Tag: clinical trials

Categories : COVIDTags :

End of the Road for Ivermectin as COVID Treatment in South Africa

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Stop sign

South Africa’s medicines regulator has officially terminated the special dispensation to use Ivermectin as a treatment for COVID, stating that “there is currently no credible evidence to support a therapeutic role for Ivermectin” in the treatment of the disease.

On Monday 30 May, the South African Health Products Regulatory Authority (SAHPRA) officially withdrew its authorisation [PDF], bringing to end something of a saga which saw vocal proponents pitched against the scientific and regulatory establishment.

The antiparasitic Ivermectin gained considerable notoriety as the COVID pandemic went on, based on preliminary studies that seemed to demonstrate its effectiveness. Pressure born out of desperation for some kind of treatment led to SAHPRA – amidst its own apparent misgivings – granting compassionate use authorisation under strict guidelines in January 2021. Use was allowed under Section 21 guidelines without having to wait for Section 21 authorisation, which was misinterpreted as full authorisation by some media sources.

The social media furore and misinformation surrounding Ivermectin led to dangerous instances of COVID self-treatment, with hospitalisations and even deaths reported.

In its terribly botched response to COVID, Brazil adopted Ivermectin on a mass scale, and essentially became a living laboratory for its effectiveness. Despite even administering Ivermectin as prophylaxis, Brazil’s health system was overwhelmed with COVID patients during the surge caused by the Gamma variant.

Studies turned up scant evidence in favour of Ivermectin’s effectiveness, with serious flaws and even outright data fabrication were picked up in a number of studies that seemed to show a significant benefit – even flying right through the peer review process only to be picked up at a later stage. This lead to a major meta-analysis by Hill et al. showing a effectiveness instead being retracted, which SAHPRA noted in its decision.

Finally, the I-TECH and the Together randomised clinical trials of 2021 showed no effect. Like hydroxychloroquine before it, Ivermectin prescribing was found to be driven by political interests. Thus, Ivermectin quietly disappeared from the media as viable antivirals such as Paxlovid came into the market.

The termination comes after a distinct decline in demand for Ivermectin use in South Africa, with no new applications for importation of unregistered Ivermectin products place since August 2021. SAHPRA also noted a marked decline in the number of health facilities applying for permission to hold bulk stock after August 2021.

Furthermore, no individual named patient applications have been approved since December 2021. Finally, there was little in the way of reporting of outcomes achieved by the treating healthcare providers.

Categories : Ethics and LawTags :

Many Clinical Trials Ignore Previous Research

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Researchers evaluating a random selection of clinical trials done in North America found that they neglected to take into account previous or ongoing trials, which may result in researchers conducting redundant or less impactful studies. The findings were published in the journal Med.

Clinical trials are a crucial tool for assessing the safety and efficacy of medical interventions, but sponsors often provide incomplete information for assessing their ethical justification. Incomplete portrayals of supporting evidence hamper the ability of individuals or authorities to evaluate the trials’ risks, benefits, and scientific merit. 

To assess the prevalence of such omissions, researchers accessed the ClinicalTrials.gov registry and evaluated 101 randomly chosen clinical trials. Among those where there was at least one previous trial testing the same drug in the same disease, 30% of industry-sponsored trials and 20% of non-industry-funded trials failed to cite related studies. “Clinical trial protocols undercite easily accessible, relevant trials and do not document systematic searches for relevant clinical trials,” the authors wrote.

“Numerous studies suggest that some clinical trials are pursued despite their clinical hypotheses having been resolved prior to study launch,” write the authors. “Failure to provide a complete and impartial account of prior and ongoing research in study protocols may enable clinical research that fails to inform clinical practice.”

Source: EurekAlert

Categories : PaediatricsTags :

Wits University Tests Nirsevimab to Protect Against RSV in Infants

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Holding a baby's hand
Photo by William-Fortunato on Pexels

Wits University has reported that a drug to prevent respiratory syncytial virus (RSV) in infants is safe and effective, enabling ways to protect vulnerable groups such as preterm babies from the virus.

