CLINICAL PHARMACOLOGY
Mechanism Of Action
Caspofungin is an echinocandin antifungal drug [see Microbiology].
Pharmacokinetics
Adult and pediatric pharmacokinetic parameters are presented in Table 8.
Distribution
Plasma concentrations of caspofungin decline in a polyphasic manner following single 1-hour IV
infusions. A short α-phase occurs immediately postinfusion, followed by a β-phase (half-life of 9 to
11 hours) that characterizes much of the profile and exhibits clear log-linear behavior from 6 to 48 hours
postdose during which the plasma concentration decreases 10-fold. An additional, longer half-life phase,
γ-phase, (half-life of 40-50 hours), also occurs. Distribution, rather than excretion or biotransformation, is
the dominant mechanism influencing plasma clearance. Caspofungin is extensively bound to albumin
(~97%), and distribution into red blood cells is minimal. Mass balance results showed that approximately
92% of the administered radioactivity was distributed to tissues by 36 to 48 hours after a single 70-mg
dose of [3H] CANCIDAS. There is little excretion or biotransformation of caspofungin during the first
30 hours after administration.
Metabolism
Caspofungin is slowly metabolized by hydrolysis and N-acetylation. Caspofungin also undergoes
spontaneous chemical degradation to an open-ring peptide compound, L-747969. At later time points
(≥5 days postdose), there is a low level (≤7 picomoles/mg protein, or ≤1.3% of administered dose) of
covalent binding of radiolabel in plasma following single-dose administration of [3H] CANCIDAS, which
may be due to two reactive intermediates formed during the chemical degradation of caspofungin to
L-747969. Additional metabolism involves hydrolysis into constitutive amino acids and their degradates,
including dihydroxyhomotyrosine and N-acetyl-dihydroxyhomotyrosine. These two tyrosine derivatives are
found only in urine, suggesting rapid clearance of these derivatives by the kidneys.
Excretion
Two single-dose radiolabeled pharmacokinetic studies were conducted. In one study, plasma, urine,
and feces were collected over 27 days, and in the second study plasma was collected over 6 months.
Plasma concentrations of radioactivity and of caspofungin were similar during the first 24 to 48 hours
postdose; thereafter drug levels fell more rapidly. In plasma, caspofungin concentrations fell below the
limit of quantitation after 6 to 8 days postdose, while radiolabel fell below the limit of quantitation at
22.3 weeks postdose. After single intravenous administration of [3H] CANCIDAS, excretion of caspofungin
and its metabolites in humans was 35% of dose in feces and 41% of dose in urine. A small amount of
caspofungin is excreted unchanged in urine (~1.4% of dose). Renal clearance of parent drug is low
(~0.15 mL/min) and total clearance of caspofungin is 12 mL/min.
Special Populations
Renal Impairment
In a clinical study of single 70-mg doses, caspofungin pharmacokinetics were similar in healthy adult
volunteers with mild renal impairment (creatinine clearance 50 to 80 mL/min) and control subjects.
Moderate (creatinine clearance 31 to 49 mL/min), severe (creatinine clearance 5 to 30 mL/min), and end-
stage (creatinine clearance less than 10 mL/min and dialysis dependent) renal impairment moderately
increased caspofungin plasma concentrations after single-dose administration (range: 30 to 49% for
AUC). However, in adult patients with invasive aspergillosis, candidemia, or other Candida infections
(intra-abdominal abscesses, peritonitis, or pleural space infections) who received multiple daily doses of
CANCIDAS 50 mg, there was no significant effect of mild to end-stage renal impairment on caspofungin
concentrations. No dosage adjustment is necessary for patients with renal impairment. Caspofungin is not
dialyzable, thus supplementary dosing is not required following hemodialysis.
Hepatic Impairment
Plasma concentrations of caspofungin after a single 70-mg dose in adult patients with mild hepatic
impairment (Child-Pugh score 5 to 6) were increased by approximately 55% in AUC compared to healthy
control subjects. In a 14-day multiple-dose study (70 mg on Day 1 followed by 50 mg daily thereafter),
plasma concentrations in adult patients with mild hepatic impairment were increased modestly (19 to 25%
in AUC) on Days 7 and 14 relative to healthy control subjects. No dosage adjustment is recommended for
patients with mild hepatic impairment.
Adult patients with moderate hepatic impairment (Child-Pugh score 7 to 9) who received a single
70-mg dose of CANCIDAS had an average plasma caspofungin increase of 76% in AUC compared to
control subjects. A dosage reduction is recommended for adult patients with moderate hepatic impairment
based upon these pharmacokinetic data [see DOSAGE AND ADMINISTRATION].
