Ritonavir: 25 Years' Experience of Concomitant Medication Management. A Narrative Review.

Ritonavir is a potent inhibitor of the cytochrome P450 3A4 enzyme and is commonly used as a pharmacokinetic (PK) enhancer in antiviral therapies because it increases bioavailability of concomitantly administered antivirals. Decades of experience with ritonavir-enhanced HIV therapies and, more recently, COVID-19 therapies demonstrate that boosting doses of ritonavir are well tolerated, with an established safety profile. The mechanisms of PK enhancement by ritonavir result in the potential for drug-drug interactions (DDIs) with several classes of drugs, thus making co-medication management an important consideration with enhanced antiviral therapies. However, rates of DDIs with contraindicated medications are low, suggesting these risks are manageable by infectious disease specialists who have experience with the use of PK enhancers. In this review, we provide an overview of ritonavir's mechanisms of action and describe approaches and resources available to mitigate adverse events and manage concomitant medication in both chronic and short-term settings.

A case report highlighting drug-drug interactions between 3 life-saving treatments: Feminizing hormones, antiretrovirals and antituberculosis drugs.

We here present a case providing valuable insights for clinicians who deliver care to patients identifying as transgender or nonbinary. A 30-year-old trans woman presented to sexual health services requesting a routine sexual health screen and was subsequently diagnosed with HIV and syphilis. She started antiretrovirals for HIV (bictegravir/tenoforvir alafenamide/emtricitabine) 12 days later and was treated with benzathine penicillin G. The patient also had a positive tuberculosis (TB) ELIspot blood test result and further investigations proved the presence of active TB in the chest with mediastinal involvement. She commenced treatment for TB with quadruple therapy, including rifampicin. Due to the clinically significant interaction between rifampicin and bictegravir, the patient's antiretroviral treatment was switched to dolutegravir 50 mg twice daily in combination with tenofovir disoproxil fumarate and emtricitabine. As the patient had transitioned from male to female and was self-medicating with oestrogen-containing feminizing hormone therapy, her hormonal treatment was optimized and blood levels of oestradiol were closely monitored and titrated to manage the drug-drug interaction between rifampicin and oestrogen to ensure the latter would be maintained within the expected therapeutic range. Our case report demonstrates the importance of combining treatment of multiple conditions under 1 team ideally integrated with gender services to prevent multiple attendances and mismanagement of feminizing hormone therapies.

Role of the NO-GC/cGMP signaling pathway in platelet biomechanics.

Cyclic guanosine monophosphate (cGMP) is a second messenger produced by the NO-sensitive guanylyl cyclase (NO-GC). The NO-GC/cGMP pathway in platelets has been extensively studied. However, its role in regulating the biomechanical properties of platelets has not yet been addressed and remains unknown. We therefore investigated the stiffness of living platelets after treatment with the NO-GC stimulator riociguat or the NO-GC activator cinaciguat using scanning ion conductance microscopy (SICM). Stimulation of human and murine platelets with cGMP-modulating drugs decreased cellular stiffness and downregulated P-selectin, a marker for platelet activation. We also quantified changes in platelet shape using deep learning-based platelet morphometry, finding that platelets become more circular upon treatment with cGMP-modulating drugs. To test for clinical applicability of NO-GC stimulators in the context of increased thrombogenicity risk, we investigated the effect of riociguat on platelets from human immunodeficiency virus (HIV)-positive patients taking abacavir sulfate (ABC)-containing regimens. Our results corroborate a functional role of the NO-GC/cGMP pathway in platelet biomechanics, indicating that biomechanical properties such as stiffness or shape could be used as novel biomarkers in clinical research.

