
Clinical Cancer Research Vol. 6, 1333-1336, April 2000
© 2000 American Association for Cancer Research
A Multicenter Phase II Trial of Losoxantrone (DuP-941) in Hormone-refractory Metastatic Prostate Cancer1
Susan D. Huan2,
Ronald B. Natale,
David J. Stewart,
George P. Sartiano,
Philip J. Stella,
John D. Roberts,
Aston L. Symes and
Michael Finizio
Ottawa Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation and University of Ottawa, Ottawa, Ontario, Canada K1Y 4K7 [S. D. H., D. J. S.]; University of Southern California, Norris Comprehensive Cancer Center, Los Angeles, California 90033 [R. B. N.]; Albany Medical College, Albany, New York 12208 [G. P. S.]; McAuley Cancer Care Center, Ypsilanti, Michigan 48197 [P. J. S.]; Massey Cancer Center, Richmond, Virginia 23298 [J. D. R.]; DuPont Pharma, Mississauga, Ontario, Canada L5K 2P8 [A. L. S.]; and the DuPont Merck Pharmaceutical Company, Wilmington, Delaware 19805 [M. F.]
 |
ABSTRACT
|
|---|
Our
purpose in this study was to determine the efficacy and toxicity of
losoxantrone (DuP-941), an anthrapyrazole, in patients with metastatic
hormone-refractory prostate cancer. Patients with metastatic prostate
cancer progressing on androgen ablation therapy without demonstrable
antiandrogen withdrawal response were treated with losoxantrone 50
mg/m2 i.v. bolus every 21 days. All of the patients had
elevated serum prostate-specific antigen (PSA) before study entry and
had no prior chemotherapy. Forty-three assessable patients were
entered. The median age was 70.6 years (range, 53.985.9), median
Karnofsky performance scale (KPS), 70% (5090%), and the median
serum PSA, 173 µg/liter (12.511,140). The median number of courses
was 4 (19). Five patients (25%) had a partial response as defined by
>50% decline in the serum PSA. Two of nine patients with measurable
disease had partial responses and three had minor responses. Thirty
percent of patients had improvement in KPS and 37% had an improvement
in symptoms with decrease in pain and/or decrease in analgesic
requirement. Nonhematological grade 3 and 4 toxicities were one each of
grade 3 headache, grade 4 hypocalcemia, grade 3 hyperbilirubinemia, and
grade 3 dyspnea. Twenty-six patients (60%) had grade 3 or 4 absolute
neutropenia. In conclusion, losoxantrone demonstrated a partial
biochemical response rate of 25%, response in measurable disease sites
in 22%, and improvement in clinical symptoms in one-third of patients.
In this study, PSA increase was not necessarily associated with lack of
palliative response.
 |
INTRODUCTION
|
|---|
Cytotoxic chemotherapy has modest activity in hormone-refractory
prostate cancer (1)
. Doxorubicin, an anthracycline, given
in different dose schedules has response rates ranging from 25 to 84%
(2, 3, 4, 5, 6)
, with higher response rates using the National
Prostate Cancer Project response criteria. The cumulative
cardiotoxicity seen with doxorubicin has limited its use in this
elderly population. The formation of superoxides by anthracyclines
triggers a series of events that eventually results in the
cardiomyopathy. By modifying the anthracenedione nucleus and replacing
the carbonyl group with an additional pyrazole group, the
anthrapyrazoles are rendered more resistant to enzymatic reduction,
which results in decreased generation of superoxides (7)
.
This property has been confirmed in experimental systems and further
supported by their protective role against lipid peroxidation
(8)
. Anthrapyrazoles have demonstrated broad spectrum
activity in experimental tumor models (9)
. Their
cytotoxicity is mediated through DNA intercalation and the inhibition
of topoisomerase II (10)
.
