cmx-001 and Cytomegalovirus-Infections

Cytomegalovirus (CMV) infection is a common complication in immunocompromised patients, especially after hematopoietic stem cell or solid organ transplantation. Therapeutic antiviral options [(val)ganciclovir, foscarnet, cidofovir] are still limited and can expose to severe toxicities. Moreover, prolonged antiviral drug exposure and ongoing viral replication are key factors in the development of antiviral drug resistance. After many years of few tangible advances in terms of new antiviral drugs, we are now experiencing an exciting period characterized by a series of phase III clinical trials incorporating three novel agents: maribavir, brincidofovir, and letermovir. This article summarizes the current state of the prevention and treatment of CMV infections as well as data of investigational drugs in clinical development.

Topics: Acetates; Antiviral Agents; Benzimidazoles; Cytomegalovirus Infections; Cytosine; Ganciclovir; Humans; Organophosphonates; Quinazolines; Ribonucleosides

Human cytomegalovirus (HCMV) represents the major viral complication after hematopoietic stem cell transplantation. HCMV infection may be controlled by the reconstituting immune system and remain subclinical or can lead to severe systemic and/or organ disease (mainly pneumonia and gastroenteritis) when immune reconstitution is delayed or impaired. In order to prevent the occurrence of HCMV disease, a prompt diagnosis of HCMV infection is mandatory. The adoption of pre-emptive therapy strategies guided by virological monitoring dramatically reduced the occurrence of HCMV disease. However, late-onset end-organ disease may occur in some patients with apparent immune reconstitution. In the near future, introduction of immunological monitoring and immunotherapies could markedly improve management of HCMV infection.

Topics: Acetates; Adult; Animals; Antiviral Agents; Asymptomatic Diseases; Benzimidazoles; Clinical Trials as Topic; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Disease Management; Gastroenteritis; Hematopoietic Stem Cell Transplantation; Humans; Immunotherapy; Monitoring, Immunologic; Organophosphonates; Pneumonia; Postoperative Complications; Quinazolines; Ribonucleosides

The 2015 Tandem American Society for Blood and Marrow Transplantation/Center for International Blood and Marrow Transplant Meetings provide an opportunity to review the current status and future perspectives on therapy for cytomegalovirus (CMV) infection in the setting of hematopoietic stem cell transplantation (HSCT). After many years during which we have seen few tangible advances in terms of new antiviral drugs, we are now experiencing an exciting period of late-stage drug development, characterized by a series of phase III trials incorporating a variety of novel agents. These trials have the potential to shift our current standard therapeutic strategies, which generally involve pre-emptive therapy based on sensitive molecular surveillance, towards the prophylactic approaches we see more generally with other herpes viruses such as herpes simplex and varicella zoster. This comes at a time when the promise of extensive preclinical research has been translated into encouraging clinical responses with several cellular immunotherapy strategies, which have also been moved towards definitive late-stage clinical trials. How these approaches will be integrated with the new wave of antiviral drugs remains open to conjecture. Although most of the focus of these cellular immunotherapy studies has been on adaptive immunity, and in particular T cells, an increasing awareness of the possible role of other cellular subsets in controlling CMV infection has developed. In particular, the role of natural killer (NK) cells is being revisited, along with that of γδ T cells. Depletion of NK cells in mice results in higher titers of murine CMV in tissues and increased mortality, whereas NK cell deficiency in humans has been linked to severe CMV disease. We will review recent progress in these areas.