Increased platelet activation and development of thrombosis has been linked to a dysfunctional NO-GC/cGMP signaling pathway. How this pathway affects platelet stiffness, however, has not been studied yet. For the first time, we used novel microscopy techniques to investigate stiffness and shape of platelets in human and murine blood samples treated with cGMP modifying drugs. Stiffness contains information about biomechanical properties of the cytoskeleton, and shape quantifies the spreading behavior of platelets. We showed that the NO-GC/cGMP signaling pathway affects platelet stiffness, shape, and activation in human and murine blood. HIV-positive patients are often treated with medication that may disrupt the NO-GC/cGMP signaling pathway, leading to increased cardiovascular risk. We showed that treatment with cGMP-modifying drugs altered platelet shape and aggregation in blood from HIV-negative volunteers but not from HIV-positive patients treated with medication. Our study suggests that platelet stiffness and shape can be biomarkers for estimating cardiovascular risk.

The predictive role of symptoms in COVID-19 diagnostic models: A longitudinal insight.

To investigate the symptoms of SARS-CoV-2 infection, their dynamics and their discriminatory power for the disease using longitudinally, prospectively collected information reported at the time of their occurrence. We have analysed data from a large phase 3 clinical UK COVID-19 vaccine trial. The alpha variant was the predominant strain. Participants were assessed for SARS-CoV-2 infection via nasal/throat PCR at recruitment, vaccination appointments, and when symptomatic. Statistical techniques were implemented to infer estimates representative of the UK population, accounting for multiple symptomatic episodes associated with one individual. An optimal diagnostic model for SARS-CoV-2 infection was derived. The 4-month prevalence of SARS-CoV-2 was 2.1%; increasing to 19.4% (16.0%-22.7%) in participants reporting loss of appetite and 31.9% (27.1%-36.8%) in those with anosmia/ageusia. The model identified anosmia and/or ageusia, fever, congestion, and cough to be significantly associated with SARS-CoV-2 infection. Symptoms' dynamics were vastly different in the two groups; after a slow start peaking later and lasting longer in PCR+ participants, whilst exhibiting a consistent decline in PCR- participants, with, on average, fewer than 3 days of symptoms reported. Anosmia/ageusia peaked late in confirmed SARS-CoV-2 infection (day 12), indicating a low discrimination power for early disease diagnosis.

Episodic disability questionnaire (EDQ) measurement properties among adults living with HIV in Canada, Ireland, United Kingdom, and United States.

BACKGROUND: The Episodic Disability Questionnaire (EDQ) is a generic 35-item patient-reported outcome measure of presence, severity and episodic nature of disability. We assessed the measurement properties of the Episodic Disability Questionnaire (EDQ) with adults living with HIV. METHODS: We conducted a measurement study with adults living with HIV in eight clinical settings in Canada, Ireland, United Kingdom, and United States. We electronically administered the EDQ followed by three reference measures (World Health Organization Disability Assessment Schedule; Patient Health Questionnaire; Social Support Scale) and a demographic questionnaire. We administered the EDQ only 1 week later. We assessed the internal consistency reliability (Cronbach's alpha; > 0.7 acceptable), and test-retest reliability (Intra Class Correlation Coefficient; > 0.7 acceptable). We estimated required change in EDQ domain scores to be 95% certain that a change was not due to measurement error (Minimum Detectable Change (MDC95%)). We evaluated construct validity by assessing 36 primary hypotheses of relationships between EDQ scores and scores on the reference measures (> 75% hypotheses confirmed indicated validity). RESULTS: Three hundred fifty nine participants completed the questionnaires at time point 1, of which 321 (89%) completed the EDQ approximately 1 week later. Cronbach's alpha for internal consistency ranged from 0.84 (social domain) to 0.91 (day domain) for the EDQ severity scale, and 0.72 (uncertainty domain) to 0.88 (day domain) for the EDQ presence scale, and 0.87 (physical, cognitive, mental-emotional domains) to 0.89 (uncertainty domain) for the EDQ episodic scale. ICCs for test-retest reliability ranged from 0.79 (physical domain) to 0.88 (day domain) for the EDQ severity scale and from 0.71 (uncertainty domain) to 0.85 (day domain) for the EDQ presence scale. Highest precision was demonstrated in the severity scale for each domain (MDC95% range: 19-25 out of 100), followed by the presence (MDC95% range: 37-54) and episodic scales (MDC95% range:44-76). Twenty-nine of 36 (81%) construct validity hypotheses were confirmed. CONCLUSIONS: The EDQ possesses internal consistency reliability, construct validity, and test-retest reliability, with limited precision when administered electronically with adults living with HIV across in clinical settings in four countries. Given the measurement properties, the EDQ can be used for group level comparisons for research and program evaluation in adults living with HIV.

