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Background Conventional regimens of immunosuppressive drugs often do not prevent chronic rejection after lung transplantation. Topical delivery of cyclosporine in addition to conventional systemic immunosuppression might help prevent acute and chronic rejection events.
Methods We conducted a single-center, randomized, double-blind, placebo-controlled trial of inhaled cyclosporine initiated within six weeks after transplantation and given in addition to systemic immunosuppression. A total of 58 patients were randomly assigned to inhale either 300 mg of aerosol cyclosporine (28 patients) or aerosol placebo (30 patients) three days a week for the first two years after transplantation. The primary end point was the rate of histologic acute rejection.
Results The rates of acute rejection of grade 2 or higher were similar in the cyclosporine and placebo groups: 0.44 episode (95 percent confidence interval, 0.31 to 0.62) vs. 0.46 episode (95 percent confidence interval, 0.33 to 0.64) per patient per year, respectively (P=0.87 by Poisson regression). Survival was improved with aerosolized cyclosporine, with 3 deaths among patients receiving cyclosporine and 14 deaths among patients receiving placebo (relative risk of death, 0.20; 95 percent confidence interval, 0.06 to 0.70; P=0.01). Chronic rejection–free survival also improved with cyclosporine, as determined by spirometric analysis (10 events in the cyclosporine group and 20 events in the placebo group; relative risk of chronic rejection, 0.38; 95 percent confidence interval, 0.18 to 0.82; P=0.01) and histologic analysis (6 vs. 19 events, respectively; relative risk, 0.27; 95 percent confidence interval, 0.11 to 0.67; P=0.005). The risks of nephrotoxic effects and opportunistic infection were similar for patients in the cyclosporine group and the placebo group.
Conclusions Inhaled cyclosporine did not improve the rate of acute rejection, but it did improve survival and extend periods of chronic rejection–free survival. (ClinicalTrials.gov number, NCT00268515
[ClinicalTrials.gov]
.)
Since the immunosuppressive effect of cyclosporine is dose-dependent, targeted delivery of this drug might improve efficacy by increasing the concentration of cyclosporine in the allograft. In animal models of lung transplantation, inhaled cyclosporine remains in high concentrations in lung tissue and reduces rejection without toxicity.15,16,17,18 Moreover, in human lung-transplant recipients with refractory acute and chronic rejection, open-label rescue treatment with inhaled cyclosporine improves clinical markers of rejection and improves survival.19,20,21,22,23,24,25 In light of these findings, we tested whether prophylactic inhaled cyclosporine would improve outcomes after lung transplantation.
Methods
Study Design
A randomized, double-blind, placebo-controlled trial of aerosol cyclosporine inhalation, given in addition to conventional immunosuppression, was conducted at the University of Pittsburgh Medical Center with approval of the institutional review board. Recipients of single or bilateral lung transplants who were at least 18 years of age were eligible. Patients were excluded from the study if they had active fungal or bacterial pneumonia, unresolved diffuse alveolar damage, or untreated bronchial stenosis or if they were receiving mechanical ventilation. From November 1998 to August 2001, patients were offered enrollment if they met the study criteria before day 42 after transplantation and were randomly assigned to a treatment group immediately after the provision of written informed consent. Study treatment began as soon as was practically possible thereafter, but no more than 55 days later.
Because mismatches between donor and recipient with respect to cytomegalovirus (CMV) serologic status are known to have an adverse effect on the outcome of transplantation, the randomization was stratified according to donor–recipient CMV status. The two categories were a primary mismatch (a CMV-positive donor and a CMV-negative recipient) and all other serologic combinations. Patients were then randomly assigned to groups according to permuted blocks of four in a 1:1 ratio to receive either inhaled cyclosporine or placebo for two years. All patients were followed for clinical outcome until the last subject completed the scheduled two-year regimen (August 2003). As a result, follow-up ranged from 24 to 56 months.
