Biogen Inc. will present new data from clinical studies aimed at assessing remaining unmet needs for people living with spinal muscular atrophy (SMA) and evaluating the potential impact of SPINRAZA® (nusinersen) in different patient populations at the SMA Research & Clinical Care Meeting hosted by Cure SMA this week in Anaheim, Calif. SMA Research Updates: Growing enrollment in the RESPOND study indicate there are residual unmet clinical needs in infants and toddlers with SMA following treatment with Zolgensma® (onasemnogene abeparvovec). The Phase 4 study is evaluating the clinical benefit and safety of SPINRAZA in infants and toddlers with SMA who have unmet needs following treatment with the gene therapy.

Since initial findings from nine patients were shared in March 2022, baseline and safety data from 16 patients enrolled in RESPOND (as of November 2021) are being presented. All enrolled study participants reported suboptimal clinical status across a variety of measures at baseline, with 13 of 16 showing this in multiple areas, including motor and respiratory functions and swallowing/feeding ability. After beginning SPINRAZA treatment, initial safety findings (median duration of 132.5 days) show three participants experienced a serious adverse event (AE) during the study period; none of these events were considered related to SPINRAZA treatment.

The RESPOND study (NCT04488133) is currently enrolling participants at 20 sites worldwide. Biogen will also share final data from Part A of the ongoing, three-part DEVOTE study evaluating the safety and tolerability of investigational, higher doses of nusinersen. Results from Part A, an open-label safety evaluation period in children and teens with later-onset SMA, suggest that a higher dosing regimen (28 mg) of nusinersen leads to higher levels of the drug in the cerebrospinal fluid and is generally well-tolerated, with most AEs reported considered to be mild in severity.

The most common AEs reported were headache and procedural pain. Two serious AEs (fall, femur fracture) were reported in one participant during the study period. No AEs were considered related to nusinersen and some were related to treatment administration.

The totality of Part A data supports further development of a higher dose of nusinersen. Currently, Part B and Part C of DEVOTE evaluating an investigational, higher dose of nusinersen are enrolling at 52 sites worldwide. Featured SPINRAZA Data Presentations Include: Results From the End of Part A of the Ongoing 3-Part DEVOTE Study to Explore Higher Doses of Nusinersen in SMA- June 17, 2022.

Baseline Characteristics and Initial Safety Results in RESPOND: A Phase 4 Study of Nusinersen in Children With SMA Who Received Onasemnogene Abeparvovec – June 17, 2022. The SPINRAZA clinical development program encompasses 10 clinical studies, which have included more than 300 individuals across a broad spectrum of patient populations,2 including two randomized controlled studies (ENDEAR and CHERISH). The ongoing SHINE and NURTURE open-label extension studies are evaluating the long-term impact of SPINRAZA.

The most common adverse events observed in clinical studies were respiratory infection, fever, constipation, headache, vomiting and back pain. Laboratory tests can monitor for renal toxicity and coagulation abnormalities, including acute severe low platelet counts, which have been observed after administration of some ASOs.