Clinical trial of tacrolimus versus cyclosporine in lung transplantation

Background. A prospective clinical trial was undertaken to compare the efficacy of tacrolimus (FK 506) versus cyclosporine as the primary immunosuppressive agent after lung transplantation. Methods. Between October 1991 and May 1994, 133 single-lung and bilateral-lung recipients were randomized to receive either cyclosporine (n = 67) or tacrolimus (n = 66). The two groups were similar in age, sex, and underlying disease. Results. One-year and 2-year survival rates were similar in the two groups, although the trend was toward increased survival with tacrolimus. Acute rejection episodes per 100 patient-days were fewer (p = 0.07) in the tacrolimus group (0.85) than in the cyclosporine group (1.09). Obliterative bronchiolitis developed in significantly fewer patients in the tacrolimus group (21.7%) compared with the cyclosporine group (38%) (p = 0.025), and there was greater freedom from obliterative bronchiolitis over time for patients receiving tacrolimus (p < 0.03). Significantly more cyclosporine-treated patients (n = 13) required crossover to tacrolimus than tacrolimus-treated patients to cyclosporine (n = 2) (p = 0.02). The switch to tacrolimus controlled persistent acute rejection in 6 of 9 patients. The overall incidence of infections was similar in the two groups, although bacterial infections were more common with cyclosporine (p = 0.0375), whereas the risk of fungal infection was higher with tacrolimus (p < 0.05). Conclusions. This trial demonstrates the advantage of tacrolimus in reducing the risk of obliterative bronchiolitis, the most important cause of long-term morbidity and mortality after lung transplantation.