There is no clinical experience in adult patients with severe hepatic impairment (Child-Pugh
score greater than 9) or in pediatric patients with any degree of hepatic impairment.
Gender
Plasma concentrations of caspofungin in healthy adult men and women were similar following a single
70-mg dose. After 13 daily 50-mg doses, caspofungin plasma concentrations in women were elevated
slightly (approximately 22% in area under the curve [AUC]) relative to men. No dosage adjustment is
necessary based on gender.
Race
Regression analyses of patient pharmacokinetic data indicated that no clinically significant differences
in the pharmacokinetics of caspofungin were seen among Caucasians, Blacks, and Hispanics. No dosage
adjustment is necessary on the basis of race.
Geriatric Patients
Plasma concentrations of caspofungin in healthy older men and women (65 years of age and older)
were increased slightly (approximately 28% AUC) compared to young healthy men after a single 70-mg
dose of caspofungin. In patients who were treated empirically or who had candidemia or other Candida
infections (intra-abdominal abscesses, peritonitis, or pleural space infections), a similar modest effect of
age was seen in older patients relative to younger patients. No dosage adjustment is necessary for the
elderly [see Use In Specific Populations].
Pediatric Patients
CANCIDAS has been studied in five prospective studies involving pediatric patients under 18 years of
age, including three pediatric pharmacokinetic studies [initial study in adolescents (12-17 years of age)
and children (2-11 years of age) followed by a study in younger patients (3-23 months of age) and then
followed by a study in neonates and infants (less than 3 months of age)] [see Use In Specific Populations].
Pharmacokinetic parameters following multiple doses of CANCIDAS in pediatric and adult patients are
presented in Table 8.
Table 8: Pharmacokinetic Parameters Following Multiple Doses of CANCIDAS
in Pediatric (3 months to 17 years) and Adult Patients
Population |
N |
Daily
Dose |
Pharmacokinetic Parameters
(Mean ± Standard Deviation) |
AUC0-24hr
(μg·hr/mL) |
C1hr
(μg/mL) |
C24hr
(μg/mL) |
t1/2
(hr)* |
CI
(mL/min) |
PEDIATRIC PATIENTS |
Adolescents, Aged 12-17 years |
8 |
50
mg/m2 |
124.9 ±
50.4 |
14.0 ±
6.9 |
2.4 ± 1.0 |
11.2 ±
1.7 |
12.6 ±
5.5 |
Children, Aged 2-11 years |
9 |
50
mg/m2 |
120.0 ±
33.4 |
16.1 ±
4.2 |
1.7 ± 0.8 |
8.2 ± 2.4 |
6.4 ± 2.6 |
Young Children, Aged 3-23
months |
8 |
50
mg/m2 |
131.2 ±
17.7 |
17.6 ±
3.9 |
1.7 ± 0.7 |
8.8 ± 2.1 |
3.2 ± 0.4 |
ADULT PATIENTS |
Adults with Esophageal
Candidiasis |
6† |
50 mg |
87.3 ± 30.0 |
8.7 ±
2.1 |
1.7 ± 0.7 |
13.0 ±
1.9 |
10.6 ±
3.8 |
Adults receiving Empirical
Therapy |
119
‡ |
50 mg§ |
-- |
8.0 ±
3.4 |
1.6 ± 0.7 |
-- |
-- |
* Harmonic Mean ± jackknife standard deviation
† N=5 for C1hr and AUC0-24hr; N=6 for C24hr
‡ N=117 for C24hr; N=119 for C1hr
§ Following an initial 70-mg loading dose on day 1 |
Drug Interactions [see DRUG INTERACTIONS]
Studies in vitro show that caspofungin acetate is not an inhibitor of any enzyme in the cytochrome P
(CYP) system. Caspofungin is not a substrate for P-glycoprotein and is a poor substrate for CYP
enzymes.
In clinical studies, caspofungin did not induce the CYP3A4 metabolism of other drugs. Clinical studies
in adult healthy volunteers also demonstrated that the pharmacokinetics of caspofungin are not altered by
itraconazole, amphotericin B, mycophenolate, nelfinavir, or tacrolimus. Caspofungin has no effect on the
pharmacokinetics of itraconazole, amphotericin B, or the active metabolite of mycophenolate.
Cyclosporine
In two adult clinical studies, cyclosporine (one 4 mg/kg dose or two 3 mg/kg doses)
increased the AUC of caspofungin by approximately 35%. CANCIDAS did not increase the plasma levels
of cyclosporine. There were transient increases in liver ALT and AST when CANCIDAS and cyclosporine
were co-administered [see WARNINGS AND PRECAUTIONS].