Topics: Acetates; Adoptive Transfer; Animals; Antiviral Agents; Benzimidazoles; Cell- and Tissue-Based Therapy; Clinical Trials, Phase III as Topic; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Hematopoietic Stem Cell Transplantation; Humans; Isoxazoles; Killer Cells, Natural; Leflunomide; Mice; Organophosphonates; Quinazolines; Ribonucleosides; T-Lymphocytes

Cytomegalovirus (CMV) remains a significant cause of morbidity and mortality in immunocompromised patients, particularly following allogeneic haematopoietic transplantation. One of the principal factors leading to this increased risk is the loss of T-cell immunity.. In a recent review, we assessed the treatment strategies for prophylaxis and pre-emptive treatment of CMV, particularly where relevant to the high-risk patient populations following allogeneic haematopoietic transplantation. This review is a focused update to our previous article and presents a more detailed analysis of the developments in drugs, vaccines and adoptive T-cell therapies since that time. Relevant studies were selected from PubMed and clinicaltrials.gov. The search terms include allogeneic transplant, cytomegalovirus, multidrug-resistant virus and adoptive T-cell therapy.. The current randomised controlled studies evaluating pharmacological agents for CMV should inform as to whether these provide significant clinical benefits. Adoptive cell therapy provides a more physiological approach to the problem of lack of CMV-specific immunity. Recent reports add to the evidence that culture-based techniques can create cellular products that are safe and efficacious, although without Phase III data to definitively support their routine application and the difficulty of satisfying GMP standards.

Topics: Acetates; Antiviral Agents; Benzimidazoles; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Hematologic Neoplasms; Hematopoietic Stem Cell Transplantation; Humans; Immunotherapy, Adoptive; Organophosphonates; Quinazolines; Ribonucleosides; T-Lymphocytes; Transplant Recipients; Transplantation, Homologous

To consider new treatment options for cytomegalovirus (CMV) infection, review recent trials, and anticipate their use in clinical practice, focussing on bone marrow transplantation, congenital infection, and intervention during pregnancy.. Three double-blind randomized placebo-controlled phase 2 proof-of-concept studies have each identified a novel antiviral drug with activity against CMV infection in bone marrow transplant patients. One of these (brincidofovir) inhibits the DNA polymerase that is the target of the currently licensed drug ganciclovir. Another new drug (maribavir) inhibits a protein kinase which, coincidentally, is the enzyme responsible for activating ganciclovir through phosphorylation. The third drug (letermovir) inhibits the terminase enzyme complex responsible for packaging unit length DNA into assembling virions.In addition, in a double-blind randomized placebo-controlled trial in neonates with symptomatic congenital CMV infection, a 6-month course of valganciclovir was superior to the standard 6-week course of the same drug. In pregnant women with primary CMV infection, administration of hyperimmune immunoglobulin did not significantly reduce transmission of CMV across the placenta.. The ability to diagnose CMV infections reliably in different clinical settings through application of molecular laboratory methods has ushered in new ways of evaluating potential new treatments for CMV. Several of these may help control the diseases caused by this important human pathogen.

Topics: Acetates; Antiviral Agents; Benzimidazoles; Bone Marrow Transplantation; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Disease Transmission, Infectious; Double-Blind Method; Female; Ganciclovir; Humans; Male; Organ Transplantation; Organophosphonates; Practice Guidelines as Topic; Pregnancy; Pregnancy Complications, Infectious; Quinazolines; Randomized Controlled Trials as Topic; Ribonucleosides

Cytomegalovirus (CMV) infection is a common complication of allogeneic hematopoietic cell transplantation (HCT). In this trial, we randomized adult CMV-seropositive HCT recipients without CMV viremia at screening 2:1 to receive brincidofovir or placebo until week 14 post-HCT. Randomization was stratified by center and risk of CMV infection. Patients were assessed weekly through week 15 and every third week thereafter through week 24 post-HCT. Patients who developed clinically significant CMV infection (CS-CMVi; CMV viremia requiring preemptive therapy or CMV disease) discontinued the study drug and began anti-CMV treatment. The primary endpoint was the proportion of patients with CS-CMVi through week 24 post-HCT; patients who discontinued the trial or with missing data were imputed as primary endpoint events. Between August 2013 and June 2015, 452 patients were randomized at a median of 15 days after HCT and received study drug. The proportion of patients who developed CS-CMVi or were imputed as having a primary endpoint event through week 24 was similar between brincidofovir-treated patients and placebo recipients (155 of 303 [51.2%] versus 78 of 149 [52.3%]; odds ratio, .95 [95% confidence interval, .64 to 1.41]; P = .805); fewer brincidofovir recipients developed CMV viremia through week 14 compared with placebo recipients (41.6%; P < .001). Serious adverse events were more frequent among brincidofovir recipients (57.1% versus 37.6%), driven by acute graft-versus-host disease (32.3% versus 6.0%) and diarrhea (6.9% versus 2.7%). Week 24 all-cause mortality was 15.5% among brincidofovir recipients and 10.1% among placebo recipients. Brincidofovir did not reduce CS-CMVi by week 24 post-HCT and was associated with gastrointestinal toxicity.

