Comparison of Healthcare Resource Utilization for Oral and Injectable Biologic Agents for Joint and Skin Conditions

Patients with moderate to severe rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), and psoriasis may require biologic immunotherapy, which can be administered via infusion, injection, or orally. The comparative effectiveness of these routes of administration is not well understood.

Researchers sought to compare drug use, healthcare resource use, and costs associated with these delivery modes in treatment-naïve patients with these joint and skin conditions. The results of the study were presented at the AMCP Annual Meeting during a poster session titled “Comparative Effectiveness Study Among Naive Users of Injectable Versus Oral Biologic Immunotherapies.”

The retrospective, observational study used claims data from a large U.S. health plan to identify new users of biologics diagnosed with a joint (RA, AS, PsA), skin (psoriasis), or joint and skin condition between July 1, 2014, and June 30, 2017. The index date was the first biologic claim, and the researchers measured treatment discontinuation, treatment switching, healthcare resource utilization—including outpatient, emergency, or inpatient visits—and costs.

Patients 18 to 90 years old with continuous enrollment in Medicaid, Medicare Advantage, and commercial plans for six months pre- and 12 months post-index were included.

The researchers could only assess oral and injectable regimens, as most infusible agents were given to previously treated patients.

Among those with joint conditions, the researchers identified 466 oral biologic users and 4,236 injectable users; for skin conditions, there were 269 oral and 980 injectable users; and for joint and skin conditions, there were 173 oral and 855 injectable users.

Weighted comparisons found that more patients switched therapies while on oral agents compared with injectables (P<0.0001):

  • For joint conditions: 18.6% vs 12.1%
  • For skin conditions: 32.3% vs 13.5%
  • For joint and skin conditions: 39.3% vs 17.1%

Mean outpatient visits were higher for oral agents compared with injectables (P<0.0001 for both) for those with joint (21.1 vs 19.8) and skin (17.4 vs 14.1) conditions, but not for those with both (12.7 vs 12.0; P=0.17). Mean inpatient visits were also higher for those on oral agents for patients with joint conditions (0.3 vs 0.2; P=0.01), but not for those with skin (0.1 vs 0.1; P=0.56) or joint and skin (0.2 vs 0.2; P=0.62) conditions.

Total costs (including all-cause medical and pharmacy costs) were lower for oral agents compared with injectables:

  • For joint conditions: $44,697 vs $53,661 (P=0.0014)
  • For skin conditions: $44,113 vs $57,013 (P<0.0001)
  • For joint and skin conditions: $47,634 vs $57,361 (P<0.0001)

Biologic costs were also lower for oral agents compared with injectables (P<0.0001 for all):

  • For joint conditions: $29,537 vs $37,879
  • For skin conditions: $30,422 vs $45,187
  • For joint and skin conditions: $31,303 vs $42,263

The study was sponsored by Humana.

Bhattacharya R, Herren C, Poonawalla I, Bunniran S, Bloomfield A, Schwab P. Comparative Effectiveness Study Among Naive Users of Injectable Versus Oral Biologic Immunotherapies. Abstract M3. Presented at the AMCP Managed Care & Specialty Pharmacy Annual Meeting, April 23-26; Boston, MA.