Influence of FK506 in clinical transplantation

Annals of Surgery, 1990

The new immunosuppressive drug FK 506 was used from the outset with low doses of prednisone to treat 120 recipients of primary liver grafts and 20 more patients undergoing liver retransplantation. The patient survival rate after 2 to 8 months in the primary liver transplantation series is 93.3%, with original graft survival of 87.5%. Of the 20 patients in the hepatic retransplant series, 17 (85%) are living. Almost all of the surviving patients have good liver function. In addition 11 hearts, 2 double lungs, and a heart-lung have been transplanted under FK 506, with survival of all 14 patients. With all of the organ systems so far tested, including the kidney (which has been reported elsewhere), rejection usually has been controlled without additional drugs and with lower average steroid doses than in the past. Nephrotoxicity has been observed, but not to an alarming degree, and there has been a notable absence of hypertension. There is a suggestion that serum cholesterol may be lowered by FK 506, but this is unproved. Although the adverse reactions of FK 506

Transplantation proceedings, 1991

Early reports on the use of FK 506 after kidney transplantation emphasized the ability to stop prednisone in a significant percentage of successfully transplanted patients. 1,2 In addition, there was a relative freedom from antihypertensive agents and a tendency toward low serum cholesterol levels. This report will summarize our experience to date with FK 506 in renal transplantation and will compare the results with a nearly concurrent group of patients treated with cyclosporine (CyA)-based immunosuppression. MATERIALS AND METHODS Between March 27, 1989, the date of the first kidney transplant under FK 506 immunosuppression, and May 1, 1991, 464 kidney transplantations were performed at the University of Pittsburgh. Of these 28 were in patients who had received concomitant or previous liver transplants, and these were the only exclusions from the analysis. Of the 436 transplants in 425 patients, 196 received CyA-based immunosuppression; over 80% of this group received azathioprine as well (Table 1). Some 240 cases were treated with FK 506 and steroids. The mean recipient age was 39.5 ± 14.9 years; 44 (10.1%) of the cases were performed in patients over 60 years of age, and 31 (7.1%) of the transplants were to children. Sixty (13.7%) of the cases involved black recipients. There was a significantly higher incidence of retransplantation in the FK 506 group-over 30% of the FK 506 cases were to patients undergoing their second to fifth transplant, whereas just under 20% of the CyA cases were retransplants (P <.005). Over 25% of the transplants were to sensitized recipients. A higher percentage of living-donor cases were done under CyA-14.3% vs 5% of the FK 506 cases (P < .02). The mean donor age was 34.0 ± 16.6 years; 73 (18.4%) of the cadaver transplants were with pediatric en bloc kidneys. The mean cold ischemia time was 36.3 ± 10.6 hours. HLA matches and mismatches revealed a small number of good matches, with less than 2% of cases being 6-antigen matches and nearly two-thirds of cases having a 2-antigen match or less. There was thus no attempt to be particularly discriminating in either donor or recipient selection. The FK 506 cases were actually a higher-risk group than was the CyA groupmore retransplants, fewer living donor cases, slightly more sensitized patients, and en bloc kidneys. This had the effect of subjecting FK 506 to a rather stringent evaluation.

Pediatric Nephrology, 1995

Between 14 December 1989 and 17 December 1993, 43 patients undergoing kidney transplantation alone at the Children's Hospital of Pittsburgh received FK506 as the primary immunosuppressive agent. The mean recipient age was 10.2±4.8 years (range 0.7–17.4 years), with 7 (16%) children under 5 years of age and 2 (5%) under 2 years of age. Fifteen (35%) children underwent retransplantation, and 5 (12%) had a panel-reactive antibody level greater than 40%. Twenty-two (51%) transplants were with cadaveric donors and 21 (49%) were with living donors. The mean follow-up was 25±14 months; there were no deaths; 1- and 3-year actuarial graft survival was 98% and 85%. The mean serum creatinine and blood urea nitrogen were 1.2±0.6 mg/dl and 26±11 mg/dl; the calculated creatinine clearance was 75±23 ml/min per 1.73 m2. Twenty-four (62%) patients have been successfully with-drawn from steroids and 24 (62%) require no anti-hypertensive medication. Improved growth was seen, particularly in pre-adolescent children off steroids. Between 28 July 1990 and 2 December 1993, 24 children were referred for rescue therapy with FK506, 14.6±16.4 months (range 1.1–53.2 months) after transplantation. Nineteen (79%) were referred because of resistant rejection; 4 (17%) were referred because of proteinuria; 1 (4%) was switched because of steroid-related obesity. There were no deaths; 1-and 2-year graft survival was 75% and 68%; 17 (71%) patients were successfully rescued, including 1 of 2 patients who arrived on dialysis; 4 (24%) of the successfully rescued patients were weaned off steroids. While not without side effects, which include nephrotoxicity, neurotoxicity, diabetogenicity, and viral complications, FK506 appears to be an effective immunosuppressive agent for both primary and rescue therapy after kidney transplantation. Its steroid-sparing qualities may be of particular importance in the pediatric population.

