OverviewDosageSide EffectsInteractionsHalf-Life

Sarilumab (Kevzara) is a relatively new prescription-only medication, receiving both FDA and EMA approval in 2017. Considering how new this drug is, it’s no surprise that many people don’t know much about this drug or how it works, including how long Kevzara stays in your system.

Effective half-life

  • 200 mg, initial: 10 days (1)
  • 150 mg, initial: 8 days (1)
  • At steady-state: 21 days (1)
  • 150 mg, following last steady-state dose: 28 to 30 days (1,2)
  • 200 mg, following last steady-state dose: 43 to 49 days (1,2)

Time to steady-state

  • 0-14 days: 14 to 16 weeks (3)
  • Trough concentration: 18 to 20 weeks (3)

Accumulation ratio

  • 150 mg, 0-14 days: 2.31 (3)
  • 200 mg, 0-14 days: 2.48 (3)
  • 150 mg, trough concentration: 2.60 (3)
  • 200 mg, trough concentration: 2.98 (3)

Initial dosing terminal half-life, concentration dependent: 2 to 4 days (2)

According to the European Medicines Agency, Kevzara has a bioavailability of 80% following subcutaneous (beneath the skin) injection. Experts currently aren’t quite sure how the body eliminates sarilumab, although some believe it is done via specialized enzymes (i.e., proteases).

What is the half-life of Kevzara?

The answer to this question depends on several factors, including time, dose and patient specific factors. Following the initial dose, the half-life of Kevzara is roughly 8 to 10 days. Following the last dose after reaching steady-state, effective half-life is roughly anywhere from 28 days to 49.

How long does Kevzara stay in your system?

The time it takes to reach an undetectable concentration of sarilumab depends on the dose and how long someone has been taking this medication.

  • After last steady-state dose, 150 mg: 28 to 30 days (1,2)
  • After last steady-state dose, 200 mg: 43 to 49 days (1,2)

Experts are currently not 100% sure how the body metabolizes this drug.

How long does Kevzara take to work?

It can take anywhere from few days to 3 months for users to feel this medication’s effects.


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