Tacrolimus
CANCIDAS reduced the blood AUC0-12 of tacrolimus (FK-506, Prograf®) by approximately
20%, peak blood concentration (Cmax) by 16%, and 12-hour blood concentration (C12hr) by 26% in healthy
adult subjects when tacrolimus (2 doses of 0.1 mg/kg 12 hours apart) was administered on the 10th day of
CANCIDAS 70 mg daily, as compared to results from a control period in which tacrolimus was
administered alone. For patients receiving both therapies, standard monitoring of tacrolimus whole blood
trough concentrations and appropriate tacrolimus dosage adjustments are recommended.
Rifampin
A drug-drug interaction study with rifampin in adult healthy volunteers has shown a 30%
decrease in caspofungin trough concentrations [see DOSAGE AND ADMINISTRATION].
Other Inducers of Hepatic CYP Enzymes
Adults:
Results from regression analyses of adult patient pharmacokinetic data suggest that
co-administration of other hepatic CYP enzyme inducers (e.g., efavirenz, nevirapine, phenytoin,
dexamethasone, or carbamazepine) with CANCIDAS may result in clinically meaningful reductions in
caspofungin concentrations. It is not known which drug clearance mechanism involved in caspofungin
disposition may be inducible [see DOSAGE AND ADMINISTRATION].
Pediatric patients:
In pediatric patients, results from regression analyses of pharmacokinetic data
suggest that co-administration of dexamethasone with CANCIDAS may result in clinically meaningful
reductions in caspofungin trough concentrations. This finding may indicate that pediatric patients will have
similar reductions with inducers as seen in adults [see DOSAGE AND ADMINISTRATION].
Microbiology
Mechanism Of Action
Caspofungin, an echinocandin, inhibits the synthesis of beta (1,3)-D-glucan, an essential component of
the cell wall of susceptible Aspergillus species and Candida species. Beta (1,3)-D-glucan is not present in
mammalian cells. Caspofungin has shown activity against Candida species and in regions of active cell
growth of the hyphae ofAspergillus fumigatus.
Drug Resistance
There have been reports of clinical failures in patients receiving caspofungin therapy due to the
development of drug resistance. Some of these reports have identified specific mutations in the Fks
subunits of the glucan synthase enzyme. These mutations are associated with higher MICs and
breakthrough infection. Candida species that exhibit reduced susceptibility to caspofungin as a result of an
increase in the chitin content of the fungal cell wall have also been identified, although the significance of
this phenomenon in vivo is not well known.
Drug Interactions
Studies in vitro and in vivo of caspofungin, in combination with amphotericin B, suggest no antagonism
of antifungal activity against either A. fumigatus or C. albicans. The clinical significance of these results is
unknown.
Activity In Vitro And In Clinical Infections
Caspofungin has been shown to be active both in vitro and in clinical infections against most strains
of the following microorganisms:
Aspergillus fumigatus
Aspergillus flavus
Aspergillus terreus
Candida albicans
Candida glabrata
Candida guilliermondii
Candida krusei
Candida parapsilosis
Candida tropicalis
Susceptibility Testing Methods
The interpretive standards for caspofungin against Candida species are applicable only to tests
performed using Clinical Laboratory and Standards Institute (CLSI) microbroth dilution reference
methods2,3 for MIC (partial inhibition endpoint) read at 24 hours. No interpretive criteria have been
established for Aspergillus species or other filamentous fungi.
When available, the clinical microbiology laboratory should provide the results of in vitro susceptibility
test results for antimicrobial drug products used in resident hospitals to the physician as periodic reports
that describe the susceptibility profile of pathogens. These reports should aid the physician in selecting an
antifungal drug product for treatment. The techniques for Broth Microdilution are described below.
Broth Microdilution Techniques
Quantitative methods are used to determine antifungal minimum inhibitory concentrations (MICs).
These MICs provide estimates of the susceptibility of Candida spp. to antifungal agents. MICs should be
determined using a standardized procedure at 24 hours2,3. Standardized procedures are based on a
microdilution method (broth) with standardized inoculum concentrations and standardized concentrations
of caspofungin powder. The MIC values should be interpreted according to the criteria provided in Table 9.
Table 9: Susceptibility Interpretive Criteria for Caspofungin
Pathogen |
Broth Microdilution MIC* (mcg/mL) at 24 hours |
Susceptible (S) |
Non-Susceptible (NS) |
Candida species |
≤2 |
>2 |
* A report of “Susceptible” indicates that he pathogen is likely to be inhibited if the antimicrobial compound in the blood reaches the
concentrations usually achievable. |
Quality Control
Standardized susceptibility test procedures require the use of quality control organisms to control the
technical aspects of the test procedures. Standard caspofungin powder should provide the following range
of values noted in Table 103. Quality control microorganisms are specific strains of organisms with intrinsic
biological properties relating to resistance mechanisms and their genetic expression within fungi; the
specific strains used for microbiological control are not clinically significant.
