In vitro assessment of the combined effect of letermovir and sirolimus on cytomegalovirus replication

OBJECTIVE

Letermovir (LMV) is used for prophylaxis of cytomegalovirus (CMV) reactivation and end-organ disease in adult CMV-seropositive allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). In turn, sirolimus (SLM) which displays in vitro anti-CMV activity, is frequently employed for prophylaxis of Graft vs. Host disease in allo-HSCT. Here, we aimed at assessing whether LMV and SLM used in combination may act synergistically in vitro on inhibiting CMV replication.

METHODS

The antiviral activity of LMV and SLM alone or in combination was evaluated by a checkerboard assay, using ARPE-19 cells infected with CMV strain BADrUL131-Y. LMV and SLM were used at concentrations ranging from 24 nM to 0.38 nM and 16 nM to 0.06 nM, respectively.

RESULTS

The mean EC50 for LMV and SLM was 2.44 nM (95% CI, 1.66-3.60) and 1.40 nM (95% CI, 0.41-4.74), respective. LMV and SLM interaction yielded mainly additive effects over the range of concentrations tested.

CONCLUSIONS

The additive nature of the combination of LMV and SLM against CMV may have relevant clinical implications in management of CMV infection in allo-HSCT recipients undergoing prophylaxis with LMV.

Sclerodermatous Chronic Graft-versus-Host Disease Treated With Imatinib: A Dermatological Perspective

INTRODUCTION

Chronic graft-versus-host disease (cGVHD) is the most important cause of late non-relapse mortality after allogeneic hematopoietic stem cell transplantation. Sclerodermatous cGVHD is usually steroid refractory and remains a therapeutic challenge. Activating antibodies against the PDGFR have been reported in patients with sclerodermatous cGVHD. These antibodies induce PDGFR phosphorylation and lead to fibrosis. There is increasing evidence of successful treatment of sclerodermatous cGVHD with imatinib, a tyrosine kinase inhibitor.

OBJECTIVE

To evaluate the response of cutaneous sclerodermatous cGVHD to imatinib.

MATERIALS AND METHODS

Retrospective study of 18 patients with sclerodermatous cGVHD refractory to immunosuppressants treated with imatinib in a single center. Evaluation of treatment response was performed by clinicians' assessment and patients' subjective response at one, 3, 6, 9, 12 and 18 months after initiation of imatinib. Response was assessed as complete, partial, significant, no change or progression. Tapper off steroids was complete, partial or not possible.

RESULTS

In our series, 4 (22%) patients achieved complete response, 9 (50%) patients partial response, 2 (11%) patients significant response, 2 (11%) patients had no change and one (6%) patient progressive disease at last follow-up. Mean time from initiation of imatinib to any degree of response was 2,75 months (range 1-9 months).

CONCLUSIONS

This study provides further evidence of the role of imatinib for the treatment of steroid refractory sclerodermatous cGVHD.

Tacrolimus plus sirolimus with or without ATG as GVHD prophylaxis in HLA-mismatched unrelated donor allogeneic stem cell transplantation

HLA-matched related or unrelated donors are not universally available. Consequently, patients can be offered hematopoietic stem cell transplantation (HSCT) from alternative donors, including mismatched unrelated donors (MMURD), known to cause a higher incidence of acute GVHD (aGVHD) and chronic GVHD. In vivo T-cell-depletion strategies, such as antithymocyte globulin (ATG) therapy, significantly decrease the risk of GVHD. We performed a multicenter, retrospective study comparing tacrolimus (TAC) and sirolimus (SIR) with or without ATG in 104 patients (TAC-SIR=45, TAC-SIR-ATG=59) who underwent MMURD HSCT. Use of ATG was associated with a lower incidence, albeit not statistically significant, of grades 2-4 aGVHD (46% vs 64%, P=0.09), no difference in grades 3-4 aGVHD (10% vs 15%, P=0.43), a trend for a lower incidence of moderate/severe chronic GVHD (16% vs 37%, P=0.09) and more frequent Epstein-Barr virus reactivation (54% vs 18%, P=0.0002). There were no statistically significant differences in 3-year overall survival (OS) (TAC-SIR-ATG=40% (95% confidence interval (CI)=24-56%) vs TAC-SIR=54% (95% CI=37-70%), P=0.43) or 3-year cumulative incidence of relapse/progression (TAC-SIR-ATG=40% (95% CI=28-58%) vs TAC-SIR=22% (95% CI=13-39%), P=0.92). An intermediate Center for International Blood & Marrow Transplant Research disease risk resulted in a significantly lower non-relapse mortality and better OS at 3 years. Our study suggests that addition of ATG to TAC-SIR in MMURD HSCT does not affect OS when compared with TAC-SIR alone.

Successful treatment of hepatitis C virus infection with sofosbuvir and simeprevir in the early phase of an allogeneic stem cell transplant

Currently, a lack of consensus exists on how to manage a hepatitis C virus (HCV) infection after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Ribavirin alone, or in combination with interferon, has been the mainstream therapy for HCV infection after transplantation. However, very few patients have been regularly treated owing to concerns about poor tolerability, frequent side effects, and limited efficacy. The present case illustrates the striking efficacy of the combination therapy of sofosbuvir with simeprevir, early after transplantation, as it was able to completely eliminate viral replication within 1 month of initiation of treatment. Moreover, tolerance was good, with only minor interactions between the immunosuppressive drugs. This case report supports the feasibility of using this combination therapy early after allo-HSCT for patients with HCV infection.