Novartis Pharmaceuticals provided cyclosporine powder, which was compounded by the University of Pittsburgh experimental pharmacy. University investigators were solely responsible for the trial design, data accrual, and study management. After completion of the study, Chiron obtained a license agreement for inhaled cyclosporine. The analyses presented in this article are those of the university investigators, unless otherwise noted. The data and safety monitoring board took no action regarding early trial cessation.
Administration of Inhaled Cyclosporine
Patients inhaled cyclosporine mixed in propylene glycol (62.5 mg per milliliter) or placebo (propylene glycol alone) initially for 10 consecutive days, then three times weekly with the use of a jet nebulizer (AeroTech II, CIS-US). Patients were instructed to continue treatment for two years. Patients were premedicated by inhalation of 2 percent lidocaine (3 ml) and 2.5 mg of albuterol by means of a nebulizer (Airlife, Cardinal Health). Inhaled cyclosporine was initiated at a dose of 100 mg and increased by incremental doses of 100 mg up to 300 mg or a maximally tolerated dose or an aerosol equivalent volume of placebo. Aerosols were self-administered by the patients and were temporarily discontinued if the treating physician reported an infection that persisted after antibiotic therapy. A study coordinator contacted the patients at least monthly to verify compliance.
Transplant Monitoring
Patients followed a typical care regimen for patients after lung transplantation, including surveillance bronchoscopy with transbronchial biopsy and bronchoalveolar lavage, spirometry, blood work, and a complete history and physical examination one month after transplantation and at intervals of approximately three months for the first two postoperative years, then at intervals of four to six months. Histologic rejection was defined according to established criteria.26 Spirometry was performed according to American Thoracic Society standards27 and the results expressed in terms of the percentage of predicted values.28 Because bronchiolitis obliterans is not uniformly detectable by biopsy, spirometry is routinely used as a surrogate marker to diagnose chronic rejection. Airflow measurements were evaluated for criteria of the bronchiolitis obliterans syndrome, which was defined as a sustained decrease in the forced expiratory volume in one second (FEV1) of at least 20 percent from the patient's maximum values in the absence of other causes.29 Cytomegalovirus status was assessed by CMV pp65 antigenemia at weekly intervals for six months after transplantation.
Clinical Management
Both groups received conventional immunosuppression, including tacrolimus (0.06 mg per kilogram of body weight per day), azathioprine (2 mg per kilogram per day), and prednisone (20 mg per day). Subsequent adjustments were made at the discretion of the treating clinician on the basis of lung function and biopsy results. Enhanced immune suppression for treatment of acute rejection (grade 2 or higher), active bronchiolitis obliterans, or both consisted of pulsed corticosteroids (intravenous methylprednisolone at a dose of 1 g per day for 3 days or oral prednisone at a dose of 100 mg tapered to 10 mg over 14 days) or rabbit antithymocyte globulin (Thymoglobulin [SangStat] at a dose of 1.5 mg per kilogram per day for 5 to 7 days). Intravenous ganciclovir was used if the level of antigenemia was more than 10 CMV-positive cells per 2x105 leukocytes.
End Points
The primary end point of the study was the frequency of histologic acute rejection. Secondary end points included chronic rejection–free survival and overall survival. Chronic rejection was identified on the basis of both histologic markers (for bronchiolitis obliterans) and spirometric markers (for the bronchiolitis obliterans syndrome).29
Adverse events were defined as infections requiring treatment, hospitalizations, and symptoms as reported by questionnaire. All evaluations of outcomes were performed in a blinded manner.
