Hospitalization Patterns with Commercial CAR T-Cell Therapy: A Single Institution Experience

Introduction: Chimeric antigen receptor T-cell therapy (CAR-T) is a revolutionary adoptive immunotherapy approach in lymphoma; however, there are substantial costs associated with CAR-T therapy. The current practice of admission for tisa-cel infusion and subsequent monitoring may contribute to these costs. Generally, our institution administers tisa-cel in the outpatient setting (Schuster NEJM 2017), and we now report our clinical approach and analyze the frequency of hospitalization post outpatient tisa-cel infusion with in the first 30 days of infusion.

Patients and Methods: We conducted a single institution, retrospective study investigating hospitalization after CAR-T of adult lymphoma patients treated with commercial tisa-cel at the University of Pennsylvania between 6/2018 and 7/2019. Data collected included number and timing of hospitalizations, symptoms leading to hospitalization, diagnosis during hospitalization, and length of stay. Patients were eligible for inclusion if they had at least 30 days of follow-up after tisa-cel or hospitalization within the first 30 days after tisa-cel. Patients were followed for hospitalization events until progression of lymphoma. Admissions for elective surgical procedures were not included in hospitalization count.

Patients received lymphodepleting therapy as an outpatient, followed by evaluation in clinic and outpatient infusion of tisa-cel. Indications for hospitalization at our institution included bulky disease, suboptimal organ function at time of tisa-cel infusion, or progressive lymphoma symptoms requiring inpatient management. After infusion, patients returned for follow-up on day 2 and day 4, then weekly starting day 8 through day 30 for physical examination, labs, and assessment for cytokine release syndrome (CRS) and neurotoxicity. Patients were instructed to contact our clinic with fever > 100.4F, any change in mental status, or for malaise. Patients were also required to stay within 1 hour driving distance of our clinic and have identified a caregiver who will remain with them for the first 28 days.

Results: 30 patients with relapsed/refractory non-Hodgkin lymphoma who received commercial tisa-cel were identified; 28 (93%) patients received outpatient tisa-cel; two pts were admitted at the time of T-cell infusion due to progressive lymphoma symptoms requiring urgent management. The length of stay for the two patients who received inpatient tisa-cel was 17.5 days (17-18). Nine of 28 patients were admitted after tisa-cel infusion a median of 5 days after tisa-cel infusion (range: day +1 to +7). No patient required a second admission within 30 days. In most instances, 8/9 (89%) patients were referred for fever (fever range: 99.6F-102.0F) and one patient was referred for altered mental status. Of those hospitalized with fever, 5/8 (63%) patients had CRS and 3/8 (37%) patients had an infection. The patient with altered mental status was diagnosed with grade 3 neurotoxicity. One of the admitted patients died during hospitalization; however, this was due to progression of lymphoma after initial admission for an infection. There were no deaths due to tisa-cel related toxicity.

Conclusion: Our experience suggests that treatment with tisa-cel in the outpatient setting is safe and feasible with close supervision and adequate institutional experience. After infusion, most admissions within the first 30 days were triggered by fever and the etiology of fever was either CRS or infection. Admission diagnoses matched prior experience with tisa-cel as previously reported.