Direct switch from an efavirenz-based regimen to intramuscular long-acting cabotegravir plus rilpivirine: A case report.

Switching from oral antiretroviral treatment to intramuscular (IM) cabotegravir (CAB) + rilpivirine (RPV) has an optional oral lead-in to ensure tolerability. The British HIV Association guidelines advise against directly switching from oral antiretroviral (ART) combinations containing strong/moderate cytochrome inducers like efavirenz (EFV) to IM CAB + RPV. EFV has a prolonged elimination half-life, leading to a residual induction of UGT1A1 and CYP3A4 after discontinuation. These enzymes are responsible for CAB and RPV metabolism and their induction might lead to sub-optimal concentrations of CAB and RPV, risking drug resistance. When switching from EFV to oral CAB + RPV, the ATLAS and ATLAS 2M studies showed reduced RPV concentrations but with maintained viral suppression during the oral lead-in and subsequent long-acting injectable (LAI) phases. Also, a recent pharmacokinetic modelling study indicated reduced RPV concentrations, without viral implication, when switching from EFV to IM CAB + RPV. However, there are limited real-world data on direct switching from EFV-based therapy to long-acting IM CAB + RPV. We describe a case where oral intake was impossible in a critical care scenario, switching from emitricitabine/tenofovir-DF (FTC/TDF) 200/245 mg + 600 mg EFV to IM CAB + RPV for treatment optimisation.

Tackling late HIV diagnosis: Lessons from the UK in the COVID-19 era.

INTRODUCTION: Late diagnosis of HIV is associated with increased morbidity and mortality, and an increased risk of non-infectious comorbidities. On a societal level, late diagnosis leads to higher treatment and healthcare costs and is a major driver of HIV transmission. Despite improvements in other areas of the HIV care pathway, late diagnosis remains an individual and public health concern globally. OBJECTIVE: To examine the barriers to HIV testing and highlight successful strategies to improve prompt diagnosis. This review describes the prevalence of late diagnosis in the UK and discusses key factors that contribute to late diagnosis, including the effect of the COVID-19 pandemic. Late HIV diagnosis is lower in the UK than in most other European countries. In this review, pilot projects and ongoing initiatives that have reduced late diagnosis in the UK are highlighted; moreover, further strategies for improving prompt diagnosis are suggested. CONCLUSIONS: Insufficient testing is the fundamental reason for late HIV diagnosis, with societal, systemic, and individual factors all contributing to inadequate testing. Improving access to testing, removing barriers to health-seeking behaviour, and ensuring all people with HIV indicator conditions are promptly tested are key to reducing the rates of late diagnosis globally.

Anastrozole as a therapeutic option for gynecomastia in a person receiving antiretroviral therapy: Case report.

A middle-aged Caucasian man living with HIV, clinically stable (viral load <20 copies/mL) on injectable antiretroviral cabotegravir plus rilpivirine every 2 months presented with a 6-month history of bilateral enlargement of the breasts associated with pain. His hormonal profile was normal, and no other underlying cause was identified. He was diagnosed with idiopathic gynecomastia. Tamoxifen is an anti-oestrogen recommended for gynecomastia and has been described in people living with HIV but can potentially induce the activity of cytochrome P450 3A4 (CYP3A4), reducing rilpivirine concentrations, which consequently may cause virological failure and resistance. This is the same for other antiretroviral agents majorly induced by CYP3A4. To date, there have been no reported cases of using anastrozole as a treatment for gynecomastia in people living with HIV or of its co-administration with antiretroviral. We describe the use of an aromatase inhibitor instead of tamoxifen in a person living with HIV, diagnosed with gynecomastia.