Statistical Analysis
Power analysis stipulating a 33 percent difference in the frequency of acute rejection suggested the enrollment of 136 patients on the basis of a two-sided test (
=0.05, 
=0.15), an assumed acute-rejection rate of 2.8 events per year, and a dropout rate of 15 percent. The study prespecified a three-year enrollment period. During this time, all qualifying lung-transplant recipients were approached for participation. Enrollment was discontinued after three years, after the accrual of only 58 subjects. The failure to achieve enrollment goals was due to an overestimation of the number of transplantations that would be performed during the accrual period (anticipated number, 180; actual number performed, 121). The study was closed two years after the last subject had been enrolled. All outcome variables were followed until either the death of the patient or the end of the study (in August 2003), independent of the continuation or discontinuation of study medication or the conclusion of the scheduled two-year study-treatment period. Patients were analyzed according to the intention to treat, and no patients were lost to follow-up. Group means were compared with the use of unpaired, two-tailed t-tests or Mann–Whitney tests. All reported P values are two-sided and have not been adjusted for multiple testing.
The frequency of acute rejection was calculated by determining the number of rejection events of grade 2 or higher per year of study time for each subject. Differences between groups were also considered with the use of a Poisson regression model, with covariates including treatment group, CMV mismatch, and the occurrence or nonoccurrence of a rejection episode before the start of the study treatment. The Poisson model was calculated by Chiron.
Log-rank and Cox proportional-hazards analyses were used to compare survival and chronic rejection–free survival. Nonaerosol covariates that were tested in multivariate analyses included CMV-mismatch status, HLA-mismatch status, the age and sex of the recipient, the age and sex of the donor, smoking history of the recipient, diagnosis before transplantation, type of transplantation (single or double), and ischemic time. After closure of the study and unblinding, Chiron performed a follow-up analysis of survival as of June 2004. Statistical analyses were performed with Statview software (SAS).
Results
Characteristics of the Patients
Of the 121 patients who received lung transplants during the enrollment period, 58 were randomly assigned to a study group and 56 received at least one dose of study medication (inhaled cyclosporine, 26; placebo aerosol, 30) (Figure 1). The baseline characteristics and clinical management in the two groups were similar (Table 1). The CMV-mismatch status, the number of biopsy procedures, the number of spirometric measurements, immunosuppressive-drug regimens, and tacrolimus levels were similar in patients in the two groups (Table 1 and Table 2).
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Acute Rejection
We performed a total of 335 biopsies in patients in the cyclosporine group and 333 biopsies among patients in the placebo group. The mean number of biopsies (5.5 per patient per year) exceeded the minimum protocol requirements. The mean follow-up for acute rejection (mean time from study initiation to the last biopsy) was 2.4±0.2 years for the cyclosporine group and 2.2±0.2 years for the placebo group (P=0.43). The estimated number of acute-rejection episodes of grade 2 or higher per patient per year after the start of study-drug administration was 0.44 (95 percent confidence interval, 0.31 to 0.62) for the cyclosporine group and 0.46 (95 percent confidence interval, 0.33 to 0.64) for the placebo group. In each group, 17 patients had no more than one event per year; 26 patients in the cyclosporine group and 23 patients in the placebo group had no more than two events per year; and 26 patients in each group had no more than three events per year. A Poisson regression model with control for CMV-mismatch status and the occurrence or nonoccurrence of a rejection episode of grade 2 or higher before study-drug administration demonstrated that there was no significant difference between the treatment groups (P=0.87).
Chronic Rejection
Chronic rejection–free survival was improved among patients who were treated with inhaled cyclosporine as determined by spirometric and histologic evaluation. Figure 2A shows the results of a hazards analysis of survival free of the bronchiolitis obliterans syndrome, with 10 events in the cyclosporine group and 20 events in the placebo group (relative risk, 0.38; 95 percent confidence interval, 0.18 to 0.82; P=0.01). Figure 2B shows the results of a similar analysis of survival free of histologic bronchiolitis obliterans, with 6 events among patients in the cyclosporine group and 19 events among patients in the placebo group (relative risk, 0.27; 95 percent confidence interval, 0.11 to 0.67; P=0.005). None of the four patients in the cyclosporine group in whom histologic bronchiolitis obliterans was diagnosed were receiving study drug at the time of diagnosis.
