Ritlecitinib

LITFULO

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Pronunciation: rit-le-SYE-ti-nib (lit-FUL-oe)

Ritlecitinib ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Ritlecitinib ballicule

Ritlecitinib LITFULO mascot mnemonic cartoon — Visual mnemonic: Ritlecitinib mascot
**“Little Foo Foo, the Riddle City nibbler”**
jack → Janus kinase (JAK) inhibitor

What it isAn oral covalent inhibitor of JAK3 and the TEC kinase family, for severe alopecia areata, including adolescents.

Why this oneIt extends the JAK-inhibitor alopecia story to age twelve and up, with kinase selectivity intended to spare the broader JAK1/2 effects.

What limits itIt still carries the JAK-class warnings — infection, thrombosis, malignancy, cardiovascular events — and hair regrowth reverses if it is stopped; screen for tuberculosis and avoid live vaccines.

Ritlecitinib molecular structure (skeletal formula) — Molecular structure: Ritlecitinib

Ritlecitinib prescription history

Animated chart of estimated U.S. prescriptions per year, Tyrosine kinase inhibitors (2001–2026). Ritlecitinib enters in 2023 (estimated).

Classes and tags

Clinical profile

Therapeutic safety burden3 / 4

Overdose danger1 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk2 / 4

Legacy pregnancy categoryN/A (post-2015 labeling)

Defining liabilitySerious infection, cytopenias and thrombotic risk

FDA label

Read the full label on DailyMed ↗

BOXED WARNING Serious infections (incl. TB — screen/treat latent TB; monitor); increased all-cause mortality incl. sudden CV death (another JAK inhibitor vs TNF blockers in RA); malignancies (lymphoma, lung cancer); MACE; thrombosis (PE, venous/arterial).

FDA dosing	Population	Start	Target	Max
Severe alopecia areata	Adults and adolescents ≥12 yr	50 mg QD	50 mg QD	50 mg QD

Renal Undefined

Hepatic No adjustment for mild-moderate (Child-Pugh A-B); not recommended in severe (Child-Pugh C)

Instructions

Swallow capsules whole; do not crush, split, or chew; with or without food
Missed dose: take ASAP unless <8 h before next dose (then skip)
Before initiation: TB evaluation, viral hepatitis screening, update immunizations (incl. herpes zoster); do not start if ALC <500/mm3 or platelets <100,000/mm3
Check ALC and platelets at baseline and at 4 wks; discontinue if platelets <50,000/mm3; interrupt if ALC <500/mm3 (may restart on recovery)
Treatment interruption <6 wks not expected to cause significant loss of regrown hair

Available strengths

cap 50 mg

Cautions

Serious/opportunistic infections incl. TB, sepsis, herpes zoster (multi-dermatomal) — avoid with active serious infection; interrupt for serious infection
Mortality, malignancy, MACE, and thrombosis risks (JAK-inhibitor class; boxed) — avoid in patients at increased thrombosis risk; discontinue after MI or stroke
Hypersensitivity incl. anaphylaxis — discontinue for clinically significant reaction
Hypoglycemia in patients with diabetes — consider increased glucose monitoring
Lab abnormalities: lymphopenia, thrombocytopenia, ALT/AST elevations (interrupt if DILI suspected), CPK elevations
Avoid live attenuated vaccines during or shortly before treatment

Adverse reactions

Headache
Diarrhea
Acne
Rash
Urticaria
Folliculitis
Pyrexia
Atopic dermatitis
Dizziness
Increased CPK
Herpes zoster
Decreased RBC count
Stomatitis

Pregnancy Insufficient human data; fetotoxicity/malformations in animals at ≥49x MRHD; exposure registry 1-877-390-2940

Lactation Do not breastfeed during treatment and for ~14 h after last dose (~6 half-lives)

Cost

Ritlecitinib (LITFULO)

Strength		#/mo	generic $/mo	CostPlus
50 mg	cap	30 qd		not offered

NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Ritlecitinib is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.

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Self-check

Ritlecitinib: What minimum age is included for alopecia?
12 years.
Ritlecitinib: What happens to regrowth if stopped?
It reverses.