A Randomised -Controlled Phase 2 trial of Molnupiravir in Unvaccinated and Vaccinated Individuals with Early SARS-CoV-2 (preprint)

Background Molnupiravir was licensed for treating high-risk patients with COVID-19 based on data from unvaccinated adults. AGILE CST-2 (NCT04746183) Phase II reports safety and virological efficacy of molnupiravir in vaccinated and unvaccinated individuals. Methods Adult out-patients with PCR-confirmed SARS-CoV-2 infection within five days of symptom onset were randomly assigned 1:1 to receive molnupiravir (800mg twice daily for five days) or placebo. The primary outcome was time to swab PCR-negativity, compared using a Bayesian model for estimating the probability of a superior virological response (Hazard Ratio>1) for molnupiravir over placebo. Secondary outcomes included change in viral titre at day 5, safety and tolerability, clinical progression and patient reported outcome measures. We analysed outcomes after the last participant reached day 29. Findings Of 180 participants randomised (90 molnupiravir, 90 placebo), 50% were vaccinated. Infections with SARS-CoV-2 variants Delta (40%), Alpha (21%), Omicron (21%) and EU1 (16%) were represented. The median time to negative-PCR was 8 versus 11 days for molnupiravir and placebo (HR=1.30, 95% CrI 0.92-1.71, p=0.7 by Logrank and p=0.03 by Breslow-Gehan tests). Although small numbers precluded subgroup analysis, no obvious differences were observed between vaccinated and unvaccinated participants. Using a two-point prior the probability of molnupiravir being superior to placebo (HR>1) was 75.4%, which was just below our defined threshold of 80% for establishing superiority. Using an uninformative continuous prior, the probability of HR>1 was 94.7%. As an exploratory analysis, the change in viral titre on day 5 (end of treatment) was significantly greater with molnupiravir compared with placebo. A total of 4 participants reported severe adverse events (grade 3+), 3 of whom were in the placebo arm. Interpretation We found molnupiravir to be well-tolerated, with evidence for high probability of antiviral efficacy in a population of vaccinated and unvaccinated individuals infected with a broad range of viral variants.

Characterisation of SARS-CoV-2 genomic variations in response to molnupiravir treatment in the AGILE Phase IIa clinical trial. (preprint)

Molnupiravir is an antiviral approved for treating COVID-19, which is thought to drive lethal error catastrophe. How this drug-induced mechanism of action impacts the emergence of resistance mutations is unclear. AGILE Candidate Specific Trial (CST)-2 is a phase IIa trial randomising 180 adult outpatients with SARS-COV-2 infection within five days of symptom onset to molnupiravir or placebo, with rich serial sampling of nasopharyngeal swabs over 29 days. Viral sequences, that passed genome quality control criteria, from subjects who received molnupiravir (n=59) or a placebo (n=65) were analysed by high-throughput amplicon sequencing. We found evidence that molnupiravir significantly increased the transition/transversion frequency in SARS-CoV-2 in patients, a hallmark of molnupiravir treatment. Over the course of treatment, no consistent, accumulated mutations were identified in either arm.

Pharmacokinetics of β-d-N4-hydroxycytidine, the active metabolite of prodrug molnupiravir, in non-plasma compartments of patients with SARS-CoV-2 infection (preprint)

BackgroundMolnupiravir, an orally administered prodrug of the broadly active, direct-acting antiviral, ribonucleoside analogue {beta}-d-N4-hydroxycytidine (NHC) is a promising COVID-19 drug candidate. We characterised the pharmacokinetics of NHC in saliva, nasal secretions and tears of patients enrolled in the phase I AGILE trial (NCT04746183) to understand its potential in preventing infection and transmission. MethodsPatients with PCR-confirmed SARS-CoV-2 infection, within 5 days of symptom onset with mild-to-moderate disease were randomised to oral molnupiravir 300, 600 or 800 mg twice daily or placebo. Plasma and non-plasma (saliva, nasal secretions and tears) samples were collected at pre-dose, 0.5, 1, 2, and 4 hours post-dose on study days 1 and 5 and molnupiravir and NHC measured by LC/MS with a lower limit of quantification of 2.5 ng/mL in all matrices. Pharmacokinetic parameters were determined by noncompartmental methods and non-plasma:plasma ratios (RNP:P; based on AUC0-4) calculated. ResultsTwelve participants (n=4 per dosing arm; 75% female) completed the study. NHC Tmax ranged between 1.00-4.00 hours for saliva (n=21) and nasal swabs (n=22) and 0.50-4.00 hours (n=17) for tears compared to 1.00-2.00 hours for plasma (n=19). Median (range) saliva RNP:P pooled across doses was 0.03 (0.01-0.11); n=16. RNP:P for nasal secretions and tears were 0.21 (0.05-0.73); n=17 and 0.22 (0.09-1.05); n=12, respectively. Non-plasma and plasma concentrations were significantly correlated (p<0.0001). ConclusionThese data provide encouraging information regarding the distribution of NHC at sites of viral transmission and have important implications for prophylactic coverage.

