Lactone stable formulation of 10-hydroxy 7-ethyl camptothecin and methods for uses thereof

10-hydroxy 7-ethyl camptothecin (HECPT), an active metabolite of the camptothecin analog CPT-11, is poorly soluble in water. Because of its poor water solubility, HECPT has not been directly administered by parenteral or oral routes in human patients for the purpose of inhibiting the growth of cancer cells. There is also unpredictable interpatient variability in the metabolic production of HECPT from CPT-11 which limits the utility of CPT-11. This invention overcomes these limitations by teaching novel pharmaceutically acceptable lactone stable HECPT formulations for the direct administration of HECPT. The claimed invention also describes novel dosages, schedules, and routes of administration of the lactone stable HECPT formulations to patients with various forms of cancer.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
10-hydroxy 7-ethyl camptothecin ("HECPT") is an active metabolite of the 
camptothecin analog CPT-11. HECPT is also poorly soluble in water. Because 
of its poor water solubility, HECPT has not been directly administered by 
parenteral or oral routes in human subjects for the purpose of inhibiting 
the growth of cancer cells. This invention overcomes these limitations and 
claims novel pharmaceutically acceptable formulations of lactone stable 
HECPT, methods of administration of lactone stable HECPT, and antitumor 
compositions comprising solutions of lactone stable HECPT. Additionally, 
this invention claims novel dosages, schedules of administration, and 
routes of administration of HECPT formulations to humans with various 
forms of cancer. 
2. Description of the Related Art 
A. Introduction 
Metabolic conversion of CPT-11 (a water soluble derivative of camptothecin) 
to its active metabolite 10-hydroxy 7-ethyl camptothecin (HECPT) varies 
from patient to patient and limits the utility of CPT-11 in achieving the 
highest plasma concentrations of HECPT which can be tolerated by the 
patient. HECPT's poor solubility in water has previously made the direct 
administration of HECPT impractical for the treatment of cancer. The 
conversion of CPT-11 to HECPT involves a putative carboxyl esterase 
enzyme, which is believed to be mainly responsible for the metabolic 
production of HECPT from CPT-11. Human lung cancer cell lines have been 
observed to convert less CPT-11 to HECPT than normal cells. The cancer 
cells' decreased metabolic conversion represents a form of resistance to 
CPT-11 and limits the utility of CPT-11 in terms of reliably and safely 
achieving adequate plasma concentrations of HECPT to inhibit the growth of 
cancer cells in humans. 
Until now, HECPT has been considered unsuitable for direct clinical use 
because it is poorly soluble in water. One useful purpose of this 
invention is to formulate HECPT in a pharmaceutically acceptable manner 
using an organic solvent or a mixture of organic co-solvents to stabilize 
HECPT in the lactone ring form. It is this lactone stable HECPT which 
permits direct administration of HECPT to cancer patients. An additional 
purpose of this invention to provide certain indications, schedules, 
dosages and routes of administration of lactone stable HECPT for the 
purpose of treating cancer in humans. 
The selection of suitable organic solvents for pharmaceutical dosage forms 
is limited to those which have a high degree of physiological safety. This 
invention describes administration of lactone stable HECPT in a 
pharmaceutically acceptable multi-solvent formulation, overcomes 
interpatient variability and drug resistance related to CPT-11 conversion 
to HECPT and is useful in instances where human cancer cells, because of 
their altered enzymatic activity, resist metabolic conversion of CPT-11 to 
HECPT. 
B. DNA Topoisomerases 
Several clinically important anticancer drugs kill tumor cells by affecting 
DNA topoisomerases. Topoisomerases are essential nuclear enzymes that 
function in DNA replication and tertiary structural modifications, such as 
overwinding, underwinding, and catenation, which normally arise during 
replication, transcription, and perhaps other DNA processes. Two major 
topoisomerases that are ubiquitous to all eukaryotic cells: (1) 
Topoisomerase I (topo I) which cleaves single stranded DNA; and (2) 
Topoisomerase II (topo II) which cleaves double stranded DNA. 
Topoisomerase I is involved in DNA replication; it relieves the torsional 
strain introduced ahead of the moving replication fork. 
Topoisomerase I purified from human colon carcinoma cells or calf thymus 
has been shown to be inhibited by (a) camptothecin, (b) a water soluble 
analog called "CPT-11," and (c) 10-hydroxy 7-ethyl camptothecin (HECPT) 
which is the proposed active metabolite of CPT-11. CPT-11, camptothecin, 
and an additional Topo I inhibitor, topotecan, has been in used in 
clinical trials to treat certain types of human cancer. For the purpose of 
this invention, camptothecin derivatives include CPT-11, 10-hydroxy 
7-ethyl camptothecin (HECPT) and topotecan. These camptothecin derivatives 
use the same mechanism to inhibit Topo I; they stabilize the covalent 
complex of enzyme and strand-cleaved DNA, which is an intermediate in the 
catalytic mechanism. These compounds have no binding affinity for either 
isolated DNA or topoisomerase I but do bind with measurable affinity to 
the enzyme-DNA complex. The stabilization of the topoisomerase I 
"cleavable complex" by camptothecin, CPT-11, or HECPT is readily 
reversible. 
Although camptothecin, CPT-11, or HECPT have no effect on topoisomerase II, 
camptothecin, CPT-11 and HECPT stabilize the "cleavable complex" in a 
manner analogous to the way in which epipodophyllotoxin glycosides and 
various anthracyclines inhibit topoisomerase II. 
Inhibition of topoisomerase I by camptothecin, CPT-11, or HECPT induces 
protein-associated-DNA single-strand breaks. Virtually all of the DNA 
strand breaks observed in vitro cells treated with CPT-11 or HECPT are 
protein linked. However, an increase in unexplained protein-free breaks 
can be detected in L1210 cells treated with camptothecin. The compounds 
appear to produce identical DNA cleavage patterns in end-labeled linear 
DNA. It has not been demonstrated that CPT-11, camptothecin, or HECPT 
cleaves DNA in the absence of the topoisomerase I enzyme. 
C. Activity of HECPT, Camptothecin and CPT-11 is Cell Cycle Specific 
The activity of camptothecin, CPT-11, and HECPT is cell cycle specific. The 
greatest quantitative biochemical effect observed in cells exposed to 
HECPT is DNA single-strand breaks that occur during the S-phase. Because 
the S-phase is a relatively short phase of the cell cycle, longer exposure 
to the drugs results in increased cell killing. Brief exposure of tumor 
cells to the drugs produces little or no cell killing, and quiescent cells 
are refractory. These results are likely due to two factors: 
(1) The drugs inhibit topoisomerase I reversibly. Although they may produce 
potentially lethal modifications of the DNA structure during DNA 
replication, the breaks may be repaired after washout of the drug; and 
(2) Cells treated with topo I inhibitors, such as CPT-11 and HECPT, tend to 
stay in GO of the cell cycle until the drug is removed and the cleaved DNA 
is repaired. Inhibitors of these enzymes can affect many aspects of cell 
metabolism including replication, transcription, recombination, and 
chromosomal segregation. 