Twelve-month effectiveness and safety of bictegravir/emtricitabine/tenofovir alafenamide in people with HIV: Real-world insights from BICSTaR cohorts.

BACKGROUND: Real-world evidence is an essential component of evidence-based medicine. The aim of the BICSTaR (BICtegravir Single Tablet Regimen) study is to assess effectiveness and safety of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in antiretroviral treatment-naïve (TN) and treatment-experienced (TE) people with HIV. METHODS: BICSTaR is a prospective, observational cohort study. Participants (≥18 years) are being followed for 24 months. A pooled analysis is presented at 12 months, with the primary endpoint of effectiveness (HIV-1 RNA <50 copies/mL) and secondary endpoints of safety and tolerability (as per protocol). An exploration of patient-reported outcome measures using standardized questionnaires is included. RESULTS: Between June 2018 and May 2021, 1552 people with HIV were enrolled across 12 countries. The analysed population comprised 1509 individuals (279 TN, 1230 TE); most were white (76%), male (84%) and had one or more comorbid conditions (68%). Median age was 47 years. After 12 months of B/F/TAF treatment, HIV-1 RNA was <50 copies/mL in 94% (221/236) of TN participants and 97% (977/1008) of TE participants. Median CD4 cell count increased by 214 cells/µL (p < 0.001) in TN participants and 13 cells/µL (p = 0.014) in TE participants; median CD4/CD8 ratios increased by 0.30 and 0.03, respectively (both p < 0.001). Persistence was high at 12 months (TN, 97%; TE, 95%). No resistance to B/F/TAF emerged. Study drug-related adverse events occurred in 13% of participants through 12 months, leading to B/F/TAF discontinuation in 6%. CONCLUSIONS: The findings of this study provide robust real-world evidence to support the broad use of B/F/TAF in both TN and TE people with HIV.

Pharmacokinetics of tecovirimat in subjects with Mpox.

OBJECTIVE: To investigate the pharmacokinetics (PK) of tecovirimat in subjects with Mpox. METHODS: This monocentric, prospective, observational study enrolled subjects with Mpox who received standard treatment with oral tecovirimat. Plasma samples for PK assessment were collected at steady state (5-8 days after initiation of antiviral therapy), before and 3, 5, 7 and 12 h after tecovirimat administration. Drug concentrations were determined by validated liquid chromatography coupled with tandem mass spectrometry. PK parameters were calculated using Phoenix 8.1. RESULTS: Overall, 14 male patients hospitalized for severe Mpox with ongoing tecovirimat treatment were enrolled in this study. Six of the 14 patients were living with human immunodeficiency virus (HIV), all of whom were on antiretroviral therapy (ART) and virologically suppressed at the time of hospitalization. Significant differences in tecovirimat PK were observed in subjects without HIV compared with subjects with HIV. In subjects with HIV, the maximum tecovirimat plasma concentration (39%, P≤0.0001), minimum tecovirimat plasma concentration (42%, P=0.0079) and area under the curve from zero to the last measured time-point (40%, P≤0.0001) were significantly lower compared with subjects without HIV, but all concentrations remained above the in-vitro calculated 90% inhibitory concentration. No significant associations were found between demographic/clinical data and tecovirimat PK. All patients recovered completely within 14 (range 6-36) days of treatment initiation. CONCLUSIONS: This study found a significant decrease in plasma exposure of tecovirimat in Mpox patients with HIV on effective ART compared with those without HIV, with no evident impact on clinical outcomes. Although these results need to be confirmed in larger studies, they may provide useful information on the PK of tecovirimat.

Practical dosing guidance for the management of clinician-administered injections of long-acting cabotegravir and rilpivirine.

