First-in-human study of the safety and efficacy of TOL101 induction to prevent kidney transplant rejection.

TOL101 is a murine IgM mAb targeting the αß TCR. Unlike other T cell targets, the αß TCR has no known intracellular signaling domains and may provide a nonmitogenic target for T cell inactivation. We report the 6-month Phase 2 trial data testing TOL101 in kidney transplantation. The study was designed to identify a dose that resulted in significant CD3 T cell modulation (<25 T cell/mm(3) ), to examine the safety and tolerability of TOL101 and to obtain preliminary efficacy information. Thirty-six patients were enrolled and given 5-10 daily doses of TOL101; 33 patients completed dosing, while three discontinued after two doses due to a self-limiting urticarial rash. Infusion adjustments, antihistamines, steroids and dose escalation of TOL101 reduced the incidence of the rash. Doses of TOL101 above 28 mg resulted in prolonged CD3 modulation, with rapid recovery observed 7 days after therapy cessation. There were no cases of patient or graft loss. Few significant adverse events were reported, with one nosocomial pneumonia. There were five biopsy-confirmed acute cellular rejections (13.9%); however, no donor-specific antibodies were detected. Overall TOL101 was well-tolerated, supporting continued clinical development using the dose escalating 21-28-42-42-42 mg regimen.

Treatment of acute cellular rejection with T10B9.1A-31 or OKT3 in renal allograft recipients.

T10B9.1A-31, a nonmitogenic immunoglobulin Mk monoclonal antibody that detects an epitope on the alpha/beta chains of the T cell antigen receptor (TCR alpha/beta), or OKT3, an anti-CD3 mAb, was employed in a randomized double-blind phase II clinical trial to treat biopsy-proven acute cellular renal allograft rejection. Two of the 40 patients initially selected for the protocol were considered to be nonevaluable. Analysis of the remaining 38 patients receiving both living related and cadaveric donor allografts revealed a patient survival of 100% and a graft survival of 97%. Primary rejection reversal was achieved in 18/19 (95%) patients treated with T10B9.1A-31 and in 20/21 (95%) of patients receiving OKT3. The two patients who did not respond to the first mAb responded to the crossover mAb. Rerejection occurred in 3/18 (17%) of patients treated with T10B9.1A-31 and in 3/20 (15%) treated with OKT3. The mean day of rejection reversal was 1.9 +/- 0.7 with T10B9.1A-31 and 3.37 +/- 1.21 with OKT3 treatment. The rise in mean serum creatinine after mAb administration and the mean creatinine on days 1 through 6 were significantly less in patients treated with T10B9.1A-31. Biopsy specimens analyzed for rejection revealed no significant difference between the T10B9.1A-31 and OKT3 cohorts. The mean serum creatinines at 30, 60, 180, and 360 days posttransplantation were the same for both groups. Significantly fewer febrile, respiratory, and untoward effects followed the first dose (day 0) and fewer febrile, gastrointestinal, and neurological side effects occurred with subsequent doses (days 1-9) in patients treated with T10B9.1A-31. Infectious complications occurred in 3/13 patients treated only with T10B9.1A-31, in 9/17 OKT3-treated patients, and in 4/8 patients treated with both mAb. Analysis of human antimouse antibody (HAMA) revealed that the development of HAMA with T10B9.1A-31 was similar to that of OKT3.

Treatment of renal allograft rejection with T10B9.1A31 or OKT3: final analysis of a phase II clinical trial.