In a Phase I study of one of the anthrapyrazoles, DuP-937, two of three
patients with metastatic prostate cancer treated at the Ottawa Regional
Cancer Center demonstrated more than a 50% decline in
PSA.3
One of these patients
with measurable disease obtained a partial response, which was reported
previously (11)
. Losoxantrone (DuP-941) was chosen as the
anthrapyrazole for this study because of a better safety profile than
DuP-937 and the availability of more clinical data from studies in
metastatic breast cancer (12
, 13)
. On the basis of the
antitumor activity of the related drug, doxorubicin, in prostate
cancer, the responses seen with a related anthrapyrazole DuP-937, and
the antitumor activity of losoxantrone in different solid tumor models,
losoxantrone was deemed as an appropriate candidate drug to explore in
metastatic prostate cancer.
 |
MATERIALS AND METHODS
|
|---|
Patients with histologically confirmed prostate cancer with
metastatic disease or locally advanced disease who progressed on
hormonal therapy were entered into the study. Patients were eligible if
they had a KPS of 5090%, had not received any prior cytotoxic
chemotherapy, had adequate renal function (serum creatinine
177
µmol/liter), and hepatic function (total bilirubin of <26
µmol/liter). All of the patients had elevated serum PSA of
10
µg/liter at study entry. All of the patients were off antiandrogen
therapy at least 2 weeks before study entry and were observed for any
withdrawal response. An interval of 3 weeks from radiation was required
in all of the patients. Patients with a history of congestive heart
failure, unstable angina, cardiomyopathy, arrhythmia requiring therapy,
myocardial infarction within 12 months of study entry, or a baseline
left ventricular ejection fraction of 45% or below by radionuclide
ventriculogram were excluded.
Before treatment, all of the patients had a complete history and
physical examination, complete blood count, differential count,
chemical survey, PSA, chest radiograph, electrocardiogram, left
ventricular gated scan, and bone scan. Computerized tomography of the
thorax, abdomen, and/or pelvis, and plain radiographs of bony lesions,
if applicable, were done for measurement or evaluation of the sites of
disease.
As approved by the Institutional Review Boards of participating
institutions, written informed consent was obtained from each patient.
Patients were treated with losoxantrone 50 mg/m2
i.v. bolus every 21 days. Patients with less than a PSA rise of 25%
from baseline without a worsening of symptoms continued to a maximum of
six courses unless there was development of excess toxicity. Weekly
complete blood count and differential counts were done. Physical
examination, assessment of subjective improvement, creatinine, liver
function tests, PSA, and ultrasound of the abdomen (when used to follow
disease sites) were done once every 3 weeks; bone radiographs,
computerized tomography scan of evaluable or measurable disease were
done every 6 weeks, and bone scan was done every 12 weeks. Left
ventricular gated scans were performed after the fifth, eighth, and
eleventh courses. All of the patients completed the EORTC QLQ-C30
questionnaire (14)
at the beginning of the study before
any treatment, at the end of the second course, and when they came off
study. Toxicities were graded according to the National Cancer
Institute-United States adult toxicity criteria (15)
.
Data Analysis and Statistical Considerations.
Evaluation of PSA response was done by calculating the percentage
decline from baseline value: (a) a complete biochemical
response was a PSA decline to within normal range; (b)
partial response was >50% decline in PSA; (c) stable
disease was <50% decline in PSA and not >25% increase in the PSA
from baseline; and (d) progressive disease was >25%
increase in the PSA. Assessment of clinical response was done using
standard criteria, and bone scan results were graded as worse, stable,
or improved. The statistical method for analysis of response was based
on the method of Fleming (16)
.
 |
RESULTS
|
|---|
Forty-four patients from five centers in North America were
registered on the study between September 1993 and December 1994. One
patient was not evaluable for response because of a lack of follow-up
data. The median number of courses of losoxantrone was 4 (range,
110). The primary efficacy variable for this study was the degree of
decrease in the serum PSA from the baseline values, supported by
clinical parameters. The secondary efficacy variable looked at
subjective responses, as measured by the EORTC QLQ-C30 responses, and
clinical response by physicians assessment of patients symptom
relief, analgesic requirement, weight, and change in the KPS. Patient
characteristics are shown in Table 1
. All
except two patients had bone metastases. All of the patients had prior
hormonal therapy, with a median of two different types of hormonal
maneuver. Leutinizing hormone-releasing hormone agonists were continued
at the discretion of individual investigators.
The median PSA value was 173 µg/liter (range 12.511,140).
