Effectiveness of Paxlovid in the treatment of the SARS-CoV-2 Omicron variant infection in children with hematologic malignancies: a retrospective cohort study

Abstract: Original Article Effectiveness of Paxlovid in the treatment of the SARS-CoV-2 Omicron variant infection in children with hematologic malignancies: a retrospective cohort study Xiaoxia Deng1#, Yuelian Jiang2#, Wenjuan Chen1#, Xia Qin3#, Jing Chen3, Hao Li4, Qing Cao1 1 Department of Infectious Disease, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; 2 Department of Pharmacy, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; 3Department of Hematology and Oncology, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; 4Clinical Research Ward, Clinical Research Center, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China Contributions: (I) Conception and design: X Deng, H Li, Q Cao; (II) Administrative support: Q Cao, J Chen; (III) Provision of study materials or patients: Q Cao, Y Jiang, W Chen, X Qin, J Chen; (IV) Collection and assembly of data: X Deng, Y Jiang, W Chen, X Qin; (V) Data analysis and interpretation: X Deng, Y Jiang, W Chen, X Qin, Q Cao, H Li; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. # These authors contributed equally to this work. Correspondence to: Qing Cao, MD, PhD. Department of Infectious Disease, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, No. 1678 Dongfang Road, Pudong New District, Shanghai 200127, China. Email: caoqing@scmc.com.cn. Background: Patients with hematologic malignancies (HMs) may be immunocompromised after receiving anti-tumor therapy. Those who also have the severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) virus infection face many challenges, including a lack of effective antiviral drugs. This study aimed to investigate the clinical features of the SARS-CoV-2 Omicron variant infection in children with HMs, and the effectiveness of Paxlovid. Methods: A retrospective, non-randomized study was conducted on pediatric patients with HMs infected with the SARS-CoV-2 Omicron variant who had been admitted to the Shanghai Children’s Medical Center, Shanghai, China from December 1, 2022 to March 1, 2023. The Paxlovid-treated group (Group P) comprised 21 patients, and the non-Paxlovid-treated group (Group N) comprised 21 patients. The patients’ demographic data, clinical features, and therapeutic outcomes were collected. Statistical tests were used to evaluate the effectiveness of the treatment and related factors. Results: The clinical course of the SARS-CoV-2 Omicron variant infection for most of the children with HMs was non-severe (97.6%), and only one child progressed to severe disease (2.4%). The most common symptoms were fever (66.7%) and cough (52.4%). Compared with the children in Group N, those in Group P had worse clinical characteristics, including those who previously underwent hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T (CAR-T) cell treatment (71.4% vs. 28.6%, P=0.005), and those in the myelosuppressive phase (57.1% vs. 4.8%, P<0.001). Most of the children in Group P were treated with more than two types of antibiotics (76.2% vs. 42.9%, P=0.02). The patients treated with Paxlovid within 5 days of diagnosis had a median viral clearance time of 5 days [interquartile range (IQR), 4–8 days], which was significantly shorter than that of the patients who..