“As more biologics become available for the treatment of psoriasis (PsO), there is a lack of direct comparisons of health care costs between patients who are treated by different medications, including ixekizumab (IXE), secukinumab (SEC), and adalimumab (ADA),” the researchers proposed.
The study authors used the IBM MarketScan commercial and Medicare databases to identify patients who received a PsO diagnosis between July 1, 2015, and May 31, 2018; they used this data to further create two patient datasets based on drug claims made between March 1, 2016, and May 31, 2018: ixekizumab versus secukinumab and ixekizumab versus adalimumab. Eligible patients were aged 18 years or older and had at least one year of continuous eligibility prior to and following the index date; those with other indications for the index drug in the preiperiod or with use of the index drug during the 90 days leading up to the index date were excluded from the study. The groups were balanced using inverse probability of treatment weighting (IPTW). Outcomes included all-cause and PsO-related healthcare costs per member per month (PMPM) incurred during one year of follow-up. Monthly costs related to PsO were adjusted using drug discount rates per the Institute for Clinical and Economic Review; annual index drug costs were determined by factoring n medication possession ratio and ICER discount rates.
The two datasets included 357 ixekizumab patients compared to 763 secukinumab patients, and 388 ixekizumab patients compared to 2,578 adalimumab patients. Ixekizumab patients had similar demographic and clinical characteristics to the secukinumab patients, but compared to adalimumab patients, they were in worse health and had older age; postweighting was used to balance out any differences. Mean monthly all-cause healthcare costs were $7,313 for ixekizumab patients and $6,477 for secukinumab patients (P=0.002); mean PsO-related costs were $6,303 and $5,437 (P<0.001), respectively. In the ixekizumab and adalimumab comparisons, mean monthly all-cause healthcare costs were $6,535 and $5,557 (P=0.026), respectively, and mean PsO-related sots were $5,792 and $4,754 (P=0.017), respectively. When ICER adjustments were implemented, mean monthly PsO-related costs did not largely differ between the groups in either dataset: ixekizumab versus secukinumab, $3,637 versus $3,443 (P=0.132), respectively; and ixekizumab versus adalimumab, $3,320 versus $3,287 (P=0.907), respectively.
The findings were published in the Journal of Managed Care & Specialty Pharmacy.
“After adjusting for drug discount programs (through application of ICER discount rate), this real-world study estimated that average monthly PsO-related costs during the first year of treatment were similar between patients treated with IXE compared with those treated with SEC or ADA,” the study authors summarized.