What is the SAPPHIRE study?

The purpose of the SAPPHIRE study is to learn more about the effectiveness and safety of an investigational (or study) drug called apitegromab in people with later-onset spinal muscular atrophy (SMA). SAPPHIRE is investigating apitegromab (SRK-015) to find out how well it works compared to placebo. Placebo is a substance that looks like the study drug but has no active drug in it.

At this time, there are approved treatments available to help treat SMA, but no treatments exist that specifically help treat the muscle atrophy in SMA. Muscle atrophy is a condition in which muscles are smaller and weaker than those of their peers. Doctors are looking to learn more about apitegromab and SMA through this clinical research study.

Who can participate in the SAPPHIRE study?

The SAPPHIRE study is for people who:

  • are 2 to 21 years of age.
  • have later-onset* spinal muscular atrophy (SMA).
  • are currently taking either Spinraza® (nusinersen) or Evrsydi® (risdiplam).

    *Later-onset SMA means you or your child has either Type 2 SMA (typically diagnosed before the age of 2) or Type 3 SMA (typically diagnosed after the age of 3).

    Other criteria will apply. Talk to your doctor to see if you or your child are able to participate in this clinical research study.

Participants under the age of 18 will need to get permission (consent) from their parent or guardian to join the study.

How long will the SAPPHIRE study last?

If you or your child qualify and decide to participate in the SAPPHIRE study, participation will last about 18 months and include:

  • screening period of up to 28 days.
  • study drug treatment period of up to 12 months, where participants will be randomly assigned (by chance; like drawing straws) to receive either the study drug, apitegromab, or placebo. Participants will continue to take their usual dose of nusinersen or risdiplam throughout the SAPPHIRE study.
  • follow-up period of approximately 5 months.
What will happen during the SAPPHIRE study?

During the SAPPHIRE study you or your child will be asked to:

  • answer questions about your health.
  • complete activities and tests.
  • have a physical exam and heart tests.
  • give blood and urine samples.
  • take a pregnancy test (if you are female and able to get pregnant.)
  • get the study drug or placebo injection through an IV.
  • continue using nusinersen or risdiplam as prescribed.

You or your child can always ask the SAPPHIRE study doctor or staff any questions about this clinical research study or the study drug at any time.

What are the costs to take part in the SAPPHIRE study?

You or your child will receive no direct payment for taking part in the SAPPHIRE study. However, you will be reimbursed for transportation or parking payments related to visiting the study center. The study drug or placebo will be given at no cost to you or your child, and you will not be charged for any study doctor visits, laboratory work, tests, or procedures needed for the SAPPHIRE study.