RSV is a major cause of lower respiratory tract infection (LRTI) and hospitalisation in infants. Globally, approximately one-third of all hospitalisations for lower respiratory tract illness are caused by RSV. Hence, there is a serious unmet medical need for RSV protection in healthy infants born at term.

The Wits Vaccines and Infectious Diseases Analytics (Wits VIDA) research unit was the lead South African collaborator in a phase 2/3 study to investigate the efficacy and safety of Nirsevimab, in healthy late-preterm and term infants.

Nirsevimab is a monoclonal antibody against RSV with an extended half-life. Monoclonal antibodies are antibodies that have a high degree of specificity (mono-specificity) for an antigen or epitope, and are generally well tolerated. Monoclonal antibodies are typically derived from a clonal expansion of antibody-producing malignant human plasma cells. Because they are large proteins (typically 150-200 000 daltons in size) they require parenteral, often intravenous, administration.

Nirsevimab has an extended half-life of three to four months, and is able to provide protection for the entire RSV season, which usually lasts for three to four months.

Compared to term infants, late preterm infants (born at 32 to 37 weeks) have a higher hospitalisation and mortality risk from RSV, due to their relative physiologic and metabolic immaturity. Late preterm infants are at increased risk of a host of morbidities and mortality, including respiratory distress and failure, feeding difficulties, poor growth, hypoglycaemia, hyperbilirubinemia, and hypothermia.

The study, published in the New England Journal of Medicine, found that the drug Nirsevimab significantly protected infants against RSV disease in the Phase 3 MELODY trial, and protected high risk children in a separate study known as MEDLEY.

“This intervention provides the opportunity to protect young infants against the most common cause of hospitalisation from lower respiratory tract infections – RSV – which kills between 60 000 to 190 000 babies each year, mainly in low- and middle-income countries,” says Wits Professor of Vaccinology Shabir Madhi, Director of Wits VIDA, and a co-author of the study.

The findings showed 74.5% efficacy against medically attended lower respiratory tract infections caused by RSV in healthy infants.

Furthermore, Nirsevimab is the first potential immunisation for all infants to demonstrate sustained protection across the entire RSV season with a single dose.

“The new drug provides the opportunity of protecting infants, including high-risk groups – such as those born prematurely or with chronic lung or congenital heart disease – against the leading cause of hospitalisation for lower respiratory tract infections among infants globally,” says Madhi.

Source: Wits University

Categories : COVIDTags :

Nitazoxanide Flops in South African COVID Trial

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Interim analysis of a South African clinical trial has revealed that nitazoxanide, an oral antiparasitic agent with antiviral properties, was ineffective in improving outcomes in ambulatory patients with mild-to-moderate COVID.

Funded by the South African Medical Research Council (SAMRC), the study was performed at four sites in South Africa. The primary goal of the trial was to evaluate the effectiveness of nitazoxanide (1g twice daily for 7 days) in reducing the progression from mild to severe COVID in ambulatory patients. Progression to severe disease was defined as hospitalisation or death. The trial underwent an interim analysis at 67% of the recruitment target (290 participants), and the data was reviewed by an independent data and safety monitoring board (DSMB). Following the interim analysis, the DSMB recommended halting recruitment of the trial on the grounds of futility.

No significant difference was seen in serious adverse events, which included all causes of hospitalisation and death, between the nitazoxanide and the placebo groups [12/144 (8.3%) vs 10/146 (6.8%)]. Hospitalisation and death specifically due to COVID showed the same pattern [7/144 (4.9%) vs 8/146 (5.5%)].

Principal investigator Prof Keertan Dheda from the University of Cape Town (UCT) and the London School of Hygiene and Tropical Medicine, said that the results of the trial, although disappointing, contributes to the growing body of evidence, clarifying what works and what doesn’t for the treatment of COVID. Thus, clarifying what does not work is as important as finding effective therapies so that clinically useful management algorithms can be developed.