Table 10: Acceptable Quality Control Ranges for caspofungin to be used in Validation of
Susceptibility Test Results
QC Strain |
Broth Microdilution
(MIC in mcg/mL) at 24 hours* |
Candida parapsilosis ATCC 22019 |
0.25 – 1.0 |
Candida krusei ATCC 6258 |
0.12 – 1.0 |
*The MIC for caspofungin is the lowest concentration at which a score of 2 (prominent decrease in turbidity [> 50% inhibition of
growth as compared to the growth control]; see CLSI document M27-A32, Section 7.6.3) is observed after 24 hours of incubation. |
Animal Toxicology And/Or Pharmacology
In one 5-week study in monkeys at doses which produced exposures approximately 4 to 6 times those
seen in adult patients treated with a 70-mg dose, scattered small foci of subcapsular necrosis were
observed microscopically in the livers of some animals (2/8 monkeys at 5 mg/kg and 4/8 monkeys at
8 mg/kg); however, this histopathological finding was not seen in another study of 27 weeks duration at
similar doses.
No treatment-related findings were seen in a 5-week study in infant monkeys at doses which produced
exposures approximately 3 times those achieved in pediatric patients receiving a maintenance dose of
50 mg/m2 daily.
Clinical Studies
Empirical Therapy In Febrile, Neutropenic Patients
A double-blind study enrolled 1111 febrile, neutropenic (<500 cells/mm3) patients who were
randomized to treatment with daily doses of CANCIDAS (50 mg/day following a 70-mg loading dose on
Day 1) or AmBisome (3 mg/kg/day). Patients were stratified based on risk category (high-risk patients had
undergone allogeneic stem cell transplantation or had relapsed acute leukemia) and on receipt of prior
antifungal prophylaxis. Twenty-four percent of patients were high risk and 56% had received prior
antifungal prophylaxis. Patients who remained febrile or clinically deteriorated following 5 days of therapy
could receive 70 mg/day of CANCIDAS or 5 mg/kg/day of AmBisome. Treatment was continued to
resolution of neutropenia (but not beyond 28 days unless a fungal infection was documented).
An overall favorable response required meeting each of the following criteria: no documented
breakthrough fungal infections up to 7 days after completion of treatment, survival for 7 days after
completion of study therapy, no discontinuation of the study drug because of drug-related toxicity or lack of
efficacy, resolution of fever during the period of neutropenia, and successful treatment of any documented
baseline fungal infection.
Based on the composite response rates, CANCIDAS was as effective as AmBisome in empirical
therapy of persistent febrile neutropenia (see Table 11).
Table 11: Favorable Response of Patients with Persistent Fever and Neutropenia
|
CANCIDAS* |
AmBisome* |
% Difference
(Confidence Interval)† |
Number of Patients‡ |
556 |
539 |
|
Overall Favorable Response |
190 (33.9%) |
181 (33.7%) |
0.2 (-5.6, 6.0) |
No documented breakthrough fungal infection |
527 (94.8%) |
515 (95.5%) |
-0.8 |
Survival 7 days after end of treatment |
515 (92.6%) |
481 (89.2%) |
3.4 |
No discontinuation due to toxicity or lack of
efficacy |
499 (89.7%) |
461 (85.5%) |
4.2 |
Resolution of fever during neutropenia |
229 (41.2%) |
223 (41.4%) |
-0.2 |
* CANCIDAS: 70 mg on Day 1, then 50 mg once daily for the remainder of treatment (daily dose increased to 70 mg for 73 patients);
AmBisome: 3 mg/kg/day (daily dose increased to 5 mg/kg for 74 patients).
† Overall Response: estimated % difference adjusted for strata and expressed as CANCIDAS – AmBisome (95.2% CI); Individual criteria
presented above are not mutually exclusive. The percent difference calculated as CANCIDAS – AmBisome.
‡Analysis population excluded subjects who did not have fever or neutropenia at study entry. |
The rate of successful treatment of documented baseline infections, a component of the primary
endpoint, was not statistically different between treatment groups.
The response rates did not differ between treatment groups based on either of the stratification
variables: risk category or prior antifungal prophylaxis.
Candidemia And the Following Other Candida Infections: Intra-Abdominal Abscesses,
Peritonitis And Pleural Space Infections
In a randomized, double-blind study, patients with a proven diagnosis of invasive candidiasis received
daily doses of CANCIDAS (50 mg/day following a 70-mg loading dose on Day 1) or amphotericin B
deoxycholate (0.6 to 0.7 mg/kg/day for non-neutropenic patients and 0.7 to 1 mg/kg/day for neutropenic
patients). Patients were stratified by both neutropenic status and APACHE II score. Patients with Candida
endocarditis, meningitis, or osteomyelitis were excluded from this study.
