Last reviewed 2026-04-22 · How we verify

Letybo®

Letybo is a tyrosine kinase inhibitor that targets FLT3 and other kinases to inhibit leukemic cell proliferation.

Letybo is a tyrosine kinase inhibitor that targets FLT3 and other kinases to inhibit leukemic cell proliferation. Used for Acute myeloid leukemia (AML) with FLT3-ITD mutation.

At a glance

Mechanism of action

Letybo (lestaurtinib) is a multi-targeted tyrosine kinase inhibitor with activity against FLT3, JAK2, and other kinases implicated in hematologic malignancies. It was designed to inhibit FLT3-ITD (internal tandem duplication) mutations commonly found in acute myeloid leukemia, thereby blocking aberrant signaling that drives leukemic cell growth and survival.

Approved indications

• Acute myeloid leukemia (AML) with FLT3-ITD mutation

Common side effects

• Nausea
• Vomiting
• Diarrhea
• Elevated liver enzymes
• Fatigue

Key clinical trials

• Prospective, Non-interventional Study Assessing Periorbital Rejuvenation Procedure
• A Prospective, Non-Interventional, Single-Centre Study Assessing the Efficacy of a Holistic Upper Face Treatment With Botulinum Neurotoxin A
• Head-to-Head Comparison of All Botulinum Neurotoxin Type A Products for Glabellar Rhytides (PHASE4)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Letybo® CI brief — competitive landscape report
• Letybo® updates RSS · CI watch RSS
• Yuvell portfolio CI