Twenty-one percent had >50% decrease in PSA from baseline, including
five who had a >75% decrease. The median duration of biochemical
response was 11 weeks (range, 422 weeks). Thirty percent of patients
had improvement in KPS, and 37% had decrease in pain and/or decrease
in analgesic requirement. Nausea and loss of appetite were reported
more frequently after course 2 of chemotherapy; however, the change in
appetite was less pronounced after course 4, and, on progression, both
nausea and anorexia became more frequently observed. The median
duration of improvement in KPS and improvement in pain was 12 weeks
(range, 326 weeks) and 6 weeks (range, 123 weeks), respectively.
The PSA responses in relation to KPS and symptoms are shown in Table 2
. Partial biochemical responders had
overall either an improvement or no change in their symptoms or KPS.
One patient had a worsening of his KPS from 90% to 80%. In the group
with stable response in PSA, only two patients had a worsening of their
symptoms. Thirty-two percent of patients who had biochemical
progression had improvement in their symptoms and 15.7%
improvement in their performance status.
Nine patients had bidimensional measurable disease. There were two
partial responsesone in the left supraclavicular nodes and the other
in the liver. Three patients had minor responses: 44, 47, and 47%
reduction in liver, retrocrural and subcarinal nodes, and peripheral
lymph nodes, respectively. Of the 22 patients who had follow-up bone
scan, 27% had improvement in bone scan, which in one-half of these
patients was associated with a PSA response of >50% decline. Stable
bone scan was observed in 45%. Median survival for patients on this
study was 56 weeks (range, 487 weeks).
There were no treatment-related deaths. Toxicities are shown in Table 3
. Sixty percent of patients had nadir
absolute neutrophil counts of <0.5 x
109/liter, and 7% experienced grade 3 and 4
anemia. There was no grade 3 or 4 thrombocytopenia. The most common
nonhematological toxicity was alopecia in 55% of the patients,
followed by nausea (grade 1 and 2) in 36.4% of patients. One patient
had transient grade 3 elevation of serum bilirubin, which subsequently
resolved with continuation of losoxantrone. One patient developed grade
3 cardiotoxicity, which responded to medical management. The median age
of patients who had any decrease in their ejection fraction was 74
years (range, 6775). The median cumulative dose at which a drop in
the ejection fraction of 15% or more was observed by Kaplan-Meier
estimate was 400 mg/m2 of losoxantrone (95%
confidence interval, 350460 mg/m2).
 |
DISCUSSION
|
|---|
Doxorubicin was one of the earliest cytotoxic agents evaluated in
metastatic hormone-refractory prostate cancer (2, 3, 4, 5, 6)
. Its
use in this patient population has been limited by its associated
cumulative cardiotoxicity. Ways to delay or decrease toxicities of
doxorubicin include giving the drug by continuous i.v. infusion rather
than by bolus (17)
, the use of free radical scavengers
such as bispiperazinediones (18)
, and the generation of
analogues with less propensity to form superoxide radicals.
Anthrapyrazoles are one such class of drugs developed in the hope of
averting cardiotoxicity. On the basis of the observation of three
partial biochemical responses (PSA decrease of >50% from baseline)
and a partial response in measurable disease in one of these patients
in a Phase I study conducted through the National Cancer Institute of
Canada using DuP-937 (11)
, it was thought that the
activity of anthrapyrazoles needed to be explored further in patients
with hormone-refractory metastatic prostate cancer. As more data were
available from studies in metastatic breast cancer on losoxantrone, an
analogue of DuP-937, losoxantrone, was chosen for this Phase II study.
PSA has become an important surrogate marker for metastatic prostate
cancer, a disease that predominantly affects the bones and in which
measurement of responses is imprecise. Hence, we chose PSA response as
the primary outcome measurement. Change in symptoms such as a decrease
in pain and in analgesic requirement, along with changes in weight and
performance status, were secondary outcomes. A decline in PSA was
observed in one-half of the patients. Twenty-one % had a >50%
decline in the PSA.
