Adrian Kielhorn1, Zheng Wang1, Kristin Moy1, Lisa Christopher-Stine2, Ingrid Lundberg3, Hector Chinoy4, Kaniah Gunter5 and Rohit Aggarwal6, 1Alexion, AstraZeneca Rare Disease, Boston, MA, 2Johns Hopkins University, Baltimore, MD, 3Karolinska Universitetssjukhuset, Karolinska Institutet, Stockholm, Sweden, 4The University of Manchester, Sale, United Kingdom, 5Patient Author, Norfolk, VA, 6Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
Background/Purpose: Dermatomyositis (DM) is a rare, chronic inflammatory disease characterized by skin manifestations and/or progressive muscle weakness and other systemic manifestations. Patients with DM were reported to have higher morbidity, hospitalization rates, and mortality than matched controls; however, more recent data on the disease burden and treatments for DM are warranted. This analysis was done to provide an updated understanding of the characteristics and treatment utilization among patients with myopathic DM in the United States.
Methods: This descriptive, retrospective cohort analysis used TriNetX US electronic medical records data to assess the characteristics and treatment utilization of adults with myopathic DM. Key inclusion criteria were DM diagnosis (ICD-9: 710.3/ICD-10: M33.1x, M33.9x, M36.0) between 1 January 2007 and 1 September 2020; age ≥18 years at index diagnosis; ≥6 months of baseline data before the index diagnosis date; and ≥6 months of follow-up after the index date. Assessments included utilization rates of medications of interest prior to DM index diagnosis; percentage of patients who received ≥2 consecutive unique non-steroidal immunosuppressive therapies within 3, 6, and 12 months of DM index diagnosis; and classification and qualification of most common post-index symptoms and comorbidities and comparisons to pre-index rates.
Results: The TriNetX database contained 1097 patients with DM (mean age, 54.6 y; female, 77%). The mean observation period was 9.7 y (6.0 y pre-index; 3.7 y post-index). Prior to the DM index date, 60% of patients were prescribed steroids and 24% were prescribed ≥1 non-steroidal immunosuppressive therapy. Within 3, 6, and 12 months of index date, 8%, 14%, and 20% of patients, respectively, received ≥2 immunosuppressive therapies. A 2–3-fold increase post-index compared with pre-index was seen for a wide range of symptoms and comorbidities, including gastroesophageal reflux disease (43% and 22%, respectively), anxiety (25% and 13%), interstitial lung diseases (26% and 10%), and osteoporosis (21% and 6%).
Conclusion: Most patients' symptoms were treated with immunosuppressive therapies for an extended time before receiving a formal diagnosis of DM, which may contribute to the delayed diagnosis; some had received ≥2 immunosuppressive therapies at 1 y post-diagnosis. Symptoms and comorbidities increased post-diagnosis. Given the high number of patients receiving ≥2 immunosuppressive therapies at 1 y post-diagnosis and the comorbidities, DM is difficult to treat effectively with existing therapies. Thus, there is a high unmet need for earlier diagnosis and better symptom control, including with therapies with novel mechanisms of action.
Disclosures: A. Kielhorn, Alexion, AstraZeneca Rare Disease; Z. Wang, Alexion, AstraZeneca Rare Disease; K. Moy, Alexion, AstraZeneca Rare Disease; L. Christopher-Stine, Janssen, Boehringer-Ingelheim, Mallinckroft, EMD-Serono, Allogene, ArgenX; I. Lundberg, Argenx, AstraZeneca, Bristol Myers Squibb, Novartis, Corbus, EMD Serono, Roche, Pfizer, Orphazyme, Octapharma, Kezar, Janssen; H. Chinoy, Eli Lilly, UCB; K. Gunter, Alexion, AstraZeneca Rare Disease, Argenx, EMD Serono; R. Aggarwal, Mallinckrodt, Bristol Myers Squibb, EMD Serono, Pfizer, Octapharma, CSL Behring, Q32, Kezar, AstraZeneca, Alexion, Argenx, Boehringer Ingelheim, Corbus, Janssen, Kyverna, Roivant, AbbVie, Jubilant, Orphazyme, Genentech.
