Abstract
The combination of liposomal amphotericin B (LAMB) and caspofungin (CAS) holds promise to improve the outcome of opportunistic invasive mycoses with poor prognosis. Little is known, however, about the safety and pharmacokinetics of the combination in patients at high risk for these infections. The safety and pharmacokinetics of the combination of LAMB and CAS were investigated in a risk-stratified, randomized, multicenter phase II clinical trial in 55 adult allogeneic hematopoietic stem cell recipients (aHSCT) with granulocytopenia and refractory fever. The patients received either CAS (50 mg/day; day 1, 70 mg), LAMB (3 mg/kg of body weight/day), or the combination of both (CASLAMB) until defervescence and granulocyte recovery. Safety, development of invasive fungal infections, and survival were assessed through day 14 after the end of therapy. Pharmacokinetic sampling and analysis were performed on days 1 and 4. All three regimens were well tolerated. Premature study drug discontinuations due to grade III/IV adverse events occurred in 1/18, 2/20, and 0/17 patients randomized to CAS, LAMB, and CASLAMB, respectively. Adverse events not leading to study drug discontinuation were frequent but similar across cohorts, except for a higher frequency of hypokalemia with CASLAMB (P < 0.05). Drug exposures were similar for patients receiving combination therapy and those randomized to monotherapy. There was no apparent difference in the occurrence of proven/probable invasive fungal infections and survival through day 14 after the end of therapy. CASLAMB combination therapy in immunocompromised aHSCT patients was as safe as monotherapy with CAS or LAMB and had similar plasma pharmacokinetics, lending support to further investigations of the combination in the management of patients with invasive opportunistic mycoses.
Invasive opportunistic fungal infections are an important cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation. Depending on the presence of well-characterized risk factors, rates of infection by opportunistic fungal pathogens are between 10 and 25%. The case fatality rates vary between 35 and 50% for invasive candidiasis and 65 and 90% for invasive aspergillosis and infections by other filamentous fungi (8, 15).
The existence of antifungal agents with different molecular targets is providing new opportunities to improve the efficacy of antifungal chemotherapy through combination therapy. Potential target populations include profoundly immunocompromised patients with prolonged granulocytopenia or following allogeneic hematopoietic stem cell transplantation, patients with fulminant or refractory infections, or those with infections in compartments that are difficult to treat and infections by fungal pathogens with decreased microbiological susceptibility (23, 31, 39, 48, 49, 50).
Based on its favorable microbiologic and pharmacokinetic properties (16), well-documented efficacy against Candida and Aspergillus infections, and excellent safety (24, 28, 32, 45), the echinocandin lipopeptide caspofungin (CAS) is a suitable candidate for antifungal combination therapies with liposomal amphotericin B (LAMB), a standard agent with broad-spectrum antifungal activity (18) and first-line indications against major opportunistic fungal infections (12, 22, 39). While preclinical studies of the combination of caspofungin and amphotericin B (CASLAMB)) have documented the absence of antagonistic effects in vitro and in animal infection models (3, 4, 5, 10, 19, 20, 30, 38), the clinical experience with combination therapies of caspofungin and lipid formulations of amphotericin B is more difficult to assess (1, 9, 21, 24, 34). Particularly in the setting of allogeneic hematopoietic stem cell transplantation and immunosuppression with cyclosporine, the safety of caspofungin alone and in combination with liposomal amphotericin B and the pharmacokinetic interactions of the combination have not been systematically studied.
MATERIALS AND METHODS
Study design overview.
The study was designed as an open, prospective, randomized multicenter phase II trial conducted to investigate the safety and pharmacokinetics of CAS, LAMB, and CASLAMB in a total of 75 adult allogeneic hematopoietic stem cell (aHSCT) recipients with granulocytopenia and refractory fever despite adequate antibacterial therapy. After informed consent, eligible patients were stratified according to donor status (HLA matched/related versus HLA mismatched and/or unrelated) and randomized into one of three treatment arms: 50 mg CAS once a day (QD) with a loading dose of 70 mg on day 1, 3 mg LAMB/kg of body weight QD, or the combination CASLAMB at similar dosages. Treatment was to continue until neutrophil engraftment (absolute neutrophil count of ≥500/μl for three consecutive days) and defervescence (<38°C for 72 h), diagnosis of probable or proven (2) invasive fungal infection, or occurrence of a nonhematological grade III/IV adverse event (NCI-CTCAE) judged to be causally related to study drug medication. Safety and absence of breakthrough infections were monitored daily while the patients were on treatment, at the end of treatment (EOT), and 14 days after EOT. Pharmacokinetic sampling was performed on days 1 and 4. Antifungal efficacy and survival were assessed at 14 days after EOT. The primary endpoint of the study was the number of toxicity-related premature study drug discontinuations, as well as clinical and laboratory adverse events (AEs) while on treatment. Pharmacokinetic assessments and the evaluation of treatment success were secondary endpoints.
Patient eligibility.
The study was performed at five German study sites under a protocol approved by the institutions' respective internal review boards. Written informed consent was obtained from each patient prior to study entry. Study-specific inclusion criteria were an age of ≥18 years, granulocytopenia (absolute neutrophil count [ANC] of ≤500/μl) following allogeneic HSCT, persisting or new fever (oral temperature of ≥38°C) despite adequate antibacterial therapy for ≥36 to 48 h that was considered to require empirical antifungal therapy, and immunosuppression with cyclosporine.
Study-specific exclusion criteria at entry were the presence of a probable or proven invasive fungal infection according to the Mycoses Study Group/European Organization for Research and Treatment of Cancer (MSG/EORTC) criteria published in 2002 (2); active veno-occlusive disease (VOD); hemodynamic instability; estimated life expectancy of <5 days; increases of bilirubin of >3 times, serum glutamate oxalate transaminase (SGOT)/serum glutamate pyruvate transaminase (SGPT) of >3 times, alkaline phosphatase of >5 times, and creatinine of >2 times the upper limit of normal values; and comedication with rifampin, phenytoin, carbamazepin, phenobarbital, or dexamethasone. The study protocol did not restrict topical or systemic antifungal prophylaxis; however, upon initiation of empirical antifungal therapy, systemic antifungal prophylaxis was to be discontinued.
