CMV PROPHYLAXIS WITH FOSCARNET IN ALLOGENEIC BONE-MARROW TRANSPLANT RECIPIENTS AT HIGH-RISK OF DEVELOPING CMV INFECTIONS

Eleven patients underwent bone marrow transplant (BMT) from an HLA-ide ntical sibling following single dose total body irradiation (TBI), wit h in vivo and ex vivo T cell depletion (TCD). In spite of CMV prophyla xis with acyclovir and high-dose iv Ig, 10 of 11 patients developed CM V antigenemia, at a median interval from BMT of 34 days (range 16-72 d ays) and five died with CMV disease. Foscarnet was then given prophyla ctically in 11 additional TCD patients to test whether we could (1) pr event CMV reactivation, and (2) reduce transplant-related mortality. F oscarnet was given daily from days +10 to +15 (180 mg/kg/day), then th rice weekly (90 mg/kg/day) until day +100. Five patients developed CMV antigenemia at a median interval from BMT of 42 days (range 16-65 day s); one progressed to CMV pneumonitis and died. The risk of developing CMV antigenemia within day 100 is currently 91% for the historical co ntrol group and 45% for the foscarnet group (p = 0.005). At diagnosis of CMV, the median number of CMV antigen-positive cells was 6.5 (range 1-13), vs 1 (range 1-5) in acyclovir vs foscarnet patients (p = 0.02) and the median highest number of CMV antigen-positive cells was 7 (ra nge 3-110) vs 1 (range 1-12), respectively, (p = 0.03). The actuarial 1 year transplant-related mortality (TRM) is 49% and 13% in the two gr oups (p = 0.08). This study suggests that foscarnet prophylaxis starti ng on day +10 post-BMT may be helpful in reducing the risk of CMV dise ase and early mortality following TCD BMT.