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LETYBO letibotulinumtoxinA-wlbg 50 U Injection, Powder, Lyophilized, For Solution, 1 vial — NDC 81165-0050-01 package photo

LETYBO letibotulinumtoxinA-wlbg 50 U Injection, Powder, Lyophilized, For Solution, 1 vial

by Hugel, Inc. · 1 VIAL, SINGLE-DOSE in 1 CARTON (81165-050-01) / 1 INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION in 1 VIAL, SINGLE-DOSE
NDC 81165-0050-01
🏷️ FDA NDC (as labeled) 81165-050-01 billing pads the product segment with a zero
Rx only Brand On market Non-controlled
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

🆔 Identity & classification

FDA NDC (as labeled) 81165-050-01
Product NDC 81165-050
11-digit billing NDC 81165005001
UNII W5O50S8A59
Application # BLA761225
SPL Set ID 910e5d0e-4d0b-4de8-8e2d-97879a044181
Established class (EPC) Acetylcholine Release Inhibitor; Neuromuscular Blocker
Mechanism of action Acetylcholine Release Inhibitors
Physiologic effect Neuromuscular Blockade
DEA schedule Non-controlled
Marketing category BLA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2024-07-30
Route INTRAMUSCULAR
Dosage form INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION
Substance LETIBOTULINUMTOXINA
GCN Seq No 085269
GCN 54703
HICL code 049200
Ingredient (HICL) Letibotulinumtoxina-Wlbg
HIC1 code S
Therapeutic class — broad (HIC1) Locomotor System
HIC2 code S7
Therapeutic class — intermediate (HIC2) Affect Primarily Skeletal Muscle
HIC3 code S7H
Therapeutic class — specific (HIC3) Neuromuscular Blocking Agents (Cosmetic)
AHFS code 12:20.20.24
AHFS class Botulinum Toxins
FDB label name LETYBO 50 UNIT VIAL
FDB brand name Letybo
Legend status F — Federal legend — prescription drug or device
Biologic (Purple Book) 351(a)
Why two NDCs? The FDA registers this code as 81165-050-01 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 81165-0050-01. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Acetylcholine Release Inhibitor class.

Pharmacologic class Acetylcholine Release Inhibitor, Neuromuscular Blocker
How it works Acetylcholine Release Inhibitors
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerHugel, Inc.
FDA applicationBLA761225 (BLA)
Labeler code81165
First marketedJul 2024
Product typeHuman Prescription Drug
Portfolio3 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

Label name LETYBO 50 UNIT VIAL Ingredient Letibotulinumtoxina-Wlbg
📖 What it is MedlinePlus · NLM

DaxibotulinumtoxinA-lanm injection is used to temporarily smooth frown lines (wrinkles between the eyebrows) in adults 18 years of age and older. DaxibotulinumtoxinA-lanm injection is in a class of medications called neurotoxins. It blocks the nerve signals that cause uncontrollable tightening and movements of the muscle.

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • Botox (onabotulinumtoxinA) has a long list of medical uses that go well beyond cosmetics. It's FDA-approved to treat overactive bladder, prevent chronic migraines, reduce muscle st...
  • I thought Botox was just for wrinkles — what else is it actually used for?
  • The effects typically last several months — the exact duration depends on what you're being treated for. For most conditions, re-injection is done no sooner than every 3 months, an...
  • How long do the effects of Botox last, and how often will I need injections?
📖 Read our full OnabotulinumtoxinA Injection guide →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

A current SPL was checked, but it does not contain a structured or narrative inactive-ingredient list for this product. This does not mean the product has no inactive ingredients.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer mLPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Letybo 50 Uthis 81165-0050-01 Hugel, 1 vial FDA listed
About this product: this is a biologic. Biologics don't have small-molecule generics — competition comes from FDA-licensed biosimilars (shown above), not generics.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & biosimilar status

🏛️
2024
First FDA approval
Feb 2024
📍
2026
Currently FDA-listed
2 years listed
🛡️
2036
Latest patent/protection listed
not a guaranteed launch date
🧬Biologic — competition comes from biosimilars

Biologics have no small-molecule generics; biosimilar competition is tracked in the FDA Purple Book.

