First patient treated in Biogen’s global RESPOND study of nusinersen, following treatment with Zolgensma™

11 January 2021

In response to a request made through our membership of SMA Europe, Biogen shared an update on the RESPOND trial with us.

The RESPOND trial is a Phase 4 open-label, multicentre study designed to evaluate the efficacy and safety of nusinersen in patients that have already shown a suboptimal clinical response to the SMN gene therapy, onasemnogene abeparvovec (Zolgensma).

It was announced today that the first patient has been treated. The study will examine the clinical benefit and safety of nusinersen treatment in infants and children with SMA who have unmet clinical needs following previous treatment with Zolgensma. The trial seeks to understand if the increased and continuous production of SMN protein by nusinersen provides any additional clinical benefit to these patients.1, 2, 3, 4

RESPOND Trial Overview

The study is projected to enrol 60 participants up to age 3, who are determined by the investigator to have the potential for additional clinical improvement.

The study groups:

  1. The primary study group aims to include 40 infants aged 9 months or younger (at the time of first nusinersen dose), who have two copies of SMN2 (thus likely to develop SMA Type 1) and received SMN gene therapy (Zolgensma) at 6 months old or younger.
  2. The second study group will include 20 children and will generate data in patients with a broader age range (up to age 3 at the time of the first nusinersen dose). After a screening period, participants will receive the approved 12 mg dose of nusinersen administered intrathecally by lumbar puncture on Days 1, 15, 29, and 64 (loading doses), followed by a maintenance period during which the participants will receive 12 mg nusinersen intrathecally every 4 months for two years.5

RESPOND is a phase 4, open-label study, so both the patient’s caregiver and their physician are aware that they are being treated with nusinersen. The study will be conducted at approximately 20 sites worldwide.

Working in partnership

The SMA Community has been instrumental in shaping the design of this study to ensure that the clinical outcome measures being used are those that matter most to patients. Biogen are grateful to all the families, caregivers and investigators who continue to help them improve care for families affected by SMA.


  1. Zolgensma EU Summary of Product Characteristics (SmPC). Available here. Accessed on Oct. 12, 2020.
  2. Finkel R, et al. Presented at the Muscular Dystrophy Association’s (MDA) 2020 Clinical & Scientific Conference.
  3. Harada Y, et al. Presented at the Muscular Dystrophy Association’s (MDA) 2020 Clinical & Scientific Conference.
  4. Finkel R, et al. Presented at the World Muscle Society (WMS) 2020 Virtual Congress.
  5. Spinraza U.S. Prescribing information available, here.

Further information

The community update
About Spinraza and how it works
About Zolgensma and how it works
About the RESPOND trial