Cabotegravir (CAB) and rilpivirine (RPV) is the first complete long-acting (LA) injectable regimen recommended by treatment guidelines for the maintenance of HIV-1 virologic suppression in people with HIV-1 who are virologically suppressed on a stable antiretroviral regimen that is administered monthly (Q1M) or every 2 months (Q2M). As an alternative regimen to lifelong daily oral antiretroviral therapy, Q1M or Q2M dosing schedules are associated with increased patient satisfaction and treatment preference. In addition, it may address challenges associated with daily oral dosing, including fear of treatment disclosure or stigma, anxiety related to oral dosing adherence, and the daily reminder of HIV disease status. Cabotegravir + RPV LA is administered by clinical staff as two intramuscular injections dosed Q1M or Q2M. In this review, we share practical dosing guidance for CAB+RPV LA injectable therapy, including how to initiate therapy, schedule injection visits, manage dosing interruptions due to missed or delayed injection visits, manage errors in dosing, and transition to alternative antiretroviral therapy after discontinuation. Practical guidance on the clinical management of CAB+RPV LA dosing, including a detailed discussion using case-based scenarios that may be encountered in clinical practice, is provided. The clinician-administered CAB+RPV LA regimen has dosing management considerations that are flexible and considerate of the patient and has the potential to provide a highly desirable and efficacious alternative to daily oral antiretroviral therapy for many people with HIV-1.

Guidance for clinicians on the management of long-acting Cabotegravir and Rilpivirine Injectable Therapy for HIV-1 Cabotegravir (CAB) and rilpivirine (RPV) is the first long-acting (LA) injectable therapy for people with HIV-1 who previously achieved undetectable virus levels using other HIV-1 medications. People with HIV-1 receive CAB+RPV LA as two injections given by their clinician every 1 month or every 2 months, providing an alternative treatment option to lifelong daily oral medications. People with HIV-1 receiving CAB+RPV LA every 1 or 2 months have higher levels of treatment satisfaction and often prefer CAB+RPV LA compared with daily oral medications. Cabotegravir+RPV LA may also address challenges associated with daily oral medications, including fear of inadvertently sharing HIV status, anxiety related to taking daily medications, and having a daily reminder of HIV. In this review, we provide guidance for clinicians on how to administer CAB+RPV LA injectable therapy, including how to start patients on CAB+RPV LA injections, schedule injection visits, manage missed or delayed injection visits, manage dosing errors, and switch patients to a different treatment if CAB+RPV LA is discontinued. This review also includes a detailed discussion of potential scenarios related to the administration and scheduling of CAB+RPV LA injections that may occur in clinical practice. Overall, this review serves as a practical guide for managing CAB+RPV LA injectable therapy in clinical practice that will be useful for HIV clinicians.

Anticholinergic medications associated with falls and frailty in people with HIV.

BACKGROUND: Anticholinergic medications (ACMs) are associated with poorer age-related outcomes, including falls and frailty. We investigate associations between ACM use and recurrent falls and frailty among older (aged ≥50 years) people with HIV in the POPPY study. METHODS: Anticholinergic potential of co-medications at study entry was coded using the anticholinergic burden score, anticholinergic risk score, and Scottish Intercollegiate Guidelines Network score; drugs scoring ≥1 on any scale were defined as ACM. Associations with recurrent falls (two or more falls in the previous 28 days) and frailty (modified Fried's) were assessed using logistic regression adjusting for (1) possible demographic/lifestyle confounders and (2) clinical factors and depressive symptoms (Patient Health Questionnaire-9). RESULTS: ACM use was reported by 193 (28%) of 699 participants, with 64 (9%) receiving two or more ACM; commonly prescribed ACMs were codeine (12%), citalopram (12%), loperamide (9%), and amitriptyline (7%). Falls were reported in 63/673 (9%), and 126/609 (21%) met the frailty criteria. Both recurrent falls and frailty were more common in ACM users than in non-users (recurrent falls: 17% in users vs. 6% in non-users, p < 0.001; frailty: 32% vs. 17%, respectively, p < 0.001). Use of two or more ACMs was associated with increased odds of falls after adjustment for demographic/lifestyle factors (odds ratio [OR] 4.53; 95% confidence interval [CI] 2.06-9.98) and for clinical factors (OR 3.58; 95% CI 1.37-9.38). Similar albeit weaker associations were seen with frailty (OR 2.26; 95% CI 1.09-4.70 and OR 2.12; 95% CI 0.89-5.0, respectively). CONCLUSIONS: ACM are commonly prescribed for people living with HIV, and evidence exists for an association with recurrent falls and frailty. Clinicians should be alert to this and reduce ACM exposure where possible.

