Understanding how nusinersen is processed in the body using a new delivery system for spinal muscular atrophy

An Open Label, Single Cohort Study to Assess the Pharmacokinetic Profile of Nusinersen (BIIB058) Administered Via the ThecaFlex DRx™ System (PIERRE-PK)

Phase 1 Interventional Biogen · NCT06555419

This study is testing a new way to deliver the medication nusinersen for spinal muscular atrophy to see how it works in the body compared to the usual method.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment58 (estimated)
Ages3 Years and up
SexAll
SponsorBiogen Industry-sponsored
Drugs / interventionsapitegromab
Locations19 sites (Orange, California and 18 other locations)
Trial IDNCT06555419 on ClinicalTrials.gov

What this trial studies

This study investigates the pharmacokinetics of nusinersen when administered through the ThecaFlex DRx™ System compared to the traditional lumbar puncture method in patients with spinal muscular atrophy (SMA). The ThecaFlex DRx system is an investigational device designed to deliver medication directly to the spinal canal. Researchers aim to determine the peak concentration of nusinersen in the blood and its distribution over the first 24 hours post-administration. Participants must be enrolled in a related study to qualify for this investigation.

Who should consider this trial

Good fit: Ideal candidates are individuals with spinal muscular atrophy who are already receiving regular nusinersen treatment.

Not a fit: Patients who are naïve to nusinersen treatment or those who have already undergone implantation of the ThecaFlex DRx system will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to a more effective and less invasive method of delivering nusinersen for patients with spinal muscular atrophy.

How similar studies have performed: While the use of nusinersen is established, the specific delivery method via the ThecaFlex DRx system is novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Key Inclusion Criteria:

* Participant is on regular maintenance dosing of nusinersen (12 milligrams \[mg\] dose) every 4 months, with 4 months (± 2 weeks) between the LP-delivered study dose and the last nusinersen dose prior to study enrollment.
* Participants must be enrolled in the PIERRE study to be eligible for enrolment in the PIERRE PK study.

Key Exclusion Criteria:

* Ongoing participation or participation within 6 months or 5 half-lives of the agent (whichever is longer) of enrollment in other interventional clinical trials for the treatment of SMA (except for the PIERRE study or interventional clinical trials of myostatin inhibitors \[e.g., apitegromab and taldefgrobep alfa\]).
* Participant is naïve to nusinersen treatment.
* Participant is receiving nusinersen at a dose other than 12 mg.
* Participant has already undergone implantation of the ThecaFlex DRx system.
* Participant is pregnant, currently breastfeeding, or intending to become pregnant during the study.

NOTE: Other protocol-defined Inclusion/Exclusion criteria may apply

Where this trial is running

Orange, California and 18 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Muscular Atrophy, Spinal
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.