Effectiveness of nirmatrelvir/ritonavir in children and adolescents aged 12-17 years following SARS-CoV-2 Omicron infection: A target trial emulation.

Currently there is a lack of randomized trial data examining the use of the antiviral nirmatrelvir/ritonavir in paediatric patients with SARS-CoV-2 infection. This target trial emulation study aims to address this gap by evaluating the use of nirmatrelvir/ritonavir in non-hospitalized paediatric patients aged 12-17 years with SARS-CoV-2 Omicron variant infection. Among paediatric patients diagnosed between 16th March 2022 and 5th February 2023, exposure was defined as outpatient nirmatrelvir/ritonavir treatment within 5 days of symptom onset or COVID-19 diagnosis. Primary outcome was 28 day all-cause mortality or all-cause hospitalization, while secondary outcomes were 28 day in-hospital disease progression, 28 day COVID-19-specific hospitalization, multisystem inflammatory syndrome in children (MIS-C), acute liver injury, acute renal failure, and acute respiratory distress syndrome. Overall, 49,378 eligible paediatric patients were included. Nirmatrelvir/ritonavir treatment was associated with reduced 28 day all-cause hospitalization (absolute risk reduction = 0.23%, 95%CI = 0.19%-0.31%; relative risk = 0.66, 95%CI = 0.56-0.71). No events of mortality, in-hospital disease progression, or adverse clinical outcomes were observed among nirmatrelvir/ritonavir users. The findings confirmed the effectiveness of nirmatrelvir/ritonavir in reducing all-cause hospitalization risk among non-hospitalized pediatric patients with SARS-CoV-2 Omicron variant infection.

Effectiveness of mRNA BNT162b2 and inactivated CoronaVac vaccines against severe COVID-19 outcomes among non-hospitalised children aged 1-3 years with SARS-CoV-2 Omicron infection.

OBJECTIVES: Clinical evidence on the effectiveness of COVID-19 vaccines for children aged 1-3 years is scarce. The effectiveness of COVID-19 vaccines was evaluated among non-hospitalised children aged 1-3 years with SARS-CoV-2 Omicron infection in Hong Kong. METHODS: A retrospective cohort of all non-hospitalised children aged 1-3 years with confirmed SARS-CoV-2 infection between 4 August 2022 and 29 January 2023 in Hong Kong was analysed. Vaccinated group was defined as the recipients of one or more doses of CoronaVac or mRNA vaccine BNT162b2 (original, monovalent) at least 14 days prior to infection. Hazard ratios (HR) with 95% confidence intervals (95% CI) of study outcomes were estimated using Cox regression models. Effectiveness outcomes included 28-day all-cause mortality and COVID-19-related hospitalisation. RESULTS: A total of 5552 vaccinated patients and 5552 propensity-score matched controls (unvaccinated patients) were included for analysis. The cumulative incidence of COVID-19-related hospitalisation over 28 days was 2.3% and 2.9% in the vaccinated and control groups, respectively. There were no deaths in both groups. COVID-19 vaccination was associated with a significant reduction in 28-day COVID-19-related hospitalisation risk (HR=0.785, 95% CI=0.626-0.985, P=0.037), particularly for children aged 3 years, those who had received two or more vaccine doses, and those who received CoronaVac as the last dose. CONCLUSION: COVID-19 vaccination is associated with a significantly lower risk of 28-day COVID-19-related hospitalisation among infected children aged 1-3 years, particularly those who had received two or more vaccine doses. This observation emphasises the importance of completing the full two-dose or three-dose series to optimise vaccine effectiveness.

Comparison of Bivalent and Monovalent mRNA Vaccine Boosters.

In this cohort study conducted in Hong Kong where both bivalent and monovalent formulations of BNT162b2 were available, there were no significant differences in the mortality or hospitalization between those who received bivalent and monovalent mRNA as second boosters. Bivalent and monovalent mRNA boosters appear equally protective against clinical outcomes.

Nirmatrelvir/ritonavir use in pregnant women with SARS-CoV-2 Omicron infection: a target trial emulation.

To date, there is a lack of randomized trial data examining the use of the antiviral nirmatrelvir/ritonavir in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected pregnant persons. This target trial emulation study aimed to address this gap by evaluating the use of nirmatrelvir/ritonavir in nonhospitalized pregnant women with symptomatic SARS-CoV-2 Omicron variant infection. Among patients diagnosed between 16 March 2022 and 5 February 2023, exposure was defined as outpatient nirmatrelvir/ritonavir treatment within 5 days of symptom onset or coronavirus disease 2019 (COVID-19) diagnosis. Primary outcomes were maternal morbidity and mortality index (MMMI), all-cause maternal death and COVID-19-related hospitalization, while secondary outcomes were individual components of MMMI, preterm birth, stillbirth, neonatal death and cesarean section. One-to-ten propensity-score matching was conducted between nirmatrelvir/ritonavir users and nonusers, followed by cloning, censoring and weighting. Overall, 211 pregnant women on nirmatrelvir/ritonavir and 1,998 nonusers were included. Nirmatrelvir/ritonavir treatment was associated with reduced 28-day MMMI risk (absolute risk reduction (ARR) = 1.47%, 95% confidence interval (CI) = 0.21-2.34%) but not 28-days COVID-19-related hospitalization (ARR = -0.09%, 95% CI = -1.08% to 0.71%). Nirmatrelvir/ritonavir treatment was also associated with reduced risks of cesarean section (ARR = 1.58%, 95% CI = 0.85-2.39%) and preterm birth (ARR = 2.70%, 95% CI = 0.98-5.31%). No events of maternal or neonatal death or stillbirth were recorded. The findings suggest that nirmatrelvir/ritonavir is an effective treatment in symptomatic pregnant women with SARS-CoV-2 Omicron variant infection.