D. Lactone Form Stabilizes HECPT 
Utilizing HPLC and NMR techniques, researchers have demonstrated that 
camptothecin, CPT-11, and HECPT undergo an alkaline, pH-dependent 
hydrolysis of the E-ring lactone. The slow reaction kinetics allow one to 
assess whether both the lactone and non-lactone forms of the drug 
stabilizes the topoisomerase I-cleaved DNA complex. Studies indicate that 
only the closed lactone form of the drug helps stabilize the cleavable 
complex. This observation provides reasoning for the high degree of CPT-11 
and HECPT activity observed in solid tumor models. Tumor cells, 
particularly hypoxic cells prevalent in solid neoplasms, have lower 
intracellular pH levels than normal cells. At pH levels below 7.0, the 
closed form of CPT-11 (and presumably of HECPT) predominates. Thus, the 
inventors predict that HECPT will be more effective at inhibiting 
topoisomerase I in an acidic environment than in cells having higher 
intracellular pH levels. It is the object of this invention to provide 
lactone stable HECPT as the basis of the claimed subject matter. Lactone 
stable HECPT is defined as HECPT which is dissolved in DMI or DMA in the 
presence of a pharmaceutically acceptable acid. The presence of the acid 
stabilizes the lactone form of HECPT. For the purpose of this invention 
lactone stable HECPT and HECPT are used interchangeably. 
E. Camptothecin, CPT-11 and Topotecan 
In 1966, Wall and Wani isolated camptothecin from the plant, Camptotheca 
acuminata. In the early 1970's, camptothecin reached Phase I trials and 
was found to have antitumor activity, but it caused unpredictable 
myelosuppression and hemorrhagic cystitis. Phase II studies with sodium 
camptothecin were limited because they induced unpredictable and severe 
myelosuppression, gastrointestinal toxicity, hemorrhagic cystitis, and 
alopecia. Clinical trials with sodium camptothecin were eventually 
discontinued because of unpredictable toxicities. 
Two camptothecin derivatives, CPT-11 and Topotecan, have less sporadic 
toxicities but retain significant activity of the parent compound. CPT-11 
and Topotecan are currently undergoing Phase I and Phase II development in 
the United States. 10, 11 methylene dioxycamptothecin is reportedly very 
active in preclinical studies, but it is also reported to be relatively 
insoluble in water which limits its use in the clinic (Pommier, et al. 
1992). 
Tables 1 and 2 present data summarizing Phase I and Phase II clinical 
trials of CPT-11. Neutropenia and diarrhea are the major reported, 
dose-limiting toxicities of CPT-11. 
TABLE 1 
__________________________________________________________________________ 
PHASE I STUDIES CPT-11 
# 
Investigator 
Schedule 
Pts 
Dose Toxicity Tumor Type 
__________________________________________________________________________ 
Clavel et al 
90 min. 37 
115 mg/m.sup.2 /d 
Neutropenia* 
Breast (1 PR) 
QD .times. 3 Q21 
(33-115) 
diarrhea, 
Mesothelioma 
days nausea and 
(1 PR) 
vomiting, 
alopecia 
Culine et al 
90 min. 59 
150 mg/m.sup.2 /wk 
Neutropenia* 
esophagus 
Q21 days (50-150) 
diarrhea* 
(1PR) cervix 
vomiting, 
(1PR) renal 
alopecia (1PR) overian 
fatigue (1PR) 
stomatitis 
Neutropenia* 
Negoro et al 
30 min 17 
100 mg/m.sup.2 
Diarrhea*, N/V, 
NS CLC (2PRs) 
infusion (50-150) 
alopecia, 
weekly liver 
dysfunction 
Ohe et al 
120 hr CI 
36 
40 mg/m.sup.2 /d 
Diarrhea* 
None 
Q3 wks (5-40) nausea and 
vomiting, 
thrombo- 
cytopenia, 
anemia, liver 
dysfunction 
Diarrhea* 
Rothenberg et al 
90 mg QW .times. 4 
32 
180 mg/m.sup.2 /wk 
Neutropenia, 
Colon Ca (2 
Q42 days (50-180) 
nausea, PRs) 
vomiting, 
alopecia 
Rowinsky et al 
90 min 32 
240 mg/m.sup.2 
Neutropenia* 
Colon Ca (1PR) 
infusion (100-345) 
vomiting, 
Cervix Ca 
Q21 day diarrhea abd. 
(1 PR) 
pain, flushing 
__________________________________________________________________________ 
*Dose Limiting Toxicity 
TABLE 2 
__________________________________________________________________________ 
CPT-11 PHASE II TRIALS 
Tumor Reported 
Investigator 
Type Schedule # Pts. 
Response Rate 
Toxicities 
__________________________________________________________________________ 
Fukuoka et al 
Untreated 
100 mg/m.sup.2 weekday 
73 (23/72) PRs 
Neutropenia 
Non Small 31.9% diarrhea, nausea, 
Cell Lung vomiting, anorexia, 
Cancer alopecia 
Masudu et al 
Refractory or 
100 mg/m.sup.2 weekly 
16 (7/15) PRs 
Neutropenia, diarrhea 
Relapsed Small 47% pneumonitis 
Cell Lung Ca (12.5%) 
Negoro et al 
Small Cell Lung 
100 mg/m.sup.2 /week 
41 2 CRs and 7 PRs 
Neutropenia (38.6%) 
Cancer 33.3% N/V (61.5%) 
diarrhea (53.8%) 
alopecia (40.0%) 
Ohono et al 
Leukemia/ 
200 mg Q3 No resp. 
62 ** Neutropenia (91%) 
Lymphoma 40 mg/m.sup.2 Q0 .times. 5 34% PR 
Thrombocytopenia 
20 mg/m.sup.2 bid .times. 7 25% PR 
Gastrointestinal (76%) 
Shimada et al 
Colon cancer 
100 mg/m.sup.2 /week or 
17 6/17(PR) Neutropenia (53%) 
150 mg/m.sup.2 /Q 2 wks 
46% N/V (35%) 
diarrhea (24%) 
Takeuchi et al 
Cervical cancer 
100 mg/m.sup.2 weekly 
69 SCR Neutropenia (89%) 
150 mg/m.sup.2 weeks 
8PR N/V (51%) 
RR of 23.6% 
Diarrhea (39.1%) 
Alopecia (38.1%) 
__________________________________________________________________________ 
**see text 
F. HECPT is the Active Metabolite of CPT-11 
Preclinical data, obtained by Barilero et al. on animals and more recently 
on humans, suggest that HECPT is the active metabolite of CPT-11 in vivo. 
Several different researchers administered CPT-11 and HECPT intravenously 
during Phase I trials and recorded the peak plasma concentrations (CpMax) 
at the end of the infusions. An analysis of the published mean peak plasma 
concentrations indicates that approximately 1.5% to 9% of the administered 
CPT-11 (on a per/mg basis) is converted into HECPT. The pharmacokinetic 
data from 30-minute intravenous infusions show a lower percentage of 
conversion (.about.1.5% ) of CPT-11 to HECPT than that observed following 
more prolonged infusions (.about.9% at 40 mg/m.sup.2 /d.times.5). The 
reported half life of HECPT observed in humans following the 
administration of CPT-11 ranges from 8.8 to 39.0 hours. 
The biochemical and pharmacological relationship between CPT-11 and HECPT, 
as well as the role these compounds play in killing cancer cells in vivo 
is not completely understood. Investigators studying in vitro tumor cell 
lines have reported that HECPT has a 3600-fold greater inhibitory activity 
than CPT-11 against topoisomerase I in P388 cells and that HECPT is 
approximately 1000-fold more potent in generating single-strand DNA breaks 
in MOLT3 cells (Kawato, et al (1991)). However, Kaneda et al. report that 
HECPT has little anti-tumor activity compared to CPT-11 in vivo. They base 
their findings on studies conducted using an intermittent bolus schedule 
(days 1, 5, and 9) and an i.p. route of administration with an 
intraperitoneal P388 tumor model in mice. 
