Repurposing Nilotinib for Cytomegalovirus Infection Prophylaxis after Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Arm, Phase II Trial

Effect of sorafenib maintenance on Epstein-Barr virus and cytomegalovirus infections in patients with FLT3-ITD AML undergoing allogeneic hematopoietic stem cell transplantation: a secondary analysis of a randomized clinical trial

BACKGROUND

Use of kinase inhibitors such as dasatinib and imatinib might increase the risk of opportunistic infections, especially Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections. However, the effect of sorafenib on EBV and CMV infections remains unclear. The aim of this study was to investigate the effect of sorafenib maintenance post-transplantation on the incidence and mortality of EBV and CMV infections in patients with FLT3-ITD acute myeloid leukemia.

METHODS

This was a follow-up of our randomized controlled trial undertaken at seven hospitals in China. The primary endpoint was EBV and CMV infections within 3 years post-transplantation. Secondary endpoints included the cumulative incidences of relapse, non-relapse mortality (NRM), overall survival (OS), leukemia-free survival (LFS), and graft-versus-host disease (GVHD)-free/relapse-free survival (GRFS) at 3 years.

RESULTS

Two hundred two patients were assigned to sorafenib maintenance (n=100) or non-maintenance (control, n=102). Median extended follow-up post-transplantation was 36.8 (range, 2.5-67.1) months. The 3-year cumulative incidences of EBV-DNAemia and EBV-associated diseases were 24.0% (95% CI: 16.1-32.8%) and 5.0% (1.8-10.6%) in the sorafenib group, and 24.5% (16.6-33.2%) and 5.9% (2.4-11.6%) in the control group (P=0.937; P=0.771). The 3-year cumulative incidences of CMV-DNAemia and CMV-associated diseases were 56.0% (45.6-65.1%) and 8.0% (3.7-14.4%) in the sorafenib group, and 52.9% (42.7-62.1%) and 8.8% (4.3-15.3%) in the control group (P=0.997; P=0.826). The 3-year cumulative mortality of EBV- and CMV-associated diseases was 0.0% (0.0-0.0%) and 2.0% (0.4-6.4%) in the sorafenib group, and 1.0% (0.1-4.8%) and 2.0% (0.4-6.3%) in the control group (P=0.322, P=0.980). The 3-year cumulative incidences of relapse, NRM, OS, LFS, and GRFS were 13.0%, 11.1%, 79.0%, 75.9%, and 65.8% in the sorafenib group and 34.8%, 12.7%, 61.4%, 52.5%, and 46.6% in the control group, respectively (P<0.001, P=0.656, P=0.005, P<0.001, P=0.003). The reconstitution of T lymphocyte subsets, B lymphocytes, and natural killer cells was similar between the two groups (all P>0.05).

CONCLUSIONS

Sorafenib maintenance post-transplantation does not increase the incidence and mortality of EBV and CMV infections, demonstrating a favorable safety profile.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02474290 . Registered on June 14, 2015.

Herpesvirus Infections Potentiated by Biologics

Herpesviruses such as herpes simplex virus (HSV) type 1 and 2, varicella-zoster virus (VZV), and cytomegalovirus (CMV) maintain lifelong latency in the host after primary infection and can reactivate periodically either as asymptomatic viral shedding or as clinical disease. Immunosuppression, including biologic therapy, may increase frequency and severity of herpesvirus reactivation and infection. Licensed biologics are reviewed regarding their risks of potentiating HSV, VZV, and CMV reactivation and infection. Approaches to prophylaxis against HSV, VZV, and CMV infection or reactivation are discussed.

A Native Human Monoclonal Antibody Targeting HCMV gB (AD-2 Site I)

Hyperimmune globulin (HIG) has shown efficacy against human cytomegalovirus (HCMV) for both transplant and congenital transmission indications. Replicating that activity with a monoclonal antibody (mAb) offers the potential for improved consistency in manufacturing, lower infusion volume, and improved pharmacokinetics, as well as reduced risk of off-target reactivity leading to toxicity. HCMV pathology is linked to its broad cell tropism. The glycoprotein B (gB) envelope protein is important for infections in all cell types. Within gB, the antigenic determinant (AD)-2 Site I is qualitatively more highly-conserved than any other region of the virus. TRL345, a high affinity (Kd = 50 pM) native human mAb to this site, has shown efficacy in neutralizing the infection of fibroblasts, endothelial and epithelial cells, as well as specialized placental cells including trophoblast progenitor cells. It has also been shown to block the infection of placental fragments grown ex vivo, and to reduce syncytial spread in fibroblasts in vitro. Manufacturing and toxicology preparation for filing an IND (investigational new drug) application with the US Food and Drug Administration (FDA) are expected to be completed in mid-2019.