`
`TWELFTH INTERNATIONAL CONGRESS
`OF
`THE TRANSPLANTATION SOCIETY
`
`August 14-19, 1988
`Sydney, Australia
`
`Guest Editor
`A.G. ROSS SHEIL
`Sydney, Australia
`
`President
`ANTHONY P. MONACO
`Boston, Massachusetts, USA
`
`BOOK II
`
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`
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`B~1L CLo' She 1
`UNIVERSITY OF CALIFORNIA,
`SAN DIEGO - LIBRARIES
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`PFIZER EX. 1535
`Page 1
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`Early Experience with Anti-Tac in Clinical Renal Transplantation
`
`R.L. Kirkman, M.E. Shapiro, G.B. Carpenter, E.L. Milford, E.L. Ramos, N.L. Tilney, T.A. Waldmann,
`C.E. Zimmerman, and T.B. Strom
`
`T HE SEARCH for more effective and less broadly toxic
`
`immunosuppressive agents remains a major goal of
`transplantation research. One approach to achieving more
`specific immunosuppression is to target only those lympho(cid:173)
`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-cells 1 and because of extensive animal model experience
`with anti-IL-2R monoclonal antibody (Mab) therapy.H
`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. 8 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(cid:173)
`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 the experimen(cid:173)
`tal group in the first week. Patients were randomized to receive
`either anti-Tac 20 mgf day for 10 days, azathioprine 2 mgf kgfday,
`and prednisone 30 mgfday, with cyclosporine 8 mgfkgf day added
`on day 8, or conventional triple therapy with cyclosporine 8 mg f
`kg/ day, azathioprine 2 mgf kg/ day, and prednisone 30 mgfday.
`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 mgf day for ten days, cyclosporine 4 mgf kgf day,
`azathioprine 2 mgfkgfday, and prednisone 30 mgfday, or conven(cid:173)
`tional triple therapy as in the second protocol. In the experimental
`group, the cyclosporine dose is increased to 8 mgf kgfday 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
`serum levels, the development of anti-mouse immunoglobulin anti(cid:173)
`bodies, T-cell subsets and expression of IL-2R on circulating lym(cid:173)
`phocytes, and the effect of therapy on the ability of circulating
`lymphocytes to participate in mixed lymphocyte reactions and
`cell-mediated lympholysis.
`
`MATERIALS AND METHODS
`
`Preparation and Administration of Anti-Tac
`
`RESULTS
`
`Protocol 1
`
`Anti-Tac, a murine IgG2a Mab has been extensively characterized
`elsewhere.'·' The antibody was purified from ascites of Balbf c mice
`inoculated with the hybridoma, suspended in saline at a concentra(cid:173)
`tion of 2 mgfml, sterilized by filtration, and stored at - 20°C. Prior
`to the first administration of the Mab, all patients were injected
`intradermally with 0.1 ml of a 1:1000 dilution of anti-Tac in saline to
`exclude hypersensitivity. Each dose of 20 mg was infused intrave(cid:173)
`nously over two hours in 50 ml normal saline containing 1% human
`serum albumin.
`
`Patient Protocols
`
`Three protocols for the use of anti-Tac were examined. In each
`protocol, only patients receiving a first cadaver allograft were
`eligible, and patients were randomized to experimental or control
`groups by a sealed envelope technique. There were no significant
`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
`plus conventional immunosuppression (n ~ 12) or conventional
`immunosuppression alone (n - 9). Anti-Tac was .tven at a dose of
`20 mg qd for 10 days beginning on posttranspi~nt day 1. Conven(cid:173)
`tional immunosuppression consisted of either cyclosporine 12 mg f
`kg/day and prednisone 30 mgf day or cycl9sporine 8 mgfkgf day,
`azathioprine 2 mgfkg/day, and prednisone 30 mgf day. In both
`groups cyclosporine doses were adjusted by blood level and clinical
`evidence of nephrotoxicity. First rejection episodes were treated with
`a methylprednisolone pulse 1 gm IV qd for 3 days.
`
`The first protocol was designed to ascertain the safety of
`anti-T AC administration and to obtain preliminary evidence
`of efficacy. Patients were randomized to receive anti-T AC
`plus conventional immunosuppression (n = 12) or conven(cid:173)
`tional immunosuppression alone (n = 9). In the group receiv(cid:173)
`ing anti-T AC, all skin tests were negative and no complica(cid:173)
`tions of antibody administration were identified.