Optimal timing of nirmatrelvir/ritonavir treatment after COVID-19 symptom onset or diagnosis: target trial emulation.

Reports of symptomatic rebound and/or test re-positivity among COVID-19 patients following the standard five-day treatment course of nirmatrelvir/ritonavir have sparked debates regarding optimal treatment timing and dosage. It is unclear whether initiating nirmatrelvir/ritonavir immediately after symptom onset would improve clinical outcomes and/or lead to post-treatment viral burden rebound due to inadequate viral clearance during treatment. Here we show that, by emulating a randomized target trial using real-world electronic medical record data from all 87,070 adult users of nirmatrelvir/ritonavir in Hong Kong between 16th March 2022 and 15th January 2023, early initiation of nirmatrelvir/ritonavir treatment (0 to 1 days after symptom onset or diagnosis) significantly reduced the incidence of 28-day all-cause mortality and hospitalization compared to delayed initiation (2 or more days) (absolute risk reduction [ARR]: 1.50% (95% confidence interval 1.17-1.80%); relative risk [RR]: 0.77 (0.73, 0.82)), but may be associated with a significant elevated risk of viral burden rebound (ARR: -1.08% (-1.55%, -0.46%)), although the latter estimates were associated with high uncertainty due to limited sample sizes. As such, patients should continue to initiate nirmatrelvir/ritonavir early after symptom onset or diagnosis to better protect against the more serious outcomes of hospitalization and mortality.

Analysis of All-Cause Hospitalization and Death Among Nonhospitalized Patients With Type 2 Diabetes and SARS-CoV-2 Infection Treated With Molnupiravir or Nirmatrelvir-Ritonavir During the Omicron Wave in Hong Kong.

Importance: Diabetes and COVID-19 are both global pandemics, and type 2 diabetes is a common comorbidity in patients with acute COVID-19 and is proven to be a key determinant of COVID-19 prognosis. Molnupiravir and nirmatrelvir-ritonavir are oral antiviral medications recently approved for nonhospitalized patients with mild to moderate COVID-19, following demonstration of their efficacies in reducing adverse outcomes of the disease; it is crucial to clarify whether both oral antiviral medications are efficacious in a population consisting exclusively of patients with type 2 diabetes. Objective: To evaluate the effectiveness of molnupiravir and nirmatrelvir-ritonavir in a contemporary population-based cohort comprising exclusively nonhospitalized patients with type 2 diabetes and SARS-CoV-2 infection. Design, Setting, and Participants: This retrospective cohort study was performed using population-based electronic medical record data for patients in Hong Kong with type 2 diabetes and confirmed SARS-CoV-2 infection between February 26 and October 23, 2022. Each patient was followed up until death, outcome event, crossover of oral antiviral treatment, or end of the observational period (October 30, 2022), whichever came first. Outpatient oral antiviral users were divided into molnupiravir and nirmatrelvir-ritonavir treatment groups, respectively, and nontreated control participants were matched through 1:1 propensity score matching. Data analysis was performed on March 22, 2023. Exposures: Molnupiravir (800 mg twice daily for 5 days) or nirmatrelvir-ritonavir (300 mg nirmatrelvir and 100 mg ritonavir twice daily for 5 days, or 150 mg nirmatrelvir and 100 mg ritonavir for patients with an estimated glomerular filtration rate of 30-59 mL/min per 1.73 m2). Main Outcomes and Measures: The primary outcome was a composite of all-cause mortality and/or hospitalization. The secondary outcome was in-hospital disease progression. Hazard ratios (HRs) were estimated with Cox regression. Results: This study identified 22 098 patients with type 2 diabetes and COVID-19. A total of 3390 patients received molnupiravir and 2877 received nirmatrelvir-ritonavir in the community setting. After application of exclusion criteria followed by 1:1 propensity score matching, this study comprised 2 groups. One group included 921 molnupiravir users (487 men [52.9%]), with a mean (SD) age of 76.7 (10.8) years, and 921 control participants (482 men [52.3%]), with a mean (SD) age of 76.6 (11.7) years. The other group included 793 nirmatrelvir-ritonavir users (401 men [50.6%]), with a mean (SD) age of 71.7 (11.5) years, and 793 control participants (395 men [49.8%]), with a mean (SD) age of 71.9 (11.6) years. At a median follow-up of 102 days (IQR, 56-225 days), molnupiravir use was associated with a lower risk of all-cause mortality and/or hospitalization (HR, 0.71 [95% CI, 0.64-0.79]; P < .001) and in-hospital disease progression (HR, 0.49 [95% CI, 0.35-0.69]; P < .001) compared with nonuse. At a median follow-up of 85 days (IQR, 56-216 days), nirmatrelvir-ritonavir use was associated with a lower risk of all-cause mortality and/or hospitalization (HR, 0.71 [95% CI, 0.63-0.80]; P < .001) and a nonsignificantly lower risk of in-hospital disease progression (HR, 0.92 [95% CI, 0.59-1.44]; P = .73) compared with nonuse. Conclusions and Relevance: These findings suggest that both molnupiravir and nirmatrelvir-ritonavir oral antiviral medications were associated with a lower risk of all-cause mortality and hospitalization among patients with COVID-19 and type 2 diabetes. Further studies in specific populations, such as individuals in residential care homes and individuals with chronic kidney disease, are suggested.

