Two recent real-world studies provide compelling evidence for the acceptance, durability, and cost-effectiveness of adalimumab biosimilars in treating inflammatory bowel disease (IBD) across different age groups, addressing longstanding concerns about biosimilar switching in clinical practice.
High Adult Patient Acceptance Despite Initial Concerns
A French observational study involving 97 adult IBD patients found remarkably high acceptance rates for biosimilar switching when patients received proper education and guidance. Despite only 45% of patients reporting no initial concerns about biosimilars, 92% ultimately accepted the switch from adalimumab reference product to one of five available biosimilars: Amgevita, Hulio, Hyrimoz, Idacio, and Imraldi.
The study population included 84 patients with Crohn's disease and 13 with ulcerative colitis, with a median disease duration of 13 years. At baseline, 95% of patients were in clinical remission, defined by Harvey Bradshaw Index of 4 or lower for Crohn's disease or Partial Mayo Score of 1 or lower for ulcerative colitis.
Patient education proved crucial in overcoming initial hesitancy. All participants received standardized verbal information about biosimilars from their gastroenterologist and guidance from a trained nurse. The only factor significantly associated with non-acceptance was having a poor opinion of generic drugs, highlighting the importance of addressing specific patient concerns about biosimilar medications.
Strong Long-Term Persistence and Clinical Outcomes
At 12-month follow-up, 71% of patients who initially switched remained on biosimilar therapy, with overall persistence rates of 77% at 6 months and 71% at 12 months. Among the 37 patients who discontinued their initial biosimilar, the most common reason was injection site pain (25%), followed by loss of efficacy (7%) and difficulties with new injection devices (4.5%).
Clinical outcomes remained robust throughout the study period. Of patients who accepted the switch, 85% maintained clinical remission at 12 months, compared to 94% at baseline. Biochemical remission rates, defined as C-reactive protein levels of 5 mg/L or lower, remained stable at 86% at 12 months among patients with available data.
Pediatric Population Shows Exceptional Durability
A separate real-world study examining pediatric IBD patients across two European centers in Scotland and Sicily demonstrated even more impressive long-term durability outcomes. The study included 130 patients with a mean age of 12.3 years, comprising 88% with Crohn's disease, 5% with ulcerative colitis, and 6% with IBD unclassified.
The durability probabilities were 93% at 6 months, 86% at 12 months, 75% at 24 months, and 57% at 54 months. After a median follow-up of 26 months, 67% of patients remained on adalimumab biosimilar treatment. Notably, patients previously exposed to the adalimumab reference product had a lower risk of biosimilar treatment failure (HR, 0.51; 95% CI, 0.26-0.99; P = .047).
Clinical remission rates improved significantly over time in the pediatric population, rising from 39% at baseline to 71% at 6 months and 72% at 12 months. The study also observed improvements in luminal remission, C-reactive protein levels, and fecal calprotectin levels throughout the follow-up period.
Therapeutic Drug Monitoring Insights
The pediatric study provided valuable insights into therapeutic drug monitoring, showing that patients who experienced treatment failure had lower drug concentrations at 6 months (10.7 μg/ml) compared to those who continued treatment (12.0 μg/ml). Trough levels of at least 11.6 μg/ml at 6 months were associated with greater durability of adalimumab biosimilar therapy.
Safety Profile and Adverse Events
Both studies reported manageable safety profiles. In the adult population, injection site pain was the primary concern leading to discontinuation. The pediatric study found adverse events in 36% of patients, mainly psoriasis (13%) and injection site reactions (13%), with one case of lymphoma reported. Notably, 94% of patients experiencing injection site pain were receiving ABP 501 (Amgevita).
Significant Cost Savings Demonstrated
The economic benefits of biosimilar adoption were substantial. The pediatric study estimated cost savings of 5,030 Euro per patient per year when using adalimumab biosimilars instead of the reference product. These findings support the cost-effectiveness of biosimilar switching in IBD management, particularly important given that IBD treatment costs are primarily driven by expensive biologic therapies.
Clinical Implications for IBD Management
Both studies emphasize the critical role of patient education and healthcare provider support in successful biosimilar transitions. The French study authors noted that "continuous patient education and healthcare providers addressing patients' individual concerns is crucial for improving overall satisfaction with biosimilars and maximizing their benefits."
The research addresses a significant clinical need, as approximately 7 million people worldwide are affected by IBD, an immune-mediated inflammatory disease requiring costly biologic treatments. The findings suggest that with appropriate patient education and clinical support, biosimilar switching can maintain clinical efficacy while providing substantial cost savings across both adult and pediatric IBD populations.
