Molnupiravir: Is It Time to Move In or Move Out?

Effectiveness of Vaccines and Antiviral Drugs in Preventing Severe and Fatal COVID-19, Hong Kong

We compared the effectiveness and interactions of molnupiravir and nirmatrelvir/ritonavir and 2 vaccines, CoronaVac and Comirnaty, in a large population of inpatients with COVID-19 in Hong Kong. Both the oral antiviral drugs and vaccines were associated with lower risks for all-cause mortality and progression to serious/critical/fatal conditions (study outcomes). No significant interaction effects were observed between the antiviral drugs and vaccinations; their joint effects were additive. If antiviral drugs were prescribed within 5 days of confirmed COVID-19 diagnosis, usage was associated with lower risks for the target outcomes for patients >60, but not <60, years of age; no significant clinical benefit was found if prescribed beyond 5 days. Among patients >80 years of age, 3-4 doses of Comirnaty vaccine were associated with significantly lower risks for target outcomes. Policies should encourage COVID-19 vaccination, and oral antivirals should be made accessible to infected persons within 5 days of confirmed diagnosis.

Neurological side effects and drug interactions of antiviral compounds against SARS-CoV-2

BACKGROUND AND PURPOSE

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), rapidly spread across the globe. Tremendous efforts have been mobilized to create effective antiviral treatment options to reduce the burden of the disease. This article summarizes the available knowledge about the antiviral drugs against SARS-CoV-2 from a neurologist's perspective.

METHODS

We summarize neurological aspects of antiviral compounds against SARS-CoV-2 with full, conditional, or previous marketing authorization by the European Medicines Agency (EMA).

RESULTS

Nirmatrelvir/ritonavir targets the SARS-CoV-2 3c-like protease using combinatorial chemistry. Nirmatrelvir/ritonavir levels are affected by medications metabolized by or inducing CYP3A4, including those used in neurological diseases. Dysgeusia with a bitter or metallic taste is a common side effect of nirmatrelvir/ritonavir. Molnupiravir is a nucleotide analog developed to inhibit the replication of viruses. No clinically significant interactions with other drugs have been identified, and no specific considerations for people with neurological comorbidity are required. In the meantime, inconsistent results from clinical trials regarding efficacy have led to the withdrawal of marketing authorization by the EMA. Remdesivir is a viral RNA polymerase inhibitor and interferes with the production of viral RNA. The most common side effect in patients with COVID-19 is nausea. Remdesivir is a substrate for CYP3A4.

CONCLUSIONS

Neurological side effects and drug interactions must be considered for antiviral compounds against SARS-CoV-2. Further studies are required to better evaluate their efficacy and adverse events in patients with concomitant neurological diseases. Moreover, evidence from real-world studies will complement the current knowledge.

A review of clinical efficacy data supporting emergency use authorization for COVID-19 therapeutics and lessons for future pandemics

Emergency Use Authorization (EUA) allows the US Food and Drug Administration (FDA) to expedite the availability of therapeutics in the context of a public health emergency. To date, an evidentiary standard for clinical efficacy to support an EUA has not yet been established. This review examines the clinical data submitted in support of EUA for antiviral and anti-inflammatory therapeutics for coronavirus disease 2019 (COVID-19) through December of 2021 and the resilience of the authorization as new clinical data arose subsequent to the authorization. In the vast majority of cases, EUA was supported by at least one well-powered randomized controlled trial (RCT) where statistically significant efficacy was demonstrated. This included branded medications already approved for use outside of the context of COVID-19. When used, the standard of a single RCT seemed to provide adequate evidence of clinical efficacy, such that subsequent clinical studies generally supported or expanded the EUA of the therapeutic in question. The lone generic agent that was granted EUA (chloroquine/hydroxychloroquine) was not supported by a well-controlled RCT, and the EUA was withdrawn within 3 months time. This highlighted not only the ambiguity of the EUA standard, but also the need to provide avenues through which high quality clinical evidence for the efficacy of a generic medication could be obtained. Therefore, maintaining the clinical trial networks assembled during the COVID-19 pandemic could be a critical component of our preparation for future pandemics. Consideration could also be given to establishing a single successful RCT as regulatory guidance for obtaining an EUA.