Patients who met the entry criteria and received one or more doses of IV study therapy were included
in the modified intention-to-treat [MITT] analysis of response at the end of IV study therapy. A favorable
response at this time point required both symptom/sign resolution/improvement and microbiological
clearance of the Candida infection.
Two hundred thirty-nine patients were enrolled. Patient disposition is shown in Table 12.
Table 12: Disposition in Candidemia and Other Candida Infections (Intra-abdominal abscesses, peritonitis,
and pleural space infections)
|
CANCIDAS* |
Amphotericin B |
Randomized patients |
114 |
125 |
Patients completing study† |
63 (55.3%) |
69 (55.2%) |
DISCONTINUATIONS OF STUDY† |
All Study Discontinuations |
51 (44.7%) |
56 (44.8%) |
Study Discontinuations due to clinical adverse events |
39 (34.2%) |
43 (34.4%) |
Study Discontinuations due to laboratory adverse events |
0 (0%) |
1 (0.8%) |
DISCONTINUATIONS OF STUDY THERAPY |
All Study Therapy Discontinuations |
48 (42.1%) |
58 (46.4%) |
Study Therapy Discontinuations due to clinical adverse events |
30 (26.3%) |
37 (29.6%) |
Study Therapy Discontinuations due to laboratory adverse events |
1 (0.9%) |
7 (5.6%) |
Study Therapy Discontinuations due to all drug-related‡ adverse
events |
3 (2.6%) |
29 (23.2%) |
* Patients received CANCIDAS 70 mg on Day 1, then 50 mg once daily for the remainder of their treatment.
† Study defined as study treatment period and 6-8 week follow-up period.
‡ Determined by the investigator to be possibly, probably, or definitely drug-related. |
Of the 239 patients enrolled, 224 met the criteria for inclusion in the MITT population (109 treated with
CANCIDAS and 115 treated with amphotericin B). Of these 224 patients, 186 patients had candidemia (92
treated with CANCIDAS and 94 treated with amphotericin B). The majority of the patients with candidemia
were non-neutropenic (87%) and had an APACHE II score less than or equal to 20 (77%) in both arms.
Most candidemia infections were caused by C. albicans (39%), followed by C. parapsilosis (20%),
C. tropicalis (17%), C. glabrata (8%), and C. krusei (3%).
At the end of IV study therapy, CANCIDAS was comparable to amphotericin B in the treatment of
candidemia in the MITT population. For the other efficacy time points (Day 10 of IV study therapy, end of
all antifungal therapy, 2-week post-therapy follow-up, and 6- to 8-week post-therapy follow-up),
CANCIDAS was as effective as amphotericin B.
Outcome, relapse and mortality data are shown in Table 13.
Table 13: Outcomes, Relapse, & Mortality in Candidemia and Other Candida Infections (Intra-abdominal
abscesses, peritonitis, and pleural space infections)
|
CANCIDAS* |
Amphotericin B |
% Difference† after adjusting for strata
(Confidence
Interval)‡ |
Number of MITT§ patients |
109 |
115 |
|
FAVORABLE OUTCOMES (MITT) AT THE END OF IV STUDY THERAPY |
All MITT patients |
81/109 (74.3%) |
78/115 (67.8%) |
7.5 (-5.4, 20.3) |
Candidemia |
67/92 (72.8%) |
63/94 (67.0%) |
7.0 (-7.0, 21.1) |
Neutropenic |
6/14 (43%) |
5/10 (50%) |
|
Non-neutropenic |
61/78 (78%) |
58/84 (69%) |
|
Endophthalmitis |
0/1 |
2/3 |
|
Multiple Sites |
4/5 |
4/4 |
|
Blood / Pleural |
1/1 |
1/1 |
|
Blood / Peritoneal |
1/1 |
1/1 |
|
Blood / Urine |
- |
1/1 |
|
Peritoneal / Pleural |
1/2 |
- |
|
Abdominal / Peritoneal |
- |
1/1 |
|
Subphrenic / Peritoneal |
1/1 |
|
|
DISSEMINATED INFECTIONS, RELAPSES AND MORTALITY |
Disseminated Infections in neutropenic
patients |
4/14 (28.6%) |
3/10 (30.0%) |
|
All relapses¶ |
7/81 (8.6%) |
8/78 (10.3%) |
|
Culture-confirmed relapse |
5/81 (6%) |
2/78 (3%) |
|
Overall study# mortality in MITT |
36/109 (33.0%) |
35/115 (30.4%) |
|
Mortality during study therapy |
18/109 (17%) |
13/115 (11%) |
|
Mortality attributed to Candida |
4/109 (4%) |
7/115 (6%) |
|
* Patients received CANCIDAS 70 mg on Day 1, then 50 mg once daily for the remainder of their treatment.