Mitoxantrone, in combination with prednisone, had an overall palliative
response of 36% in metastatic prostrate cancer (19)
. A
more recent randomized study of mitoxantrone plus prednisone
versus prednisone alone showed a significantly better
quality of life for the combined treatment arm (20)
. In
our study, although a decrease in PSA (biochemical partial
response or stable disease) was often associated with
improvement or stabilization of symptoms and performance status, a PSA
increase was not necessarily associated with a lack of palliative
responses [47% had no change in KPS, whereas 16% had improvement;
and 42% had stable symptoms, whereas 32% reported improvement in
their symptoms]. Losoxantrone, as a single agent, resulted in an
improvement of symptoms and quality of life in one-third of the
patients. This was offset by a small proportion of patients who
experienced loss of appetite and nausea while on the chemotherapy.
These two symptoms could potentially be attenuated by the concurrent
use of steroids. Losoxantrone seems to have palliative activity that is
roughly equivalent to that of mitoxantrone.
The treatment of hormone-refractory prostate cancer remains suboptimal.
Cytotoxic agents have largely been investigated in the past. As the
biology of hormone-refractory prostate cancer continues to unfold,
chemotherapy may complement other more innovative modalities.
Biological agents, cytokine-directed therapy, differentiating agents,
and antiangiogenic agents will be used increasingly. Combinations of
the different modalities to target the different mechanisms in the
progression of this disease may be warranted.
 |
FOOTNOTES
|
|---|
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 Supported by DuPont Merck Pharmaceutical
Company. 
2 To whom requests for reprints should be
addressed, at Ottawa Regional Cancer Centre, 190 Melrose Avenue,
Ottawa, Ontario, Canada K1Y 4K7. Phone: (613) 737-7700; Fax: (613)
247-3511. 
3 The abbreviations used are: PSA,
prostate-specific antigen; KPS, Karnofsky performance scale; EORTC,
European Organization for Research and Treatment of Cancer. 
Received 11/ 3/98;
revised 2/10/99;
accepted 2/12/99.
 |
REFERENCES
|
|---|
-
Eisenberger M. A., Abrams J. S. Chemotherapy for prostatic carcinoma. Semin. Urol., 6: 303-310, 1988.[Medline]
-
DeWys W. D., Bauer M., Colsky J., Cooper R. A., Creech R., Carbone P. P. Comparative trial of adriamycin and 5-fluorouracil in advanced prostatic cancerprogress report. Cancer Treat. Rep., 61: 325-328, 1977.[Medline]
-
Francini G., Petrioli R., Manganelli A., Cintorino M., Marsili S., Aquino A., Mondillo S. Weekly chemotherapy in advanced prostate cancer. Br. J. Cancer, 67: 1430-1436, 1993.[Medline]
-
Eagan R. T., Hahn R. G., Myers R. P. Adriamycin (NSC-123127) versus 5-fluorouracil (NSC-19893) and cyclophosphamide (NSC-26271) in the treatment of metastatic prostate cancer. Cancer Treat. Rep., 60: 115-117, 1976.[Medline]
-
Torti F. M., Aston D., Lum B. L., Kohler M., Williams R., Spaulding J. T., Shortliffe L., Freiha F. S. Weekly doxorubicin in endocrine-refractory carcinoma of the prostate. J. Clin. Oncol., 1: 477-482, 1983.[Abstract]
-
OBryan R. M., Baker L. H., Gottlieb J. F., Rivkin S. E., Balcerzak S. P., Grumet G. N., Salmon S. E., Moon T. E., Hoogstraten B. Dose response evaluation of adriamycin in human neoplasia. Cancer (Phila.), 39: 1940-1948, 1977.[CrossRef][Medline]
-
Gogas H., Mansi J. L. The anthrapyrazoles. Cancer Treat. Rev., 21: 541-552, 1996.[CrossRef][Medline]
-
Frank P., Novak R. F. Effects of anthrapyrazole antineoplastic agents on lipid peroxidation. Biochem. Biophys. Res. Commun., 140: 797-807, 1986.[CrossRef][Medline]
-
Graham M. A., Newell D. R., Butler J., Hoey B., Patterson L. H. The effect of the anthrapyrazole antitumour agent CI941 on rat liver microsomes and cytochrome P-450 reductase mediated free radical processes. Biochem. Pharmacol., 36: 3345-3351, 1987.[CrossRef][Medline]
-
Leteurtre F., Kohlhagen G., Paull K. D., Pommier Y. Topoisomerase II inhibition and cytotoxicity of the anthrapyrazoles DuP 937 and DuP 941 (losoxantrone) in the National Cancer Institute Preclinical Antitumor Drug Discovery Screen. J. Natl. Cancer Inst., 86: 1239-1244, 1994.[Abstract/Free Full Text]
-
Bélanger K., Jolivet J., Maroun J., Stewart D., Grillo-Lopez A., Whitfield L., Wainman N., Eisenhauer E. Phase I pharmacokinetic study of DUP-937, a new anthrapyrazole. Investig. New Drugs, 11: 301-308, 1993.[CrossRef][Medline]
-
Talbot D. C., Smith I. E., Mansi J. L., Judson I., Calvert A. H., Ashley S. E. Anthrapyrazole CI941: a highly active new agent in the treatment of advanced breast cancer. J. Clin. Oncol., 9: 2141-2147, 1991.[Abstract]
-
Vandenberg T., ten Bokkel Huinink W., Hedley D., Panasci L., Verma S., Calvert H., Francher D., Azarnia N., Sisk R., Symes A. A Phase II study of DUP941 in advanced breast cancer patients with no prior chemotherapy. Cancer Investig., 12(Suppl.1): 13-14, 1994.