An open label, adaptive, phase 1 trial of high-dose oral nitazoxanide in healthy volunteers: an antiviral candidate for SARS-CoV-2 (preprint)

Repurposing approved drugs may rapidly establish effective interventions during a public health crisis. This has yielded immunomodulatory treatments for severe COVID-19, but repurposed antivirals have not been successful to date because of redundancy of the target in vivo or suboptimal exposures at studied doses. Nitazoxanide is an FDA approved antiparasitic medicine, that physiologically-based pharmacokinetic (PBPK) modelling has indicated may provide antiviral concentrations across the dosing interval, when repurposed at higher than approved doses. Within the AGILE trial platform (NCT04746183) an open label, adaptive, phase 1 trial in healthy adult participants was undertaken with high dose nitazoxanide. Participants received 1500mg nitazoxanide orally twice-daily with food for 7 days. Primary outcomes were safety, tolerability, optimum dose and schedule. Intensive pharmacokinetic sampling was undertaken day 1 and 5 with Cmin sampling on day 3 and 7. Fourteen healthy participants were enrolled between 18th February and 11th May 2021. All 14 doses were completed by 10/14 participants. Nitazoxanide was safe and well tolerated with no significant adverse events. Moderate gastrointestinal disturbance (loose stools) occurred in 8 participants (57.1%), with urine and sclera discolouration in 12 (85.7%) and 9 (64.3%) participants, respectively, without clinically significant bilirubin elevation. This was self-limiting and resolved upon drug discontinuation. PBPK predictions were confirmed on day 1 but with underprediction at day 5. Median Cmin was above the in vitro target concentration on first dose and maintained throughout. Nitazoxanide administered at 1500mg BID with food was safe and well tolerated and a phase 1b/2a study is now being initiated in COVID-19 patients.

Optimal dose and safety of molnupiravir in patients with early SARS-CoV-2: a phase 1, dose-escalating, randomised controlled study (preprint)

Background AGILE is a phase Ib/IIa platform for rapidly evaluating COVID-19 treatments. In this trial (NCT04746183) we evaluated the safety and optimal dose of molnupiravir in participants with early symptomatic infection. Methods We undertook a dose-escalating, open-label, randomised-controlled (standard-of-care) Bayesian adaptive phase I trial at the Royal Liverpool and Broadgreen Clinical Research Facility. Participants (adult outpatients with PCR-confirmed SARS-CoV-2 infection within 5 days of symptom onset) were randomised 2:1 in groups of 6 participants to 300mg, 600mg and 800mg doses of molnupiravir orally, twice daily for 5 days or control. A dose was judged unsafe if the probability of 30% or greater dose-limiting toxicity (the primary outcome) over controls was higher than 25%. Secondary outcomes included safety, clinical progression, pharmacokinetics and virologic responses. Results Of 103 volunteers screened, 18 participants were enrolled between 17 July and 30 October 2020. Molnupiravir was well tolerated at 400, 600 or 800mg doses with no serious or severe adverse events. Overall, 4 of 4 (100%), 4 of 4 (100%) and 1 of 4 (25%) of the participants receiving 300, 600 and 800mg molnupiravir respectively, and 5 of 6 (83%) controls, had at least one adverse event, all of which were mild ([≤]grade 2). The probability of [≥]30% excess toxicity over controls at 800mg was estimated at 0.9%. Conclusion Molnupiravir was safe and well tolerated; a dose of 800mg twice-daily for 5 days was recommended for Phase II evaluation.

Accuracy of Rapid Point-of-Care Antibody Test in patients with suspected or confirmed COVID-19 (preprint)

ObjectivesTo assess the real-world diagnostic accuracy of the Livzon point-of-care rapid test for antibodies to SARS-COV-2 DesignProspective cohort study SettingDistrict general hospital in England Participants173 Patients and 224 hospital staff with a history of COVID-19 symptoms, and who underwent PCR and/or reference antibody testing for COVID-19. InterventionsThe Livzon point-of-care (POC) lateral flow immunoassay rapid antibody test (IgM and IgG) was conducted at least 7 days after onset of symptoms and compared to the composite reference standard of PCR for SARS-COV-2 plus reference laboratory testing for antibodies to SARS-COV-2. The SARS-CoV-2 RT-PCR was tested using the available molecular technology during the study time (PHE laboratories, GeneXpert(R) system Xpert, Xpress SARS-CoV-2 and Source bioscience laboratory). All molecular platforms/assays were PHE/NHSE approved. The reference antibody test was the Elecsys Anti-SARS-CoV-2 assay (Roche diagnostics GmBH). Main outcome measuresSensitivity and specificity of the rapid antibody test ResultsThe reference antibody test was positive in 190/268 (70.9%) of participants with a history of symptoms suggestive of COVID-19; in the majority (n=312) the POC test was taken 35 days or more after onset of symptoms. The POC antibody test had an overall sensitivity of 90.1% (292/328, 95% CI 86.3 - 93.1) and specificity of 100% (68/68, 95% CI 94.7 - 100) for confirming prior SARS-CoV-2 infection when compared to the composite reference standard. Sensitivity was 97.8% (89/92, 95% CI 92.3% to 99.7%) in participants who had been admitted to hospital and 84.4% (124/147, 95% CI 77.5% to 89.8%) in those with milder illness who had never been seen in hospital. ConclusionsThe Livzon point-of-care antibody test had comparable sensitivity and specificity to the reference laboratory antibody test, so could be used in clinical settings to support decision-making about patients presenting with more than 10 days of symptoms of COVID-19. What is already known on this topic- Presence of IgG and IgM antibodies to SARS-COV-2 indicates that the person was infected at least 7 days previously and is usually no longer infectious. - Rapid point-of-care tests for antibodies to SARS-COV-2 are widely available, cheap and easy to use - Preliminary evaluations suggested that rapid antibody tests may have insufficient accuracy to be useful for testing individual patients. What this study adds- The rapid point-of-care test for antibodies to SARS-COV-2 was 90.1% sensitive and 100% specific compared to reference standards for prior infection with COVID-19. - This is comparable to reference antibody tests - The point-of-care test evaluated in this study could be used to support clinical decision-making in real time, for patients presenting with symptoms of possible COVID-19 with at least 10 days of symptoms.