A retrospective analysis of healthcare resource utilization (HCRU) and disease-related complications among risdiplam-treated patients with SMA

Topic:

Clinical Management

Poster Number: 43

Author(s):

Perry Shieh, MD, PhD, Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA, Denise Boudreau, PhD, Genentech, Inc, South San Francisco, CA, USA, Yutong Liu, MS, Genesis Research, Hoboken, NJ, USA, Travis Dickendesher, PhD, Genentech, Sheila Shapouri, PharmD, MS, Genentech, Inc., Elmor Pineda, PharmD, RPh, MS, Genentech, Inc, South San Francisco, CA, USA

Background
Risdiplam is an orally administered, pre-mRNA splicing modifier that is FDA approved for the treatment of pediatric and adult patients with spinal muscular atrophy (SMA). Prior claims analyses found substantial HCRU and disease-related complications for patients with SMA prior to approval of disease-modifying therapies (DMTs); however, limited data exists for patients treated with DMTs.

Objective
To examine characteristics, HCRU and SMA-related complications among risdiplam-treated patients.

Methods
Patients with ≥1 inpatient or ≥2 outpatient diagnosis codes for SMA, ≥1 claim for risdiplam from Aug 1, 2020 to Dec 31, 2021 and continuous enrollment ≥12 months prior to and ≥30 days post index (date of first risdiplam claim) were identified from the PharMetrics Plus database. Descriptive analyses were performed for HCRU and SMA-related complications in the pre and post index periods and reported as per-patient-per-year.

Results
Sixty-three individuals were identified, with a mean (SD) follow-up period of 9.9 (4.4) months and a mean age at first risdiplam use of 20.0 (14.2) years. Seventy percent of patients were previously treated with nusinersen, another DMT for SMA. Reductions in disease-related complications were observed overall, including in acute (–8%) and chronic (–3%) respiratory failure, pneumonia/dyspnea (–19%), orthopedics (–11%) and voice and speech impediment/disorders (–11%); notably, similar reductions were observed in patients previously treated with nusinersen: –5%, –11%, –25%, –11% and –14%, respectively. Overall, the majority of patients (86%) had no hospitalizations pre or post index. Among those hospitalized, the mean number of hospitalizations increased from 1.44 (0.73) pre index to 1.99 (0.91) post index, while the mean length of stay (LOS) and number of inpatient services decreased from 16.2 (14) days to 7.8 (13.3) days and 9.3 (6.5) to 6.3 (6.9), respectively. Additionally, the mean number of outpatient visits decreased from 84.1 (88.9) pre index to 76.8 (88) post index.

Conclusions
Reductions in inpatient service use, LOS, outpatient visits and SMA-related complications were observed in patients treated with risdiplam, including those previously treated with nusinersen. Future analyses are needed to assess risdiplam’s impact on healthcare costs and other SMA-relevant outcomes, and a comparative analysis among patients on other SMA treatments and untreated patients.