Topics: Administration, Oral; Adolescent; Adult; Aged; Allografts; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Disease-Free Survival; Female; Hematopoietic Stem Cell Transplantation; Humans; Male; Middle Aged; Organophosphonates; Survival Rate

The use of available antiviral agents for the prevention of cytomegalovirus (CMV) disease is limited by frequent toxic effects and the emergence of resistance. CMX001 has potent in vitro activity against CMV and other double-stranded DNA viruses. We evaluated the safety and anti-CMV activity of CMX001 in patients who had undergone allogeneic hematopoietic-cell transplantation.. From December 2009 through June 2011, a total of 230 patients with data that could be evaluated were enrolled in the study. We randomly assigned these adult CMV-seropositive transplant recipients from 27 centers to oral administration of CMX001 or placebo. Patients were assigned in a 3:1 ratio to five sequential study cohorts according to a dose-escalating, double-blind design. Randomization was stratified according to the presence or absence of acute graft-versus-host disease and CMV DNA in plasma. Patients received the study drug after engraftment for 9 to 11 weeks, until week 13 after transplantation. Polymerase-chain-reaction analysis of CMV DNA in plasma was performed weekly. Patients in whom CMV DNA was detected at a level that required treatment discontinued the study drug and received preemptive treatment against CMV infection. The primary end point was a CMV event, defined as CMV disease or a plasma CMV DNA level greater than 200 copies per milliliter when the study drug was discontinued. The analysis was conducted in the intention-to-treat population.. The incidence of CMV events was significantly lower among patients who received CMX001 at a dose of 100 mg twice weekly than among patients who received placebo (10% vs. 37%; risk difference, -27 percentage points; 95% confidence interval, -42 to -12; P=0.002). Diarrhea was the most common adverse event in patients receiving CMX001 at doses of 200 mg weekly or higher and was dose-limiting at 200 mg twice weekly. Myelosuppression and nephrotoxicity were not observed.. Treatment with oral CMX001 at a dose of 100 mg twice weekly significantly reduced the incidence of CMV events in recipients of hematopoietic-cell transplants. Diarrhea was dose-limiting in this population at a dose of 200 mg twice weekly. (Funded by Chimerix; CMX001-201 ClinicalTrials.gov number, NCT00942305.).

Topics: Administration, Oral; Adult; Antiviral Agents; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Diarrhea; DNA, Viral; Dose-Response Relationship, Drug; Double-Blind Method; Female; Hematopoietic Stem Cell Transplantation; Humans; Incidence; Male; Organophosphonates; Polymerase Chain Reaction; Transplantation, Homologous

We have recently shown that the artemisinin derivative artemisone, which was screened against malaria in human clinical studies, is a potent inhibitor of human cytomegalovirus (HCMV). Here we evaluated the antiviral effect of artemisone when employed in 2-drug combinations with approved and experimental anti-HCMV agents. Using the Chou-Talalay method, we found that in-vitro combination of artemisone with cidofovir, brincidofovir, or with the HCMV UL97 inhibitor maribavir resulted in antiviral synergism and the combination of artemisone with ganciclovir or with the viral terminase inhibitors letermovir and BDCRB resulted in moderate synergism. Importantly, the combination of artemisone with maribavir demonstrated synergistic antiviral activity ex-vivo, in a clinically-relevant multicellular model of human placental tissues maintained in organ culture. Our findings provide the basis for the use of artemisone in synergistically acting drug combinations, to enhance viral control and reduce antiviral drug toxicities.