🛡️ Latest patent/protection date listed: FDA patent/protection data lists protections through Feb 2036. This may affect when biosimilars become widely available, but it is not a guaranteed launch date.
📅 FDA approved Feb 29, 2024 ⏳ ~9.4 yr to latest listed protection

Why the date isn’t exact: Biosimilar timing can change because patents may be challenged, settled, licensed, added or removed, and litigation can move the real date earlier or later.

FDA Purple Book — biosimilars & interchangeables
Reference product
🔒 No FDA-licensed biosimilars or interchangeable biosimilars are listed yet for this biologic. It currently has no biosimilar competition in the FDA Purple Book.
Source: FDA Purple Book (purplebooksearch.fda.gov), matched on the reference product’s active ingredient.
Patents & exclusivity — FDA Purple Book
Exclusivity RefProduct
2024 2026 2028 2030 2032 2034 2036
Today
LOE
Biologic patent Exclusivity
🏛️Reference-product exclusivity
A flat 12 years of FDA market protection from first licensure. No biosimilar can be licensed before it ends — regardless of patents.
🧪Listed biologic patents
Patents the reference maker lists covering the molecule, formulation, or manufacturing. A biosimilar generally can’t launch until these resolve.
🔁Interchangeability
An interchangeable biosimilar may be substituted at the pharmacy (state laws vary). The first one can earn its own exclusivity period.
🛈 What do these terms mean?
Biologic patent
A patent the reference product’s maker has publicly listed. A biosimilar generally can’t launch until these expire — unless they’re invalidated or resolved in a settlement.
Reference-product exclusivity
A flat 12 years of FDA market protection from the biologic’s first licensure (the BPCIA). No biosimilar can be licensed before it ends, regardless of patents.
Interchangeable exclusivity
The first interchangeable biosimilar can earn a period as the only interchangeable version (pharmacists can substitute it without the prescriber).
Earliest biosimilar (LOE)
The latest of all the dates above — the soonest a biosimilar can realistically reach the market. Litigation and settlements can move it earlier.

Biologics have no small-molecule “generics” — competition comes from FDA-licensed biosimilars, tracked in the FDA Purple Book.

FDA exclusivity
CodeWhat it grantsExpires
RefProductReference-product exclusivity (12-year, BPCIA) — no biosimilar can be licensed before this dateFeb 29, 2036
Common questions
Is there a biosimilar for LETYBO 50 UNIT VIAL?
No FDA-licensed biosimilar is currently listed for this biologic in the FDA Purple Book.
Why do different websites show different biosimilar dates?
Biosimilar availability isn’t based on one single date. Some sources use the reference-product exclusivity, some use the last listed patent, and patent litigation, settlements, and licenses can all change the real-world launch date. This page shows the underlying Purple Book dates so you can see why estimates differ.
Can a biosimilar launch before the last patent expires?
Sometimes. A biosimilar maker may settle with the reference manufacturer or receive a license to launch earlier. In other cases, the last listed protection delays competition.
What does “current Purple Book estimate” mean?
It means we’re using the latest patent and exclusivity dates currently listed in the FDA Purple Book. It is not a guaranteed launch date.
What does “FDA listed” mean?
It means the product appears in the FDA’s official directory. That’s a good sign a product exists for the U.S. market, but on its own it does not confirm a pharmacy can get it today. Where we have recent retail pricing data, we label it “Availability likely” instead.
What does a patent or protection date mean here?
It’s the latest date currently listed in the FDA Purple Book for a patent or exclusivity on the reference biologic. It can affect when a biosimilar becomes widely available — but it is not a guaranteed launch date. Settlements and licenses can move the real date earlier or later.
Built from the FDA Purple Book Patent List (patents the reference-product sponsor has publicly listed under the BPCIA) plus reference-product exclusivity. Biosimilars cannot launch until these clear; patent litigation and settlements can shift the real date. Biologics have no small-molecule generics — competition comes from FDA-licensed biosimilars, not the Orange Book.
Where does this data come from?
Patents and exclusivity from the FDA Purple Book (biologics), refreshed from public FDA data. Biosimilar launch timing is an estimate, not a guarantee.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
81165-0050-01 You're viewing this 1 VIAL, SINGLE-DOSE in 1 CARTON (81165-050-01) / 1 INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION in 1 VIAL, SINGLE-DOSE 2024-07-30 Active

🧭 About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is available.
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data ✓ Available
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 81165-050-01, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 81165-0050-01, written without dashes as 81165005001. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 81165-0050-01, the first segment (81165) is the labeler code FDA assigned to Hugel, Inc.; the middle segment (0050) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (01) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Hugel, Inc.. Listing status can change — the directory data on this page refreshes weekly.
Who lists this product with the FDA?
Hugel, Inc. is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🚨 Boxed Warning 161 words

WARNING: DISTANT SPREAD OF TOXIN EFFECT The effects of all botulinum toxin products, including LETYBO, may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening and there have been reports of death.

LETYBO is not approved for the treatment of spasticity or any conditions other than glabellar lines [see Warnings and Precautions ( 5.1 )] . WARNING: DISTANT SPREAD OF TOXIN EFFECT See full prescribing information for complete boxed warning. The effects of all botulinum toxin products, including LETYBO, may spread from the area of injection to produce symptoms consistent with botulinum toxin effects.

These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening and there have been reports of death. LETYBO is not approved for the treatment of spasticity or any conditions other than glabellar lines.

( 5.1 )

🎯 Indications and Usage 68 words

1 INDICATIONS AND USAGE LETYBO is indicated for the temporary improvement in the appearance of moderate to severe glabellar lines associated with corrugator and/or procerus muscle activity in adult patients. LETYBO is an acetylcholine release inhibitor and a neuromuscular blocking agent indicated for the temporary improvement in the appearance of moderate to severe glabellar lines associated with corrugator and/or procerus muscle activity in adult patients. ( 1 )

⏱️ Dosage and Administration ~3 min read

2 DOSAGE AND ADMINISTRATION The recommended dose is 0.1 mL (4 Units) by intramuscular injection into each of five sites, for a total dose of 20 Units ( 2.2 , 2.3 )

2.1Important Administration Instructions The potency Units of LETYBO (letibotulinumtoxinA-wlbg) for injection are specific to the preparation and assay utilized. They are not interchangeable with other preparations of botulinum toxin products and, therefore, units of biological activity of LETYBO cannot be compared to nor converted into units of any other botulinum toxin products assessed with any other specific assay [see Warnings and Precautions ( 5.2 ) and Description ( 11 )] . LETYBO should be administered no more frequently than every three months.

Consideration of the cumulative dose is necessary when treating adult patients with LETYBO for glabellar lines if other botulinum toxin products are or have been used to treat other indications approved for those products. The safe and effective use of LETYBO depends upon proper storage of the product, selection of the correct dose, and proper reconstitution and administration techniques.LETYBO After reconstitution, only use each LETYBO vial for one injection session and for only one patient. Discard any remaining solution in vial immediately after administration.

Reconstitution instructions are provided specifically for the 50 Unit and the 100 Unit vials ( Table 1 )

2.2Recommended Dosage The total recommended dose is 20 Units per treatment session divided into five equal intramuscular injections of 4 Units each (two injections in each corrugator muscle and one injection in the procerus muscle).

2.3Preparation and Dilution Technique LETYBO is supplied in a single-dose 50 or 100-Unit vial. Prior to intramuscular injection, reconstitute each freeze-dried vial of LETYBO with the required amount of sterile, preservative-free 0.9% Sodium Chloride Injection, USP to achieve a reconstituted solution at a concentration of 4 Units/0.1 mL (see Table 1). Table 1: Dilution Instructions for LETYBO Vials (50 and 100 Units) Vial Amount of Diluent* Added Resulting Dose Units per 0.1 mL 50 Units 1.25 mL 4 Units 100 Units 2.5 mL 4 Units *Preservative-free 0.9% Sodium Chloride Injection, USP Slowly inject the diluent into the vial.

Discard the vial if a vacuum does not pull the diluent into the vial. Dispose of any unused diluent. Gently mix LETYBO with 0.9% sodium chloride injection, USP by rotating the vial.

Reconstituted LETYBO is clear and colorless, and free of particulate matter. Inspect visually the reconstituted LETYBO for particulate matter and discoloration prior to administration. Do not use if the solution is cloudy or discolored or contains flakes or particles.

Administer LETYBO within 24 hours after reconstitution. During this time period, store unused reconstituted LETYBO in a refrigerator between 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. Do not freeze reconstituted LETYBO.

2.4Administration The upper eyelid margin position should be carefully examined for separation or weakness of the levator palpebrae superioris muscle. Evaluate the range of upper eyelid excursion while manually immobilizing the frontalis to assess degree of levator function and frontalis compensation. In order to reduce the complication of eyelid ptosis the following steps should be taken: Avoid injection near the levator palpebrae superioris, particularly in patients with larger brow depressor complexes.

Ensure the injected volume/dose is accurate and administer in a steady, controlled manner. Lateral corrugator injections should be placed at least 1 cm above the bony supraorbital ridge. Avoid injecting toxin closer than 1 centimeter above the central eyebrow.

Draw at least 0.5 mL of the properly reconstituted toxin into a sterile syringe and expel any air bubbles in the syringe barrel. Remove the needle used to reconstitute the product and attach a 30-31 gauge needle. Confirm the patency of the needle.

Inject a dose…

💊 Dosage Forms and Strengths 43 words

3 DOSAGE FORMS AND STRENGTHS For injection: 50 Units or 100 Units, freeze-dried powder in a single-dose vial for reconstitution with preservative-free 0.9% Sodium Chloride Injection, USP. For Injection: 50 Units or 100 Units freeze-dried powder in a single-dose vial ( 3 )

Contraindications 124 words

4 CONTRAINDICATIONS LETYBO is contraindicated in: Patients with known hypersensitivity to any botulinum toxin preparation or to any of the components in the LETYBO formulation [see Warnings and Precautions ( 5.4 )] . The presence of infection at the proposed injection site(s). Known hypersensitivity to any botulinum toxin preparation or to any of the components in the LETYBO formulation ( 4 ) Infection at the injection site ( 4 )

4.1Known Hypersensitivity to Botulinum Toxin BRANDNAME is contraindicated in individuals with known hypersensitivity to any botulinum toxin preparation or to any of the components in the formulation [see Warnings and Precautions ( 5.4 )].

4.2Infection at the Injection Site(s) BRANDNAME is contraindicated in the presence of infection at the proposed injection site(s).

⚠️ Warnings and Cautions ~3 min read

5 WARNINGS AND PRECAUTIONS Spread of toxin effects; swallowing and breathing difficulties can lead to death. Seek immediate medical attention if respiratory, speech or swallowing difficulties occur. ( 5.1 , 5.3 , 5.7 ) Potency Units of LETYBO are not interchangeable with other preparations of botulinum toxin products.

( 5.2 , 11 ) Potential serious adverse reactions after LETYBO injections for unapproved uses. ( 5.3 ) If a hypersensitivity reaction occurs, discontinue LETYBO and immediately initiate appropriate therapy. ( 5.4 ) Adverse event reports have been received involving the cardiovascular system, some with fatal outcomes.

Use caution when administering to patients with pre-existing cardiovascular disease. ( 5.5 ) Concomitant neuromuscular disorder may exacerbate clinical effects of treatment. ( 5.6 ) Use with caution in patients with compromised respiratory function or dysphagia ( 5.7 )

5.1Spread of Toxin Effects Postmarketing safety data from other approved botulinum toxins suggest that botulinum toxin effects may be observed beyond the site of local injection. The symptoms are consistent with the mechanism of action of botulinum toxin and may include asthenia, generalized muscle weakness, diplopia, ptosis, dysphagia, dysphonia, dysarthria, urinary incontinence, blurred vision and breathing difficulties. These symptoms have been reported hours to weeks after injection.

Swallowing and breathing difficulties can be life threatening and there have been reports of death related to spread of toxin effects. In unapproved uses and approved indications, symptoms consistent with spread of toxin effects have been reported at doses comparable to or lower than the maximum recommended total dose [see Use in Specific Populations ( 8.4 )] . LETYBO is not approved for any conditions other than glabellar lines.

Patients or caregivers should be advised to seek immediate medical care if swallowing, speech or respiratory difficulties occur.

5.2Lack of Interchangeability between Botulinum Toxin Products The potency units of LETYBO are specific to the preparation and assay method utilized. They are not interchangeable with other preparations of botulinum toxin products and, therefore, units of biological activity of LETYBO cannot be compared to or converted into units of any other botulinum toxin products assessed with any other specific assay method [see Description ( 11 )] .

5.3Serious Adverse Reactions with Unapproved Use Serious adverse reactions, including excessive weakness, dysphagia, and aspiration pneumonia, with some adverse reactions associated with fatal outcomes, have been reported in patients who received botulinum toxin injections for unapproved uses. In these cases, the adverse reactions may have resulted from the administration of botulinum toxin products to the site of injection and/or adjacent structures. In several of the cases, patients had preexisting dysphagia or other significant disabilities.

There is insufficient information to identify factors associated with an increased risk for adverse reactions associated with the unapproved uses of botulinum toxin products.

5.4Hypersensitivity Reactions Serious and/or immediate hypersensitivity reactions have been reported for botulinum toxin products. These reactions include anaphylaxis, serum sickness, urticaria, soft tissue edema, and dyspnea. If such a reaction occurs, discontinue further injection of LETYBO and immediately institute appropriate medical therapy [see Contraindications ( 4 )] .

5.5Cardiovascular System Adverse Reactions There have been reports following administration of botulinum toxins of adverse events involving the cardiovascular system, including arrhythmia and myocardial infarction, some with fatal outcomes. Some of these patients had risk factors including pre-existing cardiovascular disease. Use caution when administering to patients with pre-existing cardiovascular disease.

5.6 Increased Risk of Clinically Significant Effects with Pre-Existin…

🤒 Adverse Reactions ~3 min read

6 ADVERSE REACTIONS The following serious adverse reactions are discussed in greater detail in other sections of the labeling: Spread of Toxin Effects [see Warnings and Precautions ( 5.1 )] Hypersensitivity Reactions [see Contraindications ( 4 ) and Warnings and Precautions ( 5.4 )] Cardiovascular System Adverse Reactions [see Warnings and Precautions ( 5.5 )] Increased Neuromuscular Compromise in Patients with Pre-Existing Neuromuscular Disorders [see Warnings and Precautions ( 5.6 )] Dysphagia and Dyspnea [see Warnings and Precautions ( 5.7 )] Ophthalmic Adverse Reactions in Patients Treated for Glabellar Lines [see Warnings and Precautions ( 5.9 )] The most common adverse reaction is headache (2%).

( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact HUGEL at 1‑888-674-5355 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, the adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. In the three randomized, placebo-controlled, Phase 3 clinical trials that assess the use of LETYBO for the temporary improvement in the appearance of moderate to severe glabellar lines (BLESS I, II and III), 911 out of the 955 subjects who received a single dose treatment of 20 Units LETYBO and 310 out of the 317 subjects who received a single dose of placebo were included in safety analyses [see Clinical Studies ( 14 )] .

Table 2 lists the adverse reactions reported in more than one subject in the LETYBO group compared to the placebo in the placebo-controlled trials. Most adverse reactions occur within the first week following injection of LETYBO and while generally transient, may have a duration of several months or longer. Table 2: Adverse Reactions Reported in More Than One Subject in the LETYBO Group Compared to the Placebo Group in BLESS I, II and III Adverse Reaction Treatment LETYBO BLESS I, II, III N=911 n (%) PLACEBO BLESS I, II, III N=310 n (%) Headache* 17 (2%) 2 (1%) Brow ptosis** 3 (<1%) 0 Eyelid ptosis 3 (<1%) 0 Blepharospasm 2 (<1%) 0 * Includes headache, head discomfort, migraine, and procedural headache. ** Includes brow ptosis and brow heaviness.

The most frequently reported injection site reactions included administrative site swelling, facial pain, folliculitis, periorbital hematoma; and injection site bruising, reaction, pain, hematoma, nodule, pruritus, and mass. BLESS I, II and III also included an open label, extension part with LETYBO. The extension allowed subjects who had completed the double-blind portion of the trials to receive up to 3 additional elective LETYBO 20-Unit treatments for moderate to severe glabellar lines over a 48-week period.

Treatments were separated by at least a 3-month period. Of the 1,129 subjects enrolled in the open label extension part of the trials, the median number of treatments was 3. The adverse reaction profile was comparable to that reported in the randomized, single dose, double blind part of the trials.

Headache was the most common adverse reaction, reported in 2% of subjects, followed by injection site reactions (1%) [including contusion/bruising, administration site swelling, facial pain, periorbital hematoma, skin swelling; and injection site reaction, bruising, hematoma, mass, and nodule] and eyelid ptosis in 0.5% of subjects. The incidence of these adverse reactions did not increase with multiple re-treatments.

6.2Immunogenicity As with all therapeutic proteins, there is a potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant m…

🔄 Drug Interactions 112 words

7 DRUG INTERACTIONS No drug interaction studies have been conducted with LETYBO. Certain drugs may potentiate the effects of LETYBO which may result in excessive neuromuscular weakness and heighten systemic anticholinergic effects. Use caution with concurrent use of LETYBO with the following products and monitor closely for excessive neuromuscular weakness: Aminoglycosides or other agents interfering with neuromuscular transmission Anticholinergic drugs Botulinum neurotoxin products administered as the same time or within several months of LETYBO Muscle relaxants administered before or after administration of LETYBO Aminoglycoside antibiotics, anticholinergic agents, or any other agents that interfere with neuromuscular transmission may potentiate the effect of LETYBO; co-administer only with caution and close observation.

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👥 Use in Specific Populations ~2 min read

8 USE IN SPECIFIC POPULATIONS

8.1Pregnancy Risk Summary Available data from case reports with LETYBO use in pregnant women are insufficient to identify a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Systemic exposure following intramuscular injection of letibotulinumtoxinA-wlbg was not assessed [see Clinical Pharmacology ( 12.3 )] . In an animal reproduction study, intramuscular administration of letibotulinumtoxinA‑wlbg to rats during pregnancy resulted in adverse effects on fetal growth (decreased fetal body weight and skeletal ossification) at maternally toxic doses 3 times the maximum recommended human dose (MRHD) (see Data) .

The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data Animal Data An embryofetal development study was conducted in rats with letibotulinumtoxinA-wlbg. For comparison of animal to human doses based on a body weight comparison, the MRHD is set at 20 Units/subject (0.34 Units/kg for an average 60 kg subject). Administration to pregnant rats once daily during organogenesis (gestation days 5 to 16) caused decreased fetal body weight and decreased fetal skeletal ossification at doses ≥1 Unit/kg (3 times the MRHD.

These treatment related effects were associated with maternal toxicity.

8.2Lactation Risk Summary There are no data regarding the presence of letibotulinumtoxinA-wlbg in human or animal milk, its effects on the breastfed infant, or the effects on milk production. Systemic exposure following intramuscular injection of letibotulinumtoxinA-wlbg was not assessed [see Clinical Pharmacology ( 12.3 )] .The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for LETYBO and any potential adverse effects on the breastfed infant from LETYBO or from the underlying maternal condition.

8.4Pediatric Use The safety and effectiveness of LETYBO in pediatric patients have not been established.

8.5Geriatric Use The 3 clinical trials of LETYBO included 148 subjects age 65 and greater. Although no clinically meaningful differences in safety or efficacy were observed between older and younger subjects, clinical studies of LETYBO did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

🤰 Pregnancy ~1 min read

8.1Pregnancy Risk Summary Available data from case reports with LETYBO use in pregnant women are insufficient to identify a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Systemic exposure following intramuscular injection of letibotulinumtoxinA-wlbg was not assessed [see Clinical Pharmacology ( 12.3 )] . In an animal reproduction study, intramuscular administration of letibotulinumtoxinA‑wlbg to rats during pregnancy resulted in adverse effects on fetal growth (decreased fetal body weight and skeletal ossification) at maternally toxic doses 3 times the maximum recommended human dose (MRHD) (see Data) .

The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data Animal Data An embryofetal development study was conducted in rats with letibotulinumtoxinA-wlbg. For comparison of animal to human doses based on a body weight comparison, the MRHD is set at 20 Units/subject (0.34 Units/kg for an average 60 kg subject). Administration to pregnant rats once daily during organogenesis (gestation days 5 to 16) caused decreased fetal body weight and decreased fetal skeletal ossification at doses ≥1 Unit/kg (3 times the MRHD.

These treatment related effects were associated with maternal toxicity.

🧒 Pediatric Use 16 words

8.4Pediatric Use The safety and effectiveness of LETYBO in pediatric patients have not been established.

🧓 Geriatric Use 56 words

8.5Geriatric Use The 3 clinical trials of LETYBO included 148 subjects age 65 and greater. Although no clinically meaningful differences in safety or efficacy were observed between older and younger subjects, clinical studies of LETYBO did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

🆘 Overdosage 162 words

10 OVERDOSAGE Excessive doses of LETYBO may be expected to produce neuromuscular weakness with a variety of symptoms. Respiratory support may be required where excessive doses cause paralysis of the respiratory muscles. Symptoms of overdose are likely not to be present immediately following injection.

Should accidental injection or oral ingestion occur, or overdose be suspected, the person should be medically supervised for several weeks for signs and symptoms of systemic muscular weakness or paralysis. In the event of overdose, antitoxin raised against botulinum toxin is available from the Centers for Disease Control and Prevention (CDC) in Atlanta, GA. However, the antitoxin will not reverse any botulinum toxin-induced effects already apparent by the time of antitoxin administration.

In the event of suspected or actual cases of botulinum toxin poisoning, please contact your local or state Health Department to process a request for antitoxin through the CDC. If you do not receive a response within 30 minutes, please contact the CDC directly at 1-770-488-7100.

🧬 Clinical Pharmacology 131 words

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action LETYBO blocks cholinergic transmission at the neuromuscular junction by inhibiting the release of acetylcholine. When injected intramuscularly at therapeutic doses, LETYBO is internalized into the nerve terminal, translocates into the neuronal cytosol where it cleaves SNAP25, a protein necessary for synaptic membrane docking and subsequent release of acetylcholine which produces a dose dependent decrease of muscle function. Recovery of muscle function is gradual due to degradation of the neurotoxin and formation of axonal sprouts.

Muscle reinnervation occurs, leading to a slow reversal of the pharmacological effects of LETYBO.

12.2Pharmacodynamics No formal pharmacodynamic studies have been conducted with LETYBO.

12.3Pharmacokinetics Using currently available analytical technology, it is not possible to detect LETYBO in the peripheral blood following intramuscular injection at the recommended doses.

🧬 Mechanism of Action 92 words

12.1Mechanism of Action LETYBO blocks cholinergic transmission at the neuromuscular junction by inhibiting the release of acetylcholine. When injected intramuscularly at therapeutic doses, LETYBO is internalized into the nerve terminal, translocates into the neuronal cytosol where it cleaves SNAP25, a protein necessary for synaptic membrane docking and subsequent release of acetylcholine which produces a dose dependent decrease of muscle function. Recovery of muscle function is gradual due to degradation of the neurotoxin and formation of axonal sprouts.

Muscle reinnervation occurs, leading to a slow reversal of the pharmacological effects of LETYBO.

📦 How Supplied / Storage and Handling 70 words

16 HOW SUPPLIED/STORAGE AND HANDLING How Supplied LETYBO (letibotulinumtoxinA-wlbg) for injection is a sterile, white, freeze-dried powder supplied in a single-dose vial in the following sizes: Carton containing one 50 Units/vial (NDC 81165-050-01) Carton containing one 100 Units/vial (NDC 81165-100-01) Storage and Handling Unopened LETYBO vials should be stored in a refrigerator between 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. Do not freeze.

📋 Description 82 words

11 DESCRIPTION LetibotulinumtoxinA-wlbg is an acetylcholine release inhibitor and a neuromuscular blocking agent. LetibotulinumtoxinA-wlbg is a 900 kDa botulinum toxin type A, produced from fermentation of Clostridium botulinum . LETYBO (letibotulinumtoxinA-wlbg) for injection is supplied as a sterile, preservative-free, white, freeze-dried powder in a single-dose vial for intramuscular use after reconstitution.

Each vial contains either 50 Units of letibotulinumtoxinA-wlbg, albumin human (0.25 mg) and sodium chloride (0.45 mg); or 100 Units of letibotulinumtoxinA-wlbg, albumin human (0.5 mg) and sodium chloride (0.9 mg).

