Definition
- Chimeric Antigen Receptor (CAR) T-cell therapy is an adoptive cellular immunotherapy.
- Patient’s own T-cells are genetically engineered (via viral vector) to express a synthetic receptor targeting CD19, a B-cell surface antigen.
- Once infused, CAR T-cells recognize and kill malignant B-cells.
FDA/Health Canada Approved Anti-CD19 CAR T Products
| Drug (Brand) | Indications | Patient Population |
|---|---|---|
| Tisagenlecleucel (Kymriah®) | Pediatric/young adult B-cell ALL (≤25 yrs), relapsed/refractory DLBCL | Pediatric + Adult |
| Axicabtagene ciloleucel (Yescarta®) | Relapsed/refractory LBCL after ≥2 lines; follicular lymphoma (FL) | Adults |
| Lisocabtagene maraleucel (Breyanzi®) | Relapsed/refractory LBCL, FL, and CLL/SLL | Adults |
| Brexucabtagene autoleucel (Tecartus®) | Mantle cell lymphoma (MCL), B-ALL (adults) | Adults |
| Idecabtagene vicleucel (Abecma®) | (Anti-BCMA, not CD19 — for myeloma) | — |
| Ciltacabtagene autoleucel (Carvykti®) | (Anti-BCMA, not CD19 — for myeloma) | — |
(Focusing here only on CD19-directed CAR T)
Process
- Leukapheresis – Collect patient T-cells
- Genetic modification – T-cells transduced with CAR construct (anti-CD19)
- Ex-vivo expansion – Engineered T-cells multiplied
- Lymphodepleting chemotherapy – Typically fludarabine + cyclophosphamide (days –5 to –3)
- CAR T-cell infusion (Day 0) – Single IV infusion
- Monitoring phase – Close inpatient or specialized center monitoring for toxicity
Key Toxicities
- Cytokine Release Syndrome (CRS)
- Due to massive cytokine release (IL-6, IFN-γ, TNF-α)
- Symptoms: fever, hypotension, hypoxia, organ dysfunction
- Grading (ASTCT criteria): Grade 1 (fever only) → Grade 4 (life-threatening)
- Treatment:
- First-line: Tocilizumab (anti-IL-6R)
- Add corticosteroids if severe or refractory
- Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS)
- Symptoms: confusion, aphasia, seizures, cerebral edema
- Management: Corticosteroids (dexamethasone, methylprednisolone); seizure prophylaxis (levetiracetam)
- Note: Tocilizumab is not effective for isolated ICANS
- B-cell aplasia / hypogammaglobulinemia
- On-target effect → long-term risk of infections
- May require IVIG replacement
- Prolonged cytopenias
- Neutropenia, thrombocytopenia, anemia
- Monitor CBC frequently
- Infections
- From immunosuppression, prolonged cytopenias, hypogammaglobulinemia
- Antimicrobial prophylaxis needed
Pharmacist Considerations
- Pre-infusion:
- Confirm lymphodepleting chemotherapy (Flu/Cy dosing adjustments for renal function)
- Assess drug interactions (e.g., avoid steroids unless necessary before infusion → may impair CAR T expansion)
- Post-infusion:
- CRS/ICANS monitoring → every 4 hours in first 10 days
- Ensure tocilizumab availability (at least 2 doses per patient on-site before infusion, per REMS requirement)
- Seizure prophylaxis (levetiracetam often used for high-risk patients)
- Antimicrobial prophylaxis (antiviral, antifungal, PCP)
- Vaccination strategy (hold live vaccines, restart immunizations ≥6–12 months later depending on recovery)
Efficacy
- Response rates: ~50–80% complete remission in relapsed/refractory B-cell malignancies
- Many responses durable, but relapses can occur (loss of CD19 antigen, T-cell exhaustion)