Viral burden rebound in hospitalised patients with COVID-19 receiving oral antivirals in Hong Kong: a population-wide retrospective cohort study.

BACKGROUND: Viral rebound after nirmatrelvir-ritonavir treatment has implications for the clinical management and isolation of patients with COVID-19. We evaluated an unselected, population-wide cohort to identify the incidence of viral burden rebound and associated risk factors and clinical outcomes. METHODS: We did a retrospective cohort study of hospitalised patients with a confirmed diagnosis of COVID-19 in Hong Kong, China, for an observation period from Feb 26 to July 3, 2022 (during the omicron BA.2.2 variant wave). Adult patients (age ≥18 years) admitted 3 days before or after a positive COVID-19 test were selected from medical records held by the Hospital Authority of Hong Kong. We included patients with non-oxygen-dependent COVID-19 at baseline receiving either molnupiravir (800 mg twice a day for 5 days), nirmatrelvir-ritonavir (nirmatrelvir 300 mg with ritonavir 100 mg twice a day for 5 days), or no oral antiviral treatment (control group). Viral burden rebound was defined as a reduction in cycle threshold (Ct) value (≥3) on quantitative RT-PCR test between two consecutive measurements, with such decrease sustained in an immediately subsequent Ct measurement (for those patients with ≥3 Ct measurements). Logistic regression models were used to identify prognostic factors for viral burden rebound, and to assess associations between viral burden rebound and a composite clinical outcome of mortality, intensive care unit admission, and invasive mechanical ventilation initiation, stratified by treatment group. FINDINGS: We included 4592 hospitalised patients with non-oxygen-dependent COVID-19 (1998 [43·5%] women and 2594 [56·5%] men). During the omicron BA.2.2 wave, viral burden rebound occurred in 16 of 242 patients (6·6% [95% CI 4·1-10·5]) receiving nirmatrelvir-ritonavir, 27 of 563 (4·8% [3·3-6·9]) receiving molnupiravir, and 170 of 3787 (4·5% [3·9-5·2]) in the control group. The incidence of viral burden rebound did not differ significantly across the three groups. Immunocompromised status was associated with increased odds of viral burden rebound, regardless of antiviral treatment (nirmatrelvir-ritonavir: odds ratio [OR] 7·37 [95% CI 2·56-21·26], p=0·0002; molnupiravir: 3·05 [1·28-7·25], p=0·012; control: 2·21 [1·50-3·27], p<0·0001). Among patients receiving nirmatrelvir-ritonavir, the odds of viral burden rebound were higher in those aged 18-65 years (vs >65 years; 3·09 [1·00-9·53], p=0·050), those with high comorbidity burden (score >6 on the Charlson Comorbidity Index; 6·02 [2·09-17·38], p=0·0009), and those concomitantly taking corticosteroids (7·51 [1·67-33·82], p=0·0086); whereas the odds were lower in those who were not fully vaccinated (0·16 [0·04-0·67], p=0·012). In patients receiving molnupiravir, those aged 18-65 years (2·68 [1·09-6·58], p=0·032) or on concomitant corticosteroids (3·11 [1·23-7·82], p=0·016) had increased odds of viral burden rebound. We found no association between viral burden rebound and occurrence of the composite clinical outcome from day 5 of follow-up (nirmatrelvir-ritonavir: adjusted OR 1·90 [0·48-7·59], p=0·36; molnupiravir: 1·05 [0·39-2·84], p=0·92; control: 1·27 [0·89-1·80], p=0·18). INTERPRETATION: Viral burden rebound rates are similar between patients with antiviral treatment and those without. Importantly, viral burden rebound was not associated with adverse clinical outcomes. FUNDING: Health and Medical Research Fund, Health Bureau, The Government of the Hong Kong Special Administrative Region, China. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Real-world effectiveness of molnupiravir and nirmatrelvir plus ritonavir against mortality, hospitalisation, and in-hospital outcomes among community-dwelling, ambulatory patients with confirmed SARS-CoV-2 infection during the omicron wave in Hong Kong: an observational study.

