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Thursday, July 9, 2020

Near half of health care workers positive for Covid by serology have no symptoms

The IVY Research Network has completed initial studies evaluating the epidemiology of COVID-19 in health care workers and patients.
Among 249 front-line health care workers who cared for COVID-19 patients during the first month of the pandemic in Tennessee, 8% tested positive for COVID-19 antibodies by serology testing, suggesting they had contracted COVID-19 in the first several weeks of taking care of COVID-19 patients. Among these health care workers with positive serology results, 42% reported no symptoms of a respiratory illness in the prior two months. This suggests that front-line health care workers are at high risk for COVID-19 and that many health care workers with the virus may not have typical symptoms of a respiratory infection. These results were published in the journal Clinical Infectious Diseases on July 6.
“Our results suggest that screening health care workers for COVID-19 even when they don’t have any symptoms could be important to prevent the spread of the virus within hospitals,” said Wesley Self, MD, associate professor of Emergency Medicine at Vanderbilt University Medical Center and lead investigator for the IVY Network.
Investigator Bo Stubblefield, MD, instructor of Emergency Medicine, added, “We are continuing to study COVID-19 in front-line health care workers across the country to better understand what may be done to decrease their risk of infection, such as using specific types of personal protective equipment.”
In a separate study, the IVY investigators studied 350 patients across 11 medical centers in the U.S. who tested positive for COVID-19; 54% of these patients reported no close contact with another person known to have COVID-19 in the two weeks before getting sick.
“With over half of COVID-19 patients not identifying a clear source of their infection, this study reinforces the need for practical measures to reduce the spread of the virus, such as social distancing and the use of face coverings when out in public,” Self said.
Additionally, 40% of COVID-19 patients in the study remained symptomatic two weeks after a positive COVID-19 test, showing that patients with COVID-19 tend to remain ill longer than with other respiratory infections, such as influenza. The results were published by the journal Morbidity and Mortality Weekly Report on June 30.
The IVY Network is a collaborative research group of multiple medical centers in the U.S led by Vanderbilt University Medical Center. It is funded by Centers of Disease Control and Prevention (CDC) to conduct research on severe respiratory infections, including COVID-19 and influenza.

New study supports remdesivir as COVID-19 treatment

The news about remdesivir, the investigational anti-viral drug that has shown early promise in the fight against COVID-19, keeps getting better.
This week researchers at Vanderbilt University Medical Center (VUMC), the University of North Carolina at Chapel Hill and Gilead Sciences reported that remdesivir potently inhibited SARS-CoV-2, the virus which causes COVID-19, in human lung cell cultures and that it improved lung function in mice infected with the virus.
These preclinical findings help explain the clinical effect the drug has had in treating COVID-19 patients. Remdesivir has been given to patients hospitalized with COVID-19 on a compassionate use basis since late January and through clinical trials since February.
In April, a preliminary report from the multicenter Adaptive COVID-19 Treatment Trial (which included VUMC) suggested that patients who received the drug recovered more quickly.
“All of the results with remdesivir have been very encouraging, even more so than we would have hoped, but it is still investigational, so it was important to directly demonstrate its activity against SARS-CoV-2 in the lab and in an animal model of disease,” said VUMC’s Andrea Pruijssers, PhD.
Pruijssers, research assistant professor of Pediatrics at VUMC and lead antiviral scientist in the laboratory of Mark Denison, MD, is the paper’s co-corresponding author with Timothy Sheahan, PhD, assistant professor of Epidemiology at UNC-Chapel Hill.
Denison, the E.C. Stahlman Professor of Pediatrics at VUMC, directs the Division of Pediatric Infectious Diseases. He and Ralph Baric, PhD, the William R. Kenan, Jr. Distinguished Professor of Epidemiology at UNC-Chapel Hill, and colleagues have been studying remdesivir since 2014.
They were the first to perform detailed studies to demonstrate that the drug, which was developed by Gilead Sciences to combat hepatitis C and respiratory syncytial virus, and later the Ebola virus, also showed broad and highly potent activity against coronaviruses in laboratory tests.
The current findings, reported this week in the journal Cell Reports, provide “the first rigorous demonstration of potent inhibition of SARS-CoV-2 in continuous and primary human lung cultures.” The study is also the first to suggest that remdesivir can block the virus in a mouse model.
Ongoing clinical trials will determine precisely how much it benefits patients in different stages of COVID-19 disease.
Meanwhile in the laboratory, Pruijssers said, “We also are focusing on how to use remdesivir and other drugs in combinations to increase their effectiveness during COVID-19 and to be able to treat at different times of infection.”
COVID-19, which to date has infected more then 12 million people and killed nearly 600,000 worldwide, is at least the third instance since 2003 in which a coronavirus originally transmitted from bats has caused serious illness in humans.
Thus there is an urgent need to identify and evaluate broadly efficacious and robust therapies that can limit and prevent coronavirus infections. “Broad-spectrum antiviral drugs, antibodies, and vaccines are needed to combat the current pandemic and those that will emerge in the future,” the researchers said.
In addition to SARS-CoV-2, studies in the Denison and Baric labs have shown that remdesivir is effective against a vast array of coronaviruses, including other bat viruses that could emerge in the future in humans.
“We hope that will never happen, but just as we were working to characterize remdesivir over the past six years to be ready for a virus like SARS-CoV-2, we are working and investing now to prepare for any future coronavirus,” Denison said. “We want remdesivir and other drugs to be useful both now and in the future.”
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Others VUMC co-authors were Amelia George, MS, Maria Agostini, PhD, Laura Stevens, MS, James Chappell, MD, PhD, Xiaotao Lu, MS, and Tia Hughes, MS.
The study was supported by National Institutes of Health grants AI142759, AI132178 and AI132178-03S1, AI081197 and AI007151, the Dolly Parton COVID-19 Research Fund and the Elizabeth B. Lamb Center for Pediatric Research at Vanderbilt.

