FOR IMMEDIATE RELEASE
New research shows that Rytvela, an anti-inflammatory drug candidate, decreased premature birth and infant mortality when administered after the onset of preterm labor in a preclinical mouse model. The current standard treatment for preterm labor, Nifedipine, failed to confer similar benefits.
“Addressing an unmet medical need, Rytvela represents a promising treatment approach to safely prolong pregnancy and fetal growth while allowing newborn organs to develop in utero,” said Dr. Sylvain Chemtob, neonatologist, Centre Hospitalier Ste Justine, Montreal, Quebec, and senior author of the study.
“It’s rare for an innovation to combine so much scientific, clinical, and human potential. The development of new drugs to stop preterm labor is a decisive step for the health of newborns and their families around the world,” Dr. Chemtob continued.
The preclinical data, published in The Journal of Immunology , compared Rytvela, a new drug candidate, to Nifedipine, the most common drug for preterm labor in North America. Rytvela decreased rates of preterm birth by 40%, which prolonged gestation and fetal development. Neonatal complications are highly associated with preterm birth, largely due to the underdevelopment of fetal organs. Rytvela prevented inflammation-induced neonatal tissue injury and promoted neonatal development, even when administered after exposure to inflammation.
Inflammation in the uterus and placenta is a major contributor to preterm labor, as it often sets off a series of inflammatory signals that induce labor. Rytvela targets the actions of a pro-inflammatory signal, called IL-1ß, to decrease inflammation. Unlike existing IL-1ß-targeting drugs, Rytvela avoids immune suppression, leaving the immune system intact to protect the mother and fetus.
“Our intention in developing Rytvela for clinical use was to allow greater maturation of the fetus before birth while suppressing damaging inflammation, which currently available drugs do not do. Rytvela represents a promising treatment approach to safely prolong gestation and offspring maturation, thereby protecting the fetus/newborn against detrimental inflammation-triggered preterm birth,” said Dr. Tiffany Habelrih, lead author of the study.
Currently available treatments for women in preterm labor are drugs that try to stop or slow contractions. However, these drugs usually delay labor for less than 48 hours, which does not prevent preterm birth or allow the fetus more time to develop.
Preterm birth affects 13.5 million births every year and is responsible for over 900,00 deaths annually. Surviving infants may experience short- and long-term complications due to organs and systems not being fully developed at birth and exposure to dangerous inflammation. Given the promising preclinical data, Rytvela has the potential to address many of these complications. The researchers are finalizing their preclinical research and preparing to proceed to clinical trials in people.
The research article is available in The Journal of Immunology or you can read more on AAI News & Views site.
Requests for interviews with authors, The Journal of Immunology or the American Association of Immunologists can be made to kpalmer@aai.org .
About The American Association of Immunologists
The American Association of Immunologists (AAI) is one of the world’s largest organizations of immunologists and scientists in related disciplines. Our mission is to improve global health and well-being by advancing immunology and elevating public understanding of the immune system. AAI members are responsible for some of the most significant biomedical discoveries of the past century, including the development of life-saving cancer immunotherapies, antibody therapies, transplant technologies, and vaccines. We support scientists across the field of immunology through knowledge dissemination, community building, advocacy, and public outreach.
About The Journal of Immunology
The Journal of Immunology ( The JI ) publishes peer-reviewed manuscripts describing novel findings in all areas of experimental immunology, including both basic and clinical studies. The JI is owned by the American Association of Immunologists and published in partnership with Oxford University Press.
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Katherine Palmer, MPH
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The Journal of Immunology
Animals
Rytvela, an allosteric modulator of the interleukin-1 receptor, prevents preterm birth and neonatal complications in mice while nifedipine is ineffective
23-Feb-2026