Nitazoxanide is a low-cost broad-spectrum antiviral drug with an extensive safety record. Originally developed as antiparasitic, it seemed promising against SARS-CoV-2 in the lab but the real world test did not show any benefit. It is still possible that nitazoxanide may be of benefit at higher doses (greater than the dose used in the trial, which was already twice the normal dose), however this will most likely cause an increase in intolerable gastrointestinal side effects. “The next step will be to focus on formally publishing the data in a peer reviewed journal and to evaluate secondary objectives of the study, including assessing the efficacy of nitazoxanide in reducing the duration of illness, reducing SARS-CoV-2 viral load, and its efficacy, if any, in preventing COVID in close contacts,” said Prof Dheda.

Prof Dheda concluded that nitazoxanide could have a less than 30% benefit which may be detectable in a larger study. However, it is questionable whether such an effect size is clinically relevant given the number needed to treat to prevent disease progression, adverse events, cost and that other therapies have emerged (eg paxlovid) with an efficacy benefit of greater than 80%.

SAMRC President and CEO, Prof Glenda Gray said although the study did not meet its primary endpoint, the results are an important addition into the scientific repository. “COVID and HIV in their very nature are unique and complex viruses which have posed unprecedented challenges for vaccine development, globally – however, the knowledge gained from this trial will help us advance our pursuit of effective therapies and vaccines for both COVID and HIV alike,” said Prof Gray.

Prof Gray, who also has led numerous trials in search of effective HIV and COVID vaccines, said COVID poses substantial challenges for those living with HIV which evades the immune system. “Until an effective vaccine has been found, all people living with HIV should take all recommended preventive measures to minimise their exposure to COVID,” concluded Prof Gray.

Source: South African Medical Research Council

Categories : COVIDTags :

Pfizer’s Paxlovid Could Deliver Knockout Blow to COVID

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Pharmaceutical giant Pfizer announced today that Paxlovid, its investigational novel COVID oral antiviral candidate, significantly reduced hospitalisation and death, based on an interim analysis of its phase II/III clinical trials showing an 89% reduction of risk of hospitalisation or death due to COVID. 

The phase II/III EPIC-HR (Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients) randomised, double-blind study of non-hospitalised adult patients with COVID, who are at high risk of progressing to severe illness. The scheduled interim analysis showed an 89% reduction in risk of COVID-related hospitalisation or all-cause mortality compared to placebo in patients treated within three days of symptom onset (primary endpoint). Only 0.8% of patients who received Paxlovid were hospitalised through Day 28 with zero deaths, compared to 7.0% of patients who received placebo and were hospitalised or died. Similar reductions in COVID-related hospitalisation or mortality were seen in patients treated within five days of symptom onset; 1.0% of patients in the intervention arm were hospitalised through Day 28 with zero deaths, compared to 6.7% of placebo arm patients. In the overall study population through Day 28, no deaths were reported in intervention arm patients as compared to 10 (1.6%) deaths in placebo arm patients.

The results show such an overwhelming effectiveness that Pfizer, in consultation with the US Food and Drug Administration (FDA), will cease further enrollment into the study and will apply for Emergency Use Authorization (EUA) as soon as possible.

If it gets the green light, Pfizer’s Paxlovid, would be the first oral antiviral of its kind, a specifically designed SARS-CoV-2-3CL protease inhibitor. PF-07321332 inhibits viral replication at the proteolysis stage, before viral RNA replication. Co-administration with a low dose of ritonavir helps slow the metabolism of PF-07321332 in order for it to remain active in the body for longer at higher concentrations. It has shown effectiveness against multiple variants, and could have broad general effectiveness against coronaviruses.

“All of us at Pfizer are incredibly proud of our scientists, who designed and developed this molecule, working with the utmost urgency to help lessen the impact of this devastating disease on patients and their communities,” said Mikael Dolsten, MD, PhD, Chief Scientific Officer and President, Worldwide Research, Development and Medical of Pfizer. “We’re thankful to all of the patients, investigators, and sites around the world who participated in this clinical trial, all with the common goal of bringing forth a breakthrough oral therapy to help combat COVID.”