BACKGROUND: Little is known about the real-world effectiveness of oral antivirals against the SARS-CoV-2 omicron (B.1.1.529) variant. We aimed to assess the clinical effectiveness of two oral antiviral drugs among community-dwelling COVID-19 outpatients in Hong Kong. METHODS: In this observational study, we used data from the Hong Kong Hospital Authority to identify an unselected, territory-wide cohort of non-hospitalised patients with an officially registered diagnosis of SARS-CoV-2 infection between Feb 26 and June 26, 2022, during the period in which the omicron subvariant BA.2.2 was dominant in Hong Kong. We used a retrospective cohort design as primary analysis, and a case-control design as sensitivity analysis. We identified patients with COVID-19 who received either molnupiravir (800 mg twice daily for 5 days) or nirmatrelvir plus ritonavir (nirmatrelvir 300 mg and ritonavir 100 mg twice daily for 5 days, or nirmatrelvir 150 mg and ritonavir 100 mg if estimated glomerular filtration rate was 30-59 mL/min per 1·73 m2). Outpatient oral antiviral users were matched with controls using propensity score (1:10) according to age, sex, date of SARS-CoV-2 infection diagnosis, Charlson Comorbidity Index score, and vaccination status. Study outcomes were death, COVID-19-related hospitalisation, and in-hospital disease progression (in-hospital death, invasive mechanical ventilation, or intensive care unit admission). Hazard ratios (HRs) were estimated by Cox regression for the primary analysis, and odds ratios in oral antiviral users compared with non-users by logistic regression for the sensitivity analysis. FINDINGS: Among 1 074 856 non-hospitalised patients with COVID-19, 5383 received molnupiravir and 6464 received nirmatrelvir plus ritonavir in the community setting. Patients were followed up for a median of 103 days in the molnupiravir group and 99 days in the nirmatrelvir plus ritonavir group. Compared with nirmatrelvir plus ritonavir users, those on molnupiravir were older (4758 [85·9%] vs 4418 [88.7%] aged >60 years) and less likely to have been fully vaccinated (1850 [33·4%] vs 800 [16·1%]). Molnupiravir use was associated with lower risks of death (HR 0·76 [95% CI 0·61-0·95]) and in-hospital disease progression (0·57 [0·43-0·76]) than non-use was, whereas risk of hospitalisation was similar in both groups (0·98 [0·89-1·06]). Nirmatrelvir plus ritonavir use was associated with lower risks of death (0·34 [0·22-0·52]), hospitalisation (0·76 [0·67-0·86]), and in-hospital disease progression (0·57 [0·38-0·87]) than non-use was. We consistently found reduced risks of mortality and hospitalisation associated with early oral antiviral use among older patients. The findings from the case-control analysis broadly supported those from the primary analysis. INTERPRETATION: During Hong Kong's wave of SARS-CoV-2 omicron subvariant BA.2.2, among non-hospitalised patients with COVID-19, early initiation of novel oral antivirals was associated with reduced risks of mortality and in-hospital disease progression. Nirmatrelvir plus ritonavir use was additionally associated with a reduced risk of hospitalisation. FUNDING: Health and Medical Research Fund, Health Bureau, Government of Hong Kong Special Administrative Region, China. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Real-world effectiveness of early molnupiravir or nirmatrelvir-ritonavir in hospitalised patients with COVID-19 without supplemental oxygen requirement on admission during Hong Kong's omicron BA.2 wave: a retrospective cohort study.

