Instructions for Ofatumumab

1. Generic name: ofatumumab

Product name:ARZERRA/Kesimpta

All names: Ofatumumab Injection, Ofatumumab, Quanxinda, Ofatumumab Injection

2. Indications:

1. Ofatumumab (Ofatumumab) is suitable for the treatment of chronic lymphocytic leukemia (CLL):

(1) is used in combination with chlorambucil for the treatment of patients with previously untreated CLL who are considered unsuitable for treatment with fludarabine;

(2) in combination with fludarabine and cyclophosphamide for the treatment of patients with relapsed CLL;

(3) Extended treatment for patients who experience a complete or partial response after at least two courses of treatment for relapsed or progressive CLL;

(4) For the treatment of patients with CLL refractory to fludarabine and alemtuzumab.

2. Multiple sclerosis (MS): Ofatumumab is also indicated for the treatment of relapsing forms of multiple sclerosis in adults, including clinically isolated syndrome, relapsing-remitting disease and active secondary progressive disease.

3. Usage and dosage:

1. Chronic lymphocytic leukemia (CLL):

(1) Previously untreated CLL: The recommended dose and schedule for coadministration with chlorambucil is: 300 mg on day 1, 1 week later 1000 mg on day 8 (cycle 1), and 1000 mg on day 1 of subsequent 28-day cycles for a minimum of 3 cycles until optimal response or a maximum of 12 cycles.

(2) Relapsed CLL: The recommended dose and schedule for the combination of fludarabine and cyclophosphamide is: 300 mg on day 1, 1000 mg on day 8 1 week later (cycle 1), and 1000 mg on day 1 of subsequent 28-day cycles for up to 6 cycles.

(3)Extended treatment of CLL: The recommended dosage and regimen for extended treatment of CLL with single agent is: 300mg on day 1, 1000mg on day 8 after 1 week, 1000mg after 7 weeks, and once every 8 weeks thereafter, up to 2 years.

(4)RefractoryCLL: The recommended dose and regimen is12 doses, and the administration method includes: Initial dose of 300mg on day 1 week, followed by 2000 mg per week mg for 7 doses (2nd to 8th infusion) for 4 weeks, then 2000 mg for 4 doses every4 weeks thereafter (9th to 12th infusion).

2. Multiple sclerosis (MS):

The recommended dose of ofatumumab is:: 20 mg administered by subcutaneous injection initially at weeks 0, 1, and 2, subsequently 20 mg administered subcutaneously once monthly starting at week 4.

3. Dose adjustment: For infusion reactions of any severity, interrupt the infusion; patients who develop allergic reactions to ofatumumab should permanently discontinue treatment.

4. Adverse reactions:

The most common side effects of ofatumumab are upper respiratory tract infection(nose and throat infection), urinary tract infection, injection site reactions (redness, pain, itching, and swelling) and injection-related reactions (fever, headache, muscle pain, chills, and fatigue) Labor), neutropenia, etc. Adverse reactions that occurred after marketing include cardiac arrest (infusion-related cardiac events), mucocutaneous reactions (Stevens-Johnson syndrome, porphyria cutanea tarda).

5. Storage:

Ofatumumab needs to be refrigerated between 2 and 8°C (36 and 46°F). Do not freeze. Vials should be stored protected from light until use. To avoid foaming, do not shake. If necessary, ofatumumab may be stored at room temperature not exceeding 30°C (86°F) for 7 days. Write the date you removed it from the refrigerator in the space provided on the carton label. If stored below 30°C (86°F), unused ofatumumab may be returned to the refrigerator and must be used within the next 7 days or discarded after 7 days.

6. Mechanism of action:

Ofatumumab specifically binds to the large and small extracellular loops of the CD20 molecule, CD20 molecules are expressed on normal B lymphocytes (pre-B lymphocytes to mature B lymphocytes) and B-cell CLL. CD20 molecules are not shed from the cell surface, nor are they internalized upon antibody binding. The Fab domain of ofatumumab binds to the CD20 molecule, and the Fc domain mediates immune effector function, leading to B cell lysis in vitro. Data suggest that possible mechanisms of cell lysis include complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity.

The original drug of ofatumumab has been launched in China and has also been included in medical insurance. Only patients who meet the indications can be reimbursed. The price is around tens of thousands of yuan, and domestic purchase channels are relatively difficult. The European version of ofatumumab original drug specifications20mg/0.4mL each sold overseas may cost around RMB 16,000 (the price may fluctuate due to the exchange rate). It is expensive and there are currently no generics of ofatumumab. For more drug information and specific prices, please consult a medical consultant.