Molnupiravir for intra-household prevention of COVID-19: The MOVe-AHEAD randomized, placebo-controlled trial.

OBJECTIVES: To evaluate the efficacy and safety of molnupiravir for intra-household post-exposure prophylaxis (PEP) of COVID-19. METHODS: MOVe-AHEAD was a randomized, controlled, double-blind, phase 3 trial comparing molnupiravir (800 mg twice daily for 5 days) with placebo. Eligible participants were adult, unvaccinated, asymptomatic household contacts of patients with laboratory-confirmed COVID-19. The primary efficacy endpoint was the incidence of COVID-19 through day 14 in modified intention-to-treat (MITT) participants (those who received ≥1 dose of study intervention) without detectable SARS-CoV-2 at baseline, termed the MITT-VN population. Superiority of molnupiravir was prespecified as a stratified one-sided p-value of <0.0249 for the treatment difference in this endpoint. RESULTS: The MITT population comprised 763 participants randomized to molnupiravir and 764 to placebo; 83.6% had anti-SARS-CoV-2 antibodies at baseline. In the MITT-VN population, COVID-19 rates through day 14 were 6.5% with molnupiravir and 8.5% with placebo (one-sided p-value: 0.0848). In the molnupiravir arm, 25/35 of confirmed COVID-19 events (71.4%) occurred after completion of treatment (versus 17/49 [34.7%] for placebo). Adverse event rates were low and similar between molnupiravir and placebo. CONCLUSIONS: Molnupiravir was well-tolerated but did not meet the prespecified superiority criterion, possibly influenced in part by the high pre-existing immunity in the trial population.

Subgroup analysis of phase 2 study of ceftolozane/tazobactam in neonates and young infants with pyelonephritis.

Ceftolozane/tazobactam is approved for the treatment of patients from birth to <18 y old with complicated urinary tract infections (cUTI). This post hoc analysis evaluated the safety, efficacy, and pharmacokinetics (PK) of ceftolozane/tazobactam compared with meropenem in neonates and young infants. NCT03230838 was a phase 2, randomized, active comparator-controlled, double-blind study of patients from birth to <18 y of age with cUTI, including pyelonephritis, given ceftolozane/tazobactam or meropenem in a 3:1 ratio. This subset analysis included only neonates and young infants < 3 mo of age. The microbiologic modified intent-to-treat population (mMITT) included 20 patients (ceftolozane/tazobactam, n = 14; meropenem, n = 6). All patients had pyelonephritis at baseline; two patients in each treatment group had bacteremia (overall 4/20, 20%). Escherichia coli was the most common baseline pathogen (overall 16/20, 80%). Safety and efficacy results were similar between treatment groups and consistent with the overall pediatric population. There were no serious drug-related adverse events (AEs), no discontinuations due to AEs, and no AEs leading to death in either treatment group. For the ceftolozane/tazobactam and meropenem treatment groups, clinical cure rates in the mMITT population were 92.9% and 100%, respectively. The population PK analysis of neonates and young infants demonstrated similar ceftolozane and tazobactam exposures to those of adults, achieving pharmacodynamic targets associated with clinical and microbiologic cure. Ceftolozane/tazobactam has a favorable safety profile and achieves high clinical cure and microbiologic eradication rates in neonates and young infants < 3 mo of age with cUTI and pyelonephritis. IMPORTANCE Extrapolation of antibacterial agent pharmacokinetics from adults to newborns and young infants may not be appropriate; similarly, the clinical manifestations of infectious diseases and outcomes following antibacterial treatment may not be similar. Ceftolozane/tazobactam is an antibacterial drug combination active against Pseudomonas aeruginosa and other multidrug-resistant gram-negative bacteria. A clinical study led to the approval for ceftolozane/tazobactam in patients from birth to 18 y of age who have complicated urinary tract infections, including those with serious kidney infections. Based on data collected during that clinical study, we compared newborns and young infants who were treated with ceftolozane/tazobactam (14 patients) and those who were treated with meropenem (6 patients). We found that ceftolozane/tazobactam treatment of newborns and young infants up to 3 mo of age who have complicated urinary tract infections demonstrated a favorable safety profile and high clinical cure and microbiologic eradication rates, similar to meropenem.

Safety and Efficacy of Ceftolozane/Tazobactam Plus Metronidazole Versus Meropenem From a Phase 2, Randomized Clinical Trial in Pediatric Participants With Complicated Intra-abdominal Infection.