Study drug treatment.
Eligible patients were stratified according to donor status (HLA matched/related versus HLA mismatched and/or unrelated) and randomized to receive either 50 mg CAS QD with a loading dose of 70 mg on day 1, 3 mg/kg LAMB QD, or the combination CASLAMB at similar dosages. Caspofungin was provided by Merck, Sharp, and Dohme (Haar, Germany) as the approved Cancidas product, and liposomal amphotericin B was provided by Gilead Sciences (Martinsried, Germany) as the approved AmBisome product. Both compounds were prepared and administered according to the manufacturer's recommendations. The infusion time was 60 min for each drug. In the CASLAMB arm, the order of drug administration was LAMB followed by CAS. To allow pharmacokinetic comparison, no dose adjustment of CAS was made in individuals with a body weight of >80 kg.
Treatment was to continue until neutrophil engraftment (ANC ≥ 500/μl for three consecutive days) and defervescence (<38°C for 72 h), diagnosis of probable or proven invasive fungal infection according to the MSG/EORTC criteria published in 2002 (2), or occurrence of an NCI-CTCAE judged to be causally related to study drug medication. The last was selected as a stopping criterion because both agents were not investigational at the time of the study and the spectrum of related adverse events was well characterized in large, randomized clinical trials in comparable patient populations. For treatment-limiting AEs that were deemed to be unrelated, the protocol allowed for discontinuation of the study drug at the discretion of the individual clinical investigator or by stating the occurrence of exclusion criteria. The protocol did not allow for dose adjustments while on study, and the maximum duration of treatment was solely defined by the discontinuation criteria.
Monitoring and assessment of safety.
Clinical and laboratory safety were monitored at baseline (BL), daily while on treatment, at EOT, and 14 days after EOT. Toxicities were graded according to NCI-CTCAE (version 2.0), and their relationship to the study drug was determined by the investigator.
The endpoints of safety (primary endpoints of the study) were the number of nonhematologic toxicity-related (grade III and IV) premature study drug discontinuations; a predefined panel of nonhematologic clinical and laboratory AEs while on treatment; and the comparison of serum creatinine, bilirubin, and hepatic transaminase values at baseline and at EOT, as well as the maximum pathological value while on treatment.
Pharmacokinetic sampling and analysis.
Serial plasma sampling was performed on days 1 and 4 for up to 24 h after dosing at prespecified time intervals and thereafter at single time points twice weekly. Blood specimens (5 ml) were collected in heparinized tubes and immediately centrifuged for 10 min at 1,500 × g. Separated plasma was stored at −80°C until it was assayed.
Concentrations of caspofungin and total amphotericin B were measured by validated high-performance liquid chromatography (HPLC) methods as described in detail elsewhere (51). The lower limit of quantitation (LLQ) was 0.15 mg/liter for CAS and 0.1 mg/liter for amphotericin B. Accuracies were within ±8.6%, and intraday and interday variability (precision) ranged from 5.8 to 11.3% and 2.2 to 10%, respectively.
Concentration data were assessed by population pharmacokinetic analysis using the NONMEM (version 6, level 1.0) and Xpose (version 3.1) computer programs. Pharmacokinetic endpoints (secondary endpoints of the study) included the dose intensities of CAS and LAMB in the setting of aHSCT and the analysis of pharmacokinetic interactions of the combination of both agents.
Monitoring and assessment of efficacy.
The absence of breakthrough infections was monitored daily while on treatment, at EOT, and 14 days after EOT, and antifungal efficacy and survival were assessed at EOT and 14 days after EOT.
Breakthrough infection was defined as any proven/probable invasive fungal infection occurring while on treatment. Treatment success (a secondary endpoint of the study) was defined as no discontinuation for toxicity and absence of proven/probable breakthrough invasive infection at EOT plus absence of invasive infection and survival through day 14 post-EOT.
Biometrical considerations.
Because of the exploratory nature of the study, no assumptions or power calculations were performed for the primary endpoint. The data for 25 patients per study arm were deemed sufficient to estimate the safety of caspofungin and the combination of caspofungin with liposomal amphotericin B and to use it as basis for the risk/benefit assessment prior to the initiation of a larger phase III study in the therapeutic setting. All patients who had received at least one dose of study medication were included in the assessments of safety, tolerability, and treatment success (mITT). Unless otherwise indicated, data are presented as mean values ± standard deviations (SD). Comparisons of continuous variables were performed by nonparametric analysis of variance or the Mann-Whitney U test, as appropriate, and comparison between discrete variables was by chi-square analyses. A two-sided P value of ≤0.05 was considered to be statistically significant.
RESULTS
Patients.
Due to delays in patient enrolment that were related in part to changes in clinical practice, the trial was stopped after 42 months following recruitment of 57 patients.
Two patients were erroneously registered and randomized (CAS cohort) despite the presence of exclusion criteria and were removed from the analysis of safety and efficacy. The remaining 55 patients received at least one dose of study medication and constituted the mITT population. Allocation following randomization and essential demographic characteristics of the 55 patients are shown in Table 1.
TABLE 1.
Patient allocation and demographic data
| Parameter | Valuea |
|||
|---|---|---|---|---|
| Patients with allocated treatment |
All patients (n = 55) | |||
| CAS (n = 18) | LAMB (n = 20) | CASLAMB (n = 17) | ||
| Age (yr) | 40.4 ± 12.6 | 38.7 ± 13.1 | 42.8 ± 12.7 | 40.5 ± 12.7 |
| Gender (male/female) | 11/7 | 13/7 | 10/7 | 34/21 |
| Duration of study drug use(days)b | 12.9 ± 5.0 | 9.1 ± 5.6 | 14.2 ± 5.8 | 11.9 ± 5.8 |
| Type of transplant | ||||
| No, HLA matched/related | 6 | 6 | 6 | 18 |
| No. HLA mismatched/unrelated | 12 | 14 | 11 | 37 |
| Underlying condition (n)c | ||||
| ALL | 6 | 8 | 6 | 20 |
| AML | 8 | 3 | 8 | 19 |
| MDS/SAA | 1 | 3 | 2 | 6 |
| Myeloma | 1 | 3 | 4 | |
| CML | 1 | 1 | 2 | |
| CLL | 1 | 1 | 2 | |
| NHL | 1 | 1 | 2 | |
| Karnofsky score at BL | 64.4 ± 13.8 | 67.5 ± 15.9 | 64.7 ± 18.1 | 65.6 ± 15.7 |
Continuous data are presented as means ± SD.
