Successful Treatment of Refractory Acute Lymphoblastic Leukemia with Tisagenlecleucel in the Setting of Life-Threatening Infection
Authors: August Keith J , Flatt Terrie , Hall Erin Marie , Myers Doug 
Published: November 2019

Tisagenlecleucel is a CD19 directed immunotherapy approved for the treatment of young patients with relapsed or refractory precursor B-cell acute lymphoblastic leukemia (ALL). The most important toxicity related to tisagenlecleucel therapy is cytokine release syndrome (CRS). CRS is an exaggerated systemic inflammatory response that occurs frequently along with T-cell expansion following the administration of tisagenlecleucel. Tisagenlecleucel guidelines recommend delaying treatment when an active infection is present due to the concern that the pre-existing inflammatory response associated with infection may predispose patients to severe CRS. We describe two cases where tisagenlecleucel was successfully administered to patients in the setting of life-threatening infection.
Patient 1 is a 23-year-old Caucasian male with refractory Philadelphia chromosome negative B-cell ALL who had received prior treatment with chemotherapy, blinatumomab, inotuzumab ozogamicin and a haploidentical stem cell transplant (SCT) followed by multiple Zalmoxis infusions. Five months following SCT he relapsed. At relapse, he underwent leukapheresis followed by bridging chemotherapy with ifosfamide and etoposide. He developed severe neutropenia and respiratory failure associated with a right lower lung consolidation. A biopsy demonstrated a mucormycosis infection and he required surgical debridement including resection of portions of the lung, diaphragm and liver. At this time, he had 92% blasts in the bone marrow. Eleven days after his surgery he received tisagenlecleucel despite being persistently febrile. Prior to the infusion, he received a modified lymphodepleting chemotherapy regimen including two days of fludarabine and cytarabine. Due to severe neutropenia, he was receiving granulocyte transfusions. These were discontinued prior to the infusion and resumed after 12 days. CRP and ferritin the day prior to infusion were 26.2 mg/dL and 18,419 ng/mL. He remained persistently febrile for 13 days post-infusion. He received a single dose of tociluzimab 7 days following his infusion due to high fevers. He did not require any treatment with corticosteroids for CRS. The absolute neutrophil count recovered to >500x103/µL at 31 days post infusion. A bone marrow aspirate done 26 days post-infusion did not show any evidence of leukemia by multicolor flow cytometry (MFC). He remains alive without evidence of disease 11 months after treatment with tisagenlecleucel.
Patient 2 is a 4-year-old Hispanic female with refractory B-cell ALL found to have a TP53 deletion and t(1;19). She had received prior treatment with chemotherapy, blinatumomab and local radiation therapy to the site of extramedullary disease found in the left maxillary sinus at relapse. She underwent leukapheresis and received bridging chemotherapy with mercaptopurine and methotrexate. After 3 days of lymphodepleting chemotherapy she developed septic shock and E. Coli bacteremia. She became severely ill requiring continuous renal replacement therapy for 5 days and extracorporeal membrane oxygenation (ECMO) for 6 days. Shortly after ECMO decannulation she developed fever and was found to have multiple pulmonary opacities concerning for fungal infection. Blasts were noted in the peripheral blood. Sixteen days after presenting with septic shock and 11 days from ECMO she received tisagenlecleucel. CRP at the time of infusion was 22.9 mg/dL. She developed persistent fevers post-infusion for 17 days. She received two doses of tociluzimab 20- and 21-days post-infusion due to recurrence of high fever and reactive lymphadenopathy with third spacing and concern for renovascular compromise. She did not require any treatment with corticosteroids for CRS. Bone marrow aspirate done 32 days post-infusion did not show any evidence of leukemia by MFC. The absolute neutrophil count recovered to >500x103/µL at 59 days post infusion. The patient remained without evidence of disease for 7 months following treatment but died due to infectious complications with persistent pancytopenia.
Tisagenlecleucel is a potentially life-saving treatment for relapsed and refractory B-cell acute lymphoblastic leukemia in children and young adults 24 years of age or younger. Tisagenlecleucel is an option for the treatment of patients with active infection and/or inflammation with progressive leukemia when no other therapeutic alternative exists.

Disclosures
August: Novartis Pharmaceuticals: Speakers Bureau. Myers:Novartis Pharmaceuticals: Consultancy, Speakers Bureau.