Topics: Acetates; Antiviral Agents; Artemisinins; Benzimidazoles; Cidofovir; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Drug Interactions; Drug Synergism; Drugs, Investigational; Female; Ganciclovir; Humans; Organ Culture Techniques; Organophosphonates; Placenta; Pregnancy; Quinazolines; Ribonucleosides

Human cytomegalovirus (HCMV) can cause severe disease in patients with compromised or immature immune systems. Currently approved pharmacotherapies for the treatment of systemic HCMV infections [ganciclovir (GCV), cidofovir (CDV), foscarnet] are limited by a high incidence of adverse effects and/or the development of drug resistance. Given that many of these drugs have the same viral target (HCMV-encoded DNA polymerase), cross-resistance is relatively common. The primary means to combat drug resistance is combination pharmacotherapy using therapeutics with different molecular mechanisms of action with the expectation that those combinations result in an additive or synergistic enhancement of effect; combinations that result in antagonism can, in many cases, be detrimental to the outcome of the patient. We therefore tested select combinations of approved (GCV, CDV, letermovir (LMV)) and experimental (brincidofovir (BCV), cyclopropavir (CPV), maribavir (MBV), BDCRB) drugs with the hypothesis that combinations of drugs with different and distinct molecular mechanisms of action will produce an additive and/or synergistic enhancement of antiviral effect against HCMV in vitro. Using MacSynergy II (a statistical package that measures enhancement or lessening of effect relative to zero/additive), select drug combination studies demonstrated combination indices ranging from 160 to 372 with 95% confidence intervals greater than zero indicating that these combinations elicit a synergistic enhancement of effect against HCMV in vitro. These data suggest that administration of a viral DNA polymerase inhibitor, MBV, and/or a viral terminase inhibitor in combination has the potential to address the resistance/cross-resistance problems associated with currently available therapeutics.

Topics: Antiviral Agents; Benzimidazoles; Cell Line; Cidofovir; Cyclopropanes; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; DNA-Directed DNA Polymerase; Drug Antagonism; Drug Combinations; Drug Resistance, Viral; Drug Synergism; Drug Therapy, Combination; Endodeoxyribonucleases; Fibroblasts; Foscarnet; Ganciclovir; Guanine; Humans; Nucleic Acid Synthesis Inhibitors; Organophosphonates; Ribonucleosides; Viral Proteins; Virus Replication

Eight in vitro selection experiments under brincidofovir pressure elicited the known cytomegalovirus DNA polymerase amino acid substitutions N408K and V812L and the novel exonuclease domain substitutions D413Y, E303D, and E303G, which conferred ganciclovir and cidofovir resistance with 6- to 11-fold resistance to brincidofovir or 17-fold when E303G was combined with V812L. The new exonuclease domain I resistance mutations selected under brincidofovir pressure add to the single instance previously reported and show the expected patterns of cross-resistance.

Topics: Antiviral Agents; Cidofovir; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; DNA-Directed DNA Polymerase; Drug Resistance, Viral; Foscarnet; Ganciclovir; Gene Expression; Humans; Microbial Sensitivity Tests; Mutation; Organophosphonates; Protein Domains; Viral Proteins

