DARZALEX FASPRO
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DARZALEX FASPRO (DARZALEX FASPRO).
Daratumumab is a human IgG1κ monoclonal antibody that binds to CD38, a transmembrane glycoprotein highly expressed on the surface of multiple myeloma cells. It induces tumor cell death through multiple mechanisms, including complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and apoptosis via cross-linking. It also reduces the activity of CD38-positive immunosuppressive cells (e.g., regulatory T cells, B cells, and myeloid-derived suppressor cells).
| Metabolism | Daratumumab is a monoclonal antibody; it is eliminated via intracellular catabolism into small peptides and amino acids. No specific metabolic pathways or enzymes are involved. |
| Excretion | Daratumumab is eliminated primarily through intracellular catabolism and subsequent proteolytic degradation; renal excretion is minimal (<1% of dose as unchanged drug in urine), biliary/fecal excretion is negligible. |
| Half-life | Terminal elimination half-life is approximately 16 days (range 11–22 days) after subcutaneous administration of DARZALEX FASPRO, supporting once-monthly dosing due to prolonged target-mediated clearance. |
| Protein binding | Daratumumab is a monoclonal IgG1 antibody; total protein binding is primarily to serum immunoglobulins (IgG) with no specific carrier proteins; essentially 100% bound as a therapeutic antibody. |
| Volume of Distribution | Volume of distribution is approximately 5.0 L (range 4.0–6.5 L) corresponding to plasma volume (0.07 L/kg for a 70 kg patient), indicating limited extravascular distribution, consistent with monoclonal antibodies. |
| Bioavailability | Bioavailability after subcutaneous administration (DARZALEX FASPRO) is approximately 69% relative to intravenous daratumumab, based on co-formulation with recombinant human hyaluronidase. |
| Onset of Action | Time to clinical effect following subcutaneous administration: pharmacodynamic effects (complement-mediated cytotoxicity) begin within 24 hours; measurable reduction in serum M-protein typically observed within 2–4 weeks after initiation. |
| Duration of Action | Duration of action extends throughout the dosing interval (weekly to monthly); clinical efficacy maintained with continued receptor occupancy and M-protein suppression. After cessation, pharmacodynamic effects persist for several months due to slow elimination. |
Daratumumab 1800 mg subcutaneously over 3-5 minutes once weekly for 8 weeks, then every 2 weeks for 8 doses, then every 4 weeks thereafter. Administered in combination with hyaluronidase (fixed dose 30,000 U).
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (CrCl ≥30 mL/min). Data insufficient for severe renal impairment (CrCl <30 mL/min) or hemodialysis. |
| Liver impairment | No dose adjustment required for mild (Child-Pugh A) or moderate (Child-Pugh B) hepatic impairment. Data insufficient for severe (Child-Pugh C). |
| Pediatric use | Safety and efficacy not established in pediatric patients. |
| Geriatric use | No specific dose adjustment recommended based on age alone. Monitor for adverse reactions such as infusion-related reactions and infections. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for DARZALEX FASPRO (DARZALEX FASPRO).
| Breastfeeding | No data on the presence of daratumumab in human milk, its effects on the breastfed infant, or milk production. Daratumumab is a large protein molecule that is likely degraded in the infant gastrointestinal tract. However, consider the developmental and health benefits of breastfeeding alongside the mother's clinical need. M/P ratio: unknown. |
| Teratogenic Risk | Daratumumab (DARZALEX FASPRO) is an IgG1 monoclonal antibody. IgG molecules are known to cross the placental barrier. Based on its mechanism of action (CD38-directed cytolytic activity), there is a potential for fetal B-cell depletion and immunosuppression. Animal studies are not available. Advise patients of potential fetal harm. Avoid use during pregnancy unless benefit outweighs risk. First trimester: minimal transfer; risk theoretical. Second and third trimesters: increased placental transfer; risk of fetal B-cell lymphopenia and immunosuppression. |
■ FDA Black Box Warning
None.
| Serious Effects |
None.
| Precautions | ["Infusion-related reactions (severe, including anaphylactic reactions) – premedicate and monitor during infusion; discontinue if severe reactions occur.","Increased risk of infections (including opportunistic infections) – monitor for signs of infection and manage promptly.","Neutropenia and thrombocytopenia – monitor blood counts regularly.","Interference with blood transfusion compatibility testing (daratumumab binds to CD38 on red blood cells) – type and screen patients prior to treatment; notify blood bank about daratumumab use.","Hepatitis B virus reactivation – screen for HBV prior to treatment; monitor during and after therapy.","Embryo-fetal toxicity – can cause fetal harm; advise contraception in females of reproductive potential."] |
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| Fetal Monitoring | Monitor for infusion-related reactions during administration. For pregnant patients, consider fetal monitoring (ultrasound) for signs of fetal B-cell depletion or immunosuppression. Monitor maternal blood counts for cytopenias. Assess for infections due to potential immunosuppression. |
| Fertility Effects | No human data on fertility effects. In animal studies, no specific fertility studies conducted. Mechanism of action (CD38 binding) may affect immune cells; however, no direct effect on reproductive organs is expected. Potential indirect effects from disease state (multiple myeloma) may impact fertility. |