† Calculated as CANCIDAS – amphotericin B
‡ 95% CI for candidemia, 95.6% for all patients
§ Modified intention-to-treat
¶ Includes all patients who either developed a culture-confirmed recurrence of Candida infection or required antifungal therapy for the
treatment of a proven or suspected Candida infection in the follow-up period.
# Study defined as study treatment period and 6-8 week follow-up period. |
In this study, the efficacy of CANCIDAS in patients with intra-abdominal abscesses, peritonitis and
pleural space Candida infections was evaluated in 19 non-neutropenic patients. Two of these patients had
concurrent candidemia. Candida was part of a polymicrobial infection that required adjunctive surgical
drainage in 11 of these 19 patients. A favorable response was seen in 9 of 9 patients with peritonitis, 3 of
4 with abscesses (liver, parasplenic, and urinary bladder abscesses), 2 of 2 with pleural space infections,
1 of 2 with mixed peritoneal and pleural infection, 1 of 1 with mixed abdominal abscess and peritonitis, and
0 of 1 with Candida pneumonia.
Overall, across all sites of infection included in the study, the efficacy of CANCIDAS was comparable
to that of amphotericin B for the primary endpoint.
In this study, the efficacy data for CANCIDAS in neutropenic patients with candidemia were limited. In
a separate compassionate use study, 4 patients with hepatosplenic candidiasis received prolonged
therapy with CANCIDAS following other long-term antifungal therapy; three of these patients had a
favorable response.
In a second randomized, double-blind study, 197 patients with proven invasive candidiasis received
CANCIDAS 50 mg/day (following a 70-mg loading dose on Day 1) or CANCIDAS 150 mg/day. The
diagnostic criteria, evaluation time points, and efficacy endpoints were similar to those employed in the
prior study. Patients with Candida endocarditis, meningitis, or osteomyelitis were excluded. Although this
study was designed to compare the safety of the two doses, it was not large enough to detect differences
in rare or unexpected adverse events [see ADVERSE REACTIONS]. The efficacy of CANCIDAS at the
150 mg daily dose was not significantly better than the efficacy of the 50-mg daily dose of CANCIDAS.
The efficacy of doses higher than 50 mg daily in the other adult patients for whom CANCIDAS is indicated
has not been evaluated.
Esophageal Candidiasis (And Information On Oropharyngeal Candidiasis)
The safety and efficacy of CANCIDAS in the treatment of esophageal candidiasis was evaluated in one
large, controlled, noninferiority, clinical trial and two smaller dose-response studies.
In all 3 studies, patients were required to have symptoms and microbiological documentation of
esophageal candidiasis; most patients had advanced AIDS (with CD4 counts <50/mm3).
Of the 166 patients in the large study who had culture-confirmed esophageal candidiasis at baseline,
120 had Candida albicans and 2 had Candida tropicalis as the sole baseline pathogen whereas 44 had
mixed baseline cultures containing C. albicans and one or more additional Candida species.
In the large, randomized, double-blind study comparing CANCIDAS 50 mg/day versus
intravenous fluconazole 200 mg/day for the treatment of esophageal candidiasis, patients were treated for
an average of 9 days (range 7-21 days). Favorable overall response at 5 to 7 days following
discontinuation of study therapy required both complete resolution of symptoms and significant
endoscopic improvement. The definition of endoscopic response was based on severity of disease at
baseline using a 4-grade scale and required at least a two-grade reduction from baseline endoscopic
score or reduction to grade 0 for patients with a baseline score of 2 or less.
The proportion of patients with a favorable overall response was comparable for CANCIDAS and
fluconazole as shown in Table 14.
Table 14: Favorable Response Rates for Patients with Esophageal Candidiasis*
|
CANCIDAS |
Fluconazole |
% Difference†
(95% CI) |
Day 5-7 post-treatment |
66/81 (81.5%) |
80/94 (85.1%) |
-3.6 (-14.7, 7.5) |
* Analysis excluded patients without documented esophageal candidiasis or patients not receiving at least 1 day of study therapy.
†Calculated as CANCIDAS – fluconazole |
The proportion of patients with a favorable symptom response was also comparable (90.1% and
89.4% for CANCIDAS and fluconazole, respectively). In addition, the proportion of patients with a
favorable endoscopic response was comparable (85.2% and 86.2% for CANCIDAS and fluconazole,
respectively).
