Change in COVID-19 outcomes in lymphoma patients across pandemic waves: results of the COVID-19-lymphoma registry of the Bavarian Cancer Research Center (BZKF) 2020-2022.

Patients with malignant lymphomas are at increased risk for severe COVID-19. In the general population, outcomes of COVID-19 have improved dramatically over time due to increasing immunity through vaccination or infection and due to improved clinical care. It is unclear whether outcomes of COVID-19 in patients with lymphoma have improved similarly over time. We performed a multi-center retrospective study of lymphoma patients with COVID-19 at five tertiary care centers of the Bavarian Cancer Research Center (BZKF) in Germany, evaluating baseline characteristics as well as COVID-19 management and outcomes across different pandemic waves from March 2020 to March 2022. Clinical management of COVID-19 as well as vaccination rates changed significantly over time. In the most recent pandemic wave (cases after December 27th 2021), 88% of lymphoma patients had been vaccinated. Upon infection, 57% of patients were treated with monoclonal antibodies and 35% were treated with antiviral agents. Concurrent with these interventions, we observed markedly improved outcomes. Severe disease courses were significantly less frequent in the most recent pandemic wave compared to earlier pandemic waves (4/40 vs. 26/73, p = 0.03). Similarly, mortality was significantly lower in the most recent pandemic wave compared to earlier pandemic waves (2/40 vs. 14/73, p = 0.039). Although we cannot clearly distinguish the relative contribution of each intervention on the observed improvement in COVID-19 outcome, our data indicates that severity and mortality of COVID-19 in this vulnerable patient population has recently declined. Thus, our data largely supports a return to pre-pandemic treatment recommendations and protocols.