Incidence and Outcomes of Pneumocystis Pneumonia Following Chimeric Antigen Receptor T-Cell Therapy: A Real-World Analysis

Abstract

Background: Pneumocystis Pneumonia (PCP) is a known opportunistic infection after chimeric antigen receptor (CAR) T-cell therapy. However, the incidence and outcomes of PCP are poorly understood, and there has been no clear consensus on the optimal duration for PCP prophylaxis post-CAR T-cell treatment. Methods: From a large real-world database, TriNetX Research Network, we identified patients who underwent commercial anti-CD19 and anti-BCMA CAR T-cell therapy between January 2019 and January 2023. The diagnosis of PCP was established using the ICD-10-CM code B59 (pneumocystosis) or through Logical Observation Identifiers Names and Codes (LOINC) documentation of positive microbiologic tests from respiratory samples. Results: Among the 1,107 and 280 patients who received anti-CD19 and anti-BCMA CAR T-cell therapies, 19 (1.7%) and 4 (1.4%) patients developed PCP, respectively. Altogether, a total of 23 (1.7%) patients developed PCP within a median of 139 days (range 19 to 732 days) post-infusion. (Figure) Demographics, the incidence and severity of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), and the initial choice for PCP prophylaxis, were similar for patients with and without PCP. Patients who developed PCP were more likely to have used dexamethasone (65 vs 43%, p=0.02) and have a shorter duration of trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis (median 9 [range 1 to 45] vs 19 [range 1 to 106] weeks, p=0.002). In the univariate analysis, patients who received TMP/SMX prophylaxis for less than 3 months showed a trend of a higher incidence of PCP compared to those who received it for more than 3 months (hazard ratio [HR] 3.54, 95% confidence interval [CI] 0.87 to 14.3, p=0.06). (Table) Regarding survival outcomes, patients with and without PCP had similar time-to-next-treatment or death (median 84 vs 68 days, HR 0.96, 95%CI 0.61 to 1.51) and overall survival (median 518 days vs not-reached, HR 1.61, 95%CI 0.91 to 2.88). Conclusions: In real-world conditions with routine prophylaxis, PCP is an infrequent opportunistic infection following anti-CD19 or anti-BCMA CAR T-cell therapy. Patients with and without PCP were associated with similar survival outcomes.