Remdesivir emergency approvals: a comparison of the U.S., Japanese, and EU systems

Treatment effect of remdesivir on the mortality of hospitalised COVID-19 patients in Switzerland across different patient groups: a tree-based model analysis

AIMS OF THE STUDY

Remdesivir has shown benefits against COVID-19. However, it remains unclear whether, to what extent, and among whom remdesivir can reduce COVID-19-related mortality. We explored whether the treatment response to remdesivir differed by patient characteristics.

METHODS

We analysed data collected from a hospital surveillance study conducted in 21 referral hospitals in Switzerland between 2020 and 2022. We applied model-based recursive partitioning to group patients by the association between treatment levels and mortality. We included either treatment (levels: none, remdesivir within 7 days of symptom onset, remdesivir after 7 days, or another treatment), age and sex, or treatment only as regression variables. Candidate partitioning variables included a range of risk factors and comorbidities (and age and sex unless included in regression). We repeated the analyses using local centring to correct the results for the propensity to receive treatment.

RESULTS

Overall (n = 21,790 patients), remdesivir within 7 days was associated with increased mortality (adjusted hazard ratios 1.28-1.54 versus no treatment). The CURB-65 score caused the most instability in the regression parameters of the model. When adjusted for age and sex, patients receiving remdesivir within 7 days of onset had higher mortality than those not treated in all identified eight patient groups. When age and sex were included as partitioning variables instead, the number of groups increased to 19-20; in five to six of those branches, mortality was lower among patients who received early remdesivir. Factors determining the groups where remdesivir was potentially beneficial included the presence of oncological comorbidities, male sex, and high age.

CONCLUSIONS

Some subgroups of patients, such as individuals with oncological comorbidities or elderly males, may benefit from remdesivir.

Safety, Tolerability, and Pharmacokinetics of Intravenous Doses of PF-07304814, a Phosphate Prodrug Protease Inhibitor for the Treatment of SARS-CoV-2, in Healthy Adult Participants

Studies on targeted antivirals for treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of the ongoing pandemic, are limited. PF-07304814 (lufotrelvir) is the phosphate prodrug of PF-00835231, a protease inhibitor targeting the 3C-like protease of SARS-CoV-2. This phase 1 study evaluated the safety, tolerability, and pharmacokinetics (PK) of single ascending intravenous doses of lufotrelvir (continuous 24-hour infusion of 50, 150, 500, or 700 mg) versus placebo in healthy volunteers (2 interleaving cohorts: 1, n = 8; 2, n = 7). Each dosing period was separated by a washout interval (≥5 days). Treatment-emergent adverse events, PK, and biomarker concentrations were estimated from plasma/urine samples. Lufotrelvir was administered to 15 volunteers (mean [SD] age 39.7 [11.8] years). No serious adverse events, discontinuations, or deaths were reported. Mean maximum observed concentration of PF-00835231 (active moiety; 97.0 ng/mL to 1288 ng/mL) were observed between median time to maximum concentration of 14 to 16 hours after the start of the lufotrelvir infusion. Near-maximum plasma concentrations of PF-00835231 were observed ≈6 hours after infusion start and sustained until infusion end. PF-00835231 plasma concentrations declined rapidly after infusion end (mean terminal half-life: 500 mg, 2.0 hours; 700 mg, 1.7 hours). Approximately 9%-11% of the dose was recovered in urine as PF-00835231 across doses. A continuous, single-dose, 24-hour infusion of lufotrelvir (50-700 mg) was rapidly converted to PF-00835231 (active moiety), with dose-proportional PK exposures and no significant safety concerns. A daily, 24-hour continuous infusion of 270 to 350 mg is expected to maintain PF-00835231 concentration at steady state/above effective antiviral concentrations. Further studies exploring lufotrelvir efficacy in patients with coronavirus disease 2019 are ongoing.

Repurposing Molnupiravir as a new opportunity to treat COVID-19

With the emergence of new and re-emerging viral diseases, scientists have been working to produce new medications with novel targets and pathways. The discovery of safe and efficacious antiviral medicines is critical due to the constant introduction of new virus types and short lifetime of protection. Since the outbreak, there have been significant efforts to repurpose existing and licensed medications for rapid human testing and possible emergency use authorizations. The exploration of surviving medications for new restorative motives is known as drug repurposing. It is a successful, rapid, and highly reliable alternative to traditional drug methods. COVID-19 is being treated using a number of repurposed and new medicines. Molnupiravir is a repurposed Covid-19 medicine that was specifically developed to cure influenza and is used to treat mild to moderately ill Covid-19 patients with high risk of becoming seriously ill. The importance of medication repurposing, as well as the regulatory procedure for repurposed pharmaceuticals and Emergency Use Authorization in the United States, are summarized in this article.