Incidence, characteristics and risk factors of marked hyperbilirubinemia after allogeneic hematopoietic cell transplantation with reduced-intensity conditioning

To analyze the incidence, characteristics and risk factors of hyperbilirubinemia after allogeneic hematopoietic cell transplantation with reduced-intensity conditioning (allo-RIC), we conducted a retrospective study in three Spanish centers. We analyzed 452 consecutive patients receiving allo-RIC. Of these, 92 patients (20%) developed marked hyperbilirubinemia (>4 mg/day or >68.4 μM) after allo-RIC. The main causes of marked hyperbilirubinemia after transplant were cholestasis due to GVHD or sepsis (n=57, 62%) and drug-induced cholestasis (n=13, 14%). A total of 22 patients with marked hyperbilirubinemia (24%) underwent liver biopsy. The most frequent histological finding was iron overload alone (n=6) or in combination with other features (n=6). In multivariate analysis, the risk factors for marked hyperbilirubinemia after allo-RIC were non-HLA-identical sibling donors (hazard ratio (HR) 2.2 (95% confidence interval (CI) 1.4-3.6) P=0.001), female donors to male recipients (HR 2.1 (95% CI 1.3-3.3) P=0.003) and high levels of bilirubin and γ-glutamyl transpeptidase before transplant (HR 4.5 (95% CI 2.5-8.4) P<0.001 and HR 4.6 (95% CI 2.6-8.1) P<0.001, respectively). Patients with marked hyperbilirubinemia showed higher 4-year nonrelapse mortality (HR 1.3 (95% CI 1-1.7), P=0.02) and lower 4-year OS (HR 1.4 (95%CI 1.3-1.7), P<0.001) than patients without. In conclusion, we confirm that marked hyperbilirubinemia is frequent and diverse after allo-RIC. Development of marked hyperbilirubinemia after allo-RIC is associated with worse outcome of the procedure.

MTX or mycophenolate mofetil with CsA as GVHD prophylaxis after reduced-intensity conditioning PBSCT from HLA-identical siblings

Mycophenolate mofetil (MMF) in combination with CsA seems to lead to earlier post transplant hematological recovery and less mucositis than MTX, with a similar incidence of GVHD. In this study we analyzed the post transplant outcomes of two cohorts of patients who underwent an HLA-identical sibling reduced intensity conditioning transplantation (allo-RIC) with GVHD prophylaxis consisting of CsA in combination with either MMF or a short course of MTX. We included 145 consecutive allo-RIC transplants performed between April 2000 and August 2007. The median follow-up for survivors was 41 months (4-105 months). The study group included 91 males. Median age was 55 years (range 18-71 years). Diagnoses included myeloid (n=65) and lymphoid (n=80) malignancies. GVHD prophylaxis consisted of CsA/MMF in 52 and CsA/MTX in 93 patients. The conditioning regimen was based on fludarabine in combination with BU (n=59) or melphalan (n=86). The occurrence of grade 2-4 mucositis was higher in the CsA/MTX group than in the CsA/MMF group (57 vs 23%, P=0.001). The cumulative incidence of acute and chronic GVHD was similar, 48 vs 50% and 71 vs 68%, respectively (P>0.7). The 2-year relapse and OS were similar in the CsA/MTX and CsA/MMF groups (29 vs 21%, P=0.3 and 52 vs 51%, P=0.7, respectively). Our results support further prospective studies comparing the use of the CsA/MMF combination with CsA/MTX as GVHD prophylaxis in HLA-identical sibling donor allo-RIC recipients.

Lower respiratory tract respiratory virus infections increase the risk of invasive aspergillosis after a reduced-intensity allogeneic hematopoietic SCT

We have analyzed the incidence and risk factors for the occurrence of invasive aspergillosis (IA) among 219 consecutive recipients of an allogeneic hematopoietic SCT after a reduced-intensity conditioning regimen (Allo-RIC). Twenty-seven patients developed an IA at a median of 218 days (range 24–2051) post-Allo-RIC, for a 4-year incidence of 13% (95% confidence interval 4–24%). In multivariate analysis, risk factors for developing IA were steroid therapy for moderate-to-severe graft vs host disease (GVHD) (Hazard Ratio (HR) 2.9, P=0.03), occurrence of a lower respiratory tract infection (LRTI) by a respiratory virus (RV) (HR 4.3, P<0.01) and CMV disease (HR 2.8, P=0.03). Variables that decreased survival after Allo-RIC were advanced disease phase (HR 1.9, P=0.02), steroid therapy for moderate-to-severe GVHD (HR 2.2, P<0.01), not developing chronic GVHD (HR 4.3, P<0.01), occurrence of LRTI by an RV (HR 3.4, P<0.01) and CMV disease (HR 2, P=0.01), whereas occurrence of IA had no effect on survival (P=0.5). Our results show that IA is a common infectious complication after an Allo-RIC, which occurs late post-transplant and may not have a strong effect on survival. An important observation is the possible role of LRTI by conventional RVs as risk factors for IA.