalgia, diarrhea, or

mucositis were generally mild (grade 1-2) and occurred infre-

quently. There were no symptomatic bradycardia or other car-

diac complications, nor did any patient require hospitalization

due to infection or other life-threatening events.

Clinical Activity. All patients treated with NT received

at least two courses, and all were evaluable for response. The

median follow-up is 40.5 + weeks. Table 2 summarizes patients’

characteristics and their therapeutic outcome. Objective re-

sponses were seen in 14 patients (5 CR and 9 PR), resulting in

an overall 78% RR. Remissions were achieved with both NT

schedules and tended to be long enough to have clinical utility.

Median OAS is not yet reached, and median PFS is 40 weeks

(Fig. 2). Although CRs were achieved with NT-I only. RR for

NT-H was slightly higher, but not significantly so (NT-I, 73%;

NT-Il, 86%). Patient K. G., who experienced a PR of 50-week

duration after treatment with NT-I, was successfully reinduced

twice with NT-Il when presenting with recurrent disease after

6.5 months without therapy. Correspondingly, NT-Il was deliv-

ered two times to patient M. J., producing a PR of 28- and

20+-week duration. In three additional patients, disease was

stabilized (NC) for 65+, 55, and 10+ weeks, respectively. Only

one patient showed PD during NT-I therapy, and treatment thus



A

lOG

� 800>

� 60(I)

Ca,U 40a,

a-

20

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‘I)

a,a,

�1-

U,a.a,a,

Ca,U

a,a.

0 1�0 2’O 30 40 50 60 70 80 90100

V�eks after start of NT chemotherapy

0 10 20 30 40 50 60 70 80 90 100

V�eks after start of NT chemotherapy

Fig. 2. Kaplan-Meier plots for 15 patients with platinum-refractory

ovarian cancer receiving a total of 18 blocks of salvage chemotherapywith NT. A, OAS estimated for 15 patients treated. B, PFS estimated for18 NT treatments administered.


was discontinued after two cycles. Three patients (NT-I, two

patients; NT-Il, one patient) have died due to progressive recur-

rent tumor at 32, 37, and 62 weeks from the start of NT. The

remainder are still alive, and nine are even progression-free

(NT-I, six patients; NT-Il, three patients).

DISCUSSION

Taxanes such as paclitaxel are considered the most active

agents in platinum-refractory recurrent ovarian cancer, produc-

ing a 25-30% RR and a median PFS of6 months (2, 6-8, 22, 36).

Increasing the paclitaxel dose may increase the RR, but this,

unfortunately, did not improve survival (8, 9, 37).

In various preclinical studies, paclitaxel was shown to act

synergistically with a number of standard cytostatics. including

topoisomerase II inhibitors (16). In a clinical trial based on prior

ex viva evaluation of fresh tumor specimens ( I 8), we found

doxorubicin/paclitaxel to have well-tolerated activity in ovarian

cancer patients who had failed both platinum and single-agent

paclitaxel (21). Testing a limited number of human tumor cell

lines, GlOck et a!. (29) observed a strong synergism between

paclitaxel and mitoxantrone that compared favorably with other

paclitaxel-based combinations including doxorubicin, etopo-

side, cyclophosphamide, or platinum (29). Mitoxantrone is less

cardiotoxic and mucotoxic than doxorubicin, and lack of cross-

resistance has been demonstrated for various clinical tumors in

a considerable number of patients (25, 26, 38, 39). Both the

promising clinical activity of doxorubicin/paclitaxel and the

confirmed preclinical experiences provide evidence that NT

should be regarded as a logical next step in developing a

well-tolerated regimen for the treatment of platinum-refractory

recurrent ovarian carcinoma.

The ATP-TCA may be useful for ex vivo chemosensitivity

testing of clinical tumors and seems to be applicable to anthra-

cyclines and taxanes ( I 8, 27, 28). It possibly provides major

advantages over classical chemosensitivity assays in terms of

efficacy, reproducibility, robustness, and evaluability, with

promising clinical correlations reported for both ovarian and

breast cancers (1 7, 19, 20). This assay was thus considered a

suitable model to assess the preclinical activity of NT in native

platinum-refractory ovarian cancers.