Characteristics of the Compassionate Use Program in Japan: An Analysis of Expanded Access Clinical Trials from 2016 to 2021

Compassionate use is a system that provides patients with exceptional access to investigational new drugs to treat life‐threatening diseases that have no effective conventional treatments. The purpose of this study was to characterize and assess the current status of the compassionate use program’s application in Japan by evaluating expanded access clinical trials (EACTs) conducted between 2016 and 2021. In this study, a data set containing all EACTs, and pivotal clinical trials (PCTs) conducted in Japan between February 2016 and April 2021 was obtained from the Pharmaceutical and Medical Devices Agency, systemically reviewed, and analyzed. During the 5 years since EACTs began in Japan, out of 2,031 PCTs, 31 EACTs were conducted in Japan. Twenty‐four trials (77.4%) of the 31 EACTs used anticancer drugs and 5 of those trials (16.1%) were conducted in children. Furthermore, we conducted an EACT survey for drugs with a high degree of social and patient demands as recommended in the EACT notification. Among the 2,031 PCTs, we found 152 trials with high degree of social and patient demands. Of these, EACT was implemented in 17 trials (11.2%). Days from the start of the EACT to the submission of new drug applications and the approval were 9.0 (67.0–56.5) and 208.0 (172.8–308.8) days, respectively. Of the 31 EACTs conducted, 24 (77.4%) drugs have been approved as of August 2021. This first comprehensive study on EACTs clarified the current status and issues of Japan’s compassionate use system and the 5 years since the program initiated.

Remdesivir in the COVID-19 Pandemic: An Analysis of Spontaneous Reports in VigiBase During 2020

INTRODUCTION

The safety profile of remdesivir, conditionally approved for COVID-19, was limited at its 2020 introduction. Adverse drug reactions (ADRs) for medicines are collected in VigiBase, the WHO Global Database of Individual Case Safety Reports (ICSRs).

OBJECTIVE

This study aimed to provide a descriptive analysis of COVID-19 ICSR data focusing on remdesivir, including a disproportionality analysis (DA) of ADRs.

METHODS

A dedicated algorithm enabled retrieval of all COVID-19 treatment-specific ICSRs. A severity algorithm based on co-reported medicines and symptoms enabled selection of tocilizumab with its well established safety profile as comparator for remdesivir. Descriptive statistics were used for general ICSR demographics for all COVID-19-specific medicines, remdesivir and tocilizumab individually and furthermore to present treatment patterns of medicines co-reported with remdesivir. A COVID-19 indication-focused DA was deployed to minimize confounding from underlying polysymptomatic disease.

RESULTS

14,574 COVID-19-related ICSRs were entered into VigiBase during 2020. Remdesivir was the most common medicine reported. Of 4944 remdesivir ICSRs, where tocilizumab was not co-reported, 93% described remdesivir as the sole suspect medicine. Sixty percent of ICSRs concerned males, median age was 63 years and the majority originated from the Americas (72%). In 1089 (21%) of remdesivir ICSRs, data indicated severe/critical disease. Co-reported medicines peaked during the first 3 days of remdesivir treatment. The DA for the established tocilizumab and the new remdesivir were mainly in line with the safety profiles for both medicines but suggested new safety concerns. The most reported ADRs for remdesivir represented liver dysfunction, kidney injury, death and bradycardia.

CONCLUSION

Global COVID-19-related ADR reporting proved useful in providing information on ADRs as well as on treatment patterns in this patient group. Indication-focused disproportionality analysis, together with the use of a comparator with a known safety profile, proved effective in identifying known safety information and suggested new safety concerns for remdesivir.