The emergence of resistance to available antiviral drugs may cause higher Cytomegalovirus (CMV)-associated morbidity and mortality in hematopoietic cell transplant (HCT) recipients. Few novel antiviral drugs are being developed with potential effect against refractory or resistant CMV infections. Brincidofovir, an oral nucleotide analog and prodrug of cidofovir, has shown in vitro activity against CMV.. We reviewed data of 4 cancer patients with resistant CMV or herpes simplex virus (HSV) infections and were treated with brincidofovir under emergency IND application.. Three out of the 4 patients with resistant CMV or HSV infections responded to brincidofovir. Brincidofovir achieved virological response in 2 patients with confirmed UL97 mutation (ganciclovir-resistant CMV infection), but failed to control CMV when a specific UL54 mutation was present (conferring resistance to foscarnet and cidofovir), as seen with patient 3. Furthermore, brincidofovir was effective for treatment of acyclovir resistant HSV infection, as described in patient 4 which is in alignment with the high in vitro potency of brincidofovir (about 100-fold more than acyclovir) for inhibition of HSV replication. Only one patient had brincidofovir-related diarrhea without any evidence of concurrent gastrointestinal GVHD.. Without the nephrotoxicity of cidofovir, brincidofovir could be an effective alternative for CMV-resistant and HSV-resistant infections. Combination therapy of brincidofovir with other antiviral agent, at a conventional or a lower dose, could be considered to potentiate efficacy and minimize side effects of the approved antiviral agents.

Topics: Aged; Antiviral Agents; Clinical Trials as Topic; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; Drug Resistance, Viral; Female; Hematopoietic Stem Cell Transplantation; Herpes Simplex; Herpesviridae Infections; Humans; Immunocompromised Host; Male; Middle Aged; Neoplasms; Organophosphonates

Resistant cytomegalovirus-mediated infections are increasing in solid organ recipient with few available alternative treatments. Brincidofovir is an oral broad-spectrum antiviral in development for prevention and treatment of viral infection, particularly cytomegalovirus.. Although brincidofovir is an analogue of cidofovir, previous studies reported no renal toxicity.. Here, we report 2 cases of severe tubular necrosis in solid organ recipients, 1 heart and 1 kidney transplant.. Both patients received brincidofovir for the treatment of cytomegalovirus infection with mutation of UL-97. They presented an acute kidney injury without any occurrence of other clinical event such as introduction of nephrotoxic drug, graft rejection, urinary tract obstruction or infection, and calcineurin inhibitor overdosage. In each case, renal biopsy showed extended tubular necrosis.. The discontinuation of brincidofovir led to improve renal function without other any intervention. Reintroduction of brincidofovir in case 1, due to the absence of other medical alternative, led to a new episode of acute kidney injury. One more time, renal biopsy showed tubular necrosis and patient recovered renal function after discontinuation.. To our knowledge, this is the first report of brincidofovir-mediated renal adverse event. Clinicians may be aware of this severe complication in this specific population.

Topics: Acute Kidney Injury; Antiviral Agents; Cytomegalovirus Infections; Cytosine; Heart Transplantation; Humans; Kidney Transplantation; Male; Middle Aged; Organophosphonates; Postoperative Complications; Severity of Illness Index

Polyomavirus-associated nephropathy (PVAN) is common in patients who have undergone kidney transplantation and has been reported in hematopoietic stem cell (HSC) transplant recipients. Aside from reduction of immunosuppression, few therapeutic options exist for treatment of PVAN. We report a case of PVAN in a severely immunocompromised allogeneic HSC transplant recipient that was treated with brincidofovir without reduction of immunosuppression. We review our institutional experience of PVAN in HSC transplantation and discuss the potential use of brincidofovir for treatment.

