Early Experience with Anti-Tac in Clinical Renal Transplantation
`
`E.L. Milford, E.L. Ramos, N.L. Tilney, T.A. Waldmann,
`R.L. Kirkman, M.E. Shapiro, C.B. Carpenter,
`C.E. Zimmerman, and T.8. Strom
`
`THE SEARCH for more effective and Jess broadly toxic
`immunosuppressive agents remains a major goal of
`transplantation research. One approach to achieving more
`specific immunosuppression is to target only those lympho­
`cytes responding to an allograft by directing therapy at
`activation antigens. Of these antigens, the interleukin-2
`receptor (IL-2R) has proven of particular interest, both
`because of its important biological role in the activation
`T-cells1 and because of extensive animal model experience
`with anti-IL-2R monoclonal antibody (Mab) therapy.2-6
`Anti-Tac is a murine Mab with specificity for the 55KD
`beta subunit of the human IL-2R. 7 Anti-Tac blocks binding
`of IL-2 to its receptor and prevents association of the alpha
`and beta chains of the receptor to form the high affinity
`IL-2R.1 Recent work from our laboratory has shown that
`anti-Tac as a single agent will significantly delay rejection of
`renal allografts in cynomolgus monkeys.6 Encouraged by
`these results, we have initiated a randomized trial of prophy­
`lactic therapy with anti-Tac in clinical renal transplantation.
`This study presents our early experience with three protocols
`for the use of this agent.
`
`In the second protocol, no cyclosporine was used in tbe experimen·
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`
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`tal group in the first week. Patients were randomized to receive
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`either anti· Tac 20 mg/day for 10 days, azathioprine 2 mg/kg/day,
`
`and prednisone 30 mg/day, with cyclosporine 8 mg/kg/day added
`
`
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`on day 8, or conventional triple therapy with cyclosporine 8 mg/
`
`
`kg/day, azathioprine 2 mg/kg/day, and prednisone 30 mg/day.
`
`This protocol was terminated prematurely, as noted below.
`
`In the third protocol, low dose cyclosporine is being used in the
`
`experimental group. Patients are randomized to receive either
`
`anti· Tac 20 mg/day for ten days, cyclosporine 4 mg/kg/day,
`
`
`azathioprine 2 mg/kg/day, and prednisone 30 mg/day, or conven­
`tional triple therapy as in the second protocol. In the experimental
`group, the cyclosporine dose is increased to 8 mg/kg/day at the
`
`
`
`
`conclusion of anti-Tac treatment. This protocol is ongoing, with nine
`
`
`patients entered in the experimental group and ten in the control
`group to date.
`During treatment, serum and peripheral blood mononuclear cells
`
`
`
`were obtained on days 0, 2, 4, 6, 8, 10, and 14 to monitor anti-Tac
`
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`
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`serum levels, the development of anti-mouse immunoglobulin anti­
`
`bodies, T-cell subsets and expression of IL-2R on circulating lym·
`phocytes, and the effect of therapy on the ability of circulating
`
`lymphocytes to participate in mixed lymphocyte reactions and
`
`cell-mediated lympholysis.
`
`MATERIALS ANO METHODS
`
`RESULTS
`
`Preparation and Administration of Anti· Tac
`
`Patient Protocols
`
`Protocol 1
`The first protocol was designed to ascertain the safety of
`Anti-Tac, a murine IgG2a Mab has been extensively characterized
`
`
`
`
`elsewhere.'-' The antibody was purified from ascites of Balb/c mice
`anti-TAC administration and to obtain preliminary evidence
`
`inoculated with the hybridoma, suspended in saline at a concentra·
`of efficacy. Patients were randomized to receive anti-TAC
`
`
`tion of 2 mg/ml, sterilized by filtration, and stored at -200C. Prior
`plus conventional immunosuppression (n - 12) or conven­
`
`
`to the first administration of the Mab, all patients were injected
`tional immunosuppression alone (n - 9). In the group receiv­
`
`
`intradermaUy with 0.1 ml of a l: l 000 dilution of anti· Tac in saline to
`ing anti· TAC, all skin tests were negative and no complica­
`
`exclude hypersensitivity. Each dose of 20 mg was infused intrave·
`tions of antibody administration were identified.
`
`nously over two hours in 50 ml normal saline containing l % human
`In this protocol, administration of anti-TAC reduced the
`serum albumin.
`frequency of early rejection episodes and delayed the onset of
`the first rejection episode. In the first ten days posttrans­
`plant, during which anti-TAC was given to the treatment
`Three protocols for the use of anti-Tac were examined. In each
`group, only one of I 2 patients receiving anti-TAC experi­
`
`protocol, only patients receiving a first cadaver allograft were
`enced a rejection episode, compared with five of nine patients
`
`
`eligible, and patients were randomized to experimental or control
`
`in the control group (p < 0.05). The single treated patient
`
`groups by a sealed envelope technique. There were no significant
`with rejection had primary nonfunction of the graft, and
`
`differences between groups with respect to age, sex, or degree of
`HLA AB or DR matching. All protocols were approved by the
`
`
`clinical studies committtees of both hospitals.
