Infections in Patients with Solid Tumors Undergoing Adoptive Cellular Therapy

Adoptive cellular therapy (ACT) is an increasingly widely used treatment approach for malignancy. While infectious complications of ACT have been well described in patients with hematologic malignancies, limited data are available on the epidemiology of infections in patients with solid tumors. The purpose of this study was to describe the epidemiology of infections occurring within the first 180 days in adult patients with solid tumors treated with ACT and to identify risk factors predisposing these patients to infection. Data on 132 adult patients with solid tumors undergoing ACT between August 2014 and November 2021 at Memorial Sloan Kettering Cancer Center were collected. Infections were documented from the day of ACT infusion through day 180 postinfusion. Overall, 28 of 132 patients (21.2%) experienced 33 infections within the first 30 days of ACT, and 17 of 131 surviving patients (13%) were diagnosed with 24 infections between day 31 and day 180. Infection-related mortality was low. The majority of infections were bacterial. While male gender, older age, Eastern Cooperative Oncology Group (ECOG) performance status (PS) at time of ACT infusion, tocilizumab receipt, and cytokine release syndrome treated with tocilizumab were associated with shorter time to first infection on univariable analysis, only ECOG PS and tocilizumab receipt remained independent risk factors in the multivariable analysis. The proportion of patients with solid tumors experiencing early or late infections after ACT was lower compared to that reported among patients with B cell malignancies after chimeric antigen receptor T cell therapy. Most observed infections were primarily bacterial with low infection-related mortality; the incidence of viral and fungal infections was low. Based on the low frequency and timing of infections relative to neutropenia, antibacterial and antifungal prophylaxis are not likely to be beneficial. ECOG PS ≥2 and tocilizumab receipt were identified as significant predictors for infection after ACT, likely signaling an individual's debilitated state that predisposes to infection. Additional work to parse out confounders is needed to better identify risk factors for infection.