BACKGROUND: Treatment of acute renal allograft rejection with the monoclonal antibody (mAb) OKT3 has been shown to be superior to treatment with polyclonal antisera. To date, only OKT3 has demonstrated consistent efficacy in reversing rejection crisis. METHODS: From 1989 to 1993, a phase II trial comparing the mAb T10B9.1A31 (T10B9) with OKT3 for treatment of acute cellular rejection in renal allograft recipients was done at the University of Kentucky. We collected data from 178 patients potentially eligible to enter the study; 48 never rejected, 9 refused, 13 could not be biopsied, 16 received methylprednisolone, and 11 received antithymocyte globulin or OKT3. Altogether, 81 patients entered the study, 76 of whom were able to be evaluated. Patients with biopsy-confirmed acute rejection were randomly assigned to T10B9 or OKT3 for at least 10 days. RESULTS: Demographically, there was no difference between the T10B9 or OKT3 cohorts. Actuarial graft survival at 4 years was 87% for patients receiving T10B9, 79% for those receiving OKT3, and 89% for those receiving both mAbs (P=0.55). Patient survival at 4 years was 94% for T10B9, 100% for OKT3, and 89% for both mAbs (P=0.45). Mean creatinines of the cohorts were no different at 1, 6, 12, 24, and 36 months. There was less cytokine nephropathy (P<0.001) observed in patients receiving T10B9. Untoward gastrointestinal, neurological, respiratory, and febrile effects were significantly more frequent in the OKT3 cohort after the first dose (day 0) and with later (day 1-9) administration. Cytokine levels (tumor necrosis factor alpha and interferon gamma) measured 2 hr after the first dose were three to six times higher in patients treated with OKT3 than in those treated with T10B9 (P<0.005). Infectious complications were not significantly different, although serious infections occurred only in patients receiving OKT3. No cases of posttransplant lymphoproliferative disorder were seen in either cohort. Human anti-mouse antibody development was as follows: titer 1:100, 30% T10B9, 42% OKT3; titer 1:1000, 3% T10B9, 3% OKT3. There was no cross-reactivity with OKT3 in patients treated with T10B9, and there was only 9.7% cross-reactivity to T10B9 in patients treated with OKT3. CONCLUSIONS: T10B9 provides treatment for renal allograft acute cellular rejection as effective as that of OKT3 with fewer untoward effects, less cytokine release and nephropathy, fewer serious infections, and without increased development of human anti-mouse antibody. The lack of cross-reactivity offers an alternative therapy should the first mAb fail or re-rejection occur. A phase III trial should be initiated in renal allograft recipients, and phase I and phase II trials should be initiated in other solid-organ transplantations.

The pharmacokinetics of a microemulsion formulation of cyclosporine in primary renal allograft recipients. The Neoral Study Group.

This study was a randomized, double-blind, 12-week comparison of the pharmacokinetics, safety, and tolerability of two cyclosporine (CsA) formulations, cyclosporine emulsion capsules and oral solution for microemulsion and cyclosporine, in the postoperative management of renal transplant patients. Of the 101 patients, aged 18 to 65, who entered the study, 89 were evaluable for pharmacokinetics. Initial dosage was 10 mg/kg per day, administered twice daily in two equal doses. Dosages were adjusted to achieve target CsA concentrations. The pharmacokinetic (PK) parameters (dose-normalized) of greatest interest were maximum blood concentration (C(max)/dose), time to reach maximum concentration (t(max), area under the blood concentration-vs.-time curve (AUC/dose), and trough blood concentrations (Co h/dose). The relative CsA bioavailabilty was found to be significantly enhanced with cyclosporine emulsion compared with cyclosporine with a 16% to 31% increase in AUC and a 32% to 42% increase in C(max). Intrapatient variability of PK parameters was significantly lower with cyclosporine emulsion than with cyclosporine for AUC, C(oh), t(max), and C(max) in many instances. This indicates a more consistent, rapid, and more complete total absorption of CsA. Despite higher CsA C(max) levels and AUCs with cyclosporine emulsion, safety and tolerability (detailed in a parallel report) were comparable to those of cyclosporine. The PK advantages of cyclosporine emulsion over cyclosporine are either independent of food conditions or possibly reflective of more consistent absorption of CsA with cyclosporine emulsion. The findings suggest that de novo use of cyclosporine emulsion may simplify and improve management of organ transplant recipients and that the PK advantages of cyclosporine emulsion may translate into clinical benefits.

Safety and tolerability of cyclosporine microemulsion versus cyclosporine: two-year data in primary renal allograft recipients: a report of the Neoral Study Group.

BACKGROUND: The new microemulsion formulation of cyclosporine (CsA-ME) is more bioavailable than cyclosporine (CsA) in de novo renal transplant patients. Therefore, it was of interest to compare the safety profile of each formulation in such patients. METHODS: In a multicenter, double-blind, parallel-group study, 101 renal transplant recipients were randomized after transplantation to receive either CsA (n=50) or CsA-ME (n=51) capsules twice daily for 2 years. Of these patients, 54 (CsA, n=26; CsA-ME, n=28) completed 1 year of the study and entered the second-year, double-blind extension. Initial dose at the time of transplantation was 5 mg/kg b.i.d.; doses were titrated to target trough levels. METHODS: The mean (+/- SD) doses at the end of 2 years were 4.6 +/- 1.8 and 3.8 +/- 1.1 mg/kg per day for CsA- and CsA-ME-treated patients, respectively. The mean (+/- SD) CsA trough levels at end point were 187 +/- 63 and 210 +/- 95 ng/ml for CsA- and CsA-ME-treated patients, respectively. At least one adverse event was reported by 25/26 (96%) of CsA- and 27/28 (96%) of CsA-ME-treated patients. No patient discontinued the study because of adverse events. No deaths occurred during the study. Renal function, as measured by serum creatinine levels, and blood pressure were comparable over time in both treatment groups. CONCLUSIONS: There was no significant difference in safety and tolerability between CsA- and CsA-ME-treated kidney recipients for 2 years after transplantation.