Omicron BA.1-containing mRNA-1273 boosters compared with the original COVID-19 vaccine in the UK: a randomised, observer-blind, active-controlled trial.

BACKGROUND: The omicron BA.1 bivalent booster is used globally. Previous open-label studies of the omicron BA.1 (Moderna mRNA-1273.214) booster showed superior neutralising antibody responses against omicron BA.1 and other variants compared with the original mRNA-1273 booster. We aimed to compare the safety and immunogenicity of omicron BA.1 monovalent and bivalent boosters with the original mRNA-1273 vaccine in a large, randomised controlled trial. METHODS: In this large, randomised, observer-blind, active-controlled, phase 3 trial in the UK (28 hospital and vaccination clinic sites), individuals aged 16 years or older who had previously received two injections of any authorised or approved COVID-19 vaccine, with or without an mRNA vaccine booster (third dose), were randomly allocated (1:1) using interactive response technology to receive 50 µg omicron BA.1 monovalent or bivalent vaccines or 50 µg mRNA-1273 administered as boosters via deltoid intramuscular injection. The primary outcomes were safety and immunogenicity at day 29, including prespecified non-inferiority and superiority of booster immune responses, based on the neutralising antibody geometric mean concentration (GMC) ratios of the monovalent and bivalent boosters compared with mRNA-1273. Safety was assessed in all participants who received first or second boosters, and primary immunogenicity outcomes were assessed in all participants who received the planned booster dose, had pre-booster and day 29 antibody data, had no major protocol deviations, and who were SARS-CoV-2-negative. The study is registered with EudraCT (2022-000063-51) and ClinicalTrials.gov (NCT05249829) and is ongoing. FINDINGS: Between Feb 16 and March 24, 2022, 724 participants were randomly allocated to receive omicron BA.1 monovalent (n=366) or mRNA-1273 (n=357), and between April 2 and June 17, 2022, 2824 participants were randomly allocated to receive omicron BA.1 bivalent (n=1418) or mRNA-1273 (n=1395) vaccines as second boosters. Median durations (months) between the most recent COVID-19 vaccine and study boosters were similar for omicron BA.1 monovalent (4·0 months [IQR 3·6-4·7]) and mRNA-1273 (4·1 [3·5-4·7]), and for the omicron BA.1 bivalent (5·5 [4·8-6·2]) and mRNA-1273 (5·4 [4·8-6·2]) boosters. The omicron BA.1 monovalent and bivalent boosters elicited superior neutralising GMCs against the omicron BA.1 variant compared with mRNA-1273, with GMC ratios of 1·68 (99% CI 1·45-1·95) and 1·53 (1·41-1·67) at day 29 post-booster doses in participants without previous SARS-CoV-2 infection. Both boosters induced non-inferior ancestral SARS-CoV-2 (Asp614Gly) immune responses with GMCs that were similar for the bivalent (2987·2 [95% CI 2814·9-3169·9]) versus mRNA-1273 (2911·3 [2750·9-3081·0]) and lower for the monovalent (2699·7 [2431·3-2997·7] vs 3020·6 [2776·5-3286·2]) boosters, with respective GMC ratios of 1·05 (99% CI 0·96-1·15) and 0·82 (95% CI 0·74-0·91). Results were comparable regardless of previous SARS-CoV-2 infection status. Incidences of solicited adverse reactions with the omicron BA.1 monovalent (335 [91·3%] of 367 participants) and omicron BA.1 bivalent (1285 [90·4%] of 1421 participants) boosters were similar to those observed previously for mRNA-1273, with no new safety concerns identified and no occurrences of fatal adverse events. INTERPRETATION: Omicron-containing booster vaccines generated superior immunogenicity against omicron BA.1 and comparable immunogenicity against the original strain with no new safety concerns. It remains important to continuously monitor the immune responses and real-world vaccine effectiveness as divergent SARS-CoV-2 variants emerge. FUNDING: Moderna.