`
`
`In the first protocol, patients were randomized to receive anti-Tac
`From the Brigham and Women's and Beth Israel Hospitals,
`
`
`plus conventional immunosuppression (n - 12) or conventional
`Harvard Medical School, Boston, Massachusetts and the Metab·
`
`immunosuppression alone (n - 9). Anti-Tac was given at a dose of
`olism Branch, National Cancer Unit, National Institutes of Health,
`
`
`20 mg qd for 10 days beginning on posttransplant day I. Conven­
`Bethesda, Maryland.
`
`
`
`tional immunosuppression consisted of either cyclosporine 12 mg/
`Address reprint requests to
`Dr Robert L. Kirkman. Department
`
`kg/day and prednisone 30 mg/day or cyclosporine 8 mg/kg/day,
`of Surgery, Brigham and Women's Hospital, 75 Francis Street,
`
`
`azathioprine 2 mg/kg/day, and prednisone 30 mg/day. In both
`Boston, Massachusetts 02115.
`
`
`groups cyclosporine doses were adjusted by blood level and clinical
`
`e 1989 by Appleton Lange, Inc.
`evidence
`
`
`of nephrotoxicity. First rejection episodes were treated with
`
`a methylprednisolone pulse I gm IV qd for 3 days.
`0041-1345189/$03.00/ +O
`
`
`
`Supported by grants from the National Institutes of Health.
`
`1766
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`Trsnspisntstlon Proceedings, Vol 21, No 1 (February), 1989: pp 1766· 1768
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`BI Exhibit 1035
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`EARLY EXPERIENCE WITH ANTI-TAC
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`1767
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`receive anti-TAC for ten days plus low dose cyclosporine or
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`was diagnosed by biopsy on postoperative day 7.
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`rejection
`
`
`full dose cyclosporine. The cyclosporine dose in the experi­
`
`to have cyclo­
`This patient was subsequently demonstrated
`sp(;rine nephrotoxicity,
`
`
`mental group is increased following conclusion of anti-TAC
`and it is uncertain if a clinical
`
`
`
`treatment; all patients in both groups receive azathioprine
`
`rejection episode would have been noted had there been
`
`
`and prednisone. To date, nine patients have been entered in
`immediate renal function.
`
`the treated group, ten in the control. There has been one
`Rejection episodes eventually occurred in seven of twelve
`
`
`
`episode within ten days of transplantation in the
`rejection
`
`patients receiving anti-TAC and in eight of nine control
`eight in the control
`treated patients, compared with
`patients (p - ns). However, the mean time to the first
`
`(p < 0.05). There have been no immunological graft losses in
`episode was 24.7 days in the anti-TAC group,
`rejection
`
`either group, but follow-up is less than four months in all
`compared with 9.4 days in the control group (p < O.ot,
`
`cases. One patient who received anti-TAC, and who was not
`
`
`Mann-Whitney rank sum testing). Four patients with rejec­
`
`treated for rejection, died at four months from CMV and
`tion in the anti-TAC group responded to a steroid pulse,
`
`pneum\)Cystis pneumonia. A single patient receiving anti­
`
`eventu­while three required OKT3; one of the latter patients
`
`
`T AC developed pruritis, which was managed symptomati­
`
`
`ally lost his graft to uncontrolled rejection. A single control
`
`cally and did not require cessation of therapy.
`
`patient also lost his graft, with accelerated acute rejection
`
`leading to removal of a ruptured allograft on postoperative
`Anti-TAC and OKT3
`day 4.
`All patients in this initial protocol have now been followed
`
`
`
`As noted above, six patients treated with anti-TAC subse­
`
`
`
`12-21 months, with no subsequent rejection episodes or graft
`quently required therapy with OKT3. All six patients had
`
`
`losses. Graft survival is 92% in the treated group and 89% in
`
`
`rapid reversal of their rejection episodes, although one subse­
`
`
`
`the control group. Mean creatinine at last follow-up was 2.1
`
`
`
`quently had a recurrent rejection and represents the sole
`mg/di, for the anti-TAC group and 1.7 mg/di for the control
`
`graft loss from rejection in all three treatment groups.
`group (p - ns). No deaths have occurred in either group.
