Biosimilars The US Food and Drug Administration approved, the first rapid-acting interchangeable biosimilar product, Kirsty (insulin aspart-xjhz, as a 3 mL single-patient-use prefilled pen and 10 mL multiple-dose vial. Kirsty is biosimilar to and interchangeable with Novolog (insulin aspart), from Denmark’s Novo Nordisk. 16 July 2025