Foscarnet therapy for cytomegalovirus infection after allogeneic bone marrow transplantation

Foscarnet treatment of cytomegalovirus infection in haploidentical or unrelated donor transplants

We studied 97 patients who developed cytomegalovirus (CMV) viremia following an allogeneic hemopoietic stem cell transplant (HSCT) between 2010 and 2015, treated with foscarnet, with the aim of assessing efficacy and safety. The donor was unrelated in 30 patients (UD) and a family HLA-haploidentical donor (HAPLO) in 67 patients: the former (UD) received a prophylaxis for graft-versus-host disease (GvHD), based on antithymocyte globulin (ATG); the latter (HAPLO) received GvHD prophylaxis, based on post-transplant cyclophosphamide (PT-CY). Renal and hematological toxicity were defined according to NCI-CTCAE4 criteria. In univariate analysis, CMV response was 84% in HAPLO vs 59% in UD grafts (p = 0.01) and 90 vs 66% (p = 0.02) for patients with a CMV viral load within or over the median value. In multivariate analysis, the CMV viral load was the strongest predictor of response to foscarnet (p = 0.02), followed by donor type (p = 0.06). Renal impairment developed in 14% of the patients. Overall survival was 69%:, advanced phase at transplant (p = 0.01) and ATG-based regimens (p = 0.02), were  the only two predicting factor. In conclusion, CMV response to foscarnet treatment is predicted by a lower CMV load and GvHD prophylaxis. Renal toxicity of foscarnet is not a limiting factor.

Foscarnet in the management of cytomegalovirus infections in hematopoietic stem cell transplant patients

Despite significant advances in the day-to-day management of patients receiving hematopoietic stem cell transplantations, including the introduction of new antiviral drugs, cytomegalovirus (CMV) infection continues to be a major cause of morbidity and mortality. The aim of this article is to undertake a literature-based review of foscarnet in this therapeutic setting and to align current best-published evidence with recent recommendations presented at the European Conference on Infections in Leukaemia. Ganciclovir remains the mainstay of CMV infection/disease antiviral management protocols. However, approximately a third of patients develop severe neutropenia and others become resistant to ganciclovir, and thus, a reasonably large proportion of patients are not able to receive and/or continue with this medication. Foscarnet is a suitable option as both pre-emptive therapy or for the treatment of active disease in these patients. Randomized trials have demonstrated that foscarnet is equally effective when compared with ganciclovir for pre-emptive treatment of CMV infections: the outcome was comparable with ganciclovir in terms of control of antigenemia and survival rates. There is a paucity of information for its use in the prophylaxis of CMV, although preliminary data show that it was effective in some patients at high risk of CMV reactivation. The main adverse events associated with foscarnet are renal impairment, serum electrolyte and hemoglobin disturbances, seizures and local genital irritation/ulceration. Foscarnet is a well-established antiviral option in immunocompromised patients, and it is usually administered as a second-line option to ganciclovir. In patients receiving hematopoietic stem cell transplantation, it has proven efficacy when used pre-emptively to treat CMV reactivation, as an alternative to and also in combination with ganciclovir.

Foscarnet-induced electrolyte abnormalities in a bone marrow transplant patient receiving parenteral nutrition

Cytomegalovirus (CMV) is a serious complication of immunosuppressed patients receiving bone marrow transplantation. Foscarnet, a pyrophosphate analog, has been used in the treatment of CMV infections. Renal impairment and electrolyte abnormalities are potential adverse reactions associated with the use of foscarnet. We report a case of significant electrolyte changes after initiation of foscarnet in a bone marrow transplant patient receiving parenteral nutrition.

Antimicrobial prophylaxis to prevent opportunistic infections in patients with chronic lymphocytic leukemia after allogeneic blood or marrow transplantation

Opportunistic infections have been a problem after BMT in CLL. We have allografted seven patients with B-CLL (n = 6) or B-prolymphocytic leukemia (n = 1) from matched siblings (n = 6) or a mismatched unrelated donor (n = 1). Amongst the first six, we saw two cases of recurrent or prolonged cytomegaloviremia and CMV disease, one listeria meningitis, and one fatal toxoplasma encephalitis. The latter two developed in the setting of steroid therapy of GVHD with extensive prior fludarabine therapy. Prophylaxis for opportunistic infections was developed on an ongoing basis as new infectious complications were seen. The current drug prophylaxis, which has been successful for eight months in the last patient despite pretreatment with fludarabine and steroid therapy for GVHD, is directed against pneumocystis, toxoplasma, fungi, and pneumococci. It includes immunoglobulin (for 3 1/2 months), pyrimethamine-sulfadiazine (for 4 months and during steroids), fluconazole (for 2 1/2 months), cotrimoxazole or pentamidine (for 2 years) and penicillin (lifelong). Dietary precautions are followed for 4 months and during steroids to prevent listeriosis. Four patients are alive in remission with no active infectious problems 8-44 months (median 29) after BMT. We recommend adoption of these or similar prophylactic measures for BMT in CLL as a baseline which can be modified if new infections are identified and according to individual needs.