Explain Why Semglee Will Be "Interchangeable" With Lantus

Semglee (insulin glargine-yfgn U-100) will be the first "interchangeable" biosimilar.

It was originally approved as a new brand of insulin glargine, not a Lantus generic...and switching required a new Rx. Now that's changing.

Be ready to explain what an "interchangeable" biosimilar is.

Point out that biosimilars aren't generics...it's impossible to create an exact copy of the original, or "reference," biologic.

That's because biologics are made from living organisms and contain larger, more complex molecules than most traditional drugs.

Biosimilars have to show similar safety, purity, and potency as the reference biologic. But an "interchangeable" biosimilar is also shown to give the same CLINICAL result.

Semglee is the first biosimilar to have this kind of evidence. Explain that it provides similar A1C lowering at 6 months compared to Lantus...with a similar rate of hypoglycemia.

Plus an interchangeable biosimilar CAN often be automatically substituted without a new Rx, like a generic.

Expect many payers to prefer Semglee...it costs about $100/vial or $150/box of 5 pens. Lantus is $280/vial or $430/5 pens...Basaglar is $330/5 pens.

But don't start automatically substituting currently available Semglee products for Lantus yet...simply due to how they were approved.

Look for the "-yfgn" suffix on NEW Semglee products coming later this year as a clue that these are interchangeable.

And check your state laws. Some still require you to contact the prescriber before substituting an interchangeable biosimilar...or to inform the prescriber or patient if the substitution is made.

Continue to request a new Rx if switching Semglee or Lantus with Basaglar...which is its own brand of insulin glargine U-100. Use FDA's Purple Book as a guide to biosimilars and substitutions.

See our FAQ, Facts About Biosimilars, for more talking points...and to find out your state laws. Learn how all the insulin products stack up in our chart, Comparison of Insulins.

Key References

  • www.fda.gov/news-events/press-announcements/fda-approves-first-interchangeable-biosimilar-insulin-product-treatment-diabetes (8-23-21)
  • www.fda.gov/drugs/therapeutic-biologics-applications-bla/biosimilars (8-23-21)
  • https://purplebooksearch.fda.gov/ (8-23-21)
  • Medication pricing by Elsevier, accessed Aug 2021
Pharmacist's Letter. September 2021, No. 370901



Get concise advice on drug therapy, plus unlimited access to CE

Pharmacist's Letter includes:

  • 12 issues every year, with brief articles about new meds and hot topics
  • 300+ CE courses, including the popular CE-in-the-Letter
  • Quick reference drug comparison charts
  • Access to the entire archive

Already a subscriber? Log in

Volume pricing available. Get a quote