The safety and tolerability of cyclosporine emulsion versus cyclosporine in a randomized, double-blind comparison in primary renal allograft recipients. The Neoral Study Group.

A 12-week, randomized, double-blind, multicenter pharmacokinetics study was conducted to compare the clinical safety and tolerability of cyclosporine capsules and oral solution for microemulsion and cyclosporine in 101 primary renal transplant recipients Cyclosporine emulsion has more complete absorption and improved bioavailability compared with cyclosporine, and dosing of both cyclosporine formulations was adjusted to achieve comparable whole-blood trough levels. Mean serum creatinine values were higher in the cyclosporine emulsion group at baseline, 8, and 12 weeks (P<0.05). The incidence of acute rejection was similar in both treatment groups although fewer patients required monoclonal antibody therapy in the cyclosporine group (31% vs. 82%, respectively). Despite the increased bioavailability of cyclosporine emulsion, no significant differences in the incidence of adverse events were observed; the safety, tolerability, and efficacy of cyclosporine emulsion and cyclosporine were comparable.

Immunosuppression in renal-transplantation does not increase the incidence of native renal-cancer.

A patient presented with metastatic renal cell cancer arising in a native kidney nine years after undergoing cadaveric renal transplantation. Ten other cases have been detailed in the literature over the past 15 years. The risk of renal cancer in hemodialysis patients increases with the duration of dialysis and acquisition of cystic disease. The incidence of renal cell cancers in renal transplant patients and dialysis patients is equivalent. In both groups of patients the carcinomas arise from acquired cysts, but unlike hemodialysis patients, the duration of prior hemodialysis in the transplant group does not appear to correlate with the risk of renal cell carcinoma. Immunosuppression to prevent graft rejection is associated with a dramatic increase in some cancers, but does not appear to be a factor in native renal cancer development. Ultrasound followed by arteriography to diagnose tumors in the subset of patients with cysts could be used for screening of the risk population. The cost of screening though may be prohibitive in diagnosing this rare complication in renal transplant patients.

Induction immunotherapy in heart transplantation with T10B9.1A-31: a phase I study.

Cytolytic induction therapy of heart transplantation with OKT3 (immunoglobulin G2a isotype, anti CD3 idiotype) or T10B9.1A-31 (immunoglobulin MK isotype, anti-T-cell receptor alpha beta idiotype) was done in an open-label trial to determine the safety and efficacy of the latter monoclonal antibody. A total of nine patients undergoing orthotopic heart transplantation received a 10-day course of either T10B9.1A-31 (T10B9) (n = 4) 18 mg on bypass and 6 mg intravenously every 12 hours or OKT3 (n = 5) 10 mg on cardiopulmonary bypass and 5 mg intravenously daily. Endomyocardial biopsy surveillance revealed no rejection during induction therapy with T10B9, and one OKT3 induction failure was successfully treated with T10B9, all without significant side effects. T10B9 effectively prevented the onset of early acute rejection in heart transplantation with minimal side effects. T10B9 reversed rejection in one patient whose OKT3 induction failed. Results are encouraging and warrant further investigation.

Renal vein thrombosis presenting as renal mass.

The excretory urogram of patients with acute renal vein thrombosis typically demonstrates symmetric enlargement of the involved kidney. We report a case of renal vein thrombosis that presented as a discrete renal mass on excretory urography and abdominal computerized tomography. The entity of renal vein thrombosis is briefly reviewed along with the computerized tomography findings seen in this setting.

Direct neural inhibition of insulin secretion in response to systemic hypoglycemia.