Generally, the ex vivo results described herein show activ-

ity for both mitoxantrone and paclitaxel that is consistent with

clinical experience (8, 36, 40). The combination produced an

unexpectedly high rate of antineoplastic activity ex vivo. Seven

tumors with apparent resistance to both single agents were

sensitive to NT. Ex vivo resistance is a highly reliable predictor

of clinical resistance (41); thus, reversal of resistance as we

found here is a noteworthy success. The analysis of the effect of

the NT combination indicates potentiation or at least major

independent activity for both drugs in the majority of tumors.

Although the reasons for these effects are not clear at present,

our findings argue in favor of a real synergism between the

drugs.

Our first clinical results provide evidence that NT given at

either schedule has acceptable toxicity and produces exception-

ally high clinical efficacy in patients with platinum-refractory

ovarian cancer. Compared to clinical results with doxorubicin/

paclitaxel described by us and others (2 1 , 3 1 ), NT seems to be

a further improvement. Both the 78% RR and particularly the

response duration observed in this study compare favorably with

those achieved with other salvage therapies such as paclitaxel,

docetaxel, altretamine, ifosfamide, or topotecan (2, 6-8, 1 1, 12,

22, 36, 42). These findings therefore challenge the traditional

view that drug combinations have no advantage for salvage

therapy of ovarian carcinoma as compared to single agents (42).

Work in progress seeks the optimal dosage for NT-Il, which

may be preferred for future evaluation because this regimen

combines both high clinical activity and convenience for the

patients. However, NT-I seems to be a reasonable alternative to

NT-Il, particularly in patients with impaired bone marrow func-

tion or in those who are otherwise unable to undergo weekly

chemotherapy.

Responses in ovarian cancer patients failing both platinum

and paclitaxel are rare. In this setting, altretamine and topotecan

are the only drugs with proven major clinical activity (1 1, 12).

Therefore, the activity of NT that we have found in patients

pretreated with paclitaxel alone or in combination is of partic-

ular interest. Considering the published single-agent activities of

mitoxantrone (35) and paclitaxel (8, 22, 36), the results of this

pilot trial provide evidence for a clinical synergism between

these drugs that parallels our previous and current laboratory

experience (28). We made similar observations with platinum




and cytosine arabinoside even when both single agents were

completely inactive (43, 44). Moreover, it should be noted that

NT clearly produced a higher clinical activity than doxorubicin/

paclitaxel, although this was not expected from the preclinical

and clinical single-agent activities ( 1 8, 21 , 23, 25, 3 1 ). Modern

ex vivo test systems such as the ATP-TCA thus provide an

effective and time-saving method for the preclinical selection of

innovative chemotherapy regimens for further clinical use. In

conclusion, NT showed unusually promising anticancer activity

in heavily pretreated patients with platinum-refractory ovarian

cancer, without producing nontolerated toxicity. This combina-

tion should thus be considered for large-scale clinical trials.

ACKNOWLEDGMENTS

We thank H. HObner and R. Klasen for skillful technical assistance.

Special thanks are addressed to all colleagues and nurses of the onco-

logic staff of the Departments of Gynecology and Obstetrics, University

of Cologne and University of Bonn Medical Centers, for their engage-ment in care and treatment of the patients. This work was performedwithin the framework of the Preclinical Therapeutic Models Group of

the European Organization for Research and Treatment of Cancer.

REFERENCES

1 . Advanced Ovarian Cancer Trialists Group. Chemotherapy in ad-vanced ovarian cancer. An overview ‘of randomised clinical trials. Br.

Med. J., 303: 884-893, 1987.

2. Canistra, S. A. Cancer of the ovary. N. Engl. J. Med., 329: 1550-

1559, 1993.

3. Markman, M., Rothman, R., Hakes, T., Reichman, B., Hoskins, W.,Rubin, S., Jones, W., Almadrones, L., and Lewis, J. R., Jr. Second-lineplatinum therapy in patients with ovarian cancer previously treated withcisplatin. J. Clin. Oncol., 9: 389-393, 1991.

4. Van der Burg, M. E. L., Hoff, A. M.. Van Lent, M.. Rodenberg, C. J.,Van Putten, W. L. J., and Stoter, G. Carboplatin and cyclophosphamidesalvage therapy for ovarian cancer patients relapsing after cisplatin

combination chemotherapy. Eur. J. Cancer, 27: 248-250, 1991.

