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CAR T cells
Researchers have developed treatment guidelines for pediatric patients receiving chimeric antigen receptor (CAR) T-cell therapy.
The guidelines include recommendations for patient selection and consent, treatment details, and advice on managing cytokine release syndrome (CRS) and other adverse events associated with CAR T-cell therapy.
The guidelines were published in Nature Reviews Clinical Oncology.
“CAR T-cell therapy has been associated with remarkable response rates for children and young adults with ALL [acute lymphoblastic leukemia], yet this innovative form of cellular immunotherapy has resulted in unique and severe toxicities which can lead to rapid cardiorespiratory and/or neurological deterioration,” said guidelines author Kris Mahadeo, MD, of The University of Texas MD Anderson Cancer Center in Houston.
“This novel therapy requires the medical vigilance of a diverse multi-disciplinary team and associated clinical infrastructure to ensure optimal patient outcomes.”
Pediatric patient selection and consent
The guidelines state that providers of CAR T-cell therapies should adhere to product information labels and guidance from risk evaluation and mitigation strategy programs (level of evidence: IV, grade: D).
In addition, patient selection should be based on the indications approved by the US Food and Drug Administration and criteria used in pivotal studies. However, this can change as new information becomes available (level of evidence: IV, grade: D).
Informed consent should include descriptions of the risks and benefits associated with leukapheresis, lymphodepletion, CRS, CAR T-cell-related encephalopathy syndrome (CRES), bridging chemotherapy, intensive care support, and anti-IL-6 therapy (level of evidence: IIA, grade: B).
Providers should obtain child assent when appropriate and may benefit from incorporating child life and psychological services in assent discussions (level of evidence: IV, grade: D).
Treatment specifics
The guidelines recommend cyclophosphamide–fludarabine regimens for lymphodepletion, although exceptions can be considered in cases of hemorrhagic cystitis and/or resistance to a prior cyclophosphamide-based regimen (level of evidence: IIA, grade: B).
Providers should consider inpatient admission for a minimum of 3 to 7 days after receipt of tisagenlecleucel. This was based on the experience in pediatric and young adult patients with CD19+ relapsed and/or refractory B-cell acute lymphoblastic leukemia (level of evidence: IIA, grade: B).
Patients should be closely monitored for hypotension, hypocalcemia, and catheter-related pain during leukapheresis (level of evidence: IIA, grade: B).
For patients receiving tocilizumab, those weighing <30 kg should receive 12 mg/kg, and those weighing ≥30 kg should receive 8 mg/kg (level of evidence: IIA, grade: B).
Adverse events
The guidelines say parent and/or caregiver concerns should be addressed as these individuals may be best equipped to recognize early signs or symptoms of CRS (level of evidence: III, grade: C).
When CAR T-cell therapy is administered in an outpatient setting, there should be a low threshold for patient admission upon the development of signs or symptoms suggestive of CRS and/or CRES (level of evidence: IIA, grade: B).
CRS grading should be performed at least once every 12 hours (level of evidence: IIA, grade: B). Detailed information on grading is provided in the guidelines.
Providers should suspect CRS if any of the following signs/symptoms are present within the first 2 weeks of CAR T-cell infusion:
- Fever ≥38 °C
- Hypotension
- Hypoxia with an arterial oxygen saturation of <90% on room air
- Evidence of organ toxicity as determined by the most recent CTCAE grading system and considerations detailed in the guidelines (level of evidence: IIA, grade: C).
The guidelines also recommend “high vigilance” for sinus tachycardia as an early sign of CRS (level of evidence: IIA, grade: B) as well as application of the PALICC (Pediatric Acute Lung Injury Consensus Conference) at-risk P-ARDS (pediatric acute respiratory distress syndrome) criteria for the CRS grading of hypoxia (level of evidence: IIA, grade: B).
Hemophagocytic lymphohistiocytosis and/or macrophage-activation syndrome can be treated with anti-IL-6 therapy and corticosteroids. However, refractory cases may require systemic and/or intrathecal therapy or use of the IL-1 receptor antagonist anakinra (level of evidence: IIA, grade: C).
The guidelines recommend that delirium screening be performed at least twice per 24-hour period among admitted patients and at least daily among outpatients during the high-risk periods for CRES (level of evidence: IIA, grade: C). Delirium screening should be performed with the CAPD (Cornell Assessment of Pediatric Delirium) tool or CARTOX-10 (CAR T-Cell Therapy-Associated Toxicity 10-point assessment scale) for patients age 12 and older who have sufficient cognitive abilities.
Acute kidney injury in children can be graded according to the CTCAE (Common Terminology Criteria for Adverse Events) using pRIFLE (Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease) and KDIGO (Kidney Disease: Improving Global Outcomes) definitions of oliguria (level of evidence: IIA, grade: B).
Other considerations
The guidelines “strongly encourage” consideration of quality-adjusted life-years gained for pediatric patients who might achieve long-term remission from CAR T-cell therapy and encourage efforts to reduce the cost of care (level of evidence: IV, grade: D).
The guidelines also recommend that CAR T-cell programs seek FACT IEC (Foundation for the Accreditation of Cellular Therapy for Immune Effector Cells) accreditation to ensure adherence to quality standards (level of evidence: IV, grade: D).
Finally, the guidelines suggest the possibility of a prospective collaboration with intensive-care registries, which could allow accurate data entry of cell therapy variables into the CIBMTR registry with concurrent entry of intensive-care variables into an appropriate registry by pediatric critical care teams (level of evidence: IV, grade: D).