Ohe et al. suggest that HECPT is a more toxic moiety of CPT-11 and could be 
responsible for much of the toxicity attributed to CPT-11. However, these 
same investigators noted a lack of correlation between HECPT 
pharmacokinetics and dose or CPT-11 pharmacokinetics and toxicity in human 
subjects. Furthermore, Ohe et al. noted a large range of interpatient 
variability in the AUC of CPT-11 and its metabolism to HECPT, which may 
result in unpredictable variability in the pharmacokinetic behavior, 
clinical anti-tumor effects, and toxicity in the individual patient. The 
data Ohe et al. obtained (using a 5-day, continuous intravenous infusion 
of CPT-11) also suggests that the conversion of CPT-11 to HECPT is a 
saturable process. If this is so, the clinical approach to maximizing dose 
intensity of the active metabolite would impose additional limitations on 
the effective use of CPT-11. 
In preclinical studies of xenografts of human tumors in nude mice, Kawato 
et al. report that the sensitivity of human tumors to CPT-11 is 
independent of their ability to produce HECPT and that the effectiveness 
of CPT-11 is not related to the ability of the tumor to produce HECPT. 
Kawato et al. suggests that HECPT production is likely to be mediated in 
the plasma or interstitial compartment. Kaneda et al. observed that the 
plasma concentration of HECPT in mice was maintained longer after CPT-11 
administration than after treatment with HECPT and suggested that 
clinicians should maintain plasma levels of HECPT to enhance the antitumor 
activity of CPT-11. 
One of the advantages of present invention provides clinicians with the 
ability to directly adjust the plasma levels of HECPT to the point of 
therapeutic tolerance by controlling the dose and the schedule of 
administration. The inventors contend that this should lead to a superior 
ability to achieve better antitumor activity and reduce interpatient 
variability of the plasma levels of HECPT. 
The different observations made in these studies suggest that direct 
administration of HECPT by parenteral and oral administration could 
provide significant clinical benefit for the treatment of cancer. However, 
in the past, HECPT has been considered insufficiently water soluble for 
clinical use. The current invention overcomes the solubility problem by 
providing lactone stable pharmaceutically acceptable multisolvent 
formulations of HECPT for parenteral use and also oral HECPT formulations. 
SUMMARY OF THE INVENTION 
This invention involves the formulation and methods of use of lactone 
stable HECPT to treat cancer in humans. For the purposes of this 
invention, lactone stable HECPT and HECPT are used interchangeably. In the 
case of intravenous administration of HECPT, several schedules and various 
dosages produce sufficient levels of lactone stable HECPT to yield 
beneficial antitumor effects in humans. The effective levels of HECPT are 
reasonably safe in terms of the incidence and severity of specific side 
effects that may occur with administration and are acceptable within 
standard medical practice for patients undergoing treatment for cancer. 
Direct administration of HECPT is likely to offer several important 
clinical advantages over administration of CPT-11. For example: 
(1) direct administration of HECPT allows the clinician to tailor the 
administration of the active cytoxic species (lactone stable HECPT) to 
suit the patient's tolerance; 
(2) direct administration of HECPT overcomes interpatient variability which 
may be due to polymorphism of key enzyme(s) in the metabolism of CPT-11 to 
HECPT; and 
(3) clinicians can more consistently optimize the drug dosage and schedule 
to achieve the maximum tolerated dose of HECPT (the active species) which 
is likely to lead to the most beneficial clinical anti-cancer effect. 
Regarding the clinical utility of HECPT for the treatment of human cancer, 
this invention provides the following: 
(1) methods of administering lactone stable HECPT to patients with cancer; 
(2) solutions of lactone stable HECPT; 
(3) antitumor compositions comprising lactone stable HECPT; 
(4) stable formulations of lactone stable HECPT suitable for parenteral 
administration; 
(5) pharmacologic schedules for achieving the maximum tolerated dose with 
acceptable clinical toxicity observed in standard clinical practice of 
cancer treatment; 
(6) a novel oral formulation of HECPT; and 
(7) use of HECPT for the treatment of localized complications of cancer by 
direct administration via instillation into various body cavities. 
HECPT Dissolved in Dimethylisosorbide or Dimethylacetamide and Acid 
An embodiment of the claimed invention is a 10-hydroxy 7-ethyl camptothecin 
(HECPT) solution comprising HECPT dissolved in dimethylisosorbide (DMI) in 
the presence of a pharmaceutically acceptable acid or dissolved in 
dimethylacetamide (DMA) in the presence of a pharmaceutically acceptable 
acid. 
The 10-hydroxy 7-ethyl camptothecin (HECPT) solution is prepared by 
dissolving the desired components in dimethylisosorbide (DMI) or 
dimethylacetamide (DMA). Dimethylisosorbide has been used as solvent for 
muscle relaxants (U.S. Pat. No. 3,699,230), tetracyclines (U.S. Pat. No. 
3,219,529), aspirin (U.S. Pat. No. 4,228,162), and steroids (U.S. Pat. No. 
4,082,881). DMI and DMA have very good toxicity profiles and are miscible 
with ethanol, propylene glycol, isopropyl myristate, water, diethyl ether, 
corn oil, acetone, cottonseed oil, and the like. 
An object of the present invention is to provide a solution of HECPT in DMI 
or DMA. A concentrated solution is particularly useful as a filling 
solution for gelatin capsules. The solution may also be formulated for 
parenteral use providing a useful and practical means to dissolve the 
drug. 
The present invention is prepared by dissolving the desired components in 
DMI or DMA and the resulting solution is then filtered and the filtrate 
collected. The amount of HECPT contained in the solution of this invention 
is not specifically restricted but may be any amount convenient for 
pharmaceutical purposes, and may be selected according to the dosage to be 
prepared. A preferred capsule filling solution contains from about 0.1 mg 
to about 3.0 mg of HECPT activity per ml of solution. 
As a preferred embodiment of the claimed invention, the 10-hydroxy 7-ethyl 
camptothecin solution is prepared by dissolving the desired components in 
dimethylisosorbide (DMI) or dimethylacetamide (DMA) in the presence of a 
pharmaceutically acceptable acid. 
A pharmaceutically acceptable acid is preferably included in the solutions 
of the present invention. Any pharmaceutically acceptable acid may be 
used; for example mineral acids such as hydrochloric acid; and organic 
carboxylic acids, such as tartaric, citric, succinic, fumaric, or maleic 
acids. An organic carboxylic acid is preferred, and citric acid is most 
preferred. The amount of acid used may be from about 0.005 to about 0.5 
parts by weight of acid per part by weight of HECPT and preferably from 
about 0.01 to 0.3 part by weight of acid per part by weight of HECPT. 
Citric acid is preferably used in a proportion of from about 0.05 to about 
0.1, and about 0.1 part by weight in the presence of taurocholic acid or a 
pharmaceutically acceptable salt thereof. 
In the formulations provided by the instant invention, HECPT is both 
soluble and maintained in its active lactone form. The non-enzymatic 
conversion of the pH labile E ring from the closed lactone (active) to the 
open carboxylate form (inactive) is reduced by formulating HECPT under 
acidic pH conditions (&lt;5.0). Thus, a water soluble acid is included to 
assure that an acidic pH value is maintained upon dilution to form the 
micellar solution. Examples of preferred solid water-soluble organic 
carboxylic acids effective in this invention include citric, gluconic, 
maleic, tartaric, or ascorbic acids. Other acids may be employed, but 
citric acid is most preferred. 