As shown in Table 15, the esophageal candidiasis relapse rates at the Day 14 post-treatment visit were
similar for the two groups. At the Day 28 post-treatment visit, the group treated with CANCIDAS had a
numerically higher incidence of relapse; however, the difference was not statistically significant.
Table 15: Relapse Rates at 14 and 28 Days Post-Therapy in Patients with Esophageal Candidiasis at Baseline
|
CANCIDAS |
Fluconazole |
% Difference*
(95% CI) |
Day 14 post-treatment |
7/66 (10.6%) |
6/76 (7.9%) |
2.7 (-6.9, 12.3) |
Day 28 post-treatment |
18/64 (28.1%) |
12/72 (16.7%) |
11.5 (-2.5, 25.4) |
* Calculated as CANCIDAS – fluconazole |
In this trial, which was designed to establish noninferiority of CANCIDAS to fluconazole for the
treatment of esophageal candidiasis, 122 (70%) patients also had oropharyngeal candidiasis. A favorable
response was defined as complete resolution of all symptoms of oropharyngeal disease and all visible
oropharyngeal lesions. The proportion of patients with a favorable oropharyngeal response at the 5- to 7-
day post-treatment visit was numerically lower for CANCIDAS; however, the difference was not statistically
significant. Oropharyngeal candidiasis relapse rates at Day 14 and Day 28 post-treatment visits were
statistically significantly higher for CANCIDAS than for fluconazole. The results are shown in Table 16.
Table 16: Oropharyngeal Candidiasis Response Rates at 5 to 7 Days Post-Therapy and Relapse Rates at
14 and 28 Days Post-Therapy in Patients with Oropharyngeal and Esophageal Candidiasis at Baseline
|
CANCIDAS |
Fluconazole |
% Difference*
(95% CI) |
Response Rate Day 5-7 posttreatment |
40/56 (71.4%) |
55/66 (83.3%) |
-11.9 (-26.8, 3.0) |
Relapse Rate Day 14 post-treatment |
17/40 (42.5%) |
7/53 (13.2%) |
29.3 (11.5, 47.1) |
Relapse Rate Day 28 post-treatment |
23/39 (59.0%) |
18/51 (35.3%) |
23.7 (3.4, 43.9) |
* Calculated as CANCIDAS – fluconazole |
The results from the two smaller dose-ranging studies corroborate the efficacy of CANCIDAS for
esophageal candidiasis that was demonstrated in the larger study.
CANCIDAS was associated with favorable outcomes in 7 of 10 esophageal C. albicans infections
refractory to at least 200 mg of fluconazole given for 7 days, although the in vitro susceptibility of the
infecting isolates to fluconazole was not known.
Invasive Aspergillosis
Sixty-nine patients between the ages of 18 and 80 with invasive aspergillosis were enrolled in an
open-label, noncomparative study to evaluate the safety, tolerability, and efficacy of CANCIDAS. Enrolled
patients had previously been refractory to or intolerant of other antifungal therapy(ies). Refractory patients
were classified as those who had disease progression or failed to improve despite therapy for at least
7 days with amphotericin B, lipid formulations of amphotericin B, itraconazole, or an investigational azole
with reported activity against Aspergillus. Intolerance to previous therapy was defined as a doubling of
creatinine (or creatinine ≥2.5 mg/dL while on therapy), other acute reactions, or infusion-related toxicity.
To be included in the study, patients with pulmonary disease must have had definite (positive tissue
histopathology or positive culture from tissue obtained by an invasive procedure) or probable (positive
radiographic or computed tomography evidence with supporting culture from bronchoalveolar lavage or
sputum, galactomannan enzyme-linked immunosorbent assay, and/or polymerase chain reaction) invasive
aspergillosis. Patients with extrapulmonary disease had to have definite invasive aspergillosis. Patients
were administered a single 70-mg loading dose of CANCIDAS and subsequently dosed with 50 mg daily.
The mean duration of therapy was 33.7 days, with a range of 1 to 162 days.
An independent expert panel evaluated patient data, including diagnosis of invasive aspergillosis,
response and tolerability to previous antifungal therapy, treatment course on CANCIDAS, and clinical
outcome.
A favorable response was defined as either complete resolution (complete response) or clinically
meaningful improvement (partial response) of all signs and symptoms and attributable radiographic
findings. Stable, nonprogressive disease was considered to be an unfavorable response.
Among the 69 patients enrolled in the study, 63 met entry diagnostic criteria and had outcome data;
and of these, 52 patients received treatment for greater than 7 days. Fifty-three (84%) were refractory to
previous antifungal therapy and 10 (16%) were intolerant. Forty-five patients had pulmonary disease and
18 had extrapulmonary disease. Underlying conditions were hematologic malignancy (N=24), allogeneic
bone marrow transplant or stem cell transplant (N=18), organ transplant (N=8), solid tumor (N=3), or other
conditions (N=10). All patients in the study received concomitant therapies for their other underlying
conditions. Eighteen patients received tacrolimus and CANCIDAS concomitantly, of whom 8 also received
mycophenolate mofetil.
