Real-world Outcomes of Nusinersen or Onasemnogene Abeparvovec (OA) Monotherapy, or Switching to OA from Nusinersen in SMA Patients Aged ≥6 Months


Clinical Management

Poster Number: 35


Omar Dabbous, MD, MPH, Novartis Gene Therapies, Inc., Min Yang, PhD, Analysis Group, Inc., Mihaela Georgieva, PhD, Analysis Group, Inc., Walter Toro Jimenez, Novartis Gene Therapies, Nicole LaMarca, DNP, MSN, CPNP, Novartis Gene Therapies, Inc., Anish Patel, Novartis Gene Therapies, Annika Anderson, MPH, Analysis Group, Inc., Hana Akbarnejad, Analysis Group, Inc., Sandra Reyna Merida, M.D., Novartis Gene Therapies

Background: Disease-modifying treatments including nusinersen and OA have substantially improved SMA prognoses, but real-world data on treatment outcomes and health care resource utilization (HCRU) are limited.
Objective: We sought to describe real-world clinical outcomes and HCRU in US patients with SMA aged ≥6 months when treated with nusinersen monotherapy, OA monotherapy, or switched to OA from nusinersen.
Methods: We conducted a retrospective chart review with outcomes summarized descriptively for patients at or before the index date (date of monotherapy initiation or switch to OA) who had medical information available for ≥1 follow-up visit. HCRU was summarized per patient-year (PPY).
Results: This analysis included 55 patients (19 nusinersen monotherapy; 21 OA monotherapy; 15 switching to OA from nusinersen). SMA phenotypes were type 1 (8/19; 4/21; 12/15), type 2 (8/19; 9/21; 1/15), type 3 (3/19; 5/21; 0/15), and undetermined (0/19; 3/21; 2/15), respectively. Improvement/maintenance of motor milestones from index was achieved by 8/19, 12/19, and 7/14 patients, respectively. Mean time-to-improvement (±SE) was 5.8 (1.4), 2.0 (0.4), and 4.7 (1.0) months, respectively. For patients treated with nusinersen monotherapy, OA monotherapy, or switching to OA from nusinersen, 12/19, 20/21, and 8/14 achieved/maintained normal cry function; 12/14, 18/18, and 9/11 improved/maintained speech function; and 10/17, 18/19, and 7/14 improved/maintained any eating function (e.g., thin liquids by mouth, some food consistency by mouth), respectively. Inpatient admission rates at baseline vs. follow-up were 1.06 vs. 0.65, 0.34 vs. 0.00, and 1.69 vs. 0.74; emergency room visits were 1.09 vs. 0.54, 0.26 vs. 0.34, and 1.25 vs. 0.50 PPY, respectively.
Conclusions: Patients with SMA improved/maintained function across multiple outcomes after receiving OA at ≥6 months of age, regardless of prior nusinersen therapy. Time-to-improvement was shortest for patients who received OA monotherapy. Patients also experienced reductions in the rate of inpatient admissions, with no admissions after OA monotherapy.