Yet another embodiment of the claimed invention is that the solution of 
HECPT contains from about 0.1 mg to about 3.0 mg activity of 10-hydroxy 
7-ethyl camptothecin per ml of solution. This concentration would be 
effective for both oral and parenteral administration of the HECPT. 
When oral dosages are to be administered in a capsule form, it is clearly 
superior to have a concentrated solution of HECPT suitable for 
encapsulation within a soft or hard gelatin capsule. Concentrated 
solutions allow the preparation of capsules of smaller size which allows 
easier ingestion by the patient, and may also reduce the number of 
capsules to be swallowed. These factors are important in view of the 
generally poor condition of cancer patients. 
Taurocholic acid, a bile acid, may enhance in the intestinal absorption of 
the drug in certain patients. The present invention takes advantage of the 
discovery that taurocholic acid, or a pharmaceutically acceptable salt 
thereof, when included with HECPT in a solution dosage composition, 
results in improved absorption of the drug following ingestion of the 
composition. It is believed that this is due to the formation of a 
micellar solution of HECPT on dilution thereof with the gastric contents. 
The phenomenon of micellar solubilization of poorly water-soluble drugs 
mediated by bile acids, including taurocholic acid, has been previously 
reported with respect to glutethimide, hexestrol, griseofulvin (Bates et 
al.), reserpine (Malone et al.) and fatty acids and cholesterol 
(Westergaard et al.). The use of taurocholic acid or a pharmaceutically 
acceptable salt thereof in the present invention involves a pharmaceutical 
solution of HECPT which has the unique property of providing a stable 
apparent solution of the drug upon dilution thereof with from 1 to 100 
volumes of water. The solution is stable and free of precipitate for a 
period of at least two hours; sufficient time to permit administration and 
absorption by the patient. 
It has been observed with similar solutions of etoposide, a different 
insoluble anticancer drug, that the bioavailability of the drug following 
oral administration is substantially equivalent to that achieved by 
intravenous administration of a solution of etoposide (U.S. Pat. No. 
4,713,246). Analogous to that of etoposide, it is believed that ingestion 
of the present dosage form of HECPT and resulting dilution thereof by the 
stomach contents, results in the formation of a micellar solution of HECPT 
in the stomach which is readily absorbed by the gastrointestinal tract. 
Applicants do not wish to be bound, however, by any theoretical 
explanation of the mechanism by which the superior oral bioavailability of 
the present HECPT formulation is achieved. 
Antitumor Compositions Comprising HECPT 
A preferred embodiment of the claimed invention is an antitumor composition 
comprising a solution of 10-hydroxy 7-ethyl camptothecin dissolved in 
dimethylisosorbide or dimethylacetamide containing from about 0.1 mg to 
about 3.0 mg 10-hydroxy 7-ethyl camptothecin activity per ml and 
containing from about 0.01 to about 0.9 part by weight of a 
pharmaceutically acceptable organic carboxylic acid per part by weight of 
10-hydroxy 7-ethyl camptothecin. Inventors prefer to use 0.01 to 0.2 part 
by weight of a pharmaceutically acceptable organic carboxylic acid per 
part by weight of 10-hydroxy 7-ethyl camptothecin. 
An additional embodiment of the claimed subject matter is wherein said part 
by weight of a pharmaceutically organic carboxylic acid is from about 0.05 
to about 0.1 part by weight per part by weight of 10-hydroxy 7-ethyl 
camptothecin and the acid is citric acid. 
Another embodiment of this invention is an antitumor composition comprising 
a solution of 10-hydroxy 7-ethyl camptothecin dissolved in 
dimethylisosorbide or dimethylacetamide in the presence of a 
pharmaceutically acceptable acid, wherein said solution further comprises 
taurocholic acid or a pharmaceutically acceptable salt thereof, 
polyethylene glycol, and water. 
Yet another embodiment of this invention is wherein the solution of 
antitumor composition contains for each part by weight of 10-hydroxy 
7-ethyl camptothecin, 1-10 parts by weight of dimethylisosorbide or 
dimethylacetamide, 0.005-0.5 parts by weight of a pharmaceutically 
acceptable acid, 1-10 parts by weight of taurocholic acid or a 
pharmaceutically acceptable salt thereof, 1-10 parts by weight of 
polyethylene glycol, and 0.1-2.0 parts by weight water. An additional 
embodiment is wherein said acid is an organic carboxylic acid and the 
inventors prefer citric acid. 
Another embodiment of the claimed invention is the antitumor composition 
further comprises a lower alcohol. Many different alcohols would be 
effective in this invention, but the inventors prefer to use ethanol. 
Another embodiment of the claimed invention is the antitumor composition 
further comprises glycerin as a co-solvent. 
Yet another embodiment of this invention is an antitumor composition 
comprising a solution of 10-hydroxy 7-ethyl camptothecin dissolved in 
dimethylisosorbide or dimethylacetamide in the presence of a 
pharmaceutically acceptable acid, wherein said solution further comprises 
taurocholic acid or a pharmaceutically acceptable salt thereof, 
polyethylene glycol, water, ethanol, glycerin, and a buffer, such as 
sodium acetate, to maintain an acidic pH. 
An additional embodiment of this invention is wherein said solution 
contains for each part by weight of 10-hydroxy 7-ethyl camptothecin, 1-10 
parts by weight of dimethylisosorbide or dimethylacetamide, 0.005-0.5 
parts by weight of a pharmaceutically acceptable acid, 1-10 parts by 
weight of taurocholic acid or a pharmaceutically acceptable salt thereof, 
1-10 parts by weight of polyethylene glycol, 0.1-2 parts by weight of 
glycerin, 0.1-2 parts by weight of ethanol, 0.005-0.5 parts of a buffer, 
and 0.1-2.0 parts by weight water. 
Another embodiment of this invention is wherein said polyethylene glycol 
has a molecular weight of about 300 and the antitumor composition further 
comprises a non-ionic surfactant. There are many different surfactants but 
the inventors prefer a poloxamer. The preferred poloxamer is poloxamer 
407. 
Yet another embodiment of this invention is an antitumor composition 
comprising a solution of 10-hydroxy 7-ethyl camptothecin dissolved in 
dimethylisosorbide or dimethylacetamide in the presence of a 
pharmaceutically acceptable acid, wherein said solution further comprises 
a lower alcohol, polyethylene glycol, and surfactant. 
As a more preferred embodiment for this antitumor composition, the 
pharmaceutically acceptable organic acid is citric acid, the polyethylene 
glycol has a molecular weight of about 300, the lower alcohol is ethanol 
and the surfactant is polysorbate-80. 
Another embodiment of this invention is an antitumor composition comprising 
a solution of about 0.1 mg to about 2.0 mg of 10-hydroxy 7-ethyl 
camptothecin dissolved in 1 to 10 parts of dimethylisosorbide or 
dimethylacetamide in the presence of about 0.1 to 0.5 parts of a 
pharmaceutically acceptable organic carboxylic acid. This antitumor 
composition further comprises about 5 to 9 parts by weight of polyethylene 
glycol, about 0.1 to 2.0 parts of a pharmaceutically acceptable alcohol, 
and about 1 to 10 parts of a non-ionic surfactant. 
More preferred for this antitumor composition is when the acid is citric 
acid, the polyethylene glycol has a molecular weight of about 300, the 
alcohol is ethanol and the surfactant is polysorbate-80. 