Proton Pump Inhibitors Tied to COVID-19 Risk

People who use proton pump inhibitors (PPIs) may be more likely to get COVID-19, researchers say.
In light of this finding, physicians should consider which patients truly need these powerful acid-lowering drugs, said Brennan Spiegel, MD, MSHS, professor of medicine and public health at Cedars Sinai Medical Center in Los Angeles, California.
“All it means is that we’re going to have a conversation with our patients,” he told Medscape Medical News. “We don’t normally have that conversation because we don’t live in an environment with a high risk of enteric infection. But now we’re in a pandemic.”
The study by Spiegel and his colleagues was published online on July 7 in The American Journal of Gastroenterology.
Use of PPIs has skyrocketed over the past 2 decades. For ambulatory care visits, their use increased from 1.6% in 1998 to 7.6% in 2015, as reported by Medscape Medical News. The increase raised questions about overprescription.
Although studies have not borne out many of the other concerns raised about adverse reactions, they have shown that the drugs increase the risk for enteric infections, including infections by SARS-CoV-1, a virus that is related to the COVID-19 virus, SARS-CoV-2, Spiegel said.
SARS-CoV-2 uses the angiotensin-converting enzyme–2 receptor to invade enterocytes. Spiegel theorized that an increase in stomach pH above 3 as a result of use of PPIs might allow the virus to enter the GI tract more easily, leading to enteritis, colitis, and systemic spread to other organs, including the lungs. “There is a reason we have acid in our stomachs,” Spiegel said.
To see how PPI use relates to COVID-19 infections, Spiegel and his colleagues surveyed online a nationally representative sample of Americans between May 3 and June 24, 2020, as part of a larger survey on gastroenterologic health.
Participants answered questions about gastrointestinal symptoms, current use of PPIs, and COVID-19 test results. They also answered questions about histamine-2 receptor agonists (H2RAs), also known as H2 blockers, which are used to treat some of the same conditions as PPIs but that do not reduce stomach acid as much.
The surveying firm, Cint, contacted 264,058 people. Of the 86,602 eligible participants who completed the survey, 53,130 said they had experienced abdominal discomfort, acid reflux, heartburn, or regurgitation. These survey participants were subsequently asked about PPI and H2RA use.
Of these, 6.4% reported testing positive for SARS-CoV-2. The researchers adjusted for age, sex, race/ethnicity, education, marital status, household income, body mass index, smoking, alcohol consumption, US region, insurance status, and the presence of irritable bowel syndrome, celiac disease, gastroesophageal reflux disease, liver cirrhosis, Crohn’s disease, ulcerative colitis, diabetes, and HIV/AIDS.
After adjusting for these factors, the researchers found that those who took PPIs up to once a day were twice as likely to have had a positive COVID-19 test result than those who did not take the drugs (odds ratio [OR], 2.15; 95% CI, 1.90 – 2.44).
Those who took PPIs twice a day were almost four times as likely to have tested positive for the disease (OR, 3.67; 95% CI, 2.93 – 4.60).
By contrast, those taking H2RA drugs once daily were 15% less likely to report a positive COVID-19 test result (OR, 0.85; 95% CI, 0.74 – 0.99). Research is currently underway to determine whether H2RAs might protect against the disease for reasons unrelated to pH balance.
Spiegel cautioned that the current data show only an association between PPI use and COVID-19 positivity; it cannot prove cause and effect.
Nevertheless, Spiegel said the findings should encourage physicians to prescribe PPIs only when clearly indicated. “If somebody is not yet on a PPI and you’re considering whether to start them on a PPI, it’s a good idea to consider H2 blockers,” he said.
People who need a daily dose of a PPI to control a severe condition can safely continue doing so, but such patients should take care to follow standard public health recommendations for avoiding exposure to the virus. These recommendations include wearing a mask, maintaining social distance, and washing hands frequently.
