infants at highest risk of RSV

Very Preterm Infants and RSV

SYNAGIS® reduces RSV hospitalization severity among very preterm infants1


INFANTS LESS THAN 29 wGA ARE AT THE HIGHEST RISK FOR SEVERE RSV DISEASE AND HOSPITALIZATION2-4

infants at highest risk for RSV

IN A REAL-WORLD STUDY

Preterm infants Icon

SYNAGIS reduced RSVH severity among very preterm infants in the outpatient setting1

RSVH severity among very preterm infants (<29 wGA) 
by SYNAGIS use and payer1

Reduced RSVH Severity in Very Preterm Infants Graph
Reduced RSVH Severity in Very Preterm Infants Graph

RSVH severity was measured by

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RSVH-related length of hospital stay 

Chart Icon

Rates of ICU 
admission

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ICU length 
of stay

Supplemental Oxygen Icon

Rates of mechanical 
ventilation

 

*P<0.001 vs infants who received SYNAGIS;

P=0.667; P=0.008; §P=0.200; IIP=0.019; P=0.002;

#P=0.191; **P=0.007.

 

Review the additional pivotal IMpact-RSV trial data, which established the efficacy and safety of SYNAGIS in preterm infants with and without BPD.5,6

Real-world Study Design

RSVH and RSVH characteristics were compared in very preterm (<29 wGA) and term (>37 wGA) infants.1

Using the MarketScan Commercial and Multi-State Medicaid administrative claims databases, infants born between July 1, 2003, and June 30, 2020, were identified and classified as very preterm (N=40,123) or term (N=4,421,942). Infants with evidence of health conditions such as congenital heart disease and cystic fibrosis were excluded. During the 2003 through 2020 RSV seasons (November to March), claims incurred by infants while they were <12 months old were evaluated for outpatient administration of SYNAGIS and RSVH.1 

Primary objective: To characterize outpatient SYNAGIS prophylaxis and risk of RSVH among very preterm infants and to compare the course of RSVH among these infants.

Study limitations: This study used retrospectively collected administrative claims data, which could contain coding errors and omission of unbilled/over-the-counter services. Data on inpatient administration of SYNAGIS was not available in the database; only outpatient administrations were measured. Some infants in the subgroup without outpatient SYNAGIS use may have received SYNAGIS during the birth hospitalization or a subsequent hospitalization, possibly resulting in misclassification error. RSVH may have occurred in some infants prior to SYNAGIS administration. In addition, infants with a single outpatient dose of SYNAGIS were included, although the recommended dosing interval is monthly. The study was restricted to commercially insured and Medicaid-insured infants.1

 

Interrupted lung development compromises lung capacity in preterm infants2

The small airways of very preterm infants are easily obstructed by the infectious process associated with RSV disease.2-4

Use this tool to compare estimates of lung capacity by gestational age.

Interrupted lung development icon
  • 34% of lung volume
    versus full-term infants
    (60 mL vs 180 mL)
  • 26% of the lung surface area
    versus full-term infants
    (1.19 m2 vs 4.55 m2)
  • 66% thicker air-space walls
    versus full-term infants
    (20.1 μm vs 12.1 μm)

Preterm versus Full Term Lungs
  • 42% of lung volume
    versus full-term infants
    (75 mL vs 180 mL)
  • 34% of the lung surface area
    versus full-term infants
    (1.55 m2 vs 4.55 m2)
Preterm versus Full Term Lungs2
  • 52% lung volume
    versus full-term infants
    (93 mL vs 180 mL)
  • 45% of the lung surface area
    versus full-term infants
    (2.03 m2 vs 4.55 m2)
Preterm versus Full Term Lungs 3

Study Design

Normal lungs were obtained from 42 infants (29 liveborn and 13 stillborn) younger than 1 month of age coming to autopsy at Winnipeg Children's Hospital, Winnipeg, Manitoba, over a period of 3 years. Infant age (expressed as gestational age plus postnatal age) ranged from 19 weeks gestation to 3 weeks postnatal age. The lung structures studied were air spaces (saccules or alveolar ducts and alveoli); air-space wall (alveolar and/or saccular); conducting air (lumen of bronchi and bronchioles); and nonparenchyma (all other structures).2

Low serum antibody (IgG) levels place very preterm infants at high risk for severe infection and mortality3

The lower the gestational age, the lower the serum antibody (IgG) levels.3†† Lower serum antibody levels among very preterm infants, especially in the first 6 months of life, may explain their high susceptibility to infection.4

Low serum maternal antibody icon
 

Infants born at 28-31 wGA have

less than 1/3

the serum antibody levels of full-term infants

Very Preterm

(28-31 wGA)

32 percent chart
 

Preterm

(32-35 wGA)

57 percent chart

Full term

(≥37 wGA)

100 percent chart

††Full-term infants in this study had a mean serum antibody level of 954 mg/100 mL; this was the reference level and was considered to be 100%.3

RSV infection results in significant stress on already compromised very preterm infants.3,4

Study Design

Random serum samples of 182 babies of normal weight for gestational age ranging from 24 to 40 weeks were studied. Blood samples were obtained within 24 hours of birth from heel pricks or indwelling umbilical catheter inserted for other purposes. Gestational age was estimated from the date of last menstrual period and later confirmed by neurological and electroencephalographic examination whenever possible.3
 

BPD=bronchopulmonary dysplasia; ICU=intensive care unit; RSV=respiratory syncytial virus; RSVH=respiratory syncytial virus hospitalization; wGA=weeks gestational age. 

REFERENCES: 1. Packnett ER, Winer IH, Larkin H, et al. RSV-related hospitalization and outpatient palivizumab use in very preterm (born at <29 wGA) infants: 2003-2020. Hum Vaccin Immunother. 2022;18(6):2140533. doi:10.1080/21645515.2022.2140533 2. Langston C, Kida K, Reed M, Thurlbeck WM. Human lung growth in late gestation and in the neonate. Am Rev Respir Dis. 1984;129(4):607-613. 3. Yeung CY, Hobbs JR. Serum-gamma-G-globulin level in normal premature, post mature, and “small-for-dates” newborn babies. Lancet. 1968;1(7553):1167-1170. 4. Pickles RJ, DeVincenzo JP. Respiratory syncytial virus (RSV) and its propensity for causing bronchiolitis. J Pathol. 2015;235(2):266-276. 5. SYNAGIS (palivizumab) [prescribing information]. Waltham, MA: Sobi, Inc. 2021. 6. The IMpact-RSV Study Group. Palivizumab, a humanized respiratory syncytial virus monoclonal antibody, reduces hospitalization from respiratory syncytial virus infection in high-risk infants. Pediatrics. 1998;102(3):531-537. 

All imagery is for illustrative purposes only.
 

ALL INFANTS ARE NOT THE SAME

INDICATION

SYNAGIS, 50 mg and 100 mg for injection, is indicated for the prevention of serious lower respiratory tract disease caused by respiratory syncytial virus (RSV) in pediatric patients:

  • with a history of premature birth (≤35 weeks gestational age) and who are 6 months of age or younger at the beginning of RSV season
  • with bronchopulmonary dysplasia (BPD) that required medical treatment within the previous 6 months and who are 24 months of age or younger at the beginning of RSV season
  • with hemodynamically significant congenital heart disease (CHD) and who are 24 months of age or younger at the beginning of RSV season

IMPORTANT SAFETY INFORMATION

Hypersensitivity Reactions: Anaphylaxis and anaphylactic shock (including fatal cases) and other severe acute hypersensitivity reactions have been reported. Permanently discontinue SYNAGIS and administer appropriate medication if such reactions occur.

Coagulation Disorders: SYNAGIS should be given with caution to children with thrombocytopenia or any coagulation disorder.

RSV Diagnostic Test Interference: Palivizumab may interfere with immunological-based RSV diagnostic tests, such as some antigen detection-based assays.

Serious Adverse Reactions: The most common serious adverse reactions occurring with SYNAGIS are anaphylaxis and other acute hypersensitivity reactions.

Most Common Adverse Reactions: The most common adverse reactions are fever and rash.

Postmarketing Experience: Severe thrombocytopenia and injection site reactions have been identified during post approval use of SYNAGIS. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

LIMITATIONS OF USE

The safety and efficacy of SYNAGIS have not been established for treatment of RSV disease.

CONTRAINDICATIONS

Previous significant hypersensitivity reaction to SYNAGIS.

INDICATION

SYNAGIS, 50 mg and 100 mg for injection, is indicated for the prevention of serious lower respiratory tract disease caused by respiratory syncytial virus (RSV) in pediatric patients:

  • with a history of premature birth (≤35 weeks gestational age) and who are 6 months of age or younger at the beginning of RSV season
  • with bronchopulmonary dysplasia (BPD) that required medical treatment within the previous 6 months and who are 24 months of age or younger at the beginning of RSV season
  • with hemodynamically significant congenital heart disease (CHD) and who are 24 months of age or younger at the beginning of RSV season

 

These are not all the possible risks associated with SYNAGIS. Please see full Prescribing Information for SYNAGIS, including Patient Information. To report suspected adverse reactions, contact Sobi North America at 1-866-773-5274 or the FDA at 1-800-FDA-1088.

For Colorado prescribers, visit synagishcp.com/wac-pricing.