Overall, the expert panel determined that 41% (26/63) of patients receiving at least one dose of
CANCIDAS had a favorable response. For those patients who received greater than 7 days of therapy
with CANCIDAS, 50% (26/52) had a favorable response. The favorable response rates for patients who
were either refractory to or intolerant of previous therapies were 36% (19/53) and 70% (7/10), respectively.
The response rates among patients with pulmonary disease and extrapulmonary disease were 47%
(21/45) and 28% (5/18), respectively. Among patients with extrapulmonary disease, 2 of 8 patients who
also had definite, probable, or possible CNS involvement had a favorable response. Two of these
8 patients had progression of disease and manifested CNS involvement while on therapy.
CANCIDAS is effective for the treatment of invasive aspergillosis in patients who are refractory to or
intolerant of itraconazole, amphotericin B, and/or lipid formulations of amphotericin B. However, the
efficacy of CANCIDAS for initial treatment of invasive aspergillosis has not been evaluated in comparatorcontrolled
clinical studies.
Pediatric Patients
The safety and efficacy of CANCIDAS were evaluated in pediatric patients 3 months to 17 years of age
in two prospective, multicenter clinical trials.
The first study, which enrolled 82 patients between 2 to 17 years of age, was a randomized, doubleblind
study comparing CANCIDAS (50 mg/m2 IV once daily following a 70-mg/m2 loading dose on Day 1
[not to exceed 70 mg daily]) to AmBisome (3 mg/kg IV daily) in a 2:1 treatment fashion (56 on
caspofungin, 26 on AmBisome) as empirical therapy in pediatric patients with persistent fever and
neutropenia. The study design and criteria for efficacy assessment were similar to the study in adult
patients [see Clinical Studies]. Patients were stratified based on risk category (high-risk patients
had undergone allogeneic stem cell transplantation or had relapsed acute leukemia). Twenty-seven
percent of patients in both treatment groups were high risk. Favorable overall response rates of pediatric
patients with persistent fever and neutropenia are presented in Table 17.
Table 17: Favorable Overall Response Rates of Pediatric Patients with Persistent Fever and Neutropenia
|
CANCIDAS |
AmBisome* |
Number of Patients |
56 |
25 |
Overall Favorable Response |
26/56 (46.4%) |
8/25 (32.0%) |
High risk |
9/15 (60.0%) |
0/7 (0.0%) |
Low risk |
17/41 (41.5%) |
8/18 (44.4%) |
*One patient excluded from analysis due to no fever at study entry. |
The second study was a prospective, open-label, non-comparative study estimating the safety and
efficacy of caspofungin in pediatric patients (ages 3 months to 17 years) with candidemia and other
Candida infections, esophageal candidiasis, and invasive aspergillosis (as salvage therapy). The study
employed diagnostic criteria which were based on established EORTC/MSG criteria of proven or probable
infection; these criteria were similar to those criteria employed in the adult studies for these various
indications. Similarly, the efficacy time points and endpoints used in this study were similar to those
employed in the corresponding adult studies [see Candidemia And The Following Other Candida Infections: Intra-Abdominal Abscesses,
Peritonitis And Pleural Space Infections, Esophageal Candidiasis (And Information On Oropharyngeal Candidiasis) and Invasive Aspergillosis]. All patients
received CANCIDAS at 50 mg/m2 IV once daily following a 70-mg/m2 loading dose on Day 1 (not to
exceed 70 mg daily). Among the 49 enrolled patients who received CANCIDAS, 48 were included in the
efficacy analysis (one patient excluded due to not having a baseline Aspergillus or Candida infection). Of
these 48 patients, 37 had candidemia or other Candida infections, 10 had invasive aspergillosis, and
1 patient had esophageal candidiasis. Most candidemia and other Candida infections were caused by C.
albicans (35%), followed by C. parapsilosis (22%), C. tropicalis (14%), and C. glabrata (11%). The
favorable response rate, by indication, at the end of caspofungin therapy was as follows: 30/37 (81%) in
candidemia or other Candida infections, 5/10 (50%) in invasive aspergillosis, and 1/1 in esophageal
candidiasis.
REFERENCES
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USA, 2008.
3. Clinical and Laboratory Standards Institute (CLSI).Reference Method for Broth Dilution Antifungal
Susceptibility Testing of Yeasts; Third Informational Supplement. CLSI document M27-S3. Clinical and
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