P < 0.005 by analysis of variance (ANOVA) and P < 0.001 for the comparison between LAMB and CASLAMB/CAS.
All, acute lymphatic leukemia, AML, acute myeloid leukemia; MDS/SAA, myelodysplastic syndrome/severe aplastic anemia; CML, chronic myeloid leukemia; CLL, chronic lymphatic leukemia; NHL, non-Hodgkin's lymphoma.
Eighteen patients received CAS, 20 received LAMB, and 17 received the combination. The mean durations of study drug treatment were 12.9, 9.1, and 14.2 days, respectively. The mean age of the 55 patients was 40.5 years (range, 18 to 61 years), and the gender ratio was 34 males to 21 females. Most patients (n = 39) had either acute lymphatic leukemia (ALL) or acute myeloid leukemia (AML) as an underlying condition. Eighteen patients had received an HLA-matched and 37 an HLA-mismatched and/or unrelated stem cell product. The mean Karnofsky score at study entry was 65.6 ± 15.7. With the exception of a shorter duration of treatment in the LAMB cohort, demographic characteristics were not different among the three cohorts.
Safety.
Premature study drug discontinuations due to nonhematological study drug-related grade III/IV AEs occurred in 1/18, 2/20, and 0/17 patients randomized to CAS, LAMB, and CASLAMB, respectively. One patient discontinued therapy with CAS prematurely on day 14 due to grade III hyperbilirubinemia and clinical criteria of acute graft-versus-host disease (GVHD of the liver. Of the two patients who discontinued therapy with LAMB early due to toxicity or intolerance, one discontinued LAMB on day 4 due to the onset of grade III azotemia and the second on day 1 due to a hypersensitivity reaction with shortness of breath and severe back pain. In all three cases, the AEs resolved with appropriate management.
Independent of the cause, 54 of the 55 patients had at least one AE, accounting for a total of 410 AEs (105, 183, and 122 in the CAS, LAMB, and CASLAMB cohorts, respectively, including 1, 10, and 5 severe adverse events [SAEs]) (Table 2 ). Considering all grades, there was a higher frequency of hypokalemia in the CASLAMB cohort (P < 0.05) and a trend (P = 0.09) toward increased creatinine values in the LAMB-containing cohorts. Consistent with this observation, the mean creatinine values at EOT were significantly higher than BL in the LAMB and CASLAMB cohorts (1.16 versus 0.69 mg/dl [P < 0.001] and 1.08 versus 0.72 mg/dl [P < 0.05]), whereas there was no difference in CAS-treated patients (0.63 versus 0.71 mg/dl [P < 0.5]) (Fig. 1).
TABLE 2.
Adverse events while on treatment, independent of cause*
| NCI common toxicity criteriaa | No. in allocated treatment group/CTC grade |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| CAS |
LAMB |
CASLAMB |
|||||||
| I/II | III | IV | I/II | III | IV | I/II | III | IV | |
| Allergic reaction/hypersensitivity | 1 | 2 | 1 | 3 | 1 | ||||
| Fever | 17 | 18 | 16 | ||||||
| Rigor/chills | 2 | 5 | 3 | ||||||
| Dyspnea | 1 | 1 | 3 | 1 | 3 | 1 | 1 | ||
| Nausea | 13 | 11 | 13 | ||||||
| Vomiting | 9 | 8 | 9 | ||||||
| Abdominal pain | 7 | 4 | 1 | 5 | |||||
| Chest pain | 2 | 1 | 1 | ||||||
| Headache | 5 | 5 | 2 | 4 | |||||
| Myalgia | 4 | 5 | 3 | ||||||
| Skin rash | 8 | 3 | 7 | 7 | 11 | 2 | |||
| Urticaria | 1 | 2 | 2 | 2 | |||||
| Increased Bilirubin | 9 | 2 | 1 | 7 | 4 | 9 | 1 | ||
| Increased alkaline phosphatase | 7 | 1 | 7 | 1 | 8 | ||||
| Increased SGOT | 4 | 8 | 7 | ||||||
| Increased SGPT | 3 | 2 | 11 | 1 | 9 | ||||
| Increased amylase | 2 | 2 | 1 | ||||||
| Increased lipase | 1 | 1 | |||||||
| Increased creatinine | 2 | 8 | 1 | 7 | |||||
| Hypokalemia | 7 | 7 | 1 | 13 | 2 | ||||
| Hypomagnesemia | 13 | 1 | 15 | 12 | 1 | ||||
| Acidosis | 1 | 3 | 1 | 2 | 1 | ||||
| GVHD | 7 | 3 | 10 | 4 | 7 | 2 | |||
| VOD | |||||||||
| Engraftment failure | 1 | 1 | 1 | 1 | |||||
The categories listed represent the 25 categories prespecified by the study protocol. VOD, veno-occlusive disease.
FIG. 1.
Laboratory parameters of renal and hepatic function at BL and at EOT. (A) Mean and standard error of the mean (SEM) serum creatinine values; *, P = 0.0006 (LAMB) and P = 0.0250 (CASLAMB). (B) Mean and SEM serum bilirubin values. (C) Mean and SEM SGOT values; *, P = 0.0009 (CAS), P = 0.0145 (LAMB), and P = 0.0014 (CASLAMB). (D) Mean and SEM SGPT values; *, P = 0.0028 (CAS) and P = 0.0059 (CASLAMB) for the comparison of EOT versus BL by the Mann-Whitney U test.