Differences between the European Union and United States of America in Drug Regulatory Affairs Affect Global Patient Safety Standards and Public Health Awareness: The Case of Deferasirox and Other Iron Chelating Drugs

Regulatory policies on drugs have a major impact on patient safety and survival. Some pharmaceutical companies employ all possible methods to achieve maximum sales in relation to the monopoly of their patented drugs, leading sometimes to irregularities and illegal activities. Misinformation on the orphan drug deferasirox has reached the stage of criminal investigations and fines exceeding USD 100 million. Additional lawsuits of USD 3.5 billion for damages and civil fines were also filed by the FBI of the USA involving deferasirox and mycophenolic acid, which were later settled with an additional fine of USD 390 million. Furthermore, a USD 345 million fine was also settled for bribes and other illegal overseas operations including an EU country. However, no similar fines for illegal practises or regulatory control violations have been issued in the EU. Misconceptions and a lack of clear guidelines for the use of deferasirox in comparison to deferiprone and deferoxamine appear to reduce the effective treatment prospects and to increase the toxicity risks for thalassaemia and other iron loaded patients. Similar issues have been raised for the activities of other pharmaceutical companies promoting the use of new patented versus generic drugs. Treatments for different categories of patients using new patented drugs are mostly market driven with no clear safeguards or guidelines for risk/benefit assessment indications or for individualised effective and safe optimum therapies. There is a need for the establishment of an international organisation, which can monitor and assess the risk/benefit assessment and marketing of drugs in the EU and globally for the benefit of patients. The pivotal role of the regulatory drug authorities and the prescribing physicians for identifying individualised optimum therapies is essential for improving the survival and safety of millions of patients worldwide.

Japan's Special Approval for Emergency System During the COVID-19 Pandemic

The development of drugs for coronavirus disease 2019 (COVID‐19) is a global challenge. In Japan, remdesivir was approved in May 2020 for COVID‐19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. In February 2021, a vaccine against COVID‐19 was approved. These two approvals were made using the Special Approval for Emergency system in Japan. This Japanese system was started in 2010 and has been used to approve four drugs to date, including remdesivir and the Pfizer COVID‐19 vaccine. This paper discusses future challenges for Japan's Special Approval for Emergency system and organizes what can be learned from experiences to date. As a result, I would like to point Out the following issues. (i) Special Approval for Emergency is a system for approving drugs approved overseas, not a system for approving drugs originally developed in Japan. A system to approve drugs that have not been approved in foreign countries needs to be considered. (ii) In the Special Approval for Emergency system, it is necessary to ensure that postmarketing activities are conducted in accordance with the Risk Management Plan and the conditions of approval, to disclose the results in a timely and speedy manner, and to judge the appropriateness of continued approval based on the results of postmarketing activities.

Drug Repurposing in the COVID-19 Era: Insights from Case Studies Showing Pharmaceutical Peculiarities

COVID-19 may lead to severe respiratory distress syndrome and high risk of death in some patients. So far (January 2021), only the antiviral remdesivir has been approved, although no significant benefits in terms of mortality and clinical improvement were recently reported. In a setting where effective and safe treatments for COVID-19 are urgently needed, drug repurposing may take advantage of the fact that the safety profile of an agent is already well known and allows rapid investigation of the efficacy of potential treatments, at lower costs and with reduced risk of failure. Furthermore, novel pharmaceutical formulations of older agents (e.g., aerosolized administration of chloroquine/hydroxychloroquine, remdesivir, heparin, pirfenidone) have been tested in order to increase pulmonary delivery and/or antiviral effects of potentially active drugs, thus overcoming pharmacokinetic issues. In our review, we will highlight the importance of the drug repurposing strategy in the context of COVID-19, including regulatory and ethical aspects, with a specific focus on novel pharmaceutical formulations and routes of administration.

Effective drugs used to combat SARS-CoV-2 infection and the current status of vaccines

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a causal factor of the coronavirus disease 2019 (COVID-19). Drug repurposing, portraying patented drugs as a successful drug development technique, could shorten the period and minimize costs relative to de novo drug exploration. Recently several drugs have been used as anti-SARS-CoV-2 such as Remdesivir, Favipiravir, Hydroxychloroquine, Azithromycin, Lopinavir/Ritonavir, Nafamostat mesylate and so on. Despite such efforts, there is currently no successful broad-spectrum antiviral countermeasures to combat SARS-CoV-2 or possibly potential CoVs pandemic. Therefore it is desperately important to recognize and test widely efficient, reliable anti-CoV therapies now and in the future. Remdesivir and Favipiravir were more promising despite having side effects; it had prominent efficacy and efficiency while still not yet approved as the official anti-viral drug for SARS CoV-2. In this review, we summarizes the current drug and vaccine discovery status against SARS-CoV-2, predicting that these efforts will help create effective drugs and vaccines for SARS-CoV-2.