OBJECTIVES: Quantify the amount of GC use in newly diagnosed granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) commercially insured and Medicare fee for service (FFS) populations.

METHODS: Using the 2016-2019 Milliman proprietary commercial claims data and Medicare 100% FFS Innovator Research data, GPA and MPA were identified in index years 2017 and 2018 as those with at least two qualifying claims coded with a disease ICD-10-CM code. Newly diagnosed patients were identified as those with no claim coded with GPA or MPA 12 months prior to their first claim in 2017 or 2018. Oral and injectable GC use was identified in non-inpatient claims using NDC and HCPCS codes. Use of GCs during inpatient stays is not identifiable, as such this analysis underestimates the total GC load. The prednisolone-equivalent dose in milligrams (mg) was calculated by converting GC scripts/claims to a prednisolone-equivalent basis.

RESULTS: We identified 390 (GPA) and 70 (MPA) commercially insured and 3,719 (GPA) and 1,168 (MPA) Medicare FFS newly diagnosed patients with GC use who also had eligibility for 12 months prior to their first GC use date through 18 months after their first GC use date. The cumulative prednisolone-equivalent doses at 18 months were: 32% and 33% used 1-999 mg; 32% and 39% used 1,000-4,999 mg; 25% and 16% used 5,000-9,999 mg; and 11% and 13% had 10,000+ mg, respectively for the commercial population. The cumulative prednisolone-equivalent doses through 18 months were: 46% and 26% used 1-999 mg; 29% and 37% used 1,000-4,999 mg; 19% and 28% used 5,000-9,999 mg; and 6% and 8% used 10,000+ mg, respectively for the Medicare FFS population.

CONCLUSIONS: Most patients newly diagnosed with GPA and MPA were treated with high cumulative amounts of GCs. Given side-effects reported with high GC doses, this report highlights the need for GC sparing therapies.