A Phase 2 Randomized Trial Evaluating the Antiviral Activity and Safety of the Direct-Acting Antiviral Bemnifosbuvir in Ambulatory Patients with Mild or Moderate COVID-19 (MOONSONG Study).

Bemnifosbuvir is an oral antiviral drug with a dual mechanism of action targeting viral RNA polymerase, with in vitro activity against SARS-CoV-2. We conducted a phase 2, double-blind study evaluating the antiviral activity, safety, efficacy, and pharmacokinetics of bemnifosbuvir in ambulatory patients with mild/moderate COVID-19. Patients were randomized 1:1 to bemnifosbuvir 550 mg or placebo (cohort A) and 3:1 to bemnifosbuvir 1,100 mg or placebo (cohort B); all doses were given twice daily for 5 days. The primary endpoint was a change from baseline in the amount of nasopharyngeal SARS-CoV-2 viral RNA by reverse transcription PCR (RT-PCR). The modified intent-to-treat infected population comprised 100 patients (bemnifosbuvir 550 mg, n = 30; bemnifosbuvir 1,100 mg, n = 30; cohort A placebo, n = 30; cohort B placebo, n = 10). The primary endpoint was not met: the difference in viral RNA adjusted means at day 7 was -0.25 log10 copies/mL between bemnifosbuvir 550 mg and cohort A placebo (80% confidence interval [CI], -0.66 to 0.16; P = 0.4260), and -0.08 log10 copies/mL between bemnifosbuvir 1,100 mg and pooled placebo (80% CI, -0.48 to 0.33; P = 0.8083). Bemnifosbuvir 550 mg was well tolerated. Incidence of nausea and vomiting was higher with bemnifosbuvir 1,100 mg (10.0% and 16.7% of patients, respectively) than pooled placebo (2.5% nausea, 2.5% vomiting). In the primary analysis, bemnifosbuvir did not show meaningful antiviral activity on nasopharyngeal viral load as measured by RT-PCR compared with placebo in patients with mild/moderate COVID-19. The trial is registered at ClinicalTrials.gov under registration number NCT04709835. IMPORTANCE COVID-19 continues to be a major global public health challenge, and there remains a need for effective and convenient direct-acting antivirals that can be administered outside health care settings. Bemnifosbuvir is an oral antiviral with a dual mechanism of action and potent in vitro activity against SARS-CoV-2. In this study, we evaluated the antiviral activity, safety, efficacy, and pharmacokinetics of bemnifosbuvir in ambulatory patients with mild/moderate COVID-19. In the primary analysis, bemnifosbuvir did not show meaningful antiviral activity compared with placebo as assessed by nasopharyngeal viral loads. The negative predictive value of nasopharyngeal viral load reduction for clinical outcomes in COVID-19 is currently unclear, and further evaluation of bemnifosbuvir for COVID-19 may be warranted despite the findings observed in this study.

Episodic Disability Questionnaire (EDQ) measurement properties among adults living with HIV in Canada, Ireland, United Kingdom, and United States.