The innervated pancreas of an anesthetized small "pancreas" dog was cross-perfused with blood from a large "support" dog in order to separate neural from blood-borne influences on the immunoreactive insulin secretion rate (ISR). The arterial plasma reducing sugar (sugar) concentration could be varied independently in the pancreas dog systemic circulation and in its pancreas. After tying of the hepatic arteries and portal vein in the pancreas dog, its systemic arterial plasma sugar concentration was allowed to fall in 10 experiments. This was prevented in five control experiments by intravenous glucose infusion (7 mg/kg-min). In all experiments, pancreatic arterial plasma sugar concentration was sustained, and at 40 min it was elevated 50 mg/100 ml by glucose infusion into the pancreatic blood supply. Bilateral splanchnic nerve section at 120 min caused an increase of the ISR in all experiments, but a greater rise occurred from the pancreases of the 10 dogs allowed to become hypoglycemic (P less than .02). In two further experiments, the splanchnic nerves were not cut, and no rise in ISR occurred. In conclusion, systemic hypoglycemia can inhibit insulin secretion by means of the splanchnic nerves.

T10B9 (MEDI-500) mediated immunosuppression: studies on the mechanism of action.

The murine IgM anti-human CD3/TCR mAb T10B9 is an effective agent for the reversal of acute cellular renal allograft rejection which offers several advantages over conventional OKT3 therapy. These include reduced morbidity and a more rapid decrease in serum creatinine levels. In the studies presented here comparing T10B9 and OKT3, soluble T10B9 is shown to be a nonactivating anti-T cell mAb. Evidence for its lack of activating potential includes in vitro failure to stimulate PBMC proliferation either alone or in the presence of nonmitogenic doses of phorbol ester, failure to induce the expression of early and late activation antigens and failure to induce IFN-gamma, TNF-alpha, IL-6 or IL-2 release. Analysis of acute renal allograft rejection patient plasma cytokine levels 2 h after the first dose support the hypothesis that T10B9 has reduced immunoactivation activity in vivo. Both TNF alpha and IFN gamma patient plasma levels are significantly reduced in T10B9 as compared to OKT3 therapy. However, T10B9 is capable of cellular signaling as demonstrated by its ability to induce apoptosis and IL-2 release in the human T cell line Sup-T13. Thus T10B9 retains the potent immunosuppressive activity of OKT3 with reduced immunoactivation.

T10B9.1A-31 anti-T-cell monoclonal antibody: preclinical studies and clinical treatment of solid organ allograft rejection.

T10B9.1A-31 is an immunoglobulin Mk (lgMk), CD3b class, murine monoclonal antibody. It is not itself mitogenic, but it partially blocks mitogenesis produced by concanavilin-A, phytohemagglutinin, and a soluble antigen cocktail and is lytic for human peripheral blood T lymphocytes (PB-T) in the presence of fresh autologous human complement and rabbit complement. It reacts with a monomorphic epitope found on all mature PB-Ts that modulates in vitro and in vivo with the CD3/T-cell antigen receptor (TCR) complex, but unlike OKT3, which reacts with CD3 proteins, T10B9.1A-31 reacts with an epitope of the TCR alpha/beta heterodimer. Immunoprecipitation of HPB-ALL with T10B9.1A-31 or OKT3 revealed that T10B9.1A-31 does not react with the 20-to 26-kd polypeptides that compose CD3, and T10B9.1A-31 failed to bind to the PEER cell, which is CD3 gamma/delta positive, TCR alpha/beta negative. Phase 1 clinical trials demonstrated that T10B9.1A-31 caused a rapid decrease in PB-Ts and no toxic effects other than fever, chills, rigors, and transient hypotension. These side effects were absent in methylprednisolone (MP)-pretreated patients. Phase II studies revealed that T10B9.1A-31 reversed steroid refractory acute rejection in three of five renal allografts treated with cyclosporine (CyA) and prednisone (P) maintenance immunosuppression, reversed steroid and polyclonal antisera refractory rejection in three cardiac allograft recipients receiving CyA/P, and attenuated acute rejection in three of three renal patients receiving baseline azathioprine/prednisone (AZA/P) when used as primary therapy. Rerejection was not seen when patients received CyA baseline immunosuppression but was seen in patients maintained on AZA/P OKT3 was efficacious in treating rejection following T10B9.1A-31 therapy. Side effects of T10B9.1A-31 appears to reverse acute rejection crisis effectively in renal and cardiac transplantation with a low incidence of rerejection in CyA-maintained patients and with fewer, milder side effects. Sequential therapy with OKT3 is possible because OKT3 and T10B9.1A-31 are of different isotypes and idiotypes.