The review of safety data included a larger cohort of 1881 patients in EPIC-HR, whose data were available at the time of the analysis. Adverse events were comparable between paxlovid (19%) and placebo (21%), which were mostly mild.

Pfizer kicked off the EPIC-HR study in July 2021 after positive results from Phase I clinical trials, followed in August by the Phase II/III EPIC-SR (Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients), to evaluate efficacy and safety in patients with a confirmed diagnosis of SARS-CoV-2 infection who are at standard (low) risk. This trial includes a cohort of vaccinated at-risk patients who have an acute breakthrough COVID infection. A further trial is investigating prophylaxis among household members of patients with a COVID infection. 

Source: Pfizer

Categories : Diseases, Syndromes and ConditionsTags :

Tamoxifen Found to be Ineffective in Fungal Meningitis Trial

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Photomicrograph of a sample extracted from a lesion that revealed the presence of Cryptococcus neoformans. Credit: CDC

In a disappointing outcome, a clinical trial has shown that tamoxifen, a promising candidate to improve survival for a deadly form of fungal meningitis, is ineffective. The trial was conducted by University of Oxford researchers and published in eLife.

The study finds that adding tamoxifen, a breast cancer drug, to standard antifungal treatment was no faster in clearing fungal infection from the spinal fluid of people with meningitis. More patients who received tamoxifen had evidence of heart conduction disturbances, rates of severe side effects were similar.

Cryptococcal meningitis is a leading cause of death in people with HIV, but also affects those without HIV, regardless of whether they are immunocompromised. Most infections are caused by a fungus called Cryptococcus neoformans (C. neoformans) and occur in low-income tropical settings. The gold-standard treatment is a combination of three drugs: flucytosine and amphotericin B initially, followed by fluconazole. Yet, even on this gold-standard therapy, a third of patients die within 10 weeks of being diagnosed. Moreover, the drug flucytosine is severely restricted by availability and cost, meaning it is rarely used where the disease burden is highest.

Co-first author Nguyen Thi Thuy Ngan, Clinician at the Oxford University Clinical Research Unit (OUCRU): ‘Tamoxifen has shown antifungal activity against various yeasts in the lab; we subsequently showed that it acts synergistically with amphotericin against two-thirds of clinical Cryptococcus isolates from our archive. As a well-understood, off-patent, cheap and widely available medicine, it was a promising candidate for treating cryptococcal meningitis.’

Co-first author Nhat Thanh Hoang Le, Biostatistician at OUCRU, added: ‘We designed a randomised trial to determine whether using these drugs in combination could improve the speed of clearance of Cryptococcus from patients with meningitis with and without HIV.’

The trial involved 50 patients, 40 with HIV. Of the patients, 24 were assigned to receive a standard anti-fungal treatment of amphotericin B and fluconazole plus tamoxifen, and 26 received the standard anti-fungal treatment only. Researchers measured the Early Fungicidal Activity (EFA) for both groups – how quickly C. neoformans amounts declined in a patient’s spinal fluid in the two weeks following treatment.

Based on their prior work, the team were hoping for better EFA for patients receiving tamoxifen, but there was no detectable difference in EFA.

The only observed difference was increased heart toxicity in the tamoxifen group. Lab studies had shown that a tamoxifen dose five to 10 times higher than that used routinely in breast cancer would be needed to have an antifungal effect. However, high doses of tamoxifen cause QT prolongation, which can cause cardiac arrest. While there was one sudden death in the tamoxifen group in this study, this occurred after the period of tamoxifen administration and it was not associated with an abnormal heart rhythm.

Senior author Professor Jeremy Day, Professor of Infectious Diseases, Oxford University, said: “Despite its apparent anti-cryptococcal effect and synergy with other drugs, tamoxifen does not increase the rate of clearance of yeast from spinal fluid in people with meningitis and is unlikely to result in clinical benefit.

