利特昔替尼(Ritlecitinib)适应症,功效与作用,用法用量,副作用,注意事项,价格

R&D and marketing information of ritexitinib

R&D information

Ritlecitinib is a new small molecule inhibitor targeting JAK3 and TEC developed by Pfizer.

Listing information

On June 23, 2023, ritexitinib was approved in the United States for the treatment of severe alopecia areata in adults and adolescents 12 years of age and older.

On June 26, 2023, ritexitinib was approved in Japan for the treatment of alopecia areata.

On October 19, 2023, the China National Medical Products Administration approved the marketing of ritexitinib in my country, which is suitable for adolescents and adult patients with severe alopecia areata aged 12 years and above.

On October 30, 2023, the world’s first generic version of ritixitinib (trade name: LuciRit) was approved for marketing by the Food and Drug Department (FDD) of the Ministry of Health of Laos.

Indications for Ritlecitinib

It is a kinase inhibitor indicated for the treatment of severe alopecia areata in adults and adolescents aged 12 years and older. Concomitant use with other JAK inhibitors, biological immunomodulators, cyclosporine, or other potent immunosuppressants is not recommended.

The efficacy of ritexitinib

1. Suppress the immune system: Ritexitinib inhibits the immune system from killing hair follicle cells by inhibiting tyrosine kinases in the JAK3 and TEC kinase families, blocking common gamma cytokine signaling and reducing the cytolytic activity of NK and CD8+ cells.

2. Treatment of alopecia areata: Ritexitinib has a significant effect in the treatment of alopecia areata. It is a covalent AK3/TEC dual kinase inhibitor that is taken orally once a day. By inhibiting IL-15 and CD8 cytokine signal transduction, it achieves the purpose of inhibiting the immune system from killing hair follicle cells, and ultimately achieves the effect of treating alopecia areata.

3. Reduce toxicity: Compared with the first-generation pan-JAK inhibitors, ritexitinib has more advantages in reducing toxicity.

The role of ritexitinib

Ritlecitinib is a drug that selectively inhibits Janus kinase 3 (JAK3) and other tyrosine kinases. It achieves the effect of treating alopecia areata by inhibiting JAK3-dependent receptor-mediated cytokine-induced STAT phosphorylation and immune receptor signaling that depends on members of the TEC kinase family.

Ritexitinib for the treatment of alopecia areata

In a randomized, double-blind, multicenter, Phase 2b-3 trial, 1,097 patients aged 12 years and older with alopecia areata and at least 50% scalp hair loss were randomly assigned to oral rituxitinib or placebo once daily for 24 weeks. Of these, 718 were randomly assigned to receive 200 mg + 50 mg (n = 132), 200 mg + 30 mg (n = 130), 50 mg (n = 130), 30 mg (n = 132), 10 mg (n = 63), 50 mg (n = 66) placebo, or 200 mg + 50 mg (n = 66).

At Week 24, 38 of 124 patients in the 200 mg + 50 mg ritixitinib group, 27 patients in the 200 mg + 30 mg group, 29 patients in the 50 mg group, 17 patients in the 30 mg group, and 2 patients in the placebo group had a response based on a SALT score of 20 or less.

The difference in response rate based on a SALT score of 20 or less between the placebo and ritixitinib 200 mg + 50 mg groups was 29 ± 1%. Ritexitinib is effective and well tolerated in patients with alopecia areata aged 12 years and older and may be a suitable treatment option for systemic treatment candidates for alopecia areata.

Ritexitinib

1. Recommended dose: The recommended dose of ritexitinib is 50 mg, taken once a day, with or without food. Swallow the capsule whole. If you miss a dose of medication, take it as soon as possible. If the next dose is less than 8 hours away, no make-up dose is required and the dose will be resumed at the regularly scheduled time thereafter.

2. Patients with severe liver damage: Ritexitinib is not recommended for patients with severe liver damage.

Ritexitinib side effects

The main side effects of ritexitinib include headache, diarrhea, acne, rash, urticaria, folliculitis, fever, atopic dermatitis, dizziness, increased blood creatine phosphokinase, herpes zoster, decreased red blood cell count, and stomatitis. Serious side effects mainly include serious infections, malignant tumors and lymphoproliferative diseases, thromboembolic events, and hypersensitivity reactions.

Measures to deal with side effects of ritexitinib

1. Headache: Headache is usually temporary and can be relieved by rest and appropriate exercise.

2. Diarrhea: Mild diarrhea can be relieved by adjusting your diet, increasing water intake, and avoiding intestinal irritating foods. If the diarrhea continues to be severe, you should use antidiarrheal drugs, such as montmorillonite powder, as directed by your doctor.

3. Acne, rash, and urticaria: They can be relieved by keeping the skin clean, avoiding the use of irritating cosmetics and skin care products, and wearing loose, breathable clothing.

4. Folliculitis: Keep the affected area clean and dry, avoid scratching and friction, and change clothes frequently.

5. Fever: When you have a fever, drink plenty of water to replenish your body and rest properly. You can use physical cooling methods, such as nibbling warm water and applying cold compresses to your forehead. If the fever persists, you can use antipyretic drugs such as ibuprofen and acetaminophen as directed by your doctor.

6. Atopic dermatitis: If the symptoms of atopic dermatitis worsen during the medication period, you should consult your doctor to adjust the treatment plan.

7. Dizziness: When dizzy, you should stay in bed and avoid getting up suddenly.

8. Elevated blood creatine phosphokinase: Monitor regularly during medication and follow the doctor's recommendations for treatment.

9. Herpes zoster: See a doctor promptly and follow the doctor’s advice for treatment.

10. Decreased red blood cell count: Monitor red blood cell count regularly during medication.

11. Stomatitis: Keep your mouth clean, avoid eating spicy and irritating foods, and use anti-inflammatory and analgesic oral spray or mouthwash.

Ritexitinib medication

1. Hypersensitivity reaction: If a clinically significant hypersensitivity reaction occurs, ritexitinib should be discontinued.

2. Abnormal laboratory tests: Perform ALC and platelet counts before starting treatment with rituxitinib. Based on abnormal ALC and platelet counts, it is recommended to interrupt or stop treatment.

3. Vaccination: Avoid using live vaccines during or shortly before treatment with rituxitinib.

Ritexitinib price and drug purchasing channels

As of November 2, 2023, the price of ritexitinib in the United States is relatively expensive, but the reference price in my country is not yet clear. Price information will be updated as soon as possible. If you need to purchase medicine or want to know more detailed information, you can consult overseas medical institutions to obtain it.

Dosage forms and specifications of ritexitinib

Capsules: 50mg*28 tablets, the capsule body is yellow, the capsule cap is blue, the capsule body is printed with the words "RCB 50", and the capsule cap is printed with the words "Pfizer" in black.

How to store ritexitinib

1. Store at room temperature of 68℉-77℉ (20℃-25℃).

2. Keep ritexitinib in its original packaging.

3. The bottle of rituxitinib has a child-proof seal and contains a tank containing a desiccant (desiccant), which is not edible.

References:

King B, Zhang multicentre, phase 2b-3 trial. Lancet. 2023 May 6;401(10387):1518-1529. doi: 10.1016/S0140-6736(23)00222-2. Epub 2023 Apr 14. Erratum in: Lancet. 2023 Jun 10;401(10392):1928. PMID: 37062298.

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