Background: The Episodic Disability Questionnaire (EDQ) is a generic 35-item patient-reported outcome measure of presence, severity and episodic nature of disability. We assessed the measurement properties of the Episodic Disability Questionnaire (EDQ) with adults living with HIV. Methods: We conducted a measurement study with adults living with HIV in eight clinical settings in Canada, Ireland, United Kingdom, and United States. We electronically administered the EDQ followed by three reference measures (World Health Organization Disability Assessment Schedule; Patient Health Questionnaire; Social Support Scale) and a demographic questionnaire. We administered the EDQ only 1 week later. We assessed the internal consistency reliability (Cronbach's alpha; >0.7 acceptable), and test-retest reliability (Intra Class Correlation Coefficient; >0.7 acceptable). We estimated required change in EDQ domain scores to be 95% certain that a change was not due to measurement error (Minimum Detectable Change (MDC95%)). We evaluated construct validity by assessing 36 primary hypotheses of relationships between EDQ scores and scores on the reference measures (> 75% hypotheses confirmed indicated validity). Results: 359 participants completed the questionnaires at time point 1, of which 321 (89%) completed the EDQ approximately 1 week later. Cronbach's alpha for internal consistency ranged from 0.84 (social domain) to 0.91 (day domain) for the EDQ severity scale, and 0.72 (uncertainty domain) to 0.88 (day domain) for the EDQ presence scale, and 0.87 (physical, cognitive, mental-emotional domains) to 0.89 (uncertainty domain) for the EDQ episodic scale. ICCs for test-retest reliability ranged from 0.79 (physical domain) to 0.88 (day domain) for the EDQ severity scale and from 0.71 (uncertainty domain) to 0.85 (day domain) for the EDQ presence scale. Highest precision was demonstrated in the severity scale for each domain (MDC95% range: 19-25 out of 100), followed by the presence (MDC95% range: 37-54) and episodic scales (MDC95% range:44-76). Twenty-nine of 36 (81%) construct validity hypotheses were confirmed. Conclusions: The EDQ possesses internal consistency reliability, construct validity, and test-retest reliability, with limited precision when administered electronically with adults living with HIV across in clinical settings in four countries. Given the measurement properties, the EDQ can be used for group level comparisons for research and program evaluation in adults living with HIV.

COVAC1 phase 2a expanded safety and immunogenicity study of a self-amplifying RNA vaccine against SARS-CoV-2.

Background: Lipid nanoparticle (LNP) encapsulated self-amplifying RNA (saRNA) is well tolerated and immunogenic in SARS-CoV-2 seronegative and seropositive individuals aged 18-75. Methods: A phase 2a expanded safety and immunogenicity study of a saRNA SARS-CoV-2 vaccine candidate LNP-nCoVsaRNA, was conducted at participating centres in the UK between 10th August 2020 and 30th July 2021. Participants received 1 µg then 10 µg of LNP-nCoVsaRNA, ∼14 weeks apart. Solicited adverse events (AEs) were collected for one week post-each vaccine, and unsolicited AEs throughout. Binding and neutralisating anti-SARS-CoV-2 antibody raised in participant sera was measured by means of an anti-Spike (S) IgG ELISA, and SARS-CoV-2 pseudoneutralisation assay. (The trial is registered: ISRCTN17072692, EudraCT 2020-001646-20). Findings: 216 healthy individuals (median age 51 years) received 1.0 µg followed by 10.0 µg of the vaccine. 28/216 participants were either known to have previous SARS-CoV2 infection and/or were positive for anti-Spike (S) IgG at baseline. Reactogenicity was as expected based on the reactions following licensed COVID-19 vaccines, and there were no serious AEs related to vaccination. 80% of baseline SARS-CoV-2 naïve individuals (147/183) seroconverted two weeks post second immunization, irrespective of age (18-75); 56% (102/183) had detectable neutralising antibodies. Almost all (28/31) SARS-CoV-2 positive individuals had increased S IgG binding antibodies following their first 1.0 µg dose with a ≥0.5log10 increase in 71% (22/31). Interpretation: Encapsulated saRNA was well tolerated and immunogenic in adults aged 18-75 years. Seroconversion rates in antigen naïve were higher than those reported in our dose-ranging study. Further work is required to determine if this difference is related to a longer dosing interval (14 vs. 4 weeks) or dosing with 1.0 µg followed by 10.0 µg. Boosting of S IgG antibodies was observed with a single 1.0 µg injection in those with pre-existing immune responses. Funding: Grants and gifts from the Medical Research Council UKRI (MC_PC_19076), the National Institute for Health Research/Vaccine Task Force, Partners of Citadel and Citadel Securities, Sir Joseph Hotung Charitable Settlement, Jon Moulton Charity Trust, Pierre Andurand, and Restore the Earth.