5. Williams, L. L., Fudge, M., Burnett, L. A., and Jones, H. W. Salvage

carboplatin therapy for advanced ovarian cancer previously treated withcisplatin. Am. J. Clin. Oncol., 15: 331-336, 1992.

6. Thigpen, J. T., Vance, R. B., and Khansur T. Second-line chemo-therapy for recurrent carcinoma of the ovary. Cancer, (Phila.) 71:

1559-1564, 1993.

7. Guastalla, J. P. Second-line chemotherapy in epithelial ovarian car-

cinoma: platinum again? Taxanes? How to choose? Eur. J. Cancer, 30A:

1739-1741, 1994.

8. McGuire W. P. Ovarian Cancer. In: W. P. McGuire and E. K.Rowinsky (eds.), Paclitaxel in Cancer Treatment, pp. 201-221. New

York: Marcel Dekker, Inc., 1995.

9. Rowinsky, E. K., Mackey, M. K., and Goodman, S. N. Meta analysisof paclitaxel dose response and dose intensity in recurrent or refractoryovarian cancer. Proc. Am. Soc. Clin. Oncol., 15: 284, 1996.

10. McGuire, W. P., Hoskins, W. J., Brady, M. F., Kucera, P. R.,Partridge, E. E., Look, K. Y., Clarke-Pearson, D. L., and Davidson, M.

Cyclophosphamide and cisplatin compared with paclitaxel and cisplatinin patients with stage III and stage IV ovarian cancer. N. EngI. J. Med.,

334: 1-6, 1996.

1 I. Schink, J. C., Hams, L. S., Grosen, E. A., and Bailey, H. W. Al-tretamine (Hexalen#{174}): an effective salvage chemotherapy after pacli-

taxel (Taxol#{174})in women with recurrent platinum-resistant ovarian can-cer. Proc. Am. Soc. Clin. Oncol., 14: 275, 1995.

12. Gordon, A., Bookman, M., Malmstrom, H., Bolis, G., Mangioni, C.,

Hall, J., Carter. J.. Hudson, I., and Broom, C. Efficacy of topotecan inadvanced epithelial ovarian cancer after failure of platinum and pacli-

taxel: International Topotecan Study Group trial. Proc. Am. Soc. Clin.Oncol., 15: 282, 1996.

13. Shapiro, J. D., Millward, M. J., Rischin, D., Michael, M., Walcher,V., Francis, P. A., and Toner, G. C. Activity of gemcitabine in patientswith advanced ovarian cancer: responses seen following platinum andpaclitaxel. Gynecol. Oncol., 63: 89-93, 1996.

14. Kavanagh, J., Tresukosol, D., Edwards, C., Freedman, C., Gonzalezde Leon, C., Fishman, A., Mante, R., Hord, M., and Kudelka, A.

Carboplatin reinduction after taxane in patients with platinum-refractoryepithelial ovarian cancer. J. Clin. Oncol., 13: 1584-1588, 1995.

15. Tresukosol, D., Kudelka, A. P., Gonzales de Leon, C., Edwards,C. L., Freedman, R. S., Mante, R., Hord, M., and Kavanagh, J. J. Pacli-taxel retreatment in patients with platinum- and paclitaxel-resistantovarian cancer. Eur. J. Gynaecol. Oncol., 17: 188-191, 1996.

16. Rose, W. C., and Fairchild, C. R. Combination with other agents:preclinical data. In: W. P. McGuire and E. K. Rowinsky (eds.), Pacli-taxel in Cancer Treatment, pp. 55-79. New York: Marcel Dekker, Inc.,1995.

17. Andreotti, P. E., Cree, I. A., Kurbacher, C. M., Hartmann, D. M.,Linder, D., Hard, G., Gleiberman, I., Caruso, P. A., Ricks, S. H., Untch,

M., Sartori, C., and Bruckner, H. W. Chemosensitivity testing of humantumors using a microplate adenosine triphosphate assay: clinical corre-lation for cisplatin resistance of ovarian carcinoma. Cancer Res., 55:

5276-5282, 1995.

18. Bruckner, H. W., Lee, J. M., Runowicz, C. D., Goldberg, G. L.,Smith, H. 0., Caruso, P. A., Gleiberman, I., Hartmann, D. H., Linder,D., Hard, G. H., Cuttner, J., and Andreotti, P. E. AlP bioluminescencetests the sensitivity of human tumors to Adriamycin, Taxol, cisplatin,

and the combinations. Proc. Am. Assoc. Cancer Res., 35: 201, 1994.