Topics: BK Virus; Cytomegalovirus Infections; Cytosine; Hematopoietic Stem Cell Transplantation; Humans; Immunocompromised Host; Kidney Diseases; Male; Middle Aged; Organophosphonates; Polyomavirus; Polyomavirus Infections; Tumor Virus Infections; Viremia

CMX001 is an orally available lipid acyclic nucleotide phosphonate that delivers high intracellular levels of cidofovir (CDV)-diphosphate and exhibits enhanced in vitro antiviral activity against a wide range of double-stranded DNA viruses, including cytomegalovirus (CMV). Mutations in the DNA polymerase of CMV that impart resistance to CDV also render the virus resistant to CMX001. Here, we report a novel resistance mutation that arose under the selective pressure of CMX001. The wild-type CMV strain AD169 was propagated in human foreskin fibroblasts under increasing concentrations of CMX001 over 10 months, and the resulting strain (named CMX001(R)) was less susceptible to CDV and CMX001 in a plaque reduction assay. Genotypic analysis of virus strain CMX001(R) via conventional sequencing of the genes encoding the CMV DNA polymerase (UL54) and UL97 kinase (UL97) demonstrated one mutation that changed the wild-type aspartate to glutamate at position 542 in UL54. A recombinant virus with this novel D542E mutation was generated via bacterial artificial chromosome-mediated marker transfer experiments. Subsequent phenotypic resistance analysis of the D542E mutant demonstrated reductions in susceptibility of greater than 10-fold to CMX001 and CDV, but no resistance to foscarnet (FOS) or ganciclovir (GCV). Analysis of replicative fitness showed that both strain CMX001(R) and the D542E mutant viruses demonstrated a smaller plaque phenotype and slower replication kinetics than their respective parent viruses. These data describe the first resistance mutation generated under the selective pressure of CMX001 and suggest that CMX001 may have a unique resistance profile associated with reduced viral replication and maintenance of sensitivity to FOS and GCV.

Topics: Amino Acid Sequence; Antiviral Agents; Base Sequence; Cells, Cultured; Chromosomes, Artificial, Bacterial; Cidofovir; Cytomegalovirus; Cytomegalovirus Infections; Cytosine; DNA-Directed DNA Polymerase; Drug Resistance, Viral; Foscarnet; Ganciclovir; Humans; Mutation; Organophosphonates; Phenotype; Sequence Analysis, DNA

Cytomegalovirus (CMV) infection is the leading cause of congenital infection, producing both sensorineural hearing loss and mental retardation. We evaluated the in vivo efficacy of an orally bioavailable analog of cidofovir, hexadecyloxypropyl-cidofovir (HDP-CDV), against guinea pig CMV (GPCMV) in a guinea pig model of congenital CMV infection. HDP-CDV exhibited antiviral activity against GPCMV with a 50% effective concentration (EC(50)) of 0.004 μM ± 0.001 μM. To evaluate in vivo efficacy, pregnant Hartley guinea pigs were inoculated with GPCMV during the late second/early third trimester of gestation. Animals were administered 20 mg HDP-CDV/kg body weight orally at 24 h postinfection (hpi) and again at 7 days postinfection (dpi) or administered 4 mg/kg HDP-CDV orally each day for 5 days or 9 days. Virus levels in dam and pup tissues were evaluated following delivery, or levels from dam, placenta, and fetal tissues were evaluated following sacrifice of dams at 10 dpi. All HDP-CDV regimens significantly improved pup survival, from 50 to 60% in control animals to 93 to 100% in treated animals (P ≤ 0.019). Treatment with 20 mg/kg HDP-CDV significantly reduced the viral load in pup spleen (P = 0.017) and liver (P = 0.029). Virus levels in the placenta were significantly reduced at 10 dpi following daily treatment with 4 mg/kg HDP-CDV for 5 or 9 days. The 9-day treatment also significantly reduced the viral levels in the dam spleen and liver. Although the 4-mg/kg treatment improved pup survival, virus levels in the fetal tissues were similar to those in control tissues. Taken together, HDP-CDV shows potential as a well-tolerated antiviral candidate for treatment of congenital human CMV (HCMV) infection.

Topics: Administration, Oral; Animals; Antiviral Agents; Cytomegalovirus Infections; Cytosine; Disease Models, Animal; Female; Guinea Pigs; Organophosphonates; Pregnancy; Treatment Outcome