Another embodiment of this invention is an antitumor composition comprising 
a solution about 0.1 mg to about 2.0 mg of 10-hydroxy 7-ethyl camptothecin 
dissolved in 1 to 10 parts of dimethylisosorbide or dimethylacetamide in 
the presence of 0.1 to 0.5 parts of a pharmaceutically acceptable organic 
carboxylic acid. This solution further comprises about 0.1 to 2.0 parts of 
a pharmaceutically acceptable alcohol, and about 1 to about 10 parts of a 
non-ionic surfactant. 
More specifically for this antitumor composition, the acid is citric acid, 
the alcohol is ethanol, and the non-ionic surfactant is comprised of 
polyoxyethylated castor oil. 
Another embodiment of this invention is an antitumor composition comprising 
a solution of 0.1 mg to about 2.0 mg of 10-hydroxy 7-ethyl camptothecin 
dissolved in 1 to 10 parts of dimethylisosorbide or dimethylacetamide, 
wherein this solution further comprises about 1 to 10 parts 
polyoxyethylated castor oil, about 0.1 to 2 parts by weight dehydrated 
ethyl alcohol USP, and about 0.1 to 0.9 parts citric acid. 
In a more preferred embodiment, HECPT is solubilized in a manner suitable 
for clinical use by forming a sterile, nonaqueous solution of 1 part of 
HECPT per 1 to 2 ml in a vehicle comprising dehydrated ethyl alcohol 
0.1-2.0 parts by weight, benzyl alcohol 0.1-2.0 parts by weight, citric 
acid 0.1-0.9 parts by weight, polyethylene glycol (molecular weight 
200-300) 4 to 10 parts by weight, polysorbate-80 (Tween 80) 1 to 10 parts, 
and dimethylisosorbide 1 to 10 parts in acidified medium with a pH of 3 to 
4. 
This preferred embodiment of an HECPT solution in dimethylisosorbide is 
summarized in the table as follows: 
______________________________________ 
Parts by 
Ingredients Weight 
______________________________________ 
10-hydroxy 7-ethyl 
1 
Camptothecin 
EtOH 0.1-2.0 
Benzyl Alcohol 0.1-2.0 
Citric Acid 0.1-0.5 
PEG 300 5-9 
Dimethylisosorbide 
1-10 
Polysorbate 80 1-10 
(Tween-80) 
______________________________________ 
Another more preferred parenteral formulation comprises HECPT formulated 
for dilution prior to parenteral administration made of 1 part HECPT in 2 
ml of nonaqueous solvents including 1 to 10 parts Cremaphor EL 
(polyoxyethylated castor oil), 0.1 to 2 parts dehydrated ethyl alcohol 
USP, dimethylisosorbide 1 to 10 parts, and citric acid 0.1-0.9 parts to 
adjust the final pH to between 3 to 4. 
This preferred embodiment of an HECPT solution in dimethylisosorbide is as 
follows: 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
10-hydroxy 7-ethyl 
1 
Camptothecin 
Cremaphor EL 1-10 
EtOH 0.1-2.0 
Citric Acid 0.01-0.5 
Dimethylisosorbide 
1-10 
______________________________________ 
Dosages and Schedules for Parenteral Administration of HECPT Compositions 
Another embodiment of this invention is a method of administration of 
lactone stable HECPT to a patient with cancer comprising infusing a fixed 
amount of HECPT over a period of time and repeated at predetermined 
intervals. 
A more specific embodiment of the claimed invention is a method for 
administration of HECPT to a patient with cancer comprising infusing from 
about 2.0 mg/m.sup.2 to about 33.0 mg/m.sup.2 of lactone stable HECPT over 
a duration of approximately 120 minutes every 21 to 28 days. 
An additional embodiment of the claimed invention is a method for 
administration of HECPT to a patient with cancer comprising infusing from 
about 1.0 mg/m.sup.2 to about 16.0 mg/m.sup.2 of lactone stable HECPT over 
a duration of approximately 120 minutes for three consecutive days every 
21 to 28 days. 
Another embodiment of the claimed invention is a method for administration 
of HECPT to a patient with cancer comprising infusing from about 1.0 
mg/m.sup.2 to about 20.0 mg/m.sup.2 of lactone stable HECPT over a 
duration of approximately 120 minutes given once per week for three 
consecutive weeks with 2 weeks rest after each 3 week cycle. 
Another embodiment of the claimed invention is a method for administration 
of HECPT to a previously untreated patient with cancer comprising infusing 
from about 2.0 mg/m.sup.2 to about 24.0 mg/m.sup.2 of lactone stable HECPT 
over a duration of approximately 120 minutes given once per week for three 
consecutive weeks with 2 weeks rest after each 3 week cycle. 
Yet another embodiment of the claimed invention is a method for 
administration of HECPT to a patient with cancer comprising continuously 
infusing from about 0.1 mg/m.sup.2 /d to about 6.0 mg/m.sup.2 /d of 
lactone stable HECPT over a duration of approximately 24 to 120 hours 
every 21 to 28 days. 
Another embodiment of this invention when lactone stable HECPT is infused 
into a patient with cancer, is the HECPT is dissolved in 
dimethylisosorbide (DMI) in the presence of a pharmaceutically acceptable 
acid or the HECPT is dissolved in dimethylacetamide (DMA) in the presence 
of a pharmaceutically acceptable acid. 
Dosages and Schedules for Oral Administration of HECPT Compositions 
Another embodiment of this invention is a method of oral administration of 
HECPT to a patient with cancer comprising an amount of HECPT given, as a 
single dose or divided into smaller doses, over a specified amount of time 
and repeated after a fixed amount of time. 
More specifically, another embodiment of this invention is a method for 
oral administration of HECPT to a patient with cancer comprising 
administering from about 2.5 mg/m.sup.2 to about 100 mg/m.sup.2 of lactone 
stable HECPT in single or divided dosages within a 24 hour period every 21 
to 28 days. 
Yet another embodiment of this invention is a method for oral 
administration of HECPT to a patient with cancer comprising administering 
from about 1.0 mg/m.sup.2 to about 50 mg/m.sup.2 of lactone stable HECPT 
daily in single or divided doses for three consecutive days every 21 to 28 
days. 
Another embodiment of this invention is a method for oral administration of 
HECPT to a patient with cancer comprising administering from about 1.0 
mg/m.sup.2 to about 60.0 mg/m.sup.2 of lactone stable HECPT in single or 
divided dosages within a 24 hour period given once per week for three 
consecutive weeks with 2 weeks rest after each 3 week cycle. 
Another embodiment of this invention is a method for oral administration of 
HECPT to a previously untreated patient with cancer comprising 
administering from about 2.0 mg/m.sup.2 to about 75 mg/m.sup.2 of lactone 
stable HECPT in single or divided doses within a 24 hour period once per 
week for three consecutive weeks with 2 weeks rest after each 3 week 
cycle. 
For the purpose of this invention, a previously untreated patient is 
defined as a patient with cancer who has not been previously treated with 
any chemotherapeutic drugs. 
An additional embodiment of this invention is a method for oral 
administration of HECPT to a patient with cancer comprising administering 
from about 0.5 mg/m.sup.2 /d to about 18.0 mg/m.sup.2 /d of lactone stable 
HECPT in single or divided daily doses administered within each 24 hour 
period for two to five consecutive days and repeated every 21 to 28 days. 
Yet another embodiment of this invention for oral administration to a 
patient with cancer is the HECPT dissolved in dimethylisosorbide (DMI) in 
the presence of a pharmaceutically acceptable acid or the HECPT is 
dissolved in dimethylacetamide (DMA) in the presence of a pharmaceutically 
acceptable acid. 