Dose intensity and pharmacokinetic interactions.
Plasma data for both CAS and LAMB were best described by 2-compartment pharmacokinetic models (51). Estimated pharmacokinetic parameters are tabulated in Table 3. Following monotherapy with caspofungin, the mean (±SD) peak plasma concentration was 8.47 ± 1.95 mg/liter; the mean area under the concentration-time curve (AUC) was 117 ± 28.2 mg·h/liter, and clearance was 0.45 ± 0.1 liter/h. Comparison of pharmacokinetic parameters of caspofungin between patients receiving CAS and patients receiving CASLAMB revealed no differences between the two cohorts.
TABLE 3.
Estimated steady-state plasma pharmacokinetics
| Parametera | Mean value (±SD) |
|||
|---|---|---|---|---|
| CAS |
AMB |
|||
| CAS alone | CAS plus LAMB | LAMB alone | LAMB plus CAS | |
| CL (liters/h) | 0.45 ± 0.1 | 0.48 ± 0.12 | 1.03 ± 0.53 | 1.21 ± 0.87 |
| V1 (liters) | 8.99 ± 2.43 | 9.22 ± 2.12 | 18.60 ± 5.39 | 18.63 ± 5.96 |
| Q (liters/h) | 0.82b | 0.82b | 2.71 ± 1.11 | 2.15 ± 0.9 |
| V2 (liters) | 3.06b | 3.06b | 96.6 ± 30.9 | 93.9 ± 30 |
| AUC (mg·h/liter) | 117 ± 28.2 | 110 ± 26.4 | 327 ± 294 | 254 ± 142 |
| Cmin (mg/liter) | 3.04 ± 0.97 | 2.64 ± 0.98 | 10.63 ± 11.48 | 7.51 ± 5.11 |
| Cmax (mg/liter) | 8.47 ± 1.95 | 7.75 ± 1.86 | 21.87 ± 12.47 | 19.67 ± 8.46 |
CL, clearance; V1, central volume of distribution; V2, peripheral volume of distribution; Q, intercompartmental clearance; Cmin, trough, and Cmax, peak plasma concentrations.
Not estimated.
Following monotherapy with liposomal amphotericin B, the mean (±SD) peak plasma concentration was 21.87 ± 12.47 mg/liter; the mean AUC was 327 ± 294 mg·h/liter, and clearance was 1.03 ± 0.53 liter/h. Comparison of pharmacokinetic parameters of amphotericin B between patients receiving LAMB and patients receiving CASLAMB revealed no relevant differences between the two cohorts.
Treatment success.
Treatment success, as assessed at 14 days post-EOT, was similar across cohorts and was observed in 14/18, 15/20, and 16/17 patients receiving CAS, LAMB, and CASLAMB, respectively (Table 4).
TABLE 4.
Treatment success at day +14 following EOT
| Event | No./total patients |
||
|---|---|---|---|
| CAS | LAMB | CASLAMB | |
| Study drug discontinuation due to grade III/IV AEs | 1 | 2 | 0 |
| Proven/probable invasive infection | 3a,e | 2b,e | 1c,e |
| Death | 0 | 1d | 0 |
| Treatment success | 14/18 | 15/20 | 16/17 |
Probable pulmonary aspergillosis on treatment (2 patients) and at 14-day follow-up (1 patient).
Probable pulmonary aspergillosis (1 patient) and C.albicans candidemia at 14-day follow up/death (unrelated).
Probable pulmonary aspergillosis.
At 14-day follow-up (unrelated).
Finding of probable pulmonary aspergillosis was based on host factors (5 patients), major CT findings (5 patients), and antigen detection (3 patients) in the blood or isolation of Aspergillus.fumigatus (2 patients) from bronchoalveolar lavage fluid.
Whereas three patients were discontinued due to grade III/IV adverse events, breakthrough infections occurred in six patients. Breakthrough infections emerged on treatment in four patients and during the 14-day follow-up period in two patients. Two patients died from unrelated causes during the 14-day follow-up.
DISCUSSION
Irrespective of the obvious clinical need to improve the outcomes of antifungal therapy, the systematic characterization of the safety and pharmacokinetics of treatment options in a relevant patient population is a prerequisite before their investigation in phase III clinical trials. Because both liposomal amphotericin B and caspofungin were approved for this indication on the basis of two large, double-blind, randomized trials (43, 45) at their respective therapeutic dosages (12, 22, 25, 28) and because no additive toxicity was expected, we selected the setting of empirical therapy to investigate the safety and pharmacokinetics of the combination of the two agents. Empirical antifungal therapy is an accepted algorithm of supportive care in persistently febrile granulocytopenic patients (11, 14, 33, 36, 43) that has served as a window to investigate the safety and pharmacokinetics of new antifungal agents (7, 37, 46).
Combination therapy with caspofungin and liposomal amphotericin B was well tolerated: None of the patients discontinued therapy due to a drug-related adverse event. Discontinuation rates in single-agent treatment were similar to those observed in large phase III clinical trials of empirical antifungal therapy (43, 45). Importantly, no new and unexpected drug-related adverse events were observed. As was to be expected (45), patients randomized to an amphotericin B-containing cohort had a trend toward increased creatinine values, and mean creatinine values at the end of therapy were significantly higher than baseline. However, nephrotoxicity was generally mild, and only 1 of 37 patients (2.7%) receiving LAMB was discontinued because of increased creatinine values. In addition, there was a higher frequency of hypokalemia in the CASLAMB cohort, which may represent additive toxicity (45) or may be due to the longer drug exposure in the combination arm. There was no signal for increased liver toxicity among the three cohorts: Changes in serum bilirubin from baseline to end of therapy were not significant, and increases in hepatic transaminases were similar among all cohorts, indicating an unavoidable drug effect or an etiology that is related to the immunological processes around stem cell engraftment.
In order to exclude a potential confounder in the assessment of the hepatic effects of caspofungin when given concomitantly with cyclosporine (16), and based on the use of cyclosporine as a standard immunosuppressive regimen following HSCT, the use of cyclosporine was selected as an inclusion criterion. However, in contrast to one small case series (29), there was no signal for increased hepatotoxicity in this randomized comparison, which is supported by retrospective postmarketing series that found no serious hepatic events with the concomitant use of caspofungin and cyclosporine (17, 27, 35, 41).
