Association of COVID-19 pandemic with indolent lymphoma care delivery and outcomes in Ontario, Canada: A population-based analysis.

person Michael Crump Princess Margaret - University Health Network, Toronto, ON, Canada info_outline Michael Crump, Inna Y. Gong, Zharmaine Ante, Andrew Calzavara, Matthew Cheung, Anca A. Prica

Authors person Michael Crump Princess Margaret - University Health Network, Toronto, ON, Canada info_outline Michael Crump, Inna Y. Gong, Zharmaine Ante, Andrew Calzavara, Matthew Cheung, Anca A. Prica Organizations Princess Margaret - University Health Network, Toronto, ON, Canada, Department of Medicine, University of Toronto, Toronto, ON, Canada, Institute for Clinical Evaluative Sciences, Toronto, ON, Canada, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, Princess Margaret Cancer Centre, Toronto, ON, Canada Abstract Disclosures Research Funding Institutional Funding Princess Margaret Cancer Centre Background: Due to concern for infection risk, the coronavirus disease 2019 (COVID-19) pandemic presented a unique challenge for optimal management of indolent non-Hodgkin lymphoma (iNHL). We examined treatment (trt) selection, healthcare utilization, and COVID-19 outcomes of pts with iNHL receiving first-line (1L) systemic treatment during pre-pandemic vs. pandemic period. Methods: We performed a retrospective cohort study using administrative databases in Ontario, Canada, comparing outcomes in pts with iNHL who initiated trt from, with end of follow-up Mar 31 2022. The primary outcome was trt pattern (eg, 1L regimen, rituximab [R] maintenance use); secondary outcomes were death, toxicities, healthcare utilization (emergency department visit [ED], hospitalization), SARS-CoV-2 outcomes (infection, ED visit, hospitalization/death). Adjusted hazard ratios (aHR) from cause-specific proportional hazards models were used to estimate associations between factors and outcomes. Results: We identified 4,143 pts (1,079 pandemic, 3,064 pre-pandemic), median age 69 yrs, 44% female. In both pre- and pandemic periods, bendamustine (B)+R was the most frequent prescribed regimen, with no difference in number of cycles or dose delays (Table). During the pandemic, fewer pts received R maintenance and completed the full course (aHR 0.81, 95% confidence interval [CI] 0.71-0.92, p = 0.0010) (Table). Pts treated during the pandemic had less healthcare utilization (ED visit aHR 0.77, 95% CI 0.68, 0.88, p < 0.0001; hospitalization aHR 0.81, 95% CI 0.70-0.94, p = 0.0067) and trt-related complications (infection aHR 0.69, 95% CI 0.57-0.82, p < 0.0001; febrile neutropenia aHR 0.66, 95% CI 0.47-0.94, p = 0.020), with no difference in death (aHR 0.79, 95% CI 0.58-1.08, p = 0.14). R use (first dose to 1 yr post last dose) was associated with higher risk of SARS-CoV-2 infection (aHR 1.56, 95% CI 1.09-2.24, p = 0.015) and COVID-19 complications (ED visit aHR 4.28, 95% CI 1.79-10.26, p = 0.0011; hospitalization/death 1.81, 95% CI 1.11-2.93, p = 0.016). Conclusions: During the pandemic, BR remained the preferred regimen for iNHL trt, while R maintenance use was less. Despite the similar 1L regimen, healthcare utilization and infectious complications were less in the pandemic cohort. R use was associated with nearly 2-fold risk of COVID-19 hospitalization/death. Pandemic Pre-pandemic P value 1L Therapy BR 586 (91.0%) 2,328 (90.3%) 0.88 R-cyclophosphamide, vincristine, prednisone 34 (5.3%) 147 (5.7%) R 24 (3.7%) 102 (4.0%) No. cycles 5.4 (1.3) 5.4 (1.3) 0.8 No. delays over 6 cycles 0.13 (0.40) 0.13 (0.38) 0.78 R maintenance 448 (69.6%) 1,957 (75.9%) 0.0009 Full course (q3 mns x 8) 329 (48.7%) 903 (56.3%) 0.0008 Outcome ED visit 0.94 (1.62) 1.23 (1.97) 0.0006 Hospitalization 0.49 (0.95) 0.63 (1.15) 0.0028 ICU admission 0.06 (0.26) 0.08 (0.31) 0.18 Death 50 (7.4%) 226 (8.5%) 0.27 Reported as n (%) or mean (SD).