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Supplementary Figure from A Natural Polyphenol Exerts Antitumor Activity and Circumvents Anti–PD-1 Resistance through Effects on the Gut Microbiota

Several approaches to manipulate the gut microbiome for improving the activity of cancer immune-checkpoint inhibitors (ICI) are currently under evaluation. Here, we show that oral supplementation with the polyphenol-rich berry camu-camu (CC; Myrciaria dubia) in mice shifted gut microbial composition, which translated into antitumor activity and a stronger anti–PD-1 response. We identified castalagin, an ellagitannin, as the active compound in CC. Oral administration of castalagin enriched for bacteria associated with efficient immunotherapeutic responses (Ruminococcaceae and Alistipes) and improved the CD8+/FOXP3+CD4+ ratio within the tumor microenvironment. Moreover, castalagin induced metabolic changes, resulting in an increase in taurine-conjugated bile acids. Oral supplementation of castalagin following fecal microbiota transplantation from ICI-refractory patients into mice supported anti–PD-1 activity. Finally, we found that castalagin binds to Ruminococcus bromii and promoted an anticancer response. Altogether, our results identify castalagin as a polyphenol that acts as a prebiotic to circumvent anti–PD-1 resistance.Significance:The polyphenol castalagin isolated from a berry has an antitumor effect through direct interactions with commensal bacteria, thus reprogramming the tumor microenvironment. In addition, in preclinical ICI-resistant models, castalagin reestablishes the efficacy of anti–PD-1. Together, these results provide a strong biological rationale to test castalagin as part of a clinical trial.This article is highlighted in the In This Issue feature, p. 873

Background: Studies suggest that patients with cancer are more likely to experience severe outcomes from COVID-19. Therefore, cancer centers have undertaken efforts to care for patients with cancer in COVID-free zones. Nevertheless, nosocomial transmission of COVID-19 in patients with cancer likely occurs, but the frequency and relevance of these events remain unknown. The goal of this study was to determine the incidence and impact of hospital-acquired COVID-19 in this population and identify prognostic factors for COVID-19 severity in patients with cancer. Methods: Patients with cancer and a laboratory-confirmed or presumed diagnosis of COVID-19 were prospectively identified using provincial registries and hospital databases between March 3rd and May 23rd, 2020, in the provinces of Quebec and British Columbia. Patients’ baseline characteristics including age, sex, comorbidities, cancer type, and type of anticancer treatment were collected. The primary outcome was incidence of hospital-acquired infection defined by diagnosis of SARS-CoV-2 5 days after hospital admission for COVID-unrelated cause. Co-primary outcomes were death or composite outcomes of severe illness from COVID-19 such as hospitalization, supplemental oxygen, intensive-care unit (ICU) admission, and/or mechanical ventilation. Results: A total of 253 patients (N=250 adult and N=3 pediatric) with COVID-19 and cancer were identified, and the majority were residents of Quebec (N=236). Ninety patients (35.6%) received active anticancer treatment in the last 3 months prior to COVID-19 diagnosis. During a median follow-up of 23 days, 209 (82.6%) required hospitalization, 38 (15%) required admission to ICU, and 71 (28%) died. Forty-seven (19%) had a diagnosis of hospital-acquired COVID-19. Median overall survival was shorter in those with hospital-acquired infection, compared to a contemporary community-acquired population (27 days vs. 71 days, HR 2.2, 95% CI 1.2-4.0, p=0.002). Multivariate analysis demonstrated that hospital-acquired COVID-19, age, ECOG status, and advanced stage of cancer were independently associated with death. Conclusion: Our study demonstrates a high rate of nosocomial transmission of COVID-19, associated with increased mortality in both univariate and multivariate analysis in the cancer population, reinforcing the importance of treating patients with cancer in COVID-free zones. We also validated that age, poor ECOG, and advanced cancer were negative prognostic factors for COVID-19 in patients with cancer. Citation Format: Arielle Elkrief, Antoine Desilets, Neha Papneja, Lena Cvetkovic, Catherine Groleau, Yahia Abdelali Lakehal, Layla Shbat, Corentin Richard, Julie Malo, Wiam Belkaid, Erin Cook, Stephane Doucet, Thai Hoa Tran, Patrice Savard, Kevin Jao, Nathalie Daaboul, Eric Bhang, Jonathan Loree, Wilson Miller, Donald Vinh, Nathaniel Bouganim, Gerald Batist, Caroline Letendre, Bertrand Routy. High mortality among hospital-acquired COVID-19 infection in patients with cancer: An observational cohort study from Quebec and British Columbia [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr S12-01.