A further embodiment of this invention is the claimed composition and 
method of administering the composition by encapsulating the claimed 
formulations within a hard gelatin capsule. Yet another embodiment of the 
claimed composition and method of administering the composition is 
encapsulating the claimed formulations within a soft gelatin capsule. One 
of ordinary skill in the art will know that any of the claimed 
formulations adapted for oral administration can be used as the fill for 
the soft or hard gelatin capsule. 
A more specific embodiment of the claimed invention is an oral formulation 
of HECPT in soft gelatin capsules (comprised of 
gelatin/glycerin/sorbitol/purifiers/purified water) containing 1.0 part of 
HECPT in a vehicle comprising citric acid 0.1 to 0.9 parts by weight, 
purified water 1 part by weight, glycerin 1 to 10 parts by weight, 
polyethylene glycol (molecular weight 200 to 300) 5 to 9 parts by weight, 
dehydrated ethyl alcohol 10 to 20% by weight of total solution weight, 
sodium acetate 0.05 to 0.5 parts by weight, a surfactant, and 1 to 10 
parts dimethylisosorbide. A more preferred oral formulation will include 
as a surfactant pluronic F-127 poloxamer using 0.05 to 1.0 parts by 
weight. 
Another preferred oral formulation will include the addition of taurocholic 
acid 2 to 10 parts by weight. The soft gelatin capsules may also be 
composed of any of a number of compounds used for this purpose including, 
for example, a mixture of gelatin, glycerin, sorbitol, purified water, and 
parabens. 
The table below indicates parts by weight of different components to be 
included in the oral formulation to be administered in capsules. Four 
components are marked with an "**" which denotes that the components are 
"optional."For the purpose of this invention, inclusion of these 
components depends on a variety of different factors; i.e. type of cancer 
the patient has, pretreated previously, etc. 
______________________________________ 
Ingredients Parts by Weight 
______________________________________ 
10-hydroxy 7-ethyl 
1 
Camptothecin 
Citric Acid 0.1-0.5 
Purified Water 0.5-1.5 
Glycerin** 0.4-2 
PEG 300 5-9 
EtOH 10-20% by weight of 
total solution weight 
Dimethylisosorbide 
1-10 
Poloxamer surfactant 
0.05-1.0 
(Pluronic F-127)** 
Sodium Acetate 0.05-0.5 
Taurocholic Acid 
2-10 
______________________________________ 
Clinicians will administer HECPT to human patients with cancer according to 
schedules that maximize its potential antitumor effects and diminish its 
potential toxic side effects. Except at extremely high doses which produce 
high plasma concentrations of the drugs, the antitumor activity of CPT-11 
and HECPT can be increased by increasing the duration of exposure (time 
dependent) rather than increasing the dose (dose dependent) of the drug. 
The greater antitumor effects associated with increasing the duration of 
exposure is a finding that is most likely related to the predominant 
S-phase mode of antitumor activity of CPT-11 and HECPT. HECPT is an 
S-phase-active agent; therefore, the greatest antitumor effect in humans 
will likely be observed with prolonged infusion or closely spaced 
repetitive administration schedules. Such schedules of administration 
would expose more cycling tumor cells to the drug and increase the 
frequency of exposure of the tumor cells in S-phase to sufficiently toxic 
levels of the drug. 
A further embodiment of this invention is that the claimed HECPT 
composition or claimed HECPT dissolved in DMI or dissolved in DMA can be 
used in a variety of different cancer types. The claimed formulations and 
compositions of the invention may be used in treatment of a number of 
tumors including, without limitation, human cancers of the lung, breast, 
colon, prostate, melanoma, pancreas, stomach, liver, brain, kidney, 
uterus, cervix, ovaries, and urinary tract. 
The site and type of tumor to be treated will, in many cases, influence the 
preferred route of administration and therapeutic regimen to be applied. 
Consequently, although the formulations of the invention may be most 
usually administered by intravenous injection or infusion, they also can 
be delivered directly into the tumor site or by other methods designed to 
target the drug directly to the tumor site. For example, in patients with 
malignant pleural effusion, the intrapleural route may be preferred; in 
patients with poor venous access the subcutaneous route of administration 
may be preferred; in patients with primary or metastatic cancer involving 
the brain or nervous system, the intracisternal or intrathecal route of 
administration may be most advantageous; in patients with malignant 
ascites secondary to cancer, one may select intraperitoneal 
administration; and in patients with bladder cancer direct intravesicular 
instillation may be most advantageous. Similarly, in tumors of the skin, 
the formulation may be topically applied. An oral formulation is also 
provided for use where suitable. 
Thus, an additional embodiment of this invention is an HECPT solution 
comprising HECPT dissolved in DMI or DMA, in the presence of a 
pharmaceutically acceptable acid and this solution is sterilized and 
prepared for oral, intrapleural, intrathecal, subcutaneous, 
intracisternal, intravesicular, intraperitoneal, topical or parenteral 
administration to a patient with cancer. 
The formulations of the claimed invention may also be used in conjunction 
with other drugs in methods of convergent therapy whereupon an additional 
drug or drugs are co-administered along with the claimed HECPT 
composition. Thus, HECPT may be co-administered with CPT-11, topotecan, 
camptothecin, or 10,11 methylenedioxy camptothecin, using a 
pharmaceutically acceptable carrier, and the co-administration is based on 
an optimal dosage and schedule. For example, in a preferred embodiment, 
CPT-11 may be co-administered with HECPT. Also, HECPT may be 
co-administered with a combination of CPT-11, topotecan, camptothecin, and 
10,11 methylenedioxy camptothecin, using a pharmaceutically acceptable 
carrier, and the co-administration is based on an optimal dosage and 
schedule. For example, CPT-11 and topotecan may be co-administered with 
the claimed HECPT. 
A further embodiment of claimed HECPT is a method of treatment of cancer in 
humans with convergent therapy or combination therapy. This method uses 
10-hydroxy 7ethyl camptothecin dissolved in dimethylisosorbide (DMI) or 
dimethylacetamide in (DMA), in the presence of pharmaceutically acceptable 
acid and co-administers it with additional drugs selected from the group 
consisting of, but not limited to, carmustine, azathioprine, cisplatinum, 
carboplatin, iproplatin, cyclophosphamide, ifosfamide, etoposide, ara-C, 
doxorubicin, daunorubicin, nitrogen mustard, 5-fluorouracil, bleomycin, 
mitomycin-C, fluoxymesterone, mechlorethamine, teniposide, 
hexamethylmelamine, leucovorin, melphelan, methotrexate, mercaptopurine, 
mitoxantrone, BCNU, CCNU, procarbazine, vincristine, vinblastine, 
vindesine, thioTEPA, amsacrine, G-CSF, GM-CSF, erythropoietin, 
.gamma.-methylene-10-deazaaminopterin or .gamma.-methylene- 10-ethyl- 
10-deazaaminopterin, taxol, and 5-azacytidine. For the purpose of this 
invention, the terms convergent, co-administered, and combination are used 
interchangeably. 