19. Cree, I. A., Kurbacher, C. M., Untch, M., Sutherland, L. A., Hunter,E. M., Subedi, A. M. C., James, E. A., Dewar, J. A., Preece, P. E.,Andreotti, P. E., and Bruckner, H. W. Correlation of the clinical re-sponse to chemotherapy in breast cancer with ex vivo chemosensitivity.

Anticancer Drugs, 7: 630-635, 1996.

20. Untch, M., Crohns, C., Konecny, 0., Meier, W., Kurbacher, C.,Andreotti, P. E., and Bruckner, H. W. Correlation of in vitro tumorchemosensitivity assay with outcome in ovarian cancer patients givencarboplatin and cyclophosphamide. Proc. Am. Soc. Clin. Oncol., 15:

302, 1996.

21. Bruckner H. W., Gagnoni P. J., Lee, J.-M., Chesser, M. R., and

Andreotti, P. E. A sequence of Adriamycin and Taxol infusions forrefractory ovarian cancer. Proc. Am. Soc. Clin. Oncol., 13: 276, 1994.

22. McGuire, W. P., Rowinsky, E. K., Rosenshein, N. B., Grumbine,

F. C., Ettinger, D. S., Armstrong, D. K., and Donehower, R. C. Taxol: aunique antineoplastic agent with significant activity in advanced ovarianneoplasms. Ann. Intern. Med., 111: 273-279, 1989.

23. Riggs, C. E. Antitumor antibiotics and related compounds. In:

M. C. Perry (ed), The Chemotherapy Source Book, pp. 318-358. Bal-timore: Williams & Wilkins, 1992.

24. Onetto, N., Dougan, M., Hellman, S., Gustafson, N., Borroughs, J.,

Florczyk, A., Canetta, R., and Rozenczweig, M. Safety profile. In: W. P.McGuire and E. K. Rowinsky (eds.), Paclitaxel in Cancer Treatment, pp.121-149. New York: Marcel Dekker, Inc., 1995.

25. Faulds, D., Balfour, J. A., Chrisp, P., and Langtry, H. D. Mitox-antrone: a review of its pharmacodynamic and pharmacokinetic prop-erties, and therapeutic potential in the chemotherapy of cancer. Drugs,41: 400-449, 1991.

26. Posner, L. E., Dukart, G., Goldberg, J., Bernstein, J., andCartwright, K. Mitoxantrone: an overview of safety and toxicity. Invest.

New Drugs, 3: 123-132, 1985.

27. Kurbacher, C. M., Cree, I. A., Brenne, U., Bruckner, H. W.,

Kurbacher, J. A., Mallmann, P., Andreotti, P. E., and Krebs, D. Heter-ogeneity of in vitro chemosensitivity in perioperative breast cancer cellsto mitoxantrone versus doxorubicin evaluated by a microplate AlPbioluminescence assay. Breast Cancer Res. Treat., 41: 161-170, 1996.

28. Bruckner, H. W., Kurbacher, C. M., Mandeli, J., and Cuttner, J. In

vitro testing of human ovarian and breast cancers identifies new mod-




ulators of Taxol and cisplatin. Proc. Am. Assoc. Cancer Res., 36: 390,1995.

29. Gl#{252}ck,S., Sharan, N., Chadderton, T., Dietz, G., Bewick, M.,K#{246}ster,W., Lutynski, A., and Gallant, G. In vitro combination ofpaclitaxel (Taxol#{174}, TXL) with five different cytotoxic drugs: effect on

three different cell lines. Proc. Am. Assoc. Cancer Res., 35: 335, 1994.

30. Holmes, F. A., and Valero, V. Breast carcinoma. In: W. P. McGuireand E. K. Rowinsky (eds.), Paclitaxel in Cancer Treatment, pp. 223-271. New York: Marcel Dekker, Inc., 1995.

3 1. Santoro, A., Maiorino, L., and Santoro, M. Taxol plus doxorubicinin platinum pretreated advanced ovarian cancer. Proc. Am. Soc. Clin.Oncol., 15: 288, 1996.