BACKGROUND: Data on the effectiveness of oral antivirals in patients with mild-to-moderate COVID-19 are urgently needed. This retrospective cohort study aimed to evaluate the clinical and virological outcomes associated with molnupiravir or nirmatrelvir-ritonavir use in hospitalised patients with mild-to-moderate COVID-19 during a pandemic wave dominated by the omicron BA.2 subvariant. METHODS: We analysed data from a territory-wide retrospective cohort of patients in Hong Kong who were hospitalised with a confirmed diagnosis of SARS-CoV-2 infection between Feb 26 and April 26, 2022. Data were extracted from the Hospital Authority, the Department of Health, and the Hong Kong Death Registry. Patients were eligible for inclusion if their admission date was within 3 days before or after confirmation of their COVID-19 diagnosis. Those who were admitted to hospital more than 5 days after symptom onset, were younger than 18 years, had a history of oral antiviral use before admission, required supplemental oxygen on admission, had drug-related contraindications to nirmatrelvir-ritonavir use, or had severe renal or severe liver impairment were excluded. Patients who received the oral antivirals molnupiravir or nirmatrelvir-ritonavir were matched with controls using propensity-score matching in a ratio of 1:1. The primary outcome was all-cause mortality and secondary outcomes included a composite outcome of disease progression (all-cause mortality, initiation of invasive mechanical ventilation [IMV], intensive care unit [ICU] admission, or the need for oxygen therapy) and each of these individual disease progression outcomes, and time to reaching a low viral burden (RT-PCR cycle threshold value ≥30). For each event outcome, crude incidence rates were calculated and hazard ratios (HRs) estimated using Cox regression models. FINDINGS: We identified 40 776 patients hospitalised with SARS-CoV-2 infection during the study period, with a mean follow-up of 41·3 days (total 925 713 person-days). After exclusions and propensity-score matching, we included 1856 molnupiravir recipients and 1856 matched controls, and 890 nirmatrelvir-ritonavir recipients and 890 matched controls. A lower risk of all-cause mortality was observed in molnupiravir recipients (crude incidence rate per 10 000 person-days 19·98 events [95% CI 16·91-23·45]) versus matched controls (38·07 events [33·85-42·67]; HR 0·48 [95% CI 0·40-0·59], p<0·0001) and in nirmatrelvir-ritonavir recipients (10·28 events [7·03-14·51]) versus matched controls (26·47 events [21·34-32·46]; HR 0·34 [0·23-0·50], p<0·0001). Oral antiviral recipients also had lower risks of the composite disease progression outcome (molnupiravir HR 0·60 [95% CI 0·52-0·69], p<0·0001; nirmatrelvir-ritonavir 0·57 [0·45-0·72], p<0·0001) and need for oxygen therapy (molnupiravir 0·69 [0·57-0·83], p=0·0001; nirmatrelvir-ritonavir 0·73 [0·54-0·97], p=0·032) compared with controls. Time to achieving a low viral burden was significantly shorter among oral antiviral recipients than matched controls (molnupiravir HR 1·38 [95% CI 1·15-1·64], p=0·0005; nirmatrelvir-ritonavir 1·38 [1·07-1·79], p=0·013). Significant differences in initiation of IMV and ICU admission were not found. INTERPRETATION: During a wave of SARS-CoV-2 omicron BA.2, initiation of novel oral antiviral treatments in hospitalised patients not requiring oxygen therapy on admission showed substantial clinical benefit. Our findings support the early use of oral antivirals in this population of patients. FUNDING: Health and Medical Research Fund (Health Bureau, Government of the Hong Kong Special Administrative Region). TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Initiation of Tocilizumab or Baricitinib Were Associated With Comparable Clinical Outcomes Among Patients Hospitalized With COVID-19 and Treated With Dexamethasone.

Objectives: This retrospective cohort study aims to explore head-to-head clinical outcomes and complications associated with tocilizumab or baricitinib initiation among hospitalized COVID-19 patients receiving dexamethasone. Methods: Among 10,445 COVID-19 patients hospitalized between January 21st 2020 and January 31st 2021 in Hong Kong, patients who had received tocilizumab (n = 165) or baricitinib (n = 76) while on dexamethasone were included. Primary study outcome was time to clinical improvement (at least one score reduction on WHO clinical progression scale). Secondary outcomes were disease progression, viral dynamics, in-hospital death, hyperinflammatory syndrome, and COVID-19/treatment-related complications. Hazard ratios (HR) of event outcomes were estimated using Cox regression models. Results: The initiation of tocilizumab or baricitinib had no significant differences in time to clinical improvement (HR = 0.86, 95%CI 0.57-1.29, p = 0.459), hospital discharge (HR = 0.85, 95%CI 0.57-1.27, p = 0.418), recovery without the need for oxygen therapy (HR = 1.04, 95%CI 0.64-1.67, p = 0.883), low viral load (HR = 1.49, 95%CI 0.85-2.60, p = 0.162), and positive IgG antibody (HR = 0.97, 95%CI 0.61-1.54, p = 0.909). Time to viral clearance (HR = 1.94, 95%CI 1.01-3.73, p = 0.048) was shorter in the tocilizumab group with marginal significance, compared to that of baricitinib. Meanwhile, the two treatment modalities were not significantly different in their associated risks of in-hospital death (HR = 0.63, 95%CI 0.29-1.35, p = 0.233), severe liver injury (HR = 1.15, 95%CI 0.43-3.08, p = 0.778), acute renal failure (HR = 2.33, 95%CI 0.61-8.82, p = 0.213), hyperinflammatory syndrome (HR = 2.32, 95%CI 0.87-6.25, p = 0.091), thrombotic and bleeding events (HR = 1.39, 95%CI 0.32-6.00, p = 0.658), and secondary infection (HR = 2.97, 95%CI 0.62-14.31, p = 0.173). Conclusion: Among hospitalized patients with moderate-to-severe COVID-19 on background dexamethasone, the initiation of tocilizumab or baricitinib had generally comparable effects on time to clinical improvement, hospital discharge, recovery, low viral load, and positive IgG antibody; risks of in-hospital death, hepatic and renal complications, hyperinflammatory syndrome, thrombotic and bleeding events, and secondary infection. On the other hand, tocilizumab users might achieve viral clearance slightly faster than baricitinib users. Further studies and clinical trials are needed to confirm our findings regarding the evaluation of tocilizumab and baricitinib in COVID-19 patients with different disease severities, at varying stages or timing of drug initiation, and considering the concomitant use of other therapeutics.