“Our results show the importance of small-scale trials such as this for rapidly evaluating repurposable drugs and preventing the time and cost of a larger clinical study that is likely to fail. However, sadly this does mean that we urgently still need new, specific anti-cryptococcal drugs to be developed, and we also need to ensure that existing, available treatments are made accessible and affordable.”

Source: Oxford University

Categories : Cardiovascular Disease GenderTags :

Not Enough Women in Stroke Clinical Trials

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A new study published in Neurology shows that women are underrepresented in stroke clinical trials compared to the proportion who have strokes in the general population. 

“Making sure there are enough women in clinical studies to accurately reflect the proportion of women who have strokes may have implications for future treatment recommendations for women affected by this serious condition,” said study author Cheryl Carcel, MD, of The George Institute for Global Health in Sydney, Australia. “When one sex is underrepresented in clinical trials, it limits the way you can apply the results to the general public and can possibly limit access to new therapies.”

The study analysed 281 stroke trials conducted between 1990 and 2020, with a total of 588 887 participants. Of these, only 37.4 % were women. The average prevalence of stroke in women across the countries included was 48%.

Results were calculated in participation-to-prevalence ratio, a relative measure that weights the percentage of women in a trial compared to their proportion in the total population with that disease. A ratio of one indicates that the percentage of women in the study is the same as the percentage of women with the disease in the general population. An acceptable range for an ideal ratio of female participation is between 0.8 and 1.2.

Overall, women were found to be underrepresented relative to their prevalence in the underlying population, with a consistent ratio of 0.84 over time. They found the greatest differences in trials of intracerebral haemorrhage, with a ratio of 0.73; trials with average participant age under 70, with a ratio of 0.81; non-acute interventions, with a ratio of 0.80; and rehabilitation trials, with a ratio 0.77.

“Our findings have implications for how women with stroke may be treated in the future, as women typically have worse functional outcomes after stroke and require more supportive care,” Dr Carcel said. “We will only achieve more equitable representation of women in clinical trials when researchers look at the barriers that are keeping women from enrolling in studies and actively recruit more women. People who fund the research also need to demand more reliable, sex-balanced evidence.”

Source: American Academy of Neurology

Categories : COVIDTags :

New Drug Molnupiravir Halves COVID Hospitalisation Risk

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Merck today announced that their investigational oral antiviral drug molnupiravir significantly reduced the risk of hospitalisation or death in a Phase III trial in at risk patients with mild-to-moderate COVID. 

Interim analysis showed that molnupiravir reduced the risk of hospitalisation or death by approximately 50%; 7.3% of patients randomised to receive molnupiravir were either hospitalised or died through Day 29 following randomisation, compared with 14.1% of placebo-treated patients. Through Day 29, no deaths were reported in patients who received molnupiravir, as compared to 8 deaths in patients who received placebo. Study recruitment is being stopped early due to these positive results, and the company plans to submit an application for Emergency Use Authorisation (EUA) to the U.S. FDA as soon as possible.

Molnupiravir is an oral form of a potent ribonucleoside analog that inhibits the replication of SARS-CoV-2. Molnupiravir has been shown to be active in several preclinical models of SARS-CoV-2, including for prophylaxis, treatment, and prevention of transmission. 

All 775 patients had laboratory-confirmed mild-to-moderate COVID, with symptom onset within 5 days of study randomization and were required to have at least one risk factor associated with poor disease outcome at study entry. Across all key subgroups, molnupiravir reduced the risk of hospitalisation and/or death; efficacy was unaffected by timing of symptom onset or underlying risk factor. Additionally, based on the participants with available viral sequencing data (approximately 40% of participants), molnupiravir demonstrated consistent efficacy across viral variants Gamma, Delta, and Mu.

The incidence of any adverse event was comparable in the molnupiravir and placebo groups, as was incidence of drug-related adverse events, and the drug was well tolerated.

In addition, molnupiravir is being evaluated for post-exposure prophylaxis in MOVe-AHEAD, a global, multicenter, randomised, double-blind, placebo-controlled Phase III study, which is evaluating the efficacy and safety of molnupiravir in preventing the spread of COVID within households. 