HECPT in DMI or DMA when administered parenterally, is preferably diluted 
with an appropriate volume of a parenteral vehicle to a concentration of 
about 0.1 mg/ml or lower of HECPT activity. A further embodiment of the 
claimed invention is a sterile solution of any of the claimed HECPT 
compositions and formulations for sterile administration to a patient with 
cancer upon dilution with a sterile parenteral vehicle. For the purposes 
of this invention, parenteral vehicles include dextrose 5 to 10% in water, 
0.9% NaCl in water with or without 5% or 10% Dextrose, 0.45% NaCl in water 
with or without 5% or 10% Dextrose, and 3% NaCl in water with or without 
5% to 10% Dextrose, or sterile lipid formulations, such as intralipid, 
used for parenteral nutritional support for cancer patients.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
In its preferred embodiments, this invention involves preparation and 
administration of novel lactone stable HECPT formulations as described 
below. 
EXAMPLES 
The following examples illustrate selected modes for carrying out the 
claimed invention and are not to be construed as limiting the 
specification and claims in any way. 
EXAMPLE 1 
For injection or infusion into aqueous body fluids, a formulation comprises 
from about 0.1 to about 2.0 mg of HECPT dissolved in 1 to 10 parts of 
dimethylisosorbide in an acidified vehicle comprising between about 10 to 
about 40 percent of an acceptable alcohol, about 4 to about 10 parts by 
weight of polyether glycol, and about 1 to about 10 parts of a non-ionic 
surfactant. Suitable alcohols include dehydrated ethyl alcohol, benzyl 
alcohol. Suitable polyether glycols, include polyethylene glycol 200, 
polyethylene glycol 300, propylene glycol. Suitable non-ionic surfactants 
include polysorbate-80. In a preferred embodiment, the formulation of 
HECPT is supplied as an intravenous injectable in a 1 mg vial comprising a 
sterile, nonaqueous solution of drug in a vehicle comprising dehydrated 
ethyl alcohol, benzyl alcohol, citric acid, polyethylene glycol 300, and 
polysorbate (Tween 80) in acidified medium with a pH of 3 to 4 at a final 
concentration of 1 mg per 1 to 2 ml. 
EXAMPLE 2 
A second formulation comprises from about 0.1 mg to about 2.0 mg of HECPT 
in an acidified vehicle comprising between about 0.1 to 2 parts of an 
alcohol and about 1 to 10 parts of a non-ionic surfactant. Suitable 
alcohols include dehydrated ethyl alcohol USP, and benzyl alcohol. 
Suitable non-ionic surfactants include the polyoxyethylated oils, such as 
polyoxyethylated vegetable oils, such as castor oil, peanut oil, and olive 
oil. In a preferred embodiment 0.1 mg to 2 mg HECPT is formulated in 1 to 
10 parts of dimethylisosorbide, 1 to 10 parts of Cremaphor EL 
(polyoxyethylated castor oil), 0.1 to 2 parts by weight dehydrated ethyl 
alcohol USP, and 0.1 to 0.9 parts citric acid to adjust the final pH 
between 3 to 4. 
EXAMPLE 3 
An oral formulation of HECPT in soft gelatin capsules (comprised of 
gelatin/glycerin/sorbitol/purifiers/purified water) containing 1.0 part of 
HECPT in 1 to 10 parts of dimethylisosorbide, citric acid 0.1 to 0.5 parts 
by weight, purified water 1 part by weight, glycerin 1 to 10 parts by 
weight, and polyethylene glycol 200 to 300 5 to 9 parts by weight, 
dehydrated ethyl alcohol 0.2 to 2 parts by weight of total solution 
weight, sodium acetate 0.05 to 0.5 parts by weight, pluronic F-127 
poloxamer using 0.05 to 1.0 parts by weight, and taurocholic acid 2 to 10 
parts by weight. The soft gelatin capsules may also be composed of any of 
a number of compounds used for this purpose including, for example, a 
mixture of gelatin, glycerin, sorbitol, purified water, and parabens. 
To prolong the stability and solubility of HECPT for clinical infusions, 
the drug may diluted in 5% Dextrose in water (D5W) to a final 
concentration of 0.001 mg/ml to about 0.1 mg/ml of HECPT prior to 
injection or infusion. 
Maintaining an acidic pH (3 to 4) in the formulation is particularly 
important to reduce the slow conversion of HECPT lactone to the 
E-ring-hydrolyzed carboxylate, which occurs at physiological pH. At 
equilibrium under physiologic pH, the ratio of the open-ring form to 
lactone increases. Hydrolysis of the lactone ring will be substantially 
reduced if the drug is kept in an acidic environment. Some of the 
unpredictable toxicity seen in earlier clinical trials using sodium 
camptothecin may have been due to the formation of greater amounts of the 
lactone form of camptothecin, which is 10-fold more toxic than sodium 
camptothecin in mice. The lactone form of camptothecin, as in HECPT, is 
less water soluble than the carboxylate E-ring form. When early clinical 
trials were first conducted with camptothecin using NaOH, the significance 
of maintaining the closed lactone ring for uniform efficacy in treating 
patients with cancer was poorly understood. The early reported 
unpredictable clinical toxicities associated with camptothecin 
administration may have been exacerbated by the NaOH formulation which 
promotes the formation of the carboxylate form, and by the relative lack 
of understanding of the significance of the lactone form of camptothecin 
as it relates to antitumor activity. 
The foregoing description of the formulation invention has been directed to 
particular preferred embodiments in accordance with the requirements of 
the patent statutes and for purposes of explanation and illustration. 
Those skilled in the art will recognize that many modifications and 
changes may be made without departing from the scope and the spirit of the 
invention. 
Initially, patients may be treated in a dose escalation protocol to 
determine the maximal tolerated dose of the HECPT formulation. In 
determining a safe starting dose for HECPT, the data from Tables 3 and 4 
are helpful. For the purpose of this invention, "AUC" is defined as "area 
under the curve" and "CpMax" is defined as "the maximum plasma concentrate 
at the end of I.V. infusion." 
TABLE 3 
__________________________________________________________________________ 
Analysis of AUC and CpMax Ratios of CPT-11:HECPT 
AUC CpMax 
CPT-11 
AUC Ratio AUC 
CPT- CpMax Ratio 
(ug .times. 
HECPT CPT- 11:HECPT 
CPT 
hr/ml) 
(ug .times. hr/ml) 
11/HECPT 
(ug/ml) 
11:HECPT 
__________________________________________________________________________ 
Ohe et al. 
25 mg/m.sup.2 /d .times. 5 
14.1 1.08 13.0 1.178:0.0104 
11.3:1 
30 mg/m.sup.2 /d .times. 5 
20.5 0.96 21.3 1.500:0.0105 
14.2:1 
35 mg/m.sup.2 /d .times. 5 
20.5 0.91 22.5 1.538:0.0068 
22.6:1 
40 mg/m.sup.2 /d .times. 5 
28.5 0.86 33.1 2.043:0.0080 
25.5:1 
Rothenberg et al. 
50 mg/m.sup.2 /wk .times. 4 
1.13 0.0622 18.1 0.89:0.0264 
33.7:1 
100 mg/m.sup.2 /wk .times. 4 
2.23 0.2148 10.4 1.29:0.0316 
98.0:1 
125 mg/m.sup.2 /wk .times. 4 
2.97 0.1955 15.2 1.70:0.0393 
43.2:1 
150 mg/m.sup.2 /wk .times. 4 
2.81 0.1232 22.8 1.56:0.0367 
42.5:1 
180 mg/m.sup.2 /wk .times. 4 
3.83 0.2328 16.5 1.97:0.0262 
75.2:1 
__________________________________________________________________________ 
TABLE 4 
______________________________________ 
Fractional Amounts of Lactone Species of CPT-11 and HECPT as 
Function of Increasing Single Dose I.V. From Rothenberg et. al. 
