Acute Graft Versus Host Disease (GVHD) Is Increased in Patients Receiving Cyclosporine/Cellcept as Frontline Prophylaxis Against GVHD in Pediatric Patients Undergoing Allogeneic Stem Cell Transplantation.

Traditionally, pediatric patients are prophylaxed against GvHD with cyclosporine (CSA) plus either methotrexate (Mtx) or methylprednisolone (Pred). Mtx worsens the severity of mucositis and renal insufficiency while pred causes muscle wasting, hypertension, hyperglycemia and increased infections. Cellcept (myophenolic acid) is a better tolerated, less toxic agent with synergistic immunosuppressive effects when combined with cyclosporine or tacrolimus. We explored its use in combination with cyclosporine in 63 pediatric patients (49% male, 74% Caucasian, 36% CMV+) undergoing allogeneic transplantation. Patients with both malignant (n=24) and non-malignant (n=39) conditions ranging in age from 2 weeks to 26 years were transplanted after myeloablative preparative regimens with either related bone marrow or cord blood (n=11) or unrelated cord blood (n=52), using cellcept and cyclosporine for GVHD prophylaxis. Cellcept and CSA were administered intravenously through the first 40–60 days post transplant using cellcept at a dose of 15mg/kg/dose IV q8H beginning on day -2 or -3 and CSA in traditional fashion targeting trough levels of 200–450 (infusion) and 150–350 with intermittent dosing. The patient then transitioned to oral therapy at the same dose and schedule until day 100–180 for cellcept and day 270 for cyclosporine and then tapered if no active GVHD was present. There were no acute toxicities attributable to cellcept observed in patients on IV or oral therapy. Despite the lack of steroids in the GVHD prophylactic regimen, all patients required treatment with antihypertensive therapy. Grossly, infection rates did not vary from those previously observed in conventionally treated patients at our center. The cumulative incidence (CINC) of neutrophil engraftment by day 42 was 79.4% (95% CI 64.7–91.2) which is comparable to previous reports. Two patients engrafted after a second unrelated cord blood transplant. Of the six patients who did not engraft, 3 died of infectious complications, two died of VOD and multi-system organ failure and one died of congenital pulmonary hypertension. Of the 59 patients evaluable for GVHD, follow-up ranged between 52 and 994 days (median 224 days). The CINC of acute GVHD grades II–IV by day 100 was 64.1% (95% CI 47.8–82.1) and the CINC of acute GVHD grades III– IV by day 100 was 6.3% (95% CI 0–17.0). Follow-up is too short to comment on the incidence of chronic GvHD, but to date, 5 of 14 patients followed for >100 days have developed mild chronic GvHD. The incidence of grade II acute GVHD was higher than that previously reported in pediatric patients receiving CSA/Pred while the incidence of grade III–IV GVHD was comparable. While this data is early, it appears that the incidence of acute Grade II GVHD is increased compared to previous series in patients treated with cellcept instead of Mtx (related bone marrow transplantation) or pred (unrelated cord blood transplantation). Engraftment in UCBT recipients was not compromised with the use of IV cellcept administered in the peritransplant period. Overall, despite the use of steroids to treat aGVHD, there was overall steroid sparing with this regimen. Additional patients will need to be tested with this regimen and longer follow-up is necessary to fully define the risks or benefits of this therapy.