PubMed, 1994

Previous clinical evaluation of FK506 in renal transplantation has demonstrated equivalent patient and graft survival when compared with cyclosporine-based regimens. However, lower steroid and anti-hypertensive mediation requirements and lower serum cholesterol levels have been seen in patients receiving FK506. In August, 1991, a prospective, randomized trial was begun, comparing FK506/prednisone with FK506/azathioprine/prednisone. Two-hundred-and-four adults were entered into this trial between August 1, 1991, and October 11, 1992. The mean recipient age was 43.8 +/- 13.7 years, with a range of 17.6-78.0 years. Sixty-one (30%) recipients received a 2nd, 3rd or 4th transplant, while 35 (17%) had a PRA greater than 40% at the time of transplant. Thirty-three (16%) of the transplants were in recipients over 60 years of age, Thirteen percent of the kidneys were from living donors; 13% of the cadaveric kidneys were from pediatric donors less than 3 years of age and were transplanted en bloc. The mean cold ischemia time was 31.4 +/- 8.4 hours, and the mean donor age was 34 +/- 2.10 years, with a range from 4 months to 75 years. With a mean follow-up of 9 +/- 4 months, the 1-year actuarial patient survival is 93%; for the two-drug group it is 95%, and for the three-drug group it is 91% (p = NS). One-year actuarial graft survival is 86%; in the two-drug group it is 90%, while in the three-drug group it is 82% (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

JAMA: The Journal of the American Medical Association, 1990

The experimental immunosuppressive drug FK 506 was given to 36 renal transplant recipients, many of whom were highly sensitized. Ten were undergoing kidney retransplantation, 10 also underwent liver transplantation at an earlier time (6 patients) or concomitantly (4 patients), and 2 patients received a third organ (heart or pancreas) in addition to a liver and kidney. With follow-ups of 4 to 13 months, all but 2 of the 36 patients are alive, 29 (81 %) are dialysis free, and most have good renal function. Twenty of the 29 dialysis-free patients are receiving no or low-dose (2.5 to 5.0 mg/d) prednisone therapy. Only one kidney was lost to cellular rejection. However, patients who had antidonor cytotoxic antibodies in current or historical serum samples had a high rate (3 of 9) of irreversible humoral rejection. A low incidence of posttransplant hypertension was noteworthy. Hirsutism and gingival hyperplasia were not observed. Serum cholesterol levels in patients who took FK 506 were unexpectedly low, and the effect on the level of uric acid was minimal. The side effects of FK 506 therapy include nephrotoxicity, neurotoxicity, and potential induction of a diabetic state. These are similar to the side effects of cyclosporine use, but probably less severe. The seeming safety, efficacy, and relative freedom from side effects of FK 506 encourage further trials in kidney transplantation. Encouraging clinical trials in liver transplantation have been reported with the new immunosuppressive agent FK 506, 1-3 which is produced by the fungus Streptomyces tsukubaensis. 4,5 Although the molecular structure of FK 506 is unrelated to cyclosporine and has a different cytosolic binding site, 6,7 the two drugs have similar effects on the immune system. 8,9 We report here a trial of FK 506 in kidney recipients, of whom the majority had complex clinical problems or were at high risk because of adverse medical or immunologic factors. METHODS Recipient Case Material Complexity factors in the 36 patients included concomitant or prior liver transplantation (29%), previous kidney transplantation (29%), and causes of renal failure that increase the risk of transplantation (Table 1). The only child in the series (10 years old) had hemolytic uremic syndrome. Hemolytic uremic syndrome is a known complication of cyclosporine use 10 that has been treated successfully with FK 506.11 Five patients were older than 60 years.