BACKGROUND: Ceftolozane/tazobactam, a cephalosporin-ß-lactamase inhibitor combination, is approved for the treatment of complicated urinary tract infections and complicated intra-abdominal infections (cIAI). The safety and efficacy of ceftolozane/tazobactam in pediatric participants with cIAI were assessed. METHODS: This phase 2 study (NCT03217136) randomized participants to either ceftolozane/tazobactam+metronidazole or meropenem for treatment of cIAI in pediatric participants (<18 years). The primary objective was to assess the safety and tolerability of intravenous ceftolozane/tazobactam+metronidazole. Clinical cure at end of treatment (EOT) and test of cure (TOC) visits were secondary end points. RESULTS: The modified intent-to-treat (MITT) population included 91 participants (ceftolozane/tazobactam+metronidazole, n = 70; meropenem, n = 21). Complicated appendicitis was the most common diagnosis (93.4%); Escherichia coli was the most common pathogen (65.9%). Adverse events (AEs) occurred in 80.0% and 61.9% of participants receiving ceftolozane/tazobactam+metronidazole and meropenem, drug-related AEs occurred in 18.6% and 14.3% and serious AEs occurred in 11.4% and 0% of participants receiving ceftolozane/tazobactam+metronidazole and meropenem, respectively. No drug-related serious AEs or discontinuations due to drug-related AEs occurred. Rates of the clinical cure for ceftolozane/tazobactam+metronidazole and meropenem at EOT were 80.0% and 95.2% (difference: -14.3; 95% confidence interval: -26.67 to 4.93) and at TOC were 80.0% and 100.0% (difference: -19.1; 95% confidence interval: -30.18 to -2.89), respectively; 6 of the 14 clinical failures for ceftolozane/tazobactam+metronidazole at TOC were indeterminate responses imputed as failures per protocol. CONCLUSION: Ceftolozane/tazobactam+metronidazole was well tolerated in pediatric participants with cIAI and had a safety profile similar to the established safety profile in adults. In this descriptive efficacy analysis, ceftolozane/tazobactam+metronidazole appeared efficacious.

Safety and Efficacy of Ceftolozane/Tazobactam Versus Meropenem in Neonates and Children With Complicated Urinary Tract Infection, Including Pyelonephritis: A Phase 2, Randomized Clinical Trial.

BACKGROUND: Ceftolozane/tazobactam, a cephalosporin-ß-lactamase inhibitor combination, active against multidrug-resistant Gram-negative pathogens, is approved for treatment of adults with complicated urinary tract infections (cUTI). Safety and efficacy of ceftolozane/tazobactam in pediatric participants with cUTI, including pyelonephritis, were assessed. METHODS: This phase 2 study (NCT03230838) compared ceftolozane/tazobactam with meropenem for treatment of cUTI in participants from birth to <18 years of age. The primary objective was safety and tolerability. Key secondary end points included clinical cure and per-participant microbiologic response rates at end of treatment (EOT) and test of cure (TOC) visits. RESULTS: The microbiologic modified intent-to-treat (mMITT) population included 95 participants (ceftolozane/tazobactam, n = 71; meropenem, n = 24). The most common diagnosis and pathogen were pyelonephritis (ceftolozane/tazobactam, 84.5%; meropenem, 79.2%) and Escherichia coli (ceftolozane/tazobactam, 74.6%; meropenem, 87.5%); 5.7% (ceftolozane/tazobactam) and 4.8% (meropenem) of E. coli isolates were extended-spectrum ß-lactamase-producers. Rates of adverse events were similar between treatment groups (any: ceftolozane/tazobactam, 59.0% vs. meropenem, 60.6%; drug-related: ceftolozane/tazobactam, 14.0% vs. meropenem, 15.2%; serious: ceftolozane/tazobactam, 3.0% vs. meropenem, 6.1%). Rates of clinical cure for ceftolozane/tazobactam and meropenem at EOT were 94.4% and 100% and at TOC were 88.7% and 95.8%, respectively. Rates of microbiologic eradication for ceftolozane/tazobactam and meropenem at EOT were 93.0% and 95.8%, and at TOC were 84.5% and 87.5%, respectively. CONCLUSIONS: Ceftolozane/tazobactam had a favorable safety profile in pediatric participants with cUTI; rates of clinical cure and microbiologic eradication were high and similar to meropenem. Ceftolozane/tazobactam is a safe and effective new treatment option for children with cUTI, especially due to antibacterial-resistant Gram-negative pathogens.

Alteration of poly(ADP-ribose) metabolism affects murine sperm nuclear architecture by impairing pericentric heterochromatin condensation.