“People who are older, comorbid, or smokers ― if they get infected, it could be severe,” he said. “[For] someone like that, it’s reasonable to ask, do we really need to be on twice-daily PPIs? There is good evidence that they are no better off than if they are taking once-daily doses.”
Brian Lacy, MD, PhD, a professor of medicine at the Mayo Clinic in Jacksonville, Florida, agreed that the study should prompt physicians to take a second look at their patients’ PPI prescriptions. “My view is that PPIs are frequently overused, and maybe this is one more piece of data that if someone is on PPIs, maybe they don’t need to be on this medication.”
On the other hand, the drugs are important for treating conditions such as erosive esophagitis and healing ulcers, said Lacy, who is also co–editor-in-chief of The American Journal of Gastroenterology. The overall risk of contracting COVID-19 is low, so even this finding of a 3.7-fold increased risk should not lead patients or providers to stop taking or prescribing PPIs.
The study also lends support to the idea that the gastrointestinal tract could be involved in SARS-CoV-2 transmission, and it supports warnings about aerosols emitted from flushing toilets and through exhalation, Spiegel said. There is less evidence of the virus being transmitted through food. “It may not be fecal-oral; it may be fecal-respiratory,” he said.
On Twitter, several physicians and epidemiologists have pointed out surprises in the demographics of the cohort of patients who reported positive COVID-19 tests. That this cohort made up 6.4% of respondents is noteworthy, as fewer than 1% of the overall American population has been diagnosed with the disease, said Darren Dahly, PhD, principal statistician at the Clinical Research Facility at University College Cork in Cork, Ireland.
More surprising still, Dahly pointed out, 69.6% of the cohort that was positive for COVID-19 had a high school degree or less, yet 63.5% were in households making $200,001 or more per year. “I can’t find a plausible reason for any of these extremes,” Dahly told Medscape Medical News. “These data cannot be accurate data from a representative sample of Americans. There is no way.”
Study co-author Christopher V. Almario, MD, MSHPM, assistant professor of medicine Cedars Sinai, responded that there are plausible explanations for these apparent discrepancies. The cohort with positive tests was drawn from the subset of those respondents who reported gastrointestinal symptoms, not from the total population surveyed. COVID-19 is known to cause such symptoms, he pointed out.
Also, he said, respondents reported their individual education attainment but their household income. It’s possible that someone with a high school education could live in a wealthy household. And people in households with more income may be more likely to gain access to tests, he theorized.
The overall population of the survey corresponded closely to US Census data, Almario said. “It would be unclear why someone would be forthcoming as to their demographics but mislead with respect to their COVID-19 status,” he told Medscape Medical News. And in many respects, he said, the cohort with a positive test reflected what has been reported in news stories about those most likely to test positive: younger, more Latinx, more likely to smoke, and more obese.
The study was part of a larger survey on gastroenterological diseases funded by Ironwood Pharmaceuticals. Spiegel reported relationships with Alnylam Pharmaceuticals, Arena Pharmaceuticals, Ironwood Pharmaceuticals, Salix Pharmaceuticals, Shire Pharmaceuticals, Synergy Pharmaceuticals, and Takeda Pharmaceuticals. He is co–editor-in-chief of The American Journal of Gastroenterology. Lacy, who is also co-editor of The American Journal of Gastroenterology, disclosed no relevant financial relationships. Dahly reported no relevant financial relationships. Almario relationships with My Total Health, Bayer Healthcare, Synergy Pharmaceuticals, Alnylam Pharmaceuticals, Arena Pharmaceuticals, and Takeda Pharmaceuticals.
Am J Gastroenterol. Published online July 7, 2020. Full text

Twist Bioscience teams up with EVQLV in drug discovery

Twist Bioscience (TWST +3.3%) will collaborate with New York City-based computational biology shop EVQLV to discover novel antibody-based therapies.
Using an amino acid sequence as an input, EVQLV applies its proprietary AI-generated model of evolution. The model uses billions of public and proