Ilumya
Ilumya
Generic Name
Ilumya
Mechanism
- IL‑23 inhibition: Binds exclusively to the p19 subunit of IL‑23, blocking its interaction with the IL‑12/IL‑23 receptor heterodimer on T‑cells and dendritic cells.
- Th17 axis suppression: Prevents downstream activation of RORγt‑expressing Th17 cells, reducing production of IL‑17A/F, IL‑22, and GM‑CSF that drive keratinocyte hyperproliferation.
- Selective cytokine blockade: Does not inhibit IL‑12, thereby preserving host immunity against intracellular pathogens.
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Pharmacokinetics
| Parameter | Typical Value | Notes |
| Absorption | SC; bioavailability ≈ 80 % | Peak serum levels at ~26–30 days post‑dose. |
| Distribution | Volume of distribution ≈ 4–5 L | Predominantly extracellular fluid. |
| Metabolism | Proteolytic catabolism to peptides/AA | No hepatic metabolism by CYP450. |
| Elimination | CL ≈ 1.2 mL min⁻¹ kg⁻¹ | Half‑life ≈ 22 days (steady‑state troughs maintained). |
| Special Populations | No dose adjustment for age, gender, or mild‑moderate renal/hepatic impairment. | Limited data in severe hepatic dysfunction. |
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Indications
- Moderate‑to‑severe plaque psoriasis (adult patients)
- Licensed as a first‑line biologic in combination or monotherapy.
- Potential off‑label use:
- Psoriatic arthritis – limited experience; clinical trials ongoing.
- Other IL‑23–mediated inflammatory dermatoses – investigational.
*Important*: Not approved for pediatric psoriasis.
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Contraindications
- Contraindications
- Known hypersensitivity to *tildrakizumab* or any excipient.
- Severe immunodeficiency (e.g., HIV–CD4 < 200 cells/µL).
- Active, uncontrolled infections (TB, hepatitis, fungal).
- Warnings & Precautions
- Infection risk: Screening for latent TB (IGRA/QFT or TST) and hepatitis B/C before initiation.
- Malignancy surveillance: No increased risk of lymphoma established, but monitor for neoplasms per standard protocols.
- Pregnancy & Lactation: Data limited; use only if benefits outweigh risks.
- Vaccinations: Live vaccines contraindicated during therapy; non‑live vaccines tolerated.
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Dosing
| Step | Dosage | Schedule | Route | Guidance |
| Loading phase | 100 mg (SC) | Weeks 0 and 4 | Subcutaneous (deltoid or thigh) | Use pre‑filled syringe or autoinjector. |
| Maintenance | 100 mg (SC) | Every 12 weeks thereafter | Switch to an injection device if preferred. | |
| Renal/hepatic impairment | No adjustment |
• Missed dose: Administer within 48 h; after that, resume the 12‑week interval.
• Switching from TNF inhibitors: No special bridging needed; continue with *tildrakizumab* per dosing schedule.
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Monitoring
| Parameter | Frequency | Rationale |
| Baseline TB screening (IGRA/QFT or TST) | Before first dose | To rule out latent TB |
| Baseline hepatitis B/C serology | Before first dose | To detect occult infections |
| Injection site assessment | Each visit | Detect inflammation or allergic reaction |
| CBC / CMP | Every 3–6 months | Detect cytopenias, hepatic dysfunction |
| Liver enzymes | Every 3–6 months | Monitor for hepatotoxicity |
| Adverse event diary | Ongoing | Capture infections, allergic reactions, mood changes |
• Vaccination status should be updated during each visit; avoid live vaccines during therapy.
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Clinical Pearls
- “12‑Week Convenience”: The long half‑life of *tildrakizumab* permits 12‑week intervals, enhancing adherence compared with other biologics requiring monthly dosing.
- IL‑23 vs TNF‑α: Unlike TNF‑α inhibitors, *tildrakizumab* does not increase demyelinating disease risk, making it a safer option for patients with a history of multiple sclerosis.
- Drug–Interaction Profile: As it’s not metabolized by CYP450, *tildrakizumab* poses minimal drug–drug interactions, even in poly‑pharmacy patients.
- Pregnancy Label: Category B; however, limited safety data exist—obtain informed consent and consider discontinuation if pregnancy is confirmed.
- Psoriatic Arthritis Off‑Label: Emerging evidence suggests *tildrakizumab* may benefit PsA; consider it after failure of conventional therapy, but monitor joint counts closely.
- Weight Consideration: Body weight has *not* been shown to alter the pharmacokinetics; dosing remains flat 100 mg regardless of BMI.
- Switching from Other IL‑23 Inhibitors: A seamless transition (e.g., from guselkumab) is feasible without a washout period, but coordinate infusion schedules to avoid overlapping high troughs.
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• Summary: *Ilumya* (tildrakizumab) offers targeted IL‑23 blockade with a favorable safety profile and convenient dosing schedule, positioning it as a first‑line biologic for plaque psoriasis while presenting a unique benefit set for patients at risk of TNF‑α inhibitor adverse events.