`In this protocol, administration of anti-TAC reduced the
`frequency of early rejection episodes and delayed the onset of
`the first rejection episode. In the first ten days posttrans(cid:173)
`plant, during which anti-T AC was given to the treatment
`group, only one of 12 patients receiving anti-T AC experi(cid:173)
`enced a rejection episode, compared with five of nine patients
`in the control group (p < 0.05). The single treated patient
`with rejection had primary nonfunction of the graft, and
`
`From the Brigham and Women's and Beth Israel Hospitals,
`Harvard Medical School, Boston, Massachusetts and the Metab(cid:173)
`olism Branch , National Cancer Unit, National Institutes of Health,
`Bethesda, Maryland.
`Address reprint requests to Dr Robert L. Kirkman, Department
`of Surgery, Brigham and Women's Hospital, 75 Francis Street,
`Boston, Massachusetts 02115.
`Supported by grants from the National Institutes of Health.
`"' 1989 by Appleton Lange, Inc.
`0041·1345/89/$03.00 / +0
`
`1766
`
`Transplantation Proceedings, Vol 21, No 1 (February), 1989: pp 1766-1768
`
`PFIZER EX. 1535
`Page 2
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`EARLY EXPERIENCE WITH ANTI-T AC
`
`1767
`
`rejection was diagnosed by biopsy on postoperative day 7.
`This patient was subsequently demonstrated to have cyclo(cid:173)
`sporine nephrotoxicity, and it is uncertain if a clinical
`rejection episode would have been noted had there been
`immediate renal function .
`Rejection episodes eventually occurred in seven of twelve
`patients receiving anti-TAC and in eight of nine control
`patients (p = ns) . However, the mean time to the first
`rejection episode was 24.7 days in the anti-T AC group,
`compared with 9.4 days in the control group (p < O.Ql,
`Mann- Whitney rank sum testing). Four patients with rejec(cid:173)
`tion in the anti-T AC group responded to a steroid pulse,
`while three required OKT3; one of the latter patients eventu(cid:173)
`ally lost his graft to uncontrolled rejection. A single control
`patient also lost his graft, with accelerated acute rejection
`leading to removal of a ruptured allograft on postoperative
`day 4.
`All patients in this initial protocol have now been followed
`12-21 months, with no subsequent rejection episodes or graft
`losses. Graft survival is 92% in the treated group and 89% in
`the control group. Mean creatinine at last follow-up was 2.1
`mg/dl, for the anti-TAC group and 1.7 mg/dl for the control
`group (p = ns). No deaths have occurred in either group.
`
`Protocol 2
`
`As the initial protocol suggested that anti-T AC would pre(cid:173)
`vent rejection during its administration, the second protocol
`was designed to determine if the use of cyclosporine could be
`avoided in the early posttransplant period. Patients were
`randomized between quadruple therapy, consisting of anti(cid:173)
`T AC for ten days, azathioprine and prednisone, with cyclo(cid:173)
`sporine added on day 8, or triple therapy. By happenstance,
`five of the first six patients entered in this protocol were
`randomized to the anti-T AC group. None of these patients
`completed the anti-T AC protocol, one because of an appar(cid:173)
`ent reaction to anti-T AC and four because of rejection
`during therapy.
`The reaction to the antibody was the development of fever
`and pulmonary edema on the fifth day of treatment. The
`patient was not volume overloaded and there was no evidence
`of infection or rejection. Anti-T AC was discontinued and
`cyclosporine begun, with resolution of the symptoms and
`continued good graft function.
`The four patients with rejection were managed by cessa(cid:173)
`tion of anti-TAC and initiation of cyclosporine. One of the
`rejection episodes was easily reversed with a single steroid
`pulse, while the others required more than one steroid pulse
`or OKT3. One of these patients subsequently died of dissemi(cid:173)
`nated CMV. Because this protocol did not appear to obviate
`the need for cyclosporine in the early posttransplant period, it
`was terminated.