Source: Merck

Categories : Medical Research & TechnologyTags :

Most Trials in Clinical Practice Hold Up Over Time

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According to a new paper in Family Practice, medical practice can often be undermined by later research, randomised trials relevant to primary care generally hold up over time.

Medical reversal describes a problem whereby new research causes doctors to stop using a popular medication, procedure or test based on previous evidence. Vinayak Prasad, associate professor at the University of California, San Francisco, had found that up to 46% of original studies on adopted medical practices led to a reversal or shift in evidence of effect.

Evidence-based medicine lets doctors be confident when their decisions are grounded in high quality research. But decisions supported by robust evidence from randomised controlled trials can be reversed. For example, although aspirin is prescribed commonly to prevent cardiovascular disease, new studies indicate this treatment is unlikely to be effective.

Researchers studied the extent to which evidence from randomised control trials relevant to primary care were contradicted in subsequent research. Examining 408 randomised controlled trials from 2002 to 2005 relevant to primary care, the researchers found that over 12-17 years of follow up time, there were just 35 occurrences of evidence reversal, or roughly two a year. About nine in ten of such randomised control trials were not reversed.

“Conclusions from randomised trials relevant to primary care that also meet criteria for validity are stable over time,” said study lead author Christian Ruchon.

Source: EurekAlert!

Categories : Medical Research & TechnologyTags :

New Effort to Improve Diversity in Clinical Trials

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Columbia University and Pfizer Inc. have established the Columbia-Pfizer Clinical Trials Diversity Initiative, which aims to reduce health disparities by increasing the number of minorities in clinical trials and making clinical researchers more diverse.

In the United States, 12% of the population is Black and 18% is Hispanic or Latino but in 2020, only 8% were Black and 11% were Hispanic among the 32 000 patients who participated in clinical trials that led to FDA approval of new drugs. For example, a review of clinical trials between 1999 and 2015 for cystic fibrosis only had a representation of 2.0% for Latinos, 1.0% for Black individuals, and 0.1% for Asians.

“People of different ethnicities can have different responses to the same medicine or treatment, so a lack of diversity among clinical trial participants means doctors cannot know if the treatment will be effective in all the patients they treat,” said Anil K Rustgi, MD, Interim Executive Vice President and Dean of the Faculties of Health Sciences and Medicine at Columbia University and director of the Herbert Irving Comprehensive Cancer Center. “Increasing diversity in trials will improve the treatment of patients from underrepresented groups and is a moral imperative as well as a fundamental medical issue.”

Rod MacKenzie, PhD, Executive Vice President and Chief Development Officer at Pfizer, said, “Diversity of representation in clinical trials is a matter of equity, which is a core Pfizer value. We are deeply committed to ensuring our clinical trials reflect the diversity of the communities like New York in which they are conducted. We look forward to working with Columbia University both to offer any willing individual, regardless of background, the opportunity to participate in and contribute to clinical research, and to expand the roster of diverse clinical researchers who are helping us conduct studies.”

Pfizer will provide a three-year, $10 million grant to Columbia to help establish and expand the Initiative, which will improve the diversity of participants in clinical trials by looking at the barriers that prevent participation by marginalised individuals. The Initiative will expand Columbia’s Community Health Workers Program network to connect with underserved populations and create culturally sensitive engagement tools. The efforts will include researching new ways to increase the accessibility of clinical trials through telemedicine, wearable technology, and home visits.

The Initiative also aims to improve diversity among clinical research faculty and staff. Columbia will help build an additional pipeline of diverse clinical investigators through a new National Diversity Clinical Trials Leadership Program to increase the number of faculty and staff from underrepresented groups as well.

“A diverse research staff not only helps to improve trust in clinical trials among participants from underserved groups but improves the entire clinical trial enterprise by bringing different questions, experience, and perspective to the table,” Dr Rustgi said.

Source: Columbia University Irving Medical Center