Inpatient Insights
Nirsevimab effective at preventing hospitalizations due to RSV in infants
Results of a recent study published on December 23, 2023, in NEJM, found that infants treated with nirsevimab were less likely to be hospitalized with respiratory syncytial virus (RSV).
RSV is a common seasonal cause of lower respiratory tract infection, particularly in infants, young children, and older adults. In July 2023, FDA approved the use of nirsevimab, a monoclonal antibody with activity against RSV, for use in infants born during or entering their first RSV season, and in children up to 24 months who remain vulnerable to severe RSV disease. Nirsevimab had previously been approved for use in the European Union and United Kingdom in November 2022. Investigators in the HARMONIE Study Group conducted a random trial involving infants who were 12 months or younger and were entering their first RSV season in France, Germany, or the U.K. to determine efficacy of nirsevimab at preventing hospitalization from RSV.
A total of 8,058 infants who were born at a gestational age of at least 29 weeks were randomized to receive either a single I.M. injection of nirsevimab (50 mg if the infant’s weight was <5 kg or 100 mg if the infant weighed ≥5 kg) or standard care (no intervention) before or during the RSV season. The primary end point was hospitalization for RSV-associated lower respiratory tract infection, defined as hospital admission and an RSV-positive test result. A key secondary end point was very severe RSV-associated lower respiratory tract infection, defined as hospitalization for RSV-associated lower respiratory tract infection with an oxygen saturation of less than 90% and the need for supplemental oxygen.
Results showed that 11 infants (0.3%) in the nirsevimab group and 60 infants (1.5%) in the standard-care group were hospitalized for RSV-associated lower respiratory tract infection, corresponding to a nirsevimab efficacy of 83.2%. Treatment-related adverse events occurred in 86 infants (2.1%) in the nirsevimab group. ■
When should hospitalized adults with Gram-negative bloodstream infections transition to oral antibiotic therapy?
Although Gram-negative bloodstream infections are common among hospitalized patients, treatment practices vary widely among hospitals. In an effort to develop best practices, a nationwide group of physicians and pharmacists examined the transition from I.V. to oral antibiotics, including selection, timing, and associated clinical and microbial characteristics, among hospitalized patients with Gram-negative bloodstream infections.
The researchers conducted a retrospective cohort study of 4,581 hospitalized adults with Gram-negative bloodstream infections at 24 U.S. hospitals between January 1 and December 31, 2019. Baseline characteristics and clinical parameters reflecting severity of illness were evaluated in groups receiving oral and I.V. therapy. In addition, the prevalence of transition from I.V. to oral antibiotics by day 7, median day of transition, sources of infection, and oral antibiotic selection were assessed. The study was published in JAMA Network Open on January 2, 2024.
Results of the analysis showed that 43.0% of patients were transitioned to oral antibiotics by day 7, with day 5 as the median day of oral transition, most commonly with fluoroquinolones (62.2%). Although patients maintained on I.V. therapy were more likely than those transitioned to oral therapy to be immunosuppressed, require ICU admission, have a fever or hypotension as of day 5, or require kidney replacement therapy, 89.7% of patients were clinically stable within 5 days. Total duration of antibiotic treatment was significantly shorter among patients transitioned to oral antibiotics than those who remained on I.V. antibiotics. The authors suggested that because most patients were clinically stable by day 5, opportunities exist for earlier and more frequent transitions, eliminating the risks of prolonged I.V. treatment and maintaining effective antibiotic stewardship. ■
Oral lipid nanocrystal formulation of amphotericin holds promise for treatment of cryptococcal meningitis
It’s estimated that opportunistic infections such as cryptococcal disease cause close to 20% of AIDS-related deaths globally. According to WHO, the standard induction antifungal therapy for cryptococcal meningitis is I.V. amphotericin B plus flucytosine for 1 to 2 weeks or a one-time dose of 10 mg/kg liposomal amphotericin. This treatment, however, is associated with severe adverse effects, including kidney impairment, anemia, thrombophlebitis, and electrolyte abnormalities. Administration of I.V. amphotericin is also challenging, requiring hospitalization and intensive laboratory monitoring.
To protect against amphotericin B toxicity, researchers at The University of Minnesota, Makerere University (Uganda), Mbarara University of Science and Technology (Uganda), and Matinas Biopharma (Bedminster, NJ), tested the efficacy of an oral lipid nanocrystal (LNC) containing amphotericin B versus I.V. amphotericin B to treat cryptococcal meningitis.
The researchers randomized 80 participants with HIV from three hospitals in Uganda to receive oral LNC either with or without two loading I.V. doses of amphotericin. An additional 41 patients received I.V. amphotericin with flucytosine as a control. The primary end point was cerebrospinal fluid early fungicidal activity (EFA).
Results of the study, published in the December 15, 2023, issue of Clinical Infectious Diseases showed similar EFA among the three cohorts with the oral LNC groups achieving 2-week cerebrospinal fluid sterility in 63% of patients versus 68% in the control group. Severe adverse events occurred in 41% of the patients who received LNC amphotericin compared with 61% of patients in the I.V. amphotericin group. The authors suggest that the new oral LNC formulation appears promising, with similar efficacy and less toxicity than I.V. amphotericin. ■