💬 Information for Patients 164 words

17 PATIENT COUNSELING INFORMATION Advise the patient to read the FDA-approved patient labeling (Medication Guide). Swallowing, Speaking or Breathing Difficulties, or other Unusual Symptoms Advise patients or caregivers to seek immediate medical care if swallowing, speech, or respiratory disorders arise or existing symptoms worsen [see Warnings and Precautions ( 5.1 , 5.6 )] . Ability to Operate Machinery or Vehicles Advise patients that if loss of strength, muscle weakness, blurred vision or drooping eyelids occur, they should avoid driving a car or engaging in other potentially hazardous activities [see Warnings and Precautions ( 5.1 )] .

Ophthalmic Adverse Reaction Inform patients that LETYBO injection may cause eye dryness. Advise patients to report symptoms of eye dryness (e.g., eye pain, eye irritation, photosensitivity or changes in vision) to their healthcare provider [see Warnings and Precautions ( 5.9 )] . Manufactured by: Hugel, Inc.

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💬 Patient Medication Information ~3 min read

MEDICATION GUIDE MEDICATION GUIDE LETYBO (le tye boe) (letibotulinumtoxinA-wlbg) for injection, for intramuscular use What is the most important information I should know about LETYBO? LETYBO may cause serious side effects that can be life threatening. Call your healthcare provider or get medical help right away if you have any of these problems after treatment with LETYBO: Problems swallowing, speaking, or breathing.

These problems can happen hours, days, or weeks after an injection of LETYBO if the muscles that you use to breathe and swallow become weak after the injection. Death can happen as a complication if you have severe problems with swallowing or breathing after treatment with LETYBO. People with certain breathing problems may need to use muscles in their neck to help them breathe.

These people may be at greater risk for serious breathing problems with LETYBO. Swallowing problems may last for several months. People who cannot swallow well may need a feeding tube to receive food and water.

If swallowing problems are severe, food or liquids may go into your lungs. People who already have swallowing or breathing problems before receiving LETYBO have the highest risk of getting these problems. Spread of toxin effects .

In some cases, the effect of botulinum toxin may affect areas of the body away from the injection site and cause symptoms of a serious condition called botulism. The symptoms of botulism include: loss of strength and muscle weakness all over the body double vision, blurred vision, and drooping eyelids hoarseness or change or loss of voice trouble saying words clearly loss of bladder control trouble breathing trouble swallowing These symptoms can happen hours, days, or weeks after you receive an injection of LETYBO. These problems could make it unsafe for you to drive a car or do other dangerous activities.

See “What should I avoid while receiving LETYBO?” What is LETYBO? LETYBO is a prescription medicine for adults that is injected into muscles to temporarily improve the look of moderate to severe frown lines between the eyebrows (glabellar lines). It is not known if LETYBO is safe and effective for use in children.

Do not receive LETYBO if you: are allergic to LETYBO or any of the ingredients in LETYBO. See the end of this Medication Guide for a list of ingredients in LETYBO. had an allergic reaction to any other botulinum toxin product such as rimabotulinumtoxinB (MYOBLOC), onabotulinumtoxinA (BOTOX, BOTOX COSMETIC), abobotulinumtoxinA (DYSPORT), incobotulinumtoxinA (XEOMIN), prabotulinumtoxinA-xvfs (JEUVEAU), or daxibotulinumtoxinA-lanm (DAXXIFY). have a skin infection at the planned injection site. Before receiving LETYBO, tell your healthcare provider about all of your medical conditions, including if you: have a disease that affects your muscles and nerves (such as amyotrophic lateral sclerosis [ALS or Lou Gehrig’s disease], myasthenia gravis or Lambert-Easton syndrome).

See “What is the most important information I should know about LETYBO?” had any side effect from any botulinum toxin product in the past have or have had a breathing problem, such as asthma or emphysema have or have had swallowing problems have or have had bleeding problems have or have had heart problems plan to have surgery have weakness of your forehead muscles, such as trouble raising your eyebrows have drooping eyelids have had surgery on your face have had dry eyes with the use of botulinum toxin products in the past are pregnant or plan to become pregnant.

It is not known if LETYBO can harm your unborn baby. are breastfeeding or plan to breastfeed. It is not known if LETYBO passes into breast milk. Talk to your healthcare provider about the best way to feed your baby during treatment with LETYBO.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Using LETYBO with certain other medicines may cause serious side effects. Do not…

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.