32. POch, G. Combined Effects of Drugs and Toxic Agents. ModernEvaluation in Theory and Practice. Vienna: Springer-Verlag, 1993.

33. Fenelly, D., Shapiro, F., Spriggs, D., Aghajanian, C., Gogas, H.,McKenzie, M., O’Connor, C., Francis, P., Curtin, J., Barakat, R.,Hoskins, W., and Norton, L. Efficacy and feasibility of weekly (wkly)Taxol (T) administration in patients (pts) with Taxol-refractory ovariancancer: a Phase I study. Proc. Am. Soc. Clin. Oncol., 14: 272, 1995.

34. Loeffler, T. M., Freund, W., Lipke, J., and Hausamen, T. U. Sched-ule and dose-intensified paclitaxel (1) as weekly one-hour infusion.Evidence for an improved toxicity profile and response activity inpretreated solid tumors. Proc. Am. Soc. Clin. Oncol., 14: 470, 1995.

35. Fenelly, D., Shapiro, F., Aghajanian, C., McKenzie, M., O’Connor,C., O’Flaherty, C., Norton, L., and Spriggs, D. Dose-intensive paclitaxel(PTX) delivery utilizing a weekly (W) one-hour (H) infusion schedule:efficacy and feasibility in patients (pts) with persistant ovarian cancer.Proc. Am. Soc. Clin. Oncol., 15: 286, 1996.

36. Thigpen, J. T., Blessing, J. A., Ball, H., Hummel, S. J., and Barett,R. J. Phase II thaI of paclitaxel in patients with progressive ovarian

carcinoma after platinum-based chemotherapy. J. Clin. Oncol., 12:

1748-1753, 1994.

37. Kohn, E. C., Sarosy, G., Bicher, A., Link, C., Christian, M.,Steinberg, S. M., Rothenberg, M., Adamo, D. 0., Davis, P., and Og-nibene, F. P. Dose-intense Taxol: high response rate in patients withplatinum-resistant ovarian cancer. J. Natl. Cancer Inst., 86: 18-24,1994.

38. Smith, I. E. Mitoxantrone (Novantrone): a review of experimentaland early clinical studies. Cancer Treat. Rev., 10: 103-1 15, 1983.

39. Neidhart, J. A., Gochnour, D., Roach, R., Hoth, D., and Young, D.A comparison of mitoxantrone and doxorubicin in breast cancer. J. Clin.Oncol., 4: 672-677, 1986.

40. Lawton, F., Blackledge, G., Mould, J., Latief, T., Watson, R., andChetiyawardana, A. D. Phase II study of mitoxantrone in epithelialovarian cancer. Cancer Treat. Rep., 71: 627-629, 1987.

41. Bellamy, W. T. Prediction of response to drug therapy of cancer: a

review of in vitro assays. Drugs, 44: 690-708, 1992.

42. Ozols, R. F., Rubin, S. C., Dembo, A. J., and Robboy, S. Epithelialovarian cancer. ln: W. J. Hoskins, C. A. Perez, and R. C. Young (eds.),Principles and Practice of Gynecologic Oncology, pp. 73 1-781 . Phila-delphia: J. B. Lippincott Co., 1992.

43. Kurbacher, C. M., Mallmann, P., Kurbacher, J., and Krebs, D.Improvement of platinum-induced cytotoxicity in human ovarian carci-noma in vitro by cytosine arabinoside. J. Cancer Res. Clin. Oncol., 120

(Suppl.): 162, 1994.

44. Andreotti P. E., Kurbacher, C. M., Lee, J. M., Greenspan, E. M.,and Bruckner, H. W. Sensitivity of clinical ovarian cancer specimens tothe combination of cisplatin and cytosine arabinoside: evaluation byAlP bioluminescence assay. Proc. Am. Assoc. Cancer Res., 35: 201,1994.



1997;3:1527-1533. Clin Cancer Res C M Kurbacher, H W Bruckner, I A Cree, et al. clinical pilot trial.platinum-refractory ovarian cancer: laboratory study and Mitoxantrone combined with paclitaxel as salvage therapy for

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Mitoxantrone Combined with Paclitaxel as Salvage Therapy ...TDC) with 0.6 p.g/ml mitoxantrone and 13.6 pg/ml paclitaxel as 100% TDC (14, 24). Each TDC was tested in triplicate. Addi-tionally,