CPT-11 HECPT 
CPT-11 HECPT CpMax CpMax 
Dose AUC Based AUC Based Based Based 
______________________________________ 
50 mg/m.sup.2 
0.41 0.29 0.51 0.50 
80 mg/m.sup.2 
0.30 0.50 0.44 0.39 
100 mg/m.sup.2 
0.33 0.58 0.53 0.45 
125 mg/m.sup.2 
0.39 0.43 0.55 0.41 
150 mg/m.sup.2 
0.33 0.30 0.42 0.36 
180 mg/m.sup.2 
0.33 0.63 0.42 0.45 
______________________________________ 
Data obtained using the continuous infusion schedule of Ohe et al. shows 
that the ratio CPT-11 to HECPT AUCs increases gradually as a function of 
dose and that this increase is substantially more marked in a single dose 
study. The data in Table 3 supports the conclusion that conversion of 
CPT-11 to HECPT is a saturable process which is variable among patients, 
and that increases in the dose (e.g., above 30 mg/m.sup.2 /d) of CPT-11 
can result in a decrease in the CpMax of HECPT using a 5 day continuous 
infusion schedule. Although the factors involved in interpatient 
variability is not completely understood, some variability in the 
pharmacology and metabolic conversion of CPT-11 to HECPT probably exists 
based on the pharmacologic data reported from several investigators. This 
variability in the conversion of CPT-11 to HECPT is likely to be a result 
in instances of unexpected toxicity or lack of clinical effect by the use 
of CPT-11. In Table 4, the overall fractional concentration of the lactone 
species of CPT-11 and HECPT appear to remain fairly constant through a 
range of doses. 
The administration of HECPT may be carried out using various schedules and 
dosages. For example: 
1. For intravenous administration, a suitable dose is 0.45 mg to 5.4 
mg/m.sup.2 per day using a 3 to 5 day continuous infusion schedule every 
21 to 30 days or 2.7 to 32.4 mg/m.sup.2 given as a 30 to 90 minute 
infusion every 21 to 30 days. 
2. Another schedule involves the administration of 1.2 to 15.5 mg/m.sup.2 
daily for three consecutive days over 90 minutes intravenously every 21 to 
28 days. 
3. A suitable oral dose of the drug is 0.5 to 50 mg/m.sup.2 per day using 
the lower dose for a period of 3 to 5 days and using divided dosages of 
administration of two to four times per day. 
The parenteral and oral doses can be administered under the supervision of 
a physician based on gradual escalation of the dosage to achieve the 
maximum tolerated dose in the individual patient. The oral administration 
schedule of HECPT may involve multiple daily doses or single daily doses 
for one or more consecutive days with the ability of the physician to 
optimize therapy by reaching the maximum effective antitumor dose that has 
the least toxicity in the individual patient. 
In addition, patients may be given the lactone stable HECPT as an inpatient 
or outpatient using the following exemplary schedules: 
1) 2.7 to 32.4 mg/m.sup.2 given over 90 minutes I.V. every 21 to 28 days; 
2) 1.2 to 15.5 mg/m.sup.2 given daily for three consecutive days over 90 
minutes I.V. every 21 to 28 days; 
3) 1.0 to 20.0 mg/m.sup.2 week given once per week.times.3 consecutive 
weeks over 90 minutes I.V. with 2 weeks rest after each 3 week cycle for 
pretreated patients; 
4) 2.25 to 24.3 mg/m.sup.2 given once per week.times.3 consecutive weeks 
over 90 minutes I.V. for previously untreated patients with 2 weeks rest 
after each 3 week cycle; and 
5) 0.45 to 5.4 mg/m.sup.2 /d.times.3 to 5 consecutive days as a continuous 
I.V. infusion every 21 to 28 days. 
In a preferred embodiment, HECPT is initially given at a lower dose. The 
dose of HECPT is then escalated at each successive cycle of treatment 
until the patient develops side effects which demonstrates individual 
therapeutic tolerance. The purpose of dose escalation is to safely 
increases the drug levels to a maximum tolerated dose and should result in 
increased cytotoxicity and improved antitumor activity. 
Dosages can be escalated based on patient tolerance as long as unacceptable 
toxicity is not observed. "Unacceptable toxicity" is defined by World 
Health Organization (WHO) as grade 3 non-hematologic toxicity excluding 
nausea and vomiting and grade 4 vomiting or hematologic toxicity according 
to the National Cancer Institute common toxicity criteria. Since some 
clinical drug toxicity is anticipated in routine clinical oncology 
practice, appropriate treatment will be used to prevent toxicity (e.g., 
nausea and vomiting) or ameliorate signs and symptoms if they are observed 
(e.g., diarrhea). For example, antiemetics will be administered for nausea 
and vomiting, antidiarrheals for diarrhea, and antipyretics for fever. 
Appropriate dosages of steroids/antihistamines will also be used to 
prevent or ameliorate any anaphylactoid toxicity if an anaphylactoid 
reaction is observed. 
Kaneda's HPLC method and further modifications by Barilero et al. are 
useful for the measuring quantities of HECPT in plasma and tissue. In 
these assays, plasma, serum, and tissue homogenate samples containing 
HECPT are immediately diluted 10-fold with 0.1 N HCL to give final 
concentrations of about 100 ng/ml for HECPT. The diluted plasma or serum 
samples are applied to a C18 cassette of an automated sample processor 
(Analytichem International, Harbor City, Calif.), which is activated with 
1.5 ml of methanol and water. The HPLC apparatus (Model LC-4A; Shimadzu 
Seisakusho) is linked to the automated sample processor, and a C18 
reversed-phase column (LiChrosorb RP-18; 25.times.0.4 cm; Merck) with an 
RP-18 precolumn is used for chromatography. The mobile phases consists of 
CH.sub.3 CN/water (1/4,v/v) for HECPT. The flow rate and column 
temperature are 2.0 ml/min and 60 degrees Celsius for HECPT. A 
fluoro-spectromonitor (Model RF-530; Shimadzu Seisakusho) is set at an 
excitation wavelength of 373 nm and an emission wavelength of 380 nm and a 
wavelength of 540 nm for HECPT. The peak area is integrated by a data 
processor (Model C-R1BS Chromatopac; Shimadzu Seisakusho). HECPT gives 
retention times of 13.8 min. Calibration curves are established for each 
determination by 10% mouse serum in 0.1 N HCL containing HECPT. 
Validations of HECPT determinations will be made by running samples versus 
real standards. The limit of determination is about 1 to 5 ng for HECPT 
using this assay. 
REFERENCES 
The following references may facilitate understanding or practice of 
certain aspects of the present invention. Inclusion of a reference in this 
list is not intended to and does not constitute an admission that the 
reference represents prior art with respect to the present invention. 
______________________________________ 
U.S. Pat. No. 
______________________________________ 
4,545,880 10/85 Miyasaka et al. 
4,473,692 9/84 Miyasaka et al. 
4,778,891 10/88 Tagawa et al. 
5,061,800 10/91 Miyasaka et al. 
______________________________________ 
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The foregoing description has been directed to particular embodiments of 
the invention in accordance with requirements of the Patent Statutes for 
the purposes of illustration and explanation. It will be apparent, 
however, to those skilled in this art, that many modifications, changes 
and variations in the claimed antitumor compositions, solutions, methods 
of administration of the antitumor compositions set forth will be possible 
without departing from the scope and spirit of the claimed invention. It 
is intended that the following claims be interpreted to embrace all such 
modifications and changes.