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Survival Analysis
The use of inhaled cyclosporine was associated with a substantial survival advantage (Figure 3). There were 14 deaths (47 percent) in the placebo group, as compared with 3 deaths (11 percent) in the cyclosporine group (P=0.005 by log-rank analysis). Multivariate survival regression confirmed that the risk of death for patients receiving placebo was higher by a factor of 5 (relative risk of death in the cyclosporine group as compared with the placebo group, 0.20; 95 percent confidence interval, 0.06 to 0.70; P=0.01) and revealed no significant effect for CMV strata, transplant type, or HLA mismatch.
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A follow-up analysis of survival including all 56 patients who received study medication was conducted during the 10 months that followed the end of the study. During that period, an additional two patients in the cyclosporine group and one patient in the placebo group died. The results of log-rank analysis of survival were similar to those reported at study closure (P=0.02).30
Infection
The pneumonia rate was not significantly different in the two groups (13 patients in the cyclosporine group and 17 patients in the placebo group, P=0.44), and patients receiving aerosol cyclosporine were no more likely to be treated for infection than were patients in the placebo group (2.3±0.4 vs. 3.1±0.6 courses of antibiotic per patient per year, respectively; P=0.29). The risk of CMV pneumonitis was less in the cyclosporine group (3 of 28 patients) than in the placebo group (10 of 30 patients; P=0.04). The difference was confirmed by Cox proportional-hazards analysis with study drug and donor–recipient CMV status as covariates, with a relative risk of assignment to cyclosporine of 0.27 (P=0.05) and of CMV mismatch of 4.33 (P=0.009) among CMV-positive donors with CMV-negative recipients, as compared with all other combinations.
Adverse Events
Both cyclosporine and placebo aerosols were associated with local irritation, including cough, pharyngeal soreness, or dyspnea in 52 percent of study participants on the basis of responses to a questionnaire administered during clinical visits (Table 3). Such symptoms were observed in both groups, were typically transient, and were either mild or moderate in severity. When symptoms occurred, they usually resolved within 30 to 45 minutes after inhalation.
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Discussion
Chronic rejection remains the leading cause of death after lung transplantation despite the use of systemic calcineurin inhibitors.31,32,33 The immunosuppressive effects of cyclosporine have been shown to be dose-dependent. However, high systemic levels of the drug cannot be achieved without significant toxicity, especially to the kidneys. We hypothesized that the inhalation of an aerosol cyclosporine would provide high pulmonary concentrations of the drug with minimal systemic toxicity, resulting in less acute and chronic rejection. This double-blind, placebo-controlled trial of inhaled cyclosporine given in addition to conventional immunosuppression after lung transplantation was negative with respect to its primary end point, since rates of acute rejection were similar in the group receiving cyclosporine and that receiving placebo. However, survival improved significantly with aerosol cyclosporine, as did the rate of chronic rejection–free survival (on the basis of both histologic and spirometric analysis).
In the absence of notable differences in rates of acute rejection, a positive result in terms of chronic rejection was unexpected, since previous studies have linked repeated acute rejection events with chronic rejection.2 Histologically, chronic rejection presents in the airways as bronchiolitis obliterans, whereas acute rejection presents as vasculitis. Bronchioles would have higher local concentrations of a drug as a result of direct aerosol delivery, whereas pharmacokinetic studies suggest a much less substantial vascular concentration of the drug.34,35,36 Therefore, it is possible that aerosol cyclosporine has a local airway antiinflammatory effect that decreases the likelihood of chronic rejection while having a lesser effect on vascular acute rejection.
The rates of pneumonia were similar in the two groups, as were serum creatinine levels. More than half the study patients had some level of local irritation (pharyngeal soreness, cough, or dyspnea), with no significant differences noted between patients in the two groups. Less than 10 percent of patients in the cyclosporine group withdrew because of symptoms associated with the aerosol. However, supervision during the first several treatments would probably be required, given the tenuous respiratory status of patients soon after transplantation. Many patients who had some initial minor respiratory symptoms developed a tolerance for the medication after a few treatments.
