Real-World Experience with the Available Outpatient COVID-19 THErapies in Patients with canceR (CO.THER).

Background/objectives: Cancer represents an important risk factor for acquiring severe acute respiratory syndrome by Coronavirus-2 (SARS-CoV-2) and subsequent hospitalization. The utility of early antiviral therapies, including their protective effect on long COVID outcomes, in cancer patients has not yet been clearly demonstrated. We conducted the CO.THER study (COVID-19 THErapies in patients with canceR) to address this knowledge gap.

Methods: We designed an ambispective single-center cohort study. We collected clinical and oncological data from the hospital's electronic patient records at the start of COVID-19 therapy (T0), seven days after T0 (T1), two weeks after T0 (T2), one month after T0 (T3), three months after T0 (T4), six months after T0 (T5), and twelve months after T0 (T6). The primary endpoint of this ambispective single-center cohort study was the rate of hospitalization for COVID-19 disease within 14 days in cancer patients using anti-SARS-CoV-2 early therapies. The proportion of hospitalizations within 14 days (primary endpoint) was computed together with its exact binomial 95% confidence interval (95%CI).

Results: 131 patients' records (53M [40.5%], 78F, [59.5%]; median age 62.45, interquartile range [IQR] 56-71) were enrolled. As shown by the Kaplan-Meier hospitalization-free estimate, only three patients (2.1%) were hospitalized for a COVID-19 related cause within 14 days of starting early treatment (95%CI 0.5-6.6%). The cumulative survival probability beyond 12 months in hospitalization-free patients was 98% (95%CI 93-99%). Twelve patients (9.2%) reported another COVID-19 infection during the follow-up and they were all retreated with Nirmatrelvir-Ritonavir. The cumulative reinfection-free survival was 90% at 12 months (95%CI 83-95%). Further, 15 patients of the 123 evaluable at 3 months (median age 51 years, IQR 40-68) reported long COVID symptoms (12.2%, 95%CI 7.0-19.3%).

Conclusions: Our data demonstrate a low rate of hospitalization and reassuring data on safety in this cohort of high-risk subjects.