Slower Recovery with Early Lopinavir/Ritonavir use in Pediatric COVID-19 Patients: A Retrospective Observational Study.

OBJECTIVES: There was initially insufficient understanding regarding suitable pharmacological treatment for pediatric Coronavirus Disease 2019 (COVID-19) patients. Lopinavir-ritonavir (LPV/r) was originally used for the treatment of Human Immunodeficiency Virus-1 (HIV-1) infection. It was also used in patients with severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS) with positive results. Nonetheless, results from recent randomized controlled trials and observational studies on COVID-19 patients were unfavorable. We sought to evaluate the clinical outcomes associated with early treatment with LPV/r for pediatric COVID-19 patients. STUDY DESIGN: A total of 933 COVID-19 patients aged ≤ 18 years were admitted between 21 January 2020 and 31 January 2021 in Hong Kong. Exposure was receiving LPV/r within the first two days of admission. Time to clinical improvement, hospital discharge, seroconversion and hyperinflammatory syndrome, cumulative costs, and hospital length of stay were assessed. Multivariable Cox proportional hazard and linear models were performed to estimate hazard ratios (HR) and their 95% confidence intervals (CI) of time-to-event and continuous outcomes, respectively. RESULTS: LPV/r users were associated with longer time to clinical improvement (HR 0.51, 95% CI 0.38-0.70; p < 0.001), hospital discharge (HR 0.51, 95% CI 0.38-0.70; p < 0.001) and seroconversion (HR 0.59, 95% CI 0.43-0.80; p < 0.001) when compared with controls. LPV/r users were also associated with prolonged hospital length of stay (6.99 days, 95% CI 6.23-7.76; p < 0.001) and higher costs at 30 days (US$11,709 vs US$8270; p < 0.001) as opposed to controls. CONCLUSION: Early treatment with LPV/r for pediatric COVID-19 patients was associated with longer time to clinical improvement. Our study advocates the recommendation against LPV/r use for pediatric patients across age groups.

Switching to Versus Addition of Incretin-Based Drugs Among Patients With Type 2 Diabetes Taking Sodium-Glucose Cotransporter-2 Inhibitors.

Background Evidence is limited in comparing treatment modification by substitution or add-on of glucose-lowering medications in patients with type 2 diabetes. This observational study aims to compare switching versus add-on of incretin-based drugs among patients with type 2 diabetes on background sodium-glucose cotransporter-2 inhibitors (SGLT2i). Methods and Results This population-based, retrospective cohort study was conducted using the IQVIA Medical Research Data, including adults with type 2 diabetes on background SGLT2i from 2005 to 2020. New users of incretin-based drugs were allocated into the "Switch" group if they had discontinued SGLT2i treatment, or the "Add-on" group if their background SGLT2i was continued. Baseline characteristics of patients were balanced between groups. Study outcomes were all-cause mortality, cardiovascular diseases, kidney diseases, hypoglycemia, and ketoacidosis. Patients were observed from the index date of initiating incretin-based drugs until the earliest of an outcome event, death, or data cut-off date. Changes in anthropometric and metabolic parameters were also compared between groups from baseline to 12-month follow-up. A total of 2888 patients were included, classified into "Switch" (n=1461) or "Add-on" group (n=1427). Median follow-up was 18 months with 5183 person-years. Overall, no significant differences in the risks of study outcomes were observed between groups; however, patients in the "Add-on" group achieved significantly greater reductions in glycated hemoglobin, weight, percentage weight loss, and systolic blood pressure than their "Switch" counterparts. Conclusions Initiating incretin-based drugs as add-on among patients with type 2 diabetes on background SGLT2i was associated with risks of clinical end points comparable to switching treatments, in addition to better glycemic and weight control observed with the combination approach.

Remdesivir use and risks of acute kidney injury and acute liver injury among patients hospitalised with COVID-19: a self-controlled case series study.