Compared to healthy volunteers (40), at steady state, median plasma clearance (CL) was lower and median trough levels (Cmin) and median total drug exposure (AUC0-24) of caspofungin were higher in the patients enrolled in the study. This observation may be due to the concomitant administration of cyclosporine, which has been shown to increase the AUC of caspofungin in healthy volunteers by approximately 35% (16). Key pharmacokinetic parameters following administration of liposomal amphotericin B were within the range of data reported for other populations (6, 44). Similar to the findings of these studies, interpatient variability was high, likely due to the unique distribution and elimination of the liposomal carriers, which also make plasma data of the parent difficult to interpret (6). Finally, in line with preclinical data (47), the data presented in this study clearly demonstrate that the pharmacokinetics of amphotericin B following administration of liposomal amphotericin B was not altered by the concomitant administration of caspofungin, and vice versa, and that the pharmacokinetics of caspofungin was not influenced by liposomal amphotericin B.
Notable limitations of our study include the slow subject recruitment, the missed recruitment target, and the fact that half of the patients were enrolled in one center. While the fulfillment of recruitment rates in this single center indicates the absence of a fundamental problem with the study design, other factors may have contributed to recruitment failure. They include changes in clinical practice through the advent of more effective antifungal prophylaxis (13, 42) and approaches to preemptive treatment strategies (11, 26), resulting in fewer patients available for enrollment in an empirical-treatment trial, but also problems inherent to investigator-initiated trials. However, since no safety signal has emerged from the data, we may speculate that there is only a small likelihood that fulfillment of the recruitment target would have altered the assessment of the primary endpoint.
In summary, this is the first formal, randomized phase II clinical trial exploring the safety and plasma pharmacokinetics of antifungal combination therapy in a clinically relevant patient target population with multiple comorbidities. Combination therapy with caspofungin and liposomal amphotericin B was as safe as monotherapy with either agent. There were no clinically relevant differences in drug exposures relative to other populations, and no pharmacokinetic interaction was observed. Treatment success was similar across cohorts. Taken together, the results of this trial support further investigations of the combination in the management of patients with invasive opportunistic mycoses.
Acknowledgments
We thank Gudrun Benninger-Doering, Juergen Grebe, Achim Heinecke, and the entire staff of the Centre for Clinical Trials (KKS) Muenster (BMBF 01KN0705) for their excellent administrative and logistic support.
This clinical trial was initiated and conducted under the sponsorship of the Coordinating Centre for Clinical Trials (KKS), University Hospital Muenster, Muenster, Germany. The study was supported by clinical research grants from Gilead Sciences, Martinsried, Munich, Germany, and from Merck, Sharp and Dohme, Haar, Germany. Gilead Sciences and Merck, Sharp and Dohme had no role in the design of the study, data capture, or data analysis or in the writing and submission of this article. O.A.C. is supported by the German Federal Ministry of Research and Education (BMBF grant 01KN0706).
A.H.G. has received research grants and has served as a consultant and speaker for Gilead Sciences and Merck, Sharp and Dohme. H.O. and W.J.H. have served as consultants and speakers for Gilead Sciences and Merck, Sharp and Dohme. O.A.C. has received research grants from, is an advisor to, or served on the speakers' bureau of Gilead Sciences and Merck. All other authors have no conflict of interest to declare.
Footnotes
Published ahead of print on 26 July 2010.
REFERENCES
- 1.Aliff, T. B., P. G. Maslak, J. G. Jurcic, M. L. Heaney, K. N. Cathcart, K. A. Sepkowitz, and M. A. Weiss. 2003. Refractory Aspergillus pneumonia in patients with acute leukemia: successful therapy with combination caspofungin and liposomal amphotericin. Cancer 97:1025-1032. [DOI] [PubMed] [Google Scholar]
- 2.Ascioglu, S., J. H. Rex, B. de Pauw, J. E. Bennett, J. Bille, F. Crokaert, D. W. Denning, J. P. Donnelly, J. E. Edwards, Z. Erjavec, D. Fiere, O. Lortholary, J. Maertens, J. F. Meis, T. F. Patterson, J. Ritter, D. Selleslag, P. M. Shah, D. A. Stevens, T. J. Walsh, Invasive Fungal Infections Cooperative Group of the European Organization for Research and Treatment of Cancer, and Mycoses Study Group of the National Institute of Allergy and Infectious Diseases.. 2002. Defining opportunistic invasive fungal infections in immunocompromised patients with cancer and hematopoietic stem cell transplants: an international consensus. Clin. Infect. Dis. 34:7-14. [DOI] [PubMed] [Google Scholar]
