key: cord-1048944-4gn25zci
authors: Hammitt, Laura; Hammitt, Laura; Dagan, Ron; Yuan, Yuan; Cots, Manuel Baca; Bosheva, Miroslava; Mahdi, Shabhir A; Muller, William J; Muller, William J; Zar, Heather J; Brooks, Dennis; Grenham, Amy; Hamrén, Ulrika Wählby; Mankad, Vaishali S; Ren, Pin; Takas, Therese; Heinrichs, Jon; Leach, Amanda; Griffin, M Pamela; Villafana, Tonya L
title: LB13. The Efficacy and Impact in Heathy Infants of Nirsevimab on Medically Attended RSV Lower Respiratory Tract Infection
date: 2021-12-04
journal: Open Forum Infect Dis
DOI: 10.1093/ofid/ofab466.1649
sha: 84ec610eab1a491a3873e36a2444ccb6fa4f9a76
doc_id: 1048944
cord_uid: 4gn25zci

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection (LRTI) in infants. Nirsevimab is a single-dose monoclonal antibody with extended half-life that was shown to protect preterm infants 29 to < 35 weeks gestation against RSV LRTI. However, most medically attended (MA) cases occur in otherwise healthy, term infants for whom there is currently no effective RSV prevention strategy. We report the primary analysis of efficacy and safety, along with the impact of nirsevimab in late preterm and term infants (≥ 35 weeks gestation) in the phase 3 MELODY study (NCT03979313). METHODS: Infants were randomized 2:1 to receive one intramuscular injection of nirsevimab (50 mg if < 5 kg; 100 mg if ≥ 5 kg at dosing) or placebo entering their first RSV season. The primary endpoint was the incidence of MA RSV LRTI over 150 days postdose. Cases met predefined clinical criteria of disease severity and were confirmed by real-time reverse-transcriptase PCR. Safety was evaluated through 360 days postdose. Enrollment started on 23 July 2019 and was suspended following the declaration of the COVID-19 pandemic by the WHO on 11 March 2020. RESULTS: Overall, 1490 infants were randomized and included in the intent-to-treat population; 1465 (98%) completed the 150-day efficacy follow-up, and 1367 (92%) completed the 360-day safety follow-up. The incidence of MA RSV LRTI was 1.2% (n=12/994) in the nirsevimab group and 5.0% (n=25/496) in the placebo group, giving nirsevimab an efficacy of 74.5% (95% confidence interval [CI]: 49.6, 87.1; p< 0.0001). Nirsevimab averted 93.6 (95% CI 63.0, 124.0) MA LRTIs per 1000 infants dosed. Nirsevimab was well tolerated, with similar rates of adverse events (87.4% nirsevimab; 86.8% placebo) and serious adverse events (6.8% nirsevimab; 7.3% placebo) between groups. CONCLUSION: In this phase 3 study, a single dose of nirsevimab protected late preterm and term infants against MA RSV LRTI over an RSV season with a favorable safety profile. Approximately 11 infants need to be immunized to prevent 1 case of LRTI; nirsevimab has the potential to be an important intervention to reduce the burden of RSV LRTI in healthy infants. DISCLOSURES: Laura Hammitt, MD, MedImmune (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support)Merck & Co., Inc. (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support)Novavax (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support)Pfizer (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support) Laura Hammitt, MD, MedImmune (Individual(s) Involved: Self): Grant/Research Support, Research grant to my institution; Merck (Individual(s) Involved: Self): Grant/Research Support, Research grant to my institution; Pfizer (Individual(s) Involved: Self): Grant/Research Support, Research grant to my institution Ron Dagan, MD, Medimmune/AstraZeneca (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support)MSD (Consultant, Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Research Grant or Support, Speaker’s Bureau)Pfizer (Consultant, Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Research Grant or Support, Speaker’s Bureau) Yuan Yuan, PhD, AstraZeneca (Employee, Shareholder) Shabhir A. Mahdi, PhD, BMGF (Research Grant or Support)EDCTP (Research Grant or Support)GlaxoSmithKline (Research Grant or Support)Melody (Research Grant or Support)Minervax (Research Grant or Support)Novavax (Research Grant or Support)SAMRC (Research Grant or Support) William J. Muller, MD, PhD, Ansun (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)AstraZeneca (Scientific Research Study Investigator)Genentech (Scientific Research Study Investigator)Gilead (Scientific Research Study Investigator)Janssen (Scientific Research Study Investigator)Karius (Scientific Research Study Investigator)Melinta (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)Nabriva (Scientific Research Study Investigator)Seqirus (Scientific Research Study Investigator)Tetraphase (Scientific Research Study Investigator) William J. Muller, MD, PhD, Ansun (Individual(s) Involved: Self): Grant/Research Support; Astellas (Individual(s) Involved: Self): Research Grant or Support; AstraZeneca (Individual(s) Involved: Self): Grant/Research Support; BD (Individual(s) Involved: Self): Research Grant or Support; Eli Lilly (Individual(s) Involved: Self): Grant/Research Support; Gilead (Individual(s) Involved: Self): Grant/Research Support; Karius, Inc. (Individual(s) Involved: Self): Grant/Research Support, Scientific Research Study Investigator; Melinta (Individual(s) Involved: Self): Grant/Research Support; Merck (Individual(s) Involved: Self): Grant/Research Support; Moderna (Individual(s) Involved: Self): Grant/Research Support; Nabriva (Individual(s) Involved: Self): Grant/Research Support; Seqirus (Individual(s) Involved: Self): Consultant; Tetraphase (Individual(s) Involved: Self): Grant/Research Support Heather J. Zar, PhD, AstraZeneca (Grant/Research Support)Novavax (Grant/Research Support)Pfizer (Grant/Research Support, Advisor or Review Panel member) Dennis Brooks, MD, AstraZeneca (Employee) Amy Grenham, MSc, AstraZeneca (Employee, Shareholder) Ulrika Wählby Hamrén, PhD, AstraZeneca R&D (Employee, Shareholder) Vaishali S. Mankad, MD, AstraZeneca (Employee) Therese Takas, BSc, AstraZeneca (Employee, Other Financial or Material Support, Own stock in AstraZeneca) Jon Heinrichs, PhD, AstraZeneca (Shareholder)Bristol Myers Squibb (Shareholder)J&J (Shareholder)Merck (Shareholder)Organon (Shareholder)Procter & Gamble (Shareholder)Sanofi (Shareholder)Sanofi Pasteur (Employee) Amanda Leach, MRCPCH, AstraZeneca (Employee, Shareholder) M. Pamela Griffin, MD, AstraZeneca (Employee) Tonya L. Villafana, PhD, AstraZeneca (Employee)

Conclusion. The majority of EXB and PBO patients had symptom resolution. However, EXE patients achieved symptom resolution in 3 days compared with 6 days for PBO patients overall, and 7 days for PBO patients with MRSA. These data suggest that rapid bacteriolysis may translate to a clinical benefit for patients receiving EXB and aligns with a median length of hospital stay of 6 and 10 days among US MRSA patients that received EXE and PBO patients, respectively. (Fowler, et al, 2020 

Nirsevimab is a single-dose monoclonal antibody with extended half-life that was shown to protect preterm infants 29 to < 35 weeks gestation against RSV LRTI. However, most medically attended (MA) cases occur in otherwise healthy, term infants for whom there is currently no effective RSV prevention strategy. We report the primary analysis of efficacy and safety, along with the impact of nirsevimab in late preterm and term infants (≥ 35 weeks gestation) in the phase 3 MELODY study (NCT03979313).

Methods. Infants were randomized 2:1 to receive one intramuscular injection of nirsevimab (50 mg if < 5 kg; 100 mg if ≥ 5 kg at dosing) or placebo entering their first RSV season. The primary endpoint was the incidence of MA RSV LRTI over 150 days postdose. Cases met predefined clinical criteria of disease severity and were confirmed by real-time reverse-transcriptase PCR. Safety was evaluated through 360 days postdose. Enrollment started on 23 July 2019 and was suspended following the declaration of the COVID-19 pandemic by the WHO on 11 March 2020.

Results. Overall, 1490 infants were randomized and included in the intent-totreat population; 1465 (98%) completed the 150-day efficacy follow-up, and 1367 (92%) completed the 360-day safety follow-up. The incidence of MA RSV LRTI was 1.2% (n=12/994) in the nirsevimab group and 5.0% (n=25/496) in the placebo group, giving nirsevimab an efficacy of 74.5% (95% confidence interval [CI]: 49.6, 87.1; p< 0.0001). Nirsevimab averted 93.6 (95% CI 63.0, 124.0) MA LRTIs per 1000 infants dosed. Nirsevimab was well tolerated, with similar rates of adverse events (87.4% nirsevimab; 86.8% placebo) and serious adverse events (6.8% nirsevimab; 7.3% placebo) between groups.

Conclusion. In this phase 3 study, a single dose of nirsevimab protected late preterm and term infants against MA RSV LRTI over an RSV season with a favorable safety profile. Approximately 11 infants need to be immunized to prevent 1 case of LRTI; nirsevimab has the potential to be an important intervention to reduce the burden of RSV LRTI in healthy infants.

Disclosures 

Advisor or Review Panel member) Dennis Brooks, MD, AstraZeneca (Employee) Amy Grenham, MSc, AstraZeneca (Employee, Shareholder) Ulrika Wählby Hamrén, PhD, AstraZeneca R&D (Employee, Shareholder) Vaishali S

Other Financial or Material Support

Efficacy and Immunogenicity of an Ad26.RSV.preF-based Vaccine in the Prevention of RT-PCR-confirmed RSV-mediated Lower Respiratory Tract Disease in Adults Aged ≥65 Years: A Randomized, Placebo-controlled

PhD 2

SER-109, an Investigational Microbiome Therapeutic, Reduces Abundance of Antimicrobial Resistance Genes in Patients with Recurrent Clostridioides difficile Infection (rCDI) after Standard-of-Care

MD 4 ; Charles Berenson

Session: 132. Late Breaker Abstracts Saturday

CYPRESS Session: 132. Late Breaker Abstracts Saturday, October 2, 2021: 1:15 PM Background. Respiratory syncytial virus (RSV) can cause serious lower respiratory tract disease (LRTD) in older adults. Despite a high burden of disease, there is currently no licensed vaccine for RSV. Here, we report the primary efficacy and immunogenicity results from a Phase 2b proof-of-concept trial of an Ad26.RSV.preFbased vaccine for the prevention of RSV-mediated LRTD in adults aged ≥65 years.Methods. CYPRESS (NCT03982199) is a randomized, double-blind, placebo-controlled Phase 2b trial. Adults ≥65 years of age were randomized 1:1 prior to the RSV season to receive an Ad26.RSV.preF-based vaccine or placebo. Symptoms of acute respiratory infection (ARI) were collected through an RSV-specific patient-reported Respiratory Infection Intensity and Impact Questionnaire (RiiQ) and/or by a clinician assessment until the end of the RSV season. The primary endpoint was the first occurrence of RT-PCR-confirmed RSV-mediated LRTD according to any of 3 case definitions: (1) ≥3 symptoms of lower respiratory tract infection (LRTI), (2) ≥2 symptoms of LRTI, or (3) ≥2 symptoms of LRTI or ≥1 symptom of LRTI with ≥1 systemic symptom. The secondary endpoint was the first occurrence of any RT-PCR-confirmed RSV-mediated ARI. Immunogenicity assessments were performed in a subset of approximately 200 participants.Results. A total of 5782 participants (2891 in each study arm) received study treatment (92.5% white, 57.7% female, median age 71 years). Vaccine efficacy was 80% (94.2% CI, 52.2-92.9%), 75% (50.1-88.5%), and 69.8% (43.7-84.7%) for case definition 1, 2, and 3, respectively (all P values < 0.001). Efficacy for any RSV-mediated ARI was 69.8% (95% CI, 42.7-85.1%). In the vaccine arm of the immunogenicity subset, geometric mean fold increase in antibody titers 14 days after vaccination was 13.5 for RSV neutralizing antibodies and 8.6 for RSV prefusion F-specific binding antibodies. Median frequency of RSV-F-specific INFγ T-cells increased from 34 to 444 SFC/10 6 PBMC 14 days after vaccination in the vaccine arm; no relevant changes were observed in the placebo arm.Conclusion. In CYPRESS, the Ad26.RSV.preF-based vaccine was highly effective against RSV-mediated LRTD through the first RSV season and elicited robust humoral and cellular immune responses in adults aged ≥65 years.

The gastrointestinal microbiota is the first line of defense against colonization with antimicrobial resistant (AR) bacteria, particularly in vulnerable hosts with frequent antibiotic exposure. In a double-blind Phase 3 trial of rCDI patients, SER-109, an orally formulated consortia of purified Firmicutes spores, was superior to placebo in reducing CDI recurrence at week 8 post clinical resolution on standard-of-care (SoC) antibiotics. Overall recurrence rates were lower in SER-109 vs placebo (12.4% vs 39.8%, respectively) relative risk, 0.32 [95% CI, 0.18-0.58; p< 0.001 for RR< 1.0; p< 0.001 for RR< 0.833]. This is a post-hoc analysis examining the impact of SER-109 on antimicrobial resistance genes (ARGs) abundance in the intestinal microbiota compared to placebo.Methods. Subjects with rCDI received SoC antibiotics, then were randomized 1:1 to SER-109 or placebo at baseline. Of 182 subjects, 140 who had paired stool samples at baseline and 1-week post-treatment were included in this analysis. ARG abundances and taxonomic profiles were generated from whole metagenomic shotgun sequencing. t-tests were used to compare changes in ARG abundance from baseline; mixed linear models were used to associate ARG and taxon abundances across time points.Results. ARG abundance was reduced overall by week 1, with a significantly greater decrease in SER-109 subjects vs. placebo at week 1 (Fig. 1) . Proteobacteria relative abundance were positively correlated with ARG abundance across all samples (Fig.  2) , with the Enterobacteriaceae family associated with the abundance of 95 ARGs (all p < 0.05). Enterococcaceae relative abundance was associated with glycopeptide AR abundance (p < 0.001). At week 1, Proteobacteria relative abundance was significantly decreased from baseline in SER-109 subjects vs. placebo (p < 0.001). Enterobacteriaceae and Enterococcaceae relative abundances were also decreased from baseline in SER-109 subjects vs. placebo (p < 0.001 and p = 0.007, respectively).