BACKGROUND AND AIM: To investigate and quantify the risks of AKI and ALI associated with remdesivir use, given the underlying diseases of SARS-CoV-2 infection. METHODS: This self-controlled case series (SCCS) study was conducted using electronic hospital records between 23 January 2020 and 31 January 2021 as retrieved from the Hong Kong Hospital Authority which manages all laboratory-confirmed COVID-19 cases in Hong Kong. Outcomes of AKI and ALI were defined using the KDIGO Guideline and Asia Pacific Association of Study of Liver consensus guidelines. Incidence rate ratios (IRR) for AKI and ALI following the administration of remdesivir (exposure) in comparison to a non-exposure period were estimated using the conditional Poisson regression models. RESULTS: Of 860 COVID-19 patients administered remdesivir during hospitalisation, 334 (38.8%) and 137 (15.9%) had incident ALI and AKI, respectively. Compared with the baseline period, both ALI and AKI risks were increased significantly during the pre-exposure period (ALI: IRR = 6.169, 95% CI = 4.549-8.365; AKI: IRR = 7.074, 95% CI = 3.763-13.298) and remained elevated during remdesivir treatment. Compared to the pre-exposure period, risks of ALI and AKI were not significantly higher in the first 2 days of remdesivir initiation (ALI: IRR = 1.261, 95% CI = 0.915-1.737; AKI: IRR = 1.261, 95% CI = 0.889-1.789) and between days 2 and 5 of remdesivir treatment (ALI: IRR = 1.087, 95% CI = 0.793-1.489; AKI: IRR = 1.152, 95% CI = 0.821-1.616). CONCLUSION: The increased risks of AKI and ALI associated with intravenous remdesivir treatment for COVID-19 may be due to the underlying SARS-CoV-2 infection. The risks of AKI and ALI were elevated in the pre-exposure period, yet no such increased risks were observed following remdesivir initiation when compared to the pre-exposure period.

Metformin Use in Relation to Clinical Outcomes and Hyperinflammatory Syndrome Among COVID-19 Patients With Type 2 Diabetes: A Propensity Score Analysis of a Territory-Wide Cohort.

Aim: This study was conducted in order to evaluate the association between metformin use and clinical outcomes in type 2 diabetes mellitus (T2DM) patients hospitalized with coronavirus disease 2019 (COVID-19). Methods: Patients with T2DM with confirmed diagnosis of COVID-19 and admitted between January 21, 2020, and January 31, 2021 in Hong Kong were identified in our cohort. Exposure was defined as metformin use within 90 days prior to admission until hospital discharge for COVID-19. Primary outcome was defined as clinical improvement of ≥1 point on the WHO Clinical Progression Scale (CPS). Other outcomes were hospital discharge, recovery, in-hospital death, acidosis, hyperinflammatory syndrome, length of hospitalization, and changes in WHO CPS score. Results: Metformin use was associated with greater odds of clinical improvement (OR = 2.74, p = 0.009), hospital discharge (OR = 2.26, p = 0.009), and recovery (OR = 2.54, p = 0.005), in addition to lower odds of hyperinflammatory syndrome (OR = 0.71, p = 0.021) and death (OR = 0.41, p = 0.010) than control. Patients on metformin treatment had a shorter hospital stay (-2.76 days, p = 0.017) than their control counterparts. The average WHO CPS scores were significantly lower in metformin users than non-users since day 15 (p < 0.001). However, metformin use was associated with higher odds of acidosis. Conclusions: Metformin use was associated with lower mortality and lower odds for hyperinflammatory syndrome. This provides additional insights into the potential mechanisms of the benefits of metformin use in T2DM patients with COVID-19.

Use of DPP4i reduced odds of clinical deterioration and hyperinflammatory syndrome in COVID-19 patients with type 2 diabetes: Propensity score analysis of a territory-wide cohort in Hong Kong.

BACKGROUND AND OBJECTIVES: Type 2 diabetes mellitus (T2DM) patients with Coronavirus Disease 2019 (COVID-19) have poorer prognosis. Inconclusive evidence suggested dipeptidyl peptidase-4 inhibitors (DPP4i) might reduce inflammation and prevent Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) entry, hence further evaluation on DPP4i is needed. METHODS: 1214 Patients with T2DM were admitted with COVID-19 between 21st January 2020 and 31st January 2021 in Hong Kong. Exposure was DPP4i use within the 90 days prior to admission for COVID-19. Assessed outcomes included clinical deterioration, clinical improvement, low viral load, positive Immunoglobulin G (IgG) antibody, hyperinflammatory syndrome, proportion of IgG antibody, clinical status and length of hospitalization. Multivariable logistic and linear regression models were performed to estimate odds ratios (OR) and their 95% confidence intervals (CI) of event outcomes and continuous outcomes, respectively. RESULTS: DPP4i users (N = 107) was associated with lower odds of clinical deterioration (OR=0.71, 95%CI 0.54 to 0.93, P = 0.013), hyperinflammatory syndrome (OR=0.56, 95%CI 0.45 to 0.69, P < 0.001), invasive mechanical ventilation (OR=0.30, 95%CI 0.21 to 0.42, P < 0.001), reduced length of hospitalization (-4.82 days, 95%CI -6.80 to -2.84, P < 0.001), proportion of positive IgG antibody on day-3 (13% vs 8%, p = 0.007) and day-7 (41% vs 26%, P < 0.001), despite lack of association between DPP4i use and in-hospital mortality. CONCLUSION: DPP4i use was associated with reduced odds of clinical deterioration and hyperinflammatory syndrome. Prospective studies are warranted to elucidate the role of DPP4i in T2DM and COVID-19.

Optimal Timing of Remdesivir Initiation in Hospitalized Patients With Coronavirus Disease 2019 (COVID-19) Administered With Dexamethasone.