Local cyclosporine treatment had some benefit in this small, single-center trial. Further experience with inhaled cyclosporine is needed to confirm the magnitude and durability of the observed effects in recipients of single-lung and double-lung transplants.
Supported by a grant from the National Institutes of Health (HL059490 01, to Drs. Iacono and Griffith).
A U.S. patent application (20020006901) entitled "Use of Aerosolized Cyclosporine for Prevention and Treatment of Pulmonary Disease" was submitted on February 5, 1999, and assigned to the University of Pittsburgh, with Dr. Iacono listed as inventor. The patent has been licensed by the University of Pittsburgh to Chiron and Novartis Pharmaceuticals. In the event of eventual commercialization of aerosol cyclosporine, a royalty could be paid to the following investigators at the University of Pittsburgh and the State University of New York, Stony Brook: Dr. Iacono, Dr. Dauber, Dr. Smaldone, Dr. Zeevi, and Dr. Burckart. No author reports having any equity interest in either Chiron or Novartis as a stockholder or other related ownership interests. Drs. Iacono, Johnson, and Corcoran report having received consulting fees and Dr. Zeevi lecture fees from Chiron. Dr. McCurry reports having received a grant from Pfizer. Dr. Dauber reports having received lecture fees from and serving on an advisory board for InterMune. No other potential conflict of interest relevant to this article was reported.
We are indebted to Howard E. Rockette of the Department of Biostatistics at the University of Pittsburgh for trial design and for his assistance with statistical analyses; to Laurence S. Magder of the Department of Biostatistics–Informatics at the University of Maryland for his review of statistical analyses; to William B. Capra of Chiron in Emeryville, Calif., for performing the Poisson regression analysis and reviewing statistical analyses performed at the University of Pittsburgh; to Dr. Brack G. Hattler, Carmella R. Campbell, Mary C. Williams, Jan D. Manzetti, and Judi L. Vensak of the University of Pittsburgh Medical Center for their support for this project and assistance with patient care; to Dr. N. Paul Ohori of the Department of Pathology at the University of Pittsburgh for interpretation of lung biopsies; to Frank J. Clementi of the Sunrise Medical Home Healthcare Group, Somerset, Pa., for donating compressors; to Novartis in East Hanover, N.J., for supplying the cyclosporine powder needed to conduct this study; and to Dr. Maria M. Crespo of the Pulmonary Allergy and Critical Care Division, University of Pittsburgh Medical Center, and Dr. Edward P. Ingenito of the Pulmonary and Critical Care Division, Brigham and Women's Hospital, Boston, for their thoughtful review of the manuscript.
Source Information
From the Division of Pulmonary, Allergy and Critical Care Medicine (A.T.I., B.A.J., W.F.G., J.G.Y., T.E.C., D.A.S., J.H.D.), the Department of Pathology (A.Z., S.A.Y.), and the Thomas E. Starzl Transplantation Institute (J.J.F.), University of Pittsburgh Medical Center; and the Division of Cardiothoracic Surgery, University of Pittsburgh (K.R.M.) — all in Pittsburgh; the Division of Pulmonary and Critical Care Medicine, State University of New York at Stony Brook, Stony Brook (G.C.S.); the Department of Pharmacy, University of Southern California, Los Angeles (G.J.B.); and the Division of Cardiothoracic Surgery, University of Maryland, Baltimore (B.P.G.).
Address reprint requests to Dr. Iacono at the Division of Pulmonary Transplantation and Pulmonary and Critical Care Medicine, Medical School Teaching Facility 800, University of Maryland School of Medicine, 10 S. Pine St., Baltimore, MD 21201, or at aiacono{at}medicine.umaryland.edu.
References
antagonism by interferon-
and cyclosporine A in lung fibroblasts. FASEB J 2001;15:797-806.
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Related Letters:
Inhaled Cyclosporine in Lung Transplantation
Verleden G. M., Dupont L. J., Iacono A. T., Johnson B. A., Corcoran T. E.
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N Engl J Med 2006;
354:1752-1753, Apr 20, 2006.
Correspondence
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