- 3.Barchiesi, F., E. Spreghini, A. W. Fothergill, D. Arzeni, G. Greganti, D. Giannini, M. G. Rinaldi, and G. Scalise. 2005. Caspofungin in combination with amphotericin B against Candida glabrata. Antimicrob. Agents Chemother. 49:2546-2549. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Barchiesi, F., E. Spreghini, S. Tomassetti, D. Giannini, and G. Scalise. 2007. Caspofungin in combination with amphotericin B against Candida parapsilosis. Antimicrob. Agents Chemother. 51:941-945. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Bartizal, K., C. J. Gill, G. K. Abruzzo, A. M. Flattery, L. Kong, P. M. Scott, J. G. Smith, C. E. Leighton, A. Bouffard, J. F. Dropinski, and J. Balkovec. 1997. In vitro preclinical evaluation studies with the echinocandin antifungal MK-0991 (L-743,872). Antimicrob. Agents Chemother. 41:2326-2332. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Bekersky, I., R. M. Fielding, D. E. Dressler, J. W. Lee, D. N. Buell, and T. J. Walsh. 2002. Pharmacokinetics, excretion, and mass balance of liposomal amphotericin B (AmBisome) and amphotericin B deoxycholate in humans. Antimicrob. Agents Chemother. 46:828-833. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Benjamin, D. K. Jr., T. Driscoll, N. L. Seibel, C. E. Gonzalez, M. M. Roden, R. Kilaru, K. Clark, J. A. Dowell, J. Schranz, and T. J. Walsh. 2006. Safety and pharmacokinetics of intravenous anidulafungin in children with neutropenia at high risk for invasive fungal infections. Antimicrob. Agents Chemother. 50:632-638. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Bow, E. J. 2009. Invasive fungal infection in haematopoietic stem cell transplant recipients: epidemiology from the transplant physician's viewpoint. Mycopathologia 168:283-297. [DOI] [PubMed] [Google Scholar]
- 9.Caillot, D., A. Thiébaut, R. Herbrecht, S. de Botton, A. Pigneux, F. Bernard, J. Larché, F. Monchecourt, S. Alfandari, and L. Mahi. 2007. Liposomal amphotericin B in combination with caspofungin for invasive aspergillosis in patients with hematologic malignancies: a randomized pilot study (Combistrat trial). Cancer 110:2740-2746. [DOI] [PubMed] [Google Scholar]
- 10.Clemons, K. V., M. Espiritu, R. Parmar, and D. A. Stevens. 2005. Comparative efficacies of conventional amphotericin B, liposomal amphotericin B (AmBisome), caspofungin, micafungin, and voriconazole alone and in combination against experimental murine central nervous system aspergillosis. Antimicrob. Agents Chemother. 49:4867-4875. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Cordonnier, C., C. Pautas, S. Maury, A. Vekhoff, H. Farhat, F. Suarez, N. Dhédin, F. Isnard, L. Ades, F. Kuhnowski, F. Foulet, M. Kuentz, P. Maison, S. Bretagne, and M. Schwarzinger. 2009. Empirical versus preemptive antifungal therapy for high-risk, febrile, neutropenic patients: a randomized, controlled trial. Clin. Infect. Dis. 2009 48:1042-1051. [DOI] [PubMed] [Google Scholar]
- 12.Cornely, O. A., J. Maertens, M. Bresnik, R. Ebrahimi, A. J. Ullmann, E. Bouza, C. P. Heussel, O. Lortholary, C. Rieger, A. Boehme, M. Aoun, H. A. Horst, A. Thiebaut, M. Ruhnke, D. Reichert, N. Vianelli, S. W. Krause, E. Olavarria, R. Herbrecht, and the AmBiLoad Trial Study Group. 2007. Liposomal amphotericin B as initial therapy for invasive mold infection: a randomized trial comparing a high-loading dose regimen with standard dosing (AmBiLoad trial). Clin. Infect. Dis. 44:1289-1297. [DOI] [PubMed] [Google Scholar]
- 13.Cornely, O. A., J. Maertens, D. J. Winston, J. Perfect, A. J. Ullmann, T. J. Walsh, D. Helfgott, J. Holowiecki, D. Stockelberg, Y. T. Goh, M. Petrini, C. Hardalo, R. Suresh, and D. Angulo-Gonzalez. 2007. Posaconazole vs. fluconazole or itraconazole prophylaxis in patients with neutropenia. N. Engl. J. Med. 356:348-359. [DOI] [PubMed] [Google Scholar]
- 14.European Organization for Research and Treatment of Cancer (EORTC). 1989. Empiric antifungal therapy in febrile granulocytopenic patients. EORTC International Antimicrobial Therapy Cooperative Group. Am. J. Med. 86:668-672. [DOI] [PubMed] [Google Scholar]
- 15.Groll, A. H., and A. Tragiannidis. 2009. Recent advances in antifungal prevention and treatment. Semin. Hematol. 46:212-229. [DOI] [PubMed] [Google Scholar]
- 16.Groll, A. H., and T. J. Walsh. 2001. Caspofungin: pharmacology, safety and therapeutic potential in superficial and invasive fungal infections. Expert Opin. Invest. Drugs. 10:1545-1558. [DOI] [PubMed] [Google Scholar]
- 17.Groll, A. H., A. Attarbaschi, F. R. Schuster, N. Herzog, L. Grigull, M. N. Dworzak, K. Beutel, H. J. Laws, and T. Lehrnbecher. 2006. Treatment with caspofungin in immunocompromised paediatric patients: a multicentre survey. J. Antimicrob. Chemother. 57:527-535. [DOI] [PubMed] [Google Scholar]
- 18.Groll, A. H., S. C. Piscitelli, and T. J. Walsh. 1998. Clinical pharmacology of systemic antifungal agents: a comprehensive review of agents in clinical use, current investigational compounds, and putative targets for antifungal drug development. Adv. Pharmacol. 44:343-500. [DOI] [PubMed] [Google Scholar]
- 19.Hossain, M. A., G. H. Reyes, L. A. Long, P. K. Mukherjee, and M. A. Ghannoum. 2003. Efficacy of caspofungin combined with amphotericin B against azole-resistant Candida albicans. J. Antimicrob. Chemother. 51:1427-1429. [DOI] [PubMed] [Google Scholar]