BACKGROUND: Evidence is lacking about any additional benefits of introducing remdesivir on top of dexamethasone, and the optimal timing of initiation. METHODS: In a territory-wide cohort of 10 445 coronavirus disease 2019 (COVID-19) patients from Hong Kong who were hospitalized between 21 January 2020 and 31 January 2021, 1544 had received dexamethasone during hospitalization. The exposure group consisted of patients who had initiated remdesivir prior to dexamethasone (n = 93) or co-initiated the 2 drugs simultaneously (n = 373), whereas the nonexposure group included patients who were given remdesivir after dexamethasone (n = 149) or those without remdesivir use (n = 929). Multiple imputation and inverse probability of treatment weighting for propensity score were applied and hazard ratios (HRs) of event outcomes were estimated using Cox regression models. RESULTS: Time to clinical improvement (HR = 1.23; 95% CI, 1.02-1.49; P = .032) and positive IgG antibody (HR = 1.22; 95% CI, 1.02-1.46; P = .029) were significantly shorter in the exposure group than that of nonexposure. The exposure group had a shorter hospital length of stay by 2.65 days among survivors, lower WHO clinical progression scale scores from 5 days of follow-up onwards, and lower risks of in-hospital death (HR = .59; 95% CI, .36-.98; P = .042) and composite outcomes; and without experiencing an increased risk of acute respiratory distress syndrome. Differences in the cumulative direct medical costs between groups were no longer significant from 17 days of follow-up onwards. CONCLUSIONS: Initiation of remdesivir prior to or simultaneously with dexamethasone was associated with significantly shorter time to clinical improvement and positive IgG antibody, lower risk of in-hospital death, in addition to shorter length of hospital stay in patients with moderate COVID-19.

Clinical Improvement, Outcomes, Antiviral Activity, and Costs Associated With Early Treatment With Remdesivir for Patients With Coronavirus Disease 2019 (COVID-19).

BACKGROUND: Evidence remains inconclusive on any significant benefits of remdesivir in patients with mild-to-moderate COVID-19. This study explored the disease progression, various clinical outcomes, changes in viral load, and costs associated with early remdesivir treatment among COVID-19 patients. METHODS: A territory-wide retrospective cohort of 10 419 patients with COVID-19 hospitalized from 21 January 2020 to 31 January 2021 in Hong Kong was identified. Early remdesivir users were matched with controls using propensity-score matching in a ratio ≤1:4. Study outcomes were time to clinical improvement of at least 1 point on WHO clinical progression scale, hospital discharge, recovery, viral clearance, low viral load, positive IgG antibody, in-hospital death, and composite outcomes of in-hospital death requiring invasive ventilation or intensive care. RESULTS: After multiple imputation and propensity-score matching, median follow-up was 14 days for both remdesivir (n = 352) and control (n = 1347) groups. Time to clinical improvement was significantly shorter in the remdesivir group than that of control (HR: 1.14; 95% CI: 1.01-1.29; P = .038), as well as for achieving low viral load (1.51; 1.24-1.83; P < .001) and positive IgG antibody (1.50; 1.31-1.70; P < .001). Early remdesivir treatment was associated with lower risk of in-hospital death (HR: .58; 95% CI: .34-.99; P = .045), in addition to a significantly shorter length of hospital stay (difference: -2.56 days; 95% CI: -4.86 to -.26; P = .029), without increasing risks of composite outcomes for clinical deterioration. CONCLUSIONS: Early remdesivir treatment could be extended to hospitalized patients with moderate COVID-19 not requiring oxygen therapy on admission.

Repurposing sodium-glucose co-transporter 2 inhibitors (SGLT2i) for cancer treatment - A Review.

Developed as an antidiabetic drug, recent evidence suggests that several sodium-glucose co-transporter 2 inhibitors (SGLT2i), especially canagliflozin and dapagliflozin, may exhibit in vitro and in vivo anticancer activities in selected cancer types, including an inhibition of tumor growth and induction of cell death. When used in combination with chemotherapy or radiotherapy, SGLT2i may offer possible synergistic effects in enhancing their treatment efficacy while alleviating associated side effects. Potential mechanisms include a reduction of glucose uptake into cancer cells, systemic glucose restriction, modulation of multiple signaling pathways, and regulation of different gene and protein expression. Furthermore, preliminary clinical findings have reported potential anticancer properties of canagliflozin and dapagliflozin in patients with liver and colon cancers respectively, with reference to decreases in their tumor marker levels. Given its general tolerability and routine use in diabetes management, SGLT2i may be a good candidate for drug repurposing in cancer treatment and as adjunct to conventional therapies. While current evidence reveals that only certain SGLT2i appear to be effective against selected cancer types, further studies are needed to explore the antitumor abilities of each SGLT2i in various cancers. Moreover, clinical trials are called for to evaluate the safety and feasibility of introducing SGLT2i in the treatment regimen of patients with specific cancers, and to identify the preferred route of drug administration for targeted delivery to selected tumor sites.