-
Aaronson N. K., Ahmedzai S., Bergman B., Bullinger M., Cull A., Duez N. J., Filiberti A., Flechtner H., Fleishman S. B., de Haes J. C. J. M., Kaasa S., Klee M., Osoba D., Razavi D., Rofe P. B., Schraub S., Sneeuw K., Sullivan M., Takeda F. The European Organization for Research and Treatment of Cancer QLQ-C30: a quality of life instrument for use in international trials in oncology. J. Natl. Cancer Inst., 85: 365-376, 1993.[Abstract/Free Full Text]
-
Toxicity Criteria Reference. Modification of the February 1988 recommendations of representatives of the National Cancer Institutes clinical cooperative groups and the cancer treatment evaluation program. NCI, NIH, DHHS, 1998.
-
Fleming T. One-sample multiple testing procedure for Phase II clinical trials: . Biometrics, 38: 143-151, 1982.[CrossRef][Medline]
-
Legha S. S., Benjamin R. S., Mackay B., Ewer M., Wallace S., Valdivieso M., Rasmussen S. L., Blumenschein G. R., Freireich E. J. Reduction of doxorubicin cardiotoxicity by prolonged continuous intravenous infusion. Ann. Intern. Med., 96: 133-139, 1982.
-
Speyer J. L., Green M. D., Zeleniuch-Jacquotte A., Wernz J. C., Rey M., Sanger J., Kramer E., Ferrans V., Hochster H., Meyers M., Blum R. H., Feit F., Attubato M., Burrows W., Muggia F. M. ICRF-187 permits longer treatment with doxorubicin in women with breast cancer. J. Clin. Oncol., 10: 117-127, 1992.[Abstract]
-
Moore M. J., Osoba D., Murphy K., Tannock I. F., Armitage A., Findlay B., Coppin C., Neville A., Venner P., Wilson J. Use of palliative end points to evaluate the effects of mitoxantrone and low-dose prednisone in patients with hormonally resistant prostate cancer. J. Clin. Oncol., 12: 689-694, 1994.[Abstract]
-
Tannock I. F., Osoba D., Stockler M. R., Ernst D. S., Neville A. J., Moore M. J., Armitage G. R., Wilson J. J., Venner P. M., Coppin C. M. L., Murphy K. C. Chemotherapy with mitoxantrone plus prednisone or prednisone alone for symptomatic hormone-resistant prostate cancer: a Canadian randomized trial with palliative end points. J. Clin. Oncol., 14: 1756-1764, 1996.[Abstract/Free Full Text]
This article has been cited by other articles:

|
 |

|
 |
 
U. D. Renner, G. Piperopoulos, R. Gebhardt, G. Ehninger, and K.-P. Zeller
The Oxidative Biotransformation of Losoxantrone (CI-941)
Drug Metab. Dispos.,
April 1, 2002;
30(4):
464 - 478.
[Abstract]
[Full Text]
[PDF]
|
 |
|