Many Patients with Hidradenitis Suppurativa Stop Adalimumab Within a Year

Hidradenitis suppurativa is a chronic, relapsing inflammatory skin disease marked by painful nodules, abscesses, and draining tunnels beneath the skin, affecting an estimated 0.4 to 1.0 percent of the global population. From 2015 until 2023, adalimumab, a monoclonal antibody that blocks tumor necrosis factor-alpha, was the only biologic approved in the United States for patients with moderate to severe disease. A new observational cohort study drawing on insurance claims from across the country now reports that despite adalimumab’s benefits, most patients stopped taking the drug within roughly a year, and many continued to need antibiotics, pain medications, and surgeries while on treatment. The findings, published in Drugs – Real World Outcomes, quantify the residual disease burden carried by patients even while receiving the standard biologic therapy of the era.

Researchers led by Maria A. Aleshin and Alexa B. Kimball analyzed the Merative MarketScan Commercial, Medicare, and Multi-State Medicaid claims databases, which aggregate de-identified claims from more than 450 suppliers covering patients in all 50 US states. The main cohort included 2,367 adults who began adalimumab between September 2015 and December 2018, each with at least one diagnostic code for hidradenitis suppurativa and continuous insurance enrollment in the 365 days before their first adalimumab claim. A second COVID-19 cohort of 1,736 adults started treatment between March 2020 and September 2021. Patients were followed until they discontinued the drug, left the database, or data availability ended in March 2022, yielding 2,429.79 patient-years of follow-up in the main cohort and 1,085.33 patient-years in the pandemic-era group.

The central result concerns drug survival, the proportion of patients still filling adalimumab prescriptions over time. Discontinuation was defined as a gap of at least 90 days since the last recorded claim. Using Kaplan-Meier estimates, the team found that 60.3 percent of the main cohort, or 1,427 patients, discontinued adalimumab during follow-up. Drug survival stood at 68.4 percent at six months but fell to 48.0 percent at twelve months, with a median drug survival of 0.96 years. The COVID-19 cohort showed broadly similar patterns, with drug survival of 72.6 percent at six months and 55.1 percent at a year. Only 6.5 percent of patients who discontinued switched to another biologic, most commonly infliximab, followed by ustekinumab, etanercept, and secukinumab, a figure the authors attribute partly to the lack of approved alternatives during the study period.

A multivariable proportional hazards regression model identified baseline characteristics that predicted discontinuation. Female sex, younger age, Medicaid insurance, and undergoing excision surgery each increased the risk of stopping adalimumab, while patients using spironolactone were less likely to discontinue. Obesity was evaluated but showed no predictive power once the other predictors were accounted for. The highest-risk group was Medicaid-insured women under 25 years of age, whose one-year drug survival was only 22.6 percent. The authors caution that these baseline predictors are likely proxies for disease severity, healthcare access, healthcare-seeking behavior, new contraindications such as pregnancy, and social determinants of health rather than direct causal drivers, and that excision surgery probably flagged more severe disease.

Insurance type marked a sharp divide in the main cohort. One-year drug survival was 53 percent among Commercial and Medicare-insured patients compared with 37 percent among Medicaid-insured patients, and the discontinuation rate was 0.51 per year versus 0.81 per year respectively. Provider patterns differed just as starkly: 63 percent of Commercial and Medicare patients had a dermatologist as their hidradenitis suppurativa provider, against only 25 percent of Medicaid patients, and 42 percent versus 15 percent had a dermatologist initiating adalimumab. In the COVID-19 cohort, however, these insurance-related gaps largely disappeared, with similar one-year survival of 54 percent and 58 percent and identical discontinuation rates of 0.58 per year in both groups, suggesting the pandemic’s disruptions to healthcare access may have overwhelmed the usual insurance effect.

Healthcare resource utilization told a nuanced story. The proportion of patients with at least one utilization event was generally higher before treatment than during adalimumab therapy, and several claim rates fell: systemic antibiotics dropped by 978 per 1,000 person-years, opioid analgesics by 258, and nonopioid analgesics by 208. Yet other rates rose, including outpatient dermatology visits by 404 per 1,000 person-years, antidepressant use by 165, and neuropathic pain agents by 71. The authors interpret some increases as possible signs of patients gaining access to appropriate care and recommended therapeutic monitoring rather than worsening disease. Longer treatment amplified the declines: among the 33.1 percent of patients treated for at least a year, systemic antibiotic claim rates fell by 1,679 per 1,000 person-years, and among the 14.9 percent treated two years or more, by 1,909.

Concomitant treatment needs persisted throughout. Around 70 percent of patients initiated adalimumab alongside another hidradenitis suppurativa-related pharmacotherapy, including antibiotics, corticosteroids, analgesics, and antidepressants, with only about 30 percent starting the biologic alone. Baseline medication use also revealed disparities: opioid analgesic use was 20.4 percent in Medicaid-insured patients versus 7.6 percent in Commercial and Medicare patients, with anxiolytics, nonopioid analgesics, and antidepressants similarly elevated in the Medicaid group. Notably, 525 patients re-initiated adalimumab after discontinuing, with 74.3 percent of them restarting within one year and 90.7 percent within two years, a pattern the authors say underscores interruptions in care for a disease with potentially irreversible consequences.

Sensitivity analyses addressed some sources of bias. Because adalimumab treats several conditions, the team excluded 317 patients, or 13.4 percent of the main cohort, who had claims for other indications such as inflammatory bowel disease, psoriasis, psoriatic arthritis, or rheumatoid arthritis. Excluding these patients raised the apparent starting dose, indicating some participants were likely treated for conditions other than hidradenitis suppurativa, but it did not materially change drug survival results, and it lowered the percentage of patients switching to another biologic. The authors also note that reported dermatologist percentages may be underestimated because provider type information can be missing from claims data.

The study carries important limitations inherent to claims-based research. Discontinuation was inferred from pharmacy claim fills, so the reasons patients stopped, whether nonresponse, side effects, access barriers, or personal choice, remain unknown. Variables and diagnoses may be misclassified, data may be missing or incomplete, and results may not generalize to uninsured Americans or those with other insurance types, since enrollment was required. Missing data were not imputed. The authors also emphasize that the treatment landscape has shifted since the study window: secukinumab and bimekizumab, among other agents, have since been approved or reported for hidradenitis suppurativa, and patients in the United States increasingly face biosimilar switches and prior authorization requirements that may further disrupt care.

Overall, the analysis paints a picture of a therapy that delivered measurable benefits, including reduced opioid use and lower overall healthcare utilization, while leaving a substantial residual burden. High discontinuation rates, persistent need for antibiotics and surgeries, and stark differences by insurance type point, the authors conclude, to a need for more accessible and durable therapies with longer drug survival, along with better longitudinal follow-up to understand why patients pause or abandon treatment. As newer biologics enter clinical use, they suggest future studies should examine whether the residual burden and early discontinuation seen with adalimumab are repeated or relieved by the next generation of treatments.

Subject of Research: Residual disease burden and drug survival in US patients with hidradenitis suppurativa treated with adalimumab

Article Title: Residual Burden in Adalimumab-Treated Patients with Hidradenitis Suppurativa: An Observational Cohort Study Based on Insurance Claims in the USA

Article References: Aleshin, M. A., Tran, T., Pansar, I., Shang, A., Friesen, D., & Kimball, A. B. (2026). Residual Burden in Adalimumab-Treated Patients with Hidradenitis Suppurativa: An Observational Cohort Study Based on Insurance Claims in the USA. Drugs – Real World Outcomes, 13(3), 451-464. https://doi.org/10.1007/s40801-026-00564-8

Image Credits: AI Generated

DOI: 10.1007/s40801-026-00564-8

Keywords: hidradenitis suppurativa, adalimumab, drug survival, insurance claims, Medicaid, healthcare resource utilization, biologics, treatment discontinuation, observational cohort, dermatology, tumor necrosis factor-alpha, real-world evidence