`
`
`response and Details of the anti-mouse immunoglobulin
`
`
`clearance of circulating CD3 positive cells in these patients
`
`
`are described in a separate manuscript in this volume.9
`
`Protocol 2
`As the initial protocol suggested that anti-TAC would pre­
`
`
`
`Monitoring Studies
`
`
`vent rejection during its administration, the second protocol
`was designed to determine if the use of cyclosporine could be
`
`None of the monitoring studies performed revealed signifi­
`
`avoided in the early posttransplant period. Patients were
`
`
`cant differences between the treated and control patients. Of
`
`randomized between quadruple therapy, consisting of anti­
`
`particular note, treatment with anti-TAC did not prevent
`
`
`T AC for ten days, azathioprine and prednisone, with cyclo­
`expression of the IL-2 receptor on the surface of circulating
`
`sporine added on day 8, or triple therapy. By happenstance,
`
`T-cells following transplantation.10
`five of the first six patients entered in this protocol were
`randomized to the anti-TAC group. None of these patients
`DISCUSSION
`
`completed the anti-TAC protocol, one because of an appar­
`The data presented here demonstrate that anti· TAC, a Mab
`
`
`ent reaction to anti-TAC and four because of rejection
`
`directed against the human IL-2R, will reduce the frequency
`during therapy.
`
`
`
`of early rejection episodes following transplantation and
`
`
`The reaction to the antibody was the development of fever
`delay the onset of those which do occur, when used in
`
`and pulmonary edema on the fifth day of treatment. The
`
`
`
`combination with cyclosporine. The early results with proto­
`
`patient was not volume overloaded and there was no evidence
`
`
`col 3 suggest that the dose of cyclosporine can be signifi­
`
`
`
`of infection or rejection. Anti-TAC was discontinued and
`
`cantly reduced compared with standard immunosuppression
`
`begun, with resolution of the symptoms and
`cyclosporine
`
`regimens. This finding is in accord with animal models, in
`
`continued good graft function.
`
`
`which significant synergy between anti-IL-2R Mab's and
`
`
`The four patients with rejection were managed by cessa­
`cyclosporine
`
`has been shown. s This reduced dose of cyclospo­
`
`
`tion of anti-TAC and initiation of cyclosporine. One of the
`
`
`rine simplifies the management of renal transplant recipients
`
`rejection episodes was easily reversed with a single steroid
`
`by decreasing the incidence
`of nephrotoricity. When com­
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`pulse, while the others required more than one steroid pulse
`
`
`bined with the lower incidence of rejection, the early course
`
`
`or OKT3. One of these patients subsequently died of dissemi­
`
`
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`of anti-TAC-treated patients is remarkably uncomplicated.
`
`nated CMV. Because this protocol did not appear to obviate
`
`These results differ from those of Soulillou et al using
`
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`the need for cyclosporine in the early posttransplant period, it
`
`another anti-IL-2R Mab, 33B3.l.11 In that experience,
`was terminated.
`
`
`excellent results were obtained without cyclosporine; but
`
`with a higher prednisone dose. Further experimentation with
`Protocol
`3
`
`anti-IL-2R therapy will be required to determine optimal
`
`antibody characteristics and protocols.
`The current protocol was established to determine if anti­
`
`
`A critical finding of the current study was the successful
`in the
`T AC will allow the use of a lower dose of cyclosporine
`
`
`
`use of OKT3 to treat rejection in patients previously receiv-
`
`
`
`early posttransplant period. Patients are being randomized to
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`1768
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`KIRKMAN, SHAPIRO, CARPENTER ET AL
`
`r
`I
`
`3. Kirkman RL, Barrett L V, Koltun WA, et al: Transplant Proc
`ing anti-TAC. This observation permits the design of proto­
`
`19:618, 1987
`cols employing sequential use of monoclonal antibodies of
`4. Kupiec-Weglinski JW, Diamantstein T, Tilney NL et al: Proc
`
`different idiotypes directed against the same or different
`Natl Acad Sci USA 83:2624, 1986
`
`
`targets. In particular, it allows the use of one or more Mab's
`S. Kupiec-Weglinski JW, Hahn HJ, Kirkman RL, et al: Trans­
`
`
`
`precluding use of other for rejection prophylaxis without
`plant Proc 20:207, 1988
`
`
`antibodies for rejection therapy. Moreover, when this finding
`6. Reed MH, Shapiro ME, Strom TB, et al: Transplantation (in
`
`is combined with the increasing variety of Mab's defining
`press)
`
`
`the opportunity targets and subsets of immunologic interest,
`7. Uchimaya T, Broder S, Waldman TA: J lmmunol 126:1393,
`
`for more detailed manipulation of the immune response is
`1981
`evident.
`8. Wang HM, Smith KA: J Exp Med 166:1055, 1987
`9. Ramos EL, Wood IG, Rollins MR, et al: Transplant Proc (in
`press)
`JO. Ramos EL, Wood IG, Rollins MR. et al: Transplantation
`(data unpublished)
`11. Soullilou JP, Lemauff B, Olive D. et al: Lancet 1:1339, 1987
`
`I. Waldmann TA: Science 232:727, 1986
`2. Kirkman RL, Barrett LV, Gaulton GN, et al: J Exp Med
`162:358, 1985
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`REFERENCES
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