Is Semglee the Same as Lantus?
Yes, Semglee (insulin glargine-yfgn) is an FDA-approved interchangeable biosimilar to Lantus (insulin glargine), meaning it can be substituted for Lantus at the pharmacy level without prescriber intervention, as it was the first insulin biosimilar to receive this designation on July 28,2021. 1
What "Interchangeable Biosimilar" Means
- Interchangeable status means the FDA has determined that Semglee produces the same clinical result as Lantus in any given patient, and that switching between the two products carries no additional risk compared to continuing therapy with Lantus alone 1
- Both products contain insulin glargine with the same mechanism of action: they are soluble at acidic pH (4.0) but precipitate in subcutaneous tissue (pH >7.4), forming microprecipitates that gradually release insulin over approximately 24 hours 2, 3
- Both provide a relatively constant basal insulin level without pronounced peaks, unlike NPH insulin 4, 5
Clinical Equivalence
- Pharmacokinetics: Both have onset of action at approximately 1 hour, peakless profiles, and duration of action up to 24 hours 6
- Efficacy: As an interchangeable biosimilar, Semglee must demonstrate equivalent glycemic control to Lantus 1
- Dosing: Both are administered once daily at the same time each day, typically starting at 10 units daily or 0.1-0.2 units/kg/day in insulin-naive type 2 diabetes patients 6
Post-Marketing Safety Differences
While FDA-approved as interchangeable, post-marketing surveillance has identified some differences in adverse event reporting patterns:
- Both products showed no significant safety signals for serious adverse events, death, or hospitalization 1
- Semglee exhibited notably higher reporting rates for device issues (ROR = 118.7), lipodystrophy (ROR = 146.0), and product quality issues (ROR = 5.4) compared to Lantus 1
- Lantus showed significant signals for hyperglycemia (ROR = 2.7), hypoglycemia (ROR = 4.6), and metabolic investigations (ROR = 11.7) 1
Important caveat: These differences in adverse event reporting may reflect reporting bias, differences in market penetration, or device-related issues rather than true differences in the insulin molecule itself, as the FDA's interchangeable designation requires demonstration of equivalent clinical outcomes 1
Practical Prescribing Considerations
- Substitution: Pharmacists can substitute Semglee for Lantus prescriptions without contacting the prescriber, though state laws may require patient notification 1
- Administration: Both must be given subcutaneously and cannot be diluted or mixed with other insulins due to their acidic pH 6
- Monitoring: The same titration protocols apply to both products, with dose adjustments based on fasting glucose targets 6
- Cost: Semglee typically offers cost savings compared to Lantus, which may improve medication adherence, though this should be balanced against the slightly different post-marketing safety profile 1