Transplantation, 1995

A group of 204 adult patients was entered into a prospective, randomized trial comparing FK506/ prednisone with FK506/azathioprine/prednisone after renal transplantation between August 1, 1991 and October 11, 1992. The purpose of the study was to see if the addition of azathioprine would reduce the incidence of rejection and improve graft survival. The recipient population was unselected, with 61 (30%) patients undergoing retransplantation, 37 (18%) having a panel-reactive antibody greater than 40%, and 33 (16%) over 60 years of age. The mean recipient age was 43.8 ± 13.7 years (range 17.6-78). The mean donor age was 34.0 ± 20.1 years (range 0.3-75); 13% of the cadaveric kidneys were from pediatric donors less than 3 years of age and were transplanted en bloc. The mean cold ischemia time was 31.4 ± 8.4 hr. Living donors were the source of 13% of the kidneys. The mean follow-up was 22 ± 4 months (range 12-29). Overall one-year actual patient survival was 94%. Overall one-year actual graft survival was 87%. Patients starting on double therapy had a one-year actual patient survival of 96% and a one-year actual graft survival of 92%. Patients starting on triple therapy had a one-year actual patient survival of 91% (P = ns compared with double therapy), and a one-year actual graft survival of 82% (P < 0.02, compared with double therapy). Overall results with first cadaver transplants included a one-year actual patient survival of 94% and one-year actual graft survival of 88%, with no differences between double and triple therapy. The overall incidence of rejection was 48%, with 54% in the double therapy group and 41% in the triple therapy group (P < . 07). The incidence of steroid-resistant rejection requiring antilymphocyte therapy (OKT3 or ATGAM) was 13%, and was not different between the double and triple therapy groups. The mean serum creatinine was 1.8 ± 0.8 mg/dl. The mean BUN was 33 ± 21 mg/dl, with no significant difference between the therapy groups. The mean serum cholesterol was 192 ± 49 mg/dl. A total of 56% of the patients are off prednisone, and 35% of the patients are not taking any antihypertensive medications. Other complications included cytomegalovirus-14%; new-onset diabetes-16% (half of which was reversible); and posttransplant lymphoproliferative disorder-1%. There was a high incidence of crossover between the two groups, 27% of the patients in the double therapy group requiring the addition of azathioprine, and 45% of the patients in the triple therapy group requiring its discontinuation (usually temporary). These results show that FK506 is an excellent immunosuppressive agent after renal transplantation and that azathioprine is not routinely effective 1

Transplantation Proceedings

We recently reported our initial experience with FK 506 in 36 patients undergoing renal transplantation. 1 This series was characterized by a high average complexity, and included 10 patients who also were liver recipients either concomitantly or at an earlier time. Additionally, 2 of the 10 also were given a heart or pancreas.

PubMed, 1990

Transplantation, 1991

Plasma FK506 was studied in 49 liver, 13 heart, 3 double-lung or heart-lung, and 21 kidney recipients. The levels were correlated with the drug doses used, kidney function, and liver function. In all varieties of recipients, there was an early rise in the FK506 plasma levels that occurred at the time of intravenous administration of the drug. At the same time or shortly after, there were increases in serum creatinine that were transitory except in liver recipients with continuing suboptimal graft function. The quality of hepatic function dominated all aspects of FK506 management in the liver recipients. Those who received well-functioning grafts could be given about the same drug doses as recipients of kidneys and the thoracic organs. Liver recipients with defective grafts had astronomical rises in plasma FK506, a high incidence of renal failure, and probably increased neurotoxicity. In kidney transplant recipients, the FK506 plasma levels and doses were essentially the same in patients with prompt versus delayed renal function. These studies have highlighted the necessity, first, of close pharmacologic monitoring of patients who are given FK506 in the presence of abnormal liver function, and second, of using smaller intravenous induction doses than in past practice.

Transplantation, 1994

Seventy-seven patients with ongoing acute rejection on initial CsA therapy were converted to FK506 to attempt graft salvage. Fifty-nine patients had undergone primary transplantation and 18 had been retransplanted; there were 52 cadaveric and 25 living-donor transplants. The indications for conversion to FK506 were ongoing, biopsy-confirmed rejection in all patients, including vascular rejection in 20. The median interval to rescue was 2 months (range 2 weeks to 36 months) after transplantation. Sixty-one of the 77 patients (79%) had already received one or more courses of an antilymphocyte preparation (OKT3: n=33; ALG or ATG: n=l; OKT3+ALG/ATG: n=27). Of the 77 patients, 57 (74%) have been successfully rescued and still have functioning grafts with a mean follow-up of 14 months, with a mean serum creatinine of 2.35±0.97 mg/dl. Eighteen patients were already dialysis-dependent at the time of conversion to FK506; of these, 9 (50%) were successfully salvaged and have a mean serum creatinine of 2.3 mg/dl. Of the 61 patients previously treated with antilymphocyte preparations, 48 (79%) were rescued. In those salvaged, prednisone doses have been lowered from 22.2±7.2 mg/day preconversion to 7.5±5.6 mg/day postconversion, and 12 patients are on FK506 monotherapy. In nondiabetics, mean serum glucose was 101.4±20.5 mg/dl preconversion and 93.2±22 postconversion (P=0.07), uric acid 7.3±2.3 and 7.1±1.5 mg/dl (P=0.53), and triglycerides 199.2±101.6 and 167.2±106.4 mg/dl (P=0.06). Cholesterol levels were significantly lower following FK conversion (207.7±46.5 mg/dl pre. vs. 188.3±39.7 post., P=0.007). FK506 is capable of salvaging renal allografts with ongoing acute rejection on CsA therapy, even when antilymphocyte preparations have been ineffective.