`
`Protocol3
`
`The current protocol was established to determine if anti(cid:173)
`T AC will allow the use of a lower dose of cyclosporine in the
`early posttransplant period. Patients are being randomized to
`
`receive anti-T AC for ten days plus low dose cyclosporine or
`full dose cyclosporine. The cyclosporine dose in the experi(cid:173)
`mental group is increased following conclusion of anti-T AC
`treatment; all patients in both groups receive azathioprine
`and prednisone. To date, nine patients have been entered in
`the treated .group, ten in the control. There has been one
`rejection e6isode within ten days of transplantation in the
`treated patients, compared with eight in
`the control
`(p < 0.05) . There have been no immunological graft losses in
`either group, but follow-up is less than four months in all
`cases. One patient who received anti-T AC, and who was not
`treated for rejection, died at four months from CMV and
`pneumocystis pneumonia. A single patient receiving anti(cid:173)
`T AC developed pruritis, which was managed symptomati(cid:173)
`cally and did not require cessation of therapy.
`
`Anti-TAG and OKT3
`
`As noted above, six patients treated with anti-T AC subse(cid:173)
`quently required therapy with OKT3. All six patients had
`rapid reversal of their rejection episodes, although one subse(cid:173)
`quently had a recurrent rejection and represents the sole
`graft loss from rejection in all three treatment groups.
`Details of the anti-mouse immunoglobulin response and
`clearance of circulating CD3 positive cells in these patients
`are described in a separate manuscript in this volume. 9
`
`Monitoring Studies
`
`None of the monitoring studies performed revealed signifi(cid:173)
`cant differences between the treated and control patients. Of
`particular note, treatment with anti-TAC did not prevent
`expression of the IL-2 receptor on the surface of circulating
`T -cells following transplantation. 10
`
`DISCUSSION
`
`The data presented here demonstrate that anti-T AC, a Mab
`directed against the human IL-2R, will reduce the frequency
`of early rejection episodes following transplantation and
`delay the onset of those which do occur, when used in
`combination with cyclosporine. The early results with proto(cid:173)
`col 3 suggest that the dose of cyclosporine can be signifi(cid:173)
`cantly reduced compared with standard immunosuppression
`regimens. This finding is in accord with animal models, in
`which significant synergy between anti-IL-2R Mab's and
`cyclosporine has been shown.s This reduced dose of cyclospo(cid:173)
`rine simplifies the management of renal transplant recipients
`by decreasing the incidence of nephrotoxicity. When com(cid:173)
`bined with the lower incidence of rejection, the early course
`of anti-T AC-treated patients is remarkably uncomplicated.
`These results differ from those of Soulillou et a! using
`another anti-IL-2R Mab, 33B3.1. 11
`In that experience,
`excellent results were obtained without cyclosporine; but
`with a higher prednisone dose. Further experimentation with
`anti-IL-2R therapy will be required to determine optimal
`antibody characteristics and protocols.
`A critical finding of the current study was the successful
`use of OKT3 to treat rejection in patients previously receiv-
`
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`1768
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`KIRKMAN, SHAPIRO, CARPENTER ET Al
`
`ing anti-T AC. This observation permits the design of proto(cid:173)
`cols employing sequential use of monoclonal antibodies of
`different idiotypes directed against the same or different
`targets. In particular, it allows the use of one or more Mab's
`for rejection prophylaxis without precluding use of other
`antibodies for rejection therapy. Moreover, when this finding
`is combined with the increasing variety of Mab's defining
`targets and subsets of immunologic interest, the opportunity
`for more detailed manipulation of the immune response is
`evident.
`
`REFERENCES
`I. Waldmann TA: Science 232:727, 1986
`2. Kirkman RL, Barrett LV, Gaulton GN, et a!: J Exp Med
`162:358, 1985
`
`3. Kirkman RL, Barrett LV, Koltun WA, eta!: Transplant Proc
`19:618, 1987
`4. Kupiec-Weglinski Jw, Diamantstein T, Tilney NL eta!: Proc
`Nat! Acad Sci USA 83:2624, 1986
`5. Kupiec-Weglinski JW, Hahn HJ, Kirkman RL, eta!: Trans(cid:173)
`plant Proc 20:207, 1988
`6. Reed MH, Shapiro ME, Strom TB, eta!: Transplantation (in
`press)
`7. Uchimaya T, Broder S, Waldman TA: J Immunol 126:1393,
`1981
`8. Wang HM, Smith KA: J Exp Med 166:1055, 1987
`9. Ramos EL, Wood IG, Rollins MR, et al: Transplant Proc (in
`press)
`10. Ramos EL, Wood IG, Rollins MR, et al: Transplantation
`(data unpublished)
`II. Soullilou JP, Lemauff B, Olive D, eta!: Lancet I: 1339, 1987
`
`f
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