The mammalian sperm nucleus is characterized by unique properties that are important for fertilization. Sperm DNA retains only small numbers of histones in distinct positions, and the majority of the genome is protamine associated, which allows for extreme condensation and protection of the genetic material. Furthermore, sperm nuclei display a highly ordered architecture that is characterized by a centrally located chromocenter comprising the pericentromeric chromosome regions and peripherally positioned telomeres. Establishment of this unique and well-conserved nuclear organization during spermiogenesis is not well understood. Utilizing fluorescence in situ hybridization (FISH), we show that a large fraction of the histone-associated sperm genome is repetitive in nature, while a smaller fraction is associated with unique DNA sequences. Coordinated activity of poly(ADP-ribose) (PAR) polymerase and topoisomerase II beta has been shown to facilitate DNA relaxation and histone to protamine transition during spermatid condensation, and altered PAR metabolism is associated with an increase in sperm histone content. Combining FISH with three-dimensional laser scanning microscopy technology, we further show that altered PAR metabolism by genetic or pharmacological intervention leads to a disturbance of the overall sperm nuclear architecture with a lower degree of organization and condensation of the chromocenters formed by chromosomal pericentromeric heterochromatin.

Poly(ADP-ribose) polymerases PARP1 and PARP2 modulate topoisomerase II beta (TOP2B) function during chromatin condensation in mouse spermiogenesis.

To achieve the specialized nuclear structure in sperm necessary for fertilization, dramatic chromatin reorganization steps in developing spermatids are required where histones are largely replaced first by transition proteins and then by protamines. This entails the transient formation of DNA strand breaks to allow for, first, DNA relaxation and then chromatin compaction. However, the nature and origin of these breaks are not well understood. We previously reported that these DNA strand breaks trigger the activation of poly(ADP-ribose) (PAR) polymerases PARP1 and PARP2 and that interference with PARP activation causes poor chromatin integrity with abnormal retention of histones in mature sperm and impaired embryonic survival. Here we show that the activity of topoisomerase II beta (TOP2B), an enzyme involved in DNA strand break formation in elongating spermatids, is strongly inhibited by the activity of PARP1 and PARP2 in vitro, and this is in turn counteracted by the PAR-degrading activity of PAR glycohydrolase. Moreover, genetic and pharmacological PARP inhibition both lead to increased TOP2B activity in murine spermatids in vivo as measured by covalent binding of TOP2B to the DNA. In summary, the available data suggest a functional relationship between the DNA strand break-generating activity of TOP2B and the DNA strand break-dependent activation of PARP enzymes that in turn inhibit TOP2B. Because PARP activity also facilitates histone H1 linker removal and local chromatin decondensation, cycles of PAR formation and degradation may be necessary to coordinate TOP2B-dependent DNA relaxation with histone-to-protamine exchange necessary for spermatid chromatin remodeling.

Poly(ADP-ribose) metabolism is essential for proper nucleoprotein exchange during mouse spermiogenesis.

Sperm chromatin is organized in a protamine-based, highly condensed form, which protects the paternal chromosome complement in transit, facilitates fertilization, and supports correct gene expression in the early embryo. Very few histones remain selectively associated with genes and defined regulatory sequences essential to embryonic development, while most of the genome becomes bound to protamine during spermiogenesis. Chromatin remodeling processes resulting in the dramatically different nuclear structure of sperm are poorly understood. This study shows that perturbation of poly(ADP-ribose) (PAR) metabolism, which is mediated by PAR polymerases and PAR glycohydrolase in response to naturally occurring endogenous DNA strand breaks during spermatogenesis, results in the abnormal retention of core histones and histone linker HIST1H1T (H1t) and H1-like linker protein HILS1 in mature sperm. Moreover, genetic or pharmacological alteration of PAR metabolism caused poor sperm chromatin quality and an abnormal nuclear structure in mice, thus reducing male fertility.

Disruption of poly(ADP-ribose) homeostasis affects spermiogenesis and sperm chromatin integrity in mice.

The major function of sperm is the delivery of the paternal genome to the metaphase II oocyte, ensuring transmission of the genetic information to the next generation. For successful fertilization and healthy offspring, sperm DNA must be protected from exogenous insults. This is achieved by packaging the sperm DNA into a condensed protamine-bound form, preceded by the precisely orchestrated removal of histones and intermittent insertion and removal of transition proteins. This remodeling process requires relaxation of supercoiled DNA by transient formation of physiological strand breaks that spermatids, being haploid, cannot repair by homologous recombination. In somatic cells, the presence of DNA strand breaks rapidly induces the formation of poly(ADP-ribose) by nuclear poly(ADP-ribose) polymerases, which in turn facilitates DNA strand break signaling and assembly of DNA repair complexes. We reported earlier that chromatin remodeling steps during spermiogenesis trigger poly(ADP-ribose) (PAR) formation. Here, we show that knockout mice deficient in PARP1, PARG (110-kDa isoform), or both display morphological and functional sperm abnormalities that are dependent on the individual genotypes, including residual DNA strand breaks associated with varying degrees of subfertility. The data presented highlight the importance of PAR metabolism, particularly PARG function, as a prerequisite of proper sperm chromatin quality.