Daratumumab: Effects, dosage and usage notes

Article by Pharmacist Nguyen Le Trang - Faculty of Pharmacy - Vinmec Times City International General Hospital

Daratumumab is commonly prescribed in the treatment of multiple myeloma. Depending on the patient's condition, the doctor may prescribe a different dose and form of Daratumumab. Therefore, you are absolutely not allowed to arbitrarily use drugs without a prescription.

Daratumumab is a CD38 inhibitor monoclonal antibody. This is a glycoprotein expressed at high levels on the surface of myeloma cells, with low levels on healthy bone marrow cells and lymphocytes. Upon binding to CD38, the drug inhibits the growth of CD38-expressing cells by initiating direct apotosis as well as immune-mediated cell lysis. This drug has the brand name Darzalex 100mg, 400mg

Daratumumab is indicated in the treatment of multiple myeloma. During the use of this drug, the doctor will diagnose and may prescribe a combination of several different drugs to increase the healing effect. Specifically:
For early stage multiple myeloma: Daratumumab is combined with bortezomib, melphalan, prednisone for patients who are not planning to have autologous stem cell transplantation. Or in combination with lenalidomide and low-dose dexamethasone for patients who are not planning on autologous stem cell transplantation. This drug is used in combination with thalidomide, bortezamide, and dexamethasone for patients planning autologous stem cell transplantation.
For patients with recurrent, progressive multiple myeloma: alone or in combination with lenalidomide/pomalidomide and low-dose dexamethasone; in combination with bortezomib and dexamethasone.

3.1. Dosage of Daratumumab will have a different dosage regimen between regimens, usually starting at 16mg/kg weekly, then every 2 weeks and every 4 weeks.
3.2. How to use Daratumumab is used intravenously, not intravenously, using a 0.2 or 0.22mcm filter when infusion.
Administer medication 1-3 hours before infusion to prevent infusion/allergic reactions: corticosteroids (methylprednisolone 100mg IV or equivalent, may reduce dose in later cycles if tolerated), paracetamol (oral) or intravenous 650mg-1000mg), antihistamines (oral or intravenous diphenhydramine 25-50mg). Rates should be closely controlled: start at 50ml/h for 1 hour, monitor if no reaction occurs, increase dose by 50ml/hour every hour, maximum rate 200ml/h.
After infusion of Daratumumab: methylprednisolone 20mg (or equivalent)/day for 2 days (note that patients with a history of chronic obstructive pulmonary disease consider bronchodilators and inhaled corticosteroids).

Based on the available data, Daratumumab is highly susceptible to post-infusion reactions. Therefore, doctors as well as patients need to have some notes when using this drug:
Infusion reactions occur with a very high rate. Patients may present with mild to moderate symptoms such as cough, irritability, chills, vomiting, nausea, chest tightness, pruritus, and hypotension, which may include anaphylaxis with other manifestations. present bronchospasm, dyspnea, laryngeal edema, acute pulmonary edema). Drugs that interfere with serological tests: CD38 receptors are attached to the surface of both red blood cells when the drug is administered. Daratumumab interferes with the results of the indirect Coombs test, causing false-positive results that can persist for up to 6 months after stopping the drug. It is necessary to test Coombs before taking the drug and notify the blood bank/hematology department about the patient's drug use. Daratumumab does not change ABO or Rh blood type. Effects on hepatitis B reactivation: hepatitis B-associated tests should be reviewed (HbsAg, HbsAb, HbcAb). If the patient tests positive, clinical and laboratory findings should be monitored for at least 6 months after discontinuation of the drug. Doctors recommend that even if you have any symptoms after the infusion of Daratumumab, you need to inform your doctor. Thanks to that, the doctor will have methods to improve and control this condition.