New RSV drug tested in kids – but trial halted early

NCT ID NCT06102174

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This study tested the safety and dosing of sisunatovir, an experimental antiviral drug, in infants and children up to 5 years old with RSV lower respiratory tract infection. Ten participants received either the drug or a placebo. The goal was to find the right dose for future studies. However, the trial was terminated early, so the full results may not be available.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance

Sisunatovir (also known as PF-07923568, RV521)

What this could lead to

If successful, this study could help determine the right dose of sisunatovir for future trials in children with RSV, potentially leading to a treatment for severe RSV infections.

What could go wrong

This is a very early (phase 1b) and small study (only 10 participants) focused on safety and dosing, not on proving the drug works. The trial was terminated, so results may be limited.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Conditions

The condition(s) this trial relates to.

respiratory syncytial virus infectious disease

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Kaiser Permanente

    Los Angeles, California, 90027, United States

  • Kaiser Permanente Los Angeles Medical center

    Los Angeles, California, 90027, United States

  • Kojunkai Daido Hospital

    Nagoya, Aichi-ken, 457-8511, Japan

  • Monti Clinical Research Centre

    Mdantsane, Eastern Cape, 5219, South Africa

  • Nintenkai Kagoshima Children's Hospital

    Hioki, Kagoshima-ken, 899-2503, Japan

  • Osaka City General Hospital

    Osaka, 534-0021, Japan

  • University of Witwatersrand (WITS) - Vaccines and Infectious Diseases Analytics (VIDA)

    Johannesburg, Gauteng, 2013, South Africa

  • Washington University School of Medicine

    St Louis, Missouri, 63110, United States

  • Yamanashi Prefectural Central Hospital

    Kofu, Yamanashi, 400-8506, Japan