- 20.Ibrahim, A. S., T. Gebremariam, Y. Fu, J. E. Edwards, and B. Spellberg. 2008. Combination echinocandin-polyene treatment of murine mucormycosis. Antimicrob. Agents Chemother. 52:1556-1558. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Kontoyiannis, D. P., R. Hachem, R. E. Lewis, G. A. Rivero, H. A. Torres, J. Thornby, R. Champlin, H. Kantarjian, G. P. Bodey, and I. I. Raad. 2003. Efficacy and toxicity of caspofungin in combination with liposomal amphotericin B as primary or salvage treatment of invasive aspergillosis in patients with hematologic malignancies. Cancer 98:292-299. [DOI] [PubMed] [Google Scholar]
- 22.Kuse, E. R., P. Chetchotisakd, C. A. da Cunha, M. Ruhnke, C. Barrios, D. Raghunadharao, J. S. Sekhon, A. Freire, V. Ramasubramanian, I. Demeyer, M. Nucci, A. Leelarasamee, F. Jacobs, J. Decruyenaere, D. Pittet, A. J. Ullmann, L. Ostrosky-Zeichner, O. Lortholary, S. Koblinger, H. Diekmann-Berndt, O. A. Cornely, and the Micafungin Invasive Candidiasis Working Group. 2007. Micafungin versus liposomal amphotericin B for candidaemia and invasive candidosis: a phase III randomised double-blind trial. Lancet 369:1519-1527. [DOI] [PubMed] [Google Scholar]
- 23.Lewis, R. E., and D. P. Kontoyiannis. 2001. Rationale for combinations antifungal therapy. Pharmacotherapy 21:149S-164S. [DOI] [PubMed] [Google Scholar]
- 24.Maertens, J., A. Glasmacher, R. Herbrecht, A. Thiebaut, C. Cordonnier, B. H. Segal, J. Killar, A. Taylor, N. Kartsonis, T. F. Patterson, M. Aoun, D. Caillot, C. Sable, and the Caspofungin Combination Therapy Study Group. 2006. Multicenter, noncomparative study of caspofungin in combination with other antifungals as salvage therapy in adults with invasive aspergillosis. Cancer 107:2888-2897. [DOI] [PubMed] [Google Scholar]
- 25.Maertens, J., I. Raad, G. Petrikkos, M. Boogaerts, D. Selleslag, F. B. Petersen, C. A. Sable, N. A. Kartsonis, A. Ngai, A. Taylor, T. F. Patterson, D. W. Denning, T. J. Walsh, and the Caspofungin Salvage Aspergillosis Study Group. 2004. Efficacy and safety of caspofungin for treatment of invasive aspergillosis in patients refractory to or intolerant of conventional antifungal therapy. Clin. Infect. Dis. 39:1563-1571. [DOI] [PubMed] [Google Scholar]
- 26.Maertens, J., K. Theunissen, G. Verhoef, J. Verschakelen, K. Lagrou, E. Verbeken, A. Wilmer, J. Verhaegen, M. Boogaerts, and J. Van Eldere. 2005. Galactomannan and computed tomography-based preemptive antifungal therapy in neutropenic patients at high risk for invasive fungal infection: a prospective feasibility study. Clin. Infect. Dis. 41:1242-1250. [DOI] [PubMed] [Google Scholar]
- 27.Marr, K. A., R. Hachem, G. Papanicolaou, J. Somani, J. M. Arduino, C. J. Lipka, A. L. Ngai, N. Kartsonis, J. Chodakewitz, and C. Sable. 2004. Retrospective study of the hepatic safety profile of patients concomitantly treated with caspofungin and cyclosporin A. Transpl. Infect. Dis. 6:110-116. [DOI] [PubMed] [Google Scholar]
- 28.Mora-Duarte, J., R. Betts, C. Rotstein, A. L. Colombo, L. Thompson-Moya, J. Smietana, R. Lupinacci, C. Sable, N. Kartsonis, J. Perfect, and the Caspofungin Invasive Candidiasis Study Group. 2002. Comparison of caspofungin and amphotericin B for invasive candidiasis. N. Engl. J. Med. 347:2020-2029. [DOI] [PubMed] [Google Scholar]
- 29.Morrissey, C. O., M. A. Slavin, M. A. O'Reilly, J. R. Daffy, J. F. Seymour, A. P. Schwarer, and J. Szer. 2007. Caspofungin as salvage monotherapy for invasive aspergillosis in patients with haematological malignancies or following allogeneic stem cell transplantation: efficacy and concomitant cyclosporin A. Mycoses 50(Suppl. 1):24-37. [DOI] [PubMed] [Google Scholar]
- 30.Olson, J. A., J. P. Adler-Moore, P. J. Smith, and R. T. Proffitt. 2005. Treatment of Candida glabrata infection in immunosuppressed mice by using a combination of liposomal amphotericin B with caspofungin or micafungin. Antimicrob. Agents Chemother. 49:4895-4902. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Ostrosky-Zeichner, L. 2008. Combination antifungal therapy: a critical review of the evidence. Clin. Microbiol. Infect. 14(Suppl. 4):65-70. [DOI] [PubMed] [Google Scholar]
- 32.Pappas, P. G., C. M. Rotstein, R. F. Betts, M. Nucci, D. Talwar, J. J. De Waele, J. A. Vazquez, B. F. Dupont, D. L. Horn, L. Ostrosky-Zeichner, A. C. Reboli, B. Suh, R. Digumarti, C. Wu, L. L. Kovanda, L. J. Arnold, and D. N. Buell. 2007. Micafungin versus caspofungin for treatment of candidemia and other forms of invasive candidiasis. Clin. Infect. Dis. 45:883-893. (Erratum, 47:302, 2008.) [DOI] [PubMed] [Google Scholar]
- 33.Pizzo, P. A., K. J. Robichaud, F. A. Gill, and F. G. Witebsky. 1982. Empiric antibiotic and antifungal therapy for cancer patients with prolonged fever and granulocytopenia. Am. J. Med. 72:101-111. [DOI] [PubMed] [Google Scholar]
- 34.Reed, C., R. Bryant, A. S. Ibrahim, J. E. Edwards, S. G. Filler, R. Goldberg, and B. Spellberg. 2008. Combination polyene-caspofungin treatment of rhino-orbital-cerebral mucormycosis. Clin. Infect. Dis. 47:364-371. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Sanz-Rodriguez, C., M. Lopez-Duarte, M. Jurado, J. Lopez, R. Arranz, J. M. Cisneros, M. L. Martino, P. J. Garcia-Sanchez, P. Morales, T. Olivé, M. Rovira, and C. Solano. 2004. Safety of the concomitant use of caspofungin and cyclosporin A in patients with invasive fungal infections. Bone Marrow Transplant. 34:13-20. [DOI] [PubMed] [Google Scholar]
- 36.Segal, B. H., N. G. Almyroudis, M. Battiwalla, R. Herbrecht, J. R. Perfect, T. J. Walsh, and J. R. Wingard. 2007. Prevention and early treatment of invasive fungal infection in patients with cancer and neutropenia and in stem cell transplant recipients in the era of newer broad-spectrum antifungal agents and diagnostic adjuncts. Clin. Infect. Dis. 44:402-409. [DOI] [PubMed] [Google Scholar]
- 37.Seibel, N. L., C. Schwartz, A. Arrieta, P. Flynn, A. Shad, E. Albano, J. Keirns, W. M. Lau, D. P. Facklam, D. N. Buell, and T. J. Walsh. 2005. Safety, tolerability, and pharmacokinetics of Micafungin (FK463) in febrile neutropenic pediatric patients. Antimicrob. Agents Chemother. 49:3317-3324. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Sionov, E., S. Mendlovic, and F. Segal. 2006. Efficacy of amphotericin B or amphotericin B-intralipid in combination with caspofungin against experimental aspergillosis. J. Infect. 53:131-139. [DOI] [PubMed] [Google Scholar]
- 39.Spellberg, B., T. J. Walsh, D. P. Kontoyiannis, J. E. Edwards, and A. S. Ibrahim. 2009. Recent advances in the management of mucormycosis: from bench to bedside. Clin. Infect. Dis. 48:1743-1751. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40.Stone, J. A., S. D. Holland, P. J. Wickersham, A. Sterrett, M. Schwartz, C. Bonfiglio, M. Hesney, G. A. Winchell, P. J. Deutsch, H. Greenberg, T. L. Hunt, and S. A. Waldman. 2002. Single- and multiple-dose pharmacokinetics of caspofungin in healthy men. Antimicrob. Agents Chemother. 46:739-745. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Trenschel, R., M. Ditschkowski, A. H. Elmaagacli, M. Koldehoff, H. Ottinger, N. Steckel, M. Hlinka, R. Peceny, P. M. Rath, H. Dermoumi, and D. W. Beelen. 2005. Caspofungin as second-line therapy for fever of unknown origin or invasive fungal infection following allogeneic stem cell transplantation. Bone Marrow Transplant. 35:583-586. [DOI] [PubMed] [Google Scholar]
- 42.Ullmann, A. J., O. A. Cornely, A. Burchardt, R. Hachem, D. P. Kontoyiannis, K. Töpelt, R. Courtney, D. Wexler, G. Krishna, M. Martinho, G. Corcoran, and I. Raad. 2006. Pharmacokinetics, safety, and efficacy of posaconazole in patients with persistent febrile neutropenia or refractory invasive fungal infection. Antimicrob. Agents Chemother. 50:658-666. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 43.Walsh, T. J., R. W. Finberg, C. Arndt, J. Hiemenz, C. Schwartz, D. Bodensteiner, P. Pappas, N. Seibel, R. N. Greenberg, S. Dummer, M. Schuster, and J. S. Holcenberg. 1999. Liposomal amphotericin B for empirical therapy in patients with persistent fever and neutropenia. National Institute of Allergy and Infectious Diseases Mycoses Study Group. N. Engl. J. Med. 340:764-771. [DOI] [PubMed] [Google Scholar]
- 44.Walsh, T. J., V. Yeldandi, M. McEvoy, C. Gonzalez, S. Chanock, A. Freifeld, N. L. Seibel, P. O. Whitcomb, P. Jarosinski, G. Boswell, I. Bekersky, A. Alak, D. Buell, J. Barret, and W. Wilson. 1998. Safety, tolerance, and pharmacokinetics of a small unilamellar liposomal formulation of amphotericin B (AmBisome) in neutropenic patients. Antimicrob. Agents Chemother. 42:2391-2398. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Walsh, T. J., H. Teppler, G. R. Donowitz, J. A. Maertens, L. R. Baden, A. Dmoszynska, O. A. Cornely, M. R. Bourque, R. J. Lupinacci, C. A. Sable, and B. E. dePauw. 2004. Caspofungin versus liposomal amphotericin B for empirical antifungal therapy in patients with persistent fever and neutropenia. N. Engl. J. Med. 351:1391-1402. [DOI] [PubMed] [Google Scholar]
- 46.Walsh, T. J., P. C. Adamson, N. H. Seibel, P. M. Flynn, M. N. Neely, C. Schwartz, A. Shad, S. L. Kaplan, M. M. Roden, J. A. Stone, A. Miller, S. K. Bradshaw, S. X. Li, C. A. Sable, and N. A. Kartsonis. 2005. Pharmacokinetics, safety, and tolerability of caspofungin in children and adolescents. Antimicrob. Agents Chemother. 49:4536-4545. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 47.Wasan, K. M., O. Sivak, M. Rosland, V. Risovic, and K. Bartlett. 2007. Assessing the antifungal activity, pharmacokinetics, and tissue distribution of amphotericin B following the administration of Abelcet and AmBisome in combination with caspofungin to rats infected with Aspergillus fumigatus. J. Pharm. Sci. 96:1737-1747. [DOI] [PubMed] [Google Scholar]
- 48.Wheat, L. J. 2003. Combination therapy for aspergillosis: is it needed, and which combination? J. Infect. Dis. 187:1831-1833. [DOI] [PubMed] [Google Scholar]
- 49.Wilson, D. T., R. H. Drew, and J. R. Perfect. 2009. Antifungal therapy for invasive fungal diseases in allogeneic stem cell transplant recipients: an update. Mycopathologia 168:313-327. [DOI] [PubMed] [Google Scholar]
- 50.Wirk, B., and J. R. Wingard. 2008. Combination antifungal therapy: from bench to bedside. Curr. Fungal Infect. Rep. 2:43-48. [DOI] [PubMed] [Google Scholar]
- 51.Wuerthwein, G., C. Young, C. Lanvers-Kaminsky, G. Silling, G. Hempel, J. Boos, and A. H. Groll. 2009. Population pharmacokinetics of liposomal amphotericin B, caspofungin and the combination of both in allogeneic hematopoietic stem cell recipients, abstr. A1-591′ Abstr. 49th Intersci. Conf. Antimicrob. Agents Chemother. American Society for Microbiology, Washington, DC.