Erelzi(etanercept-szzs)

Erelzi (etanercept-szzs) is a biosimilar to Enbrel, indicated for the treatment of Rheumatoid Arthritis (RA), Polyarticular Juvenile Idiopathic Arthritis (JIA) in patients aged 2 years or older, and Ankylosing Spondylitis (AS). The recommended dosage for adult RA and AS is 50 mg once weekly, and for JIA patients over 63 kg, 0.8 mg/kg weekly up to a maximum of 50 mg per week.

Efficacy studies demonstrated pharmacokinetic (PK) similarity, with 90% confidence intervals for ratios of geometric mean of AUC0-inf, AUC0-τlast, and Cmax falling within 80% to 125%. In a study comparing Erelzi (GP2015) to EU-approved Enbrel, the PASI 75 at Week 12 was 70.5% for GP2015 and 71.5% for EU-approved Enbrel. The 90% confidence interval for the difference in PASI 75 at Week 12 was (-8.3, 6.0)%, within the pre-specified margin of ±18%. The mean percent change in PASI at Week 12 was -82.6% for GP2015 and -81.7% for EU-approved Enbrel. The proportion of IGA responders was 58.2% for GP2015 and 55.1% for EU-approved Enbrel.

Notable safety findings include an increased risk of serious infections, including tuberculosis, bacterial sepsis, and invasive fungal infections. Lymphoma and other malignancies, some fatal, have been reported in children and adolescent patients treated with TNF blockers. The most common adverse reactions (incidence > 5%) were infections and injection site reactions. Allergic reactions occurred in less than 2% of patients. In a study, 4 out of 264 subjects in the GP2015 group experienced SAEs, compared to 3 out of 267 subjects in the EU-approved Enbrel group. Discontinuations due to AEs were 5 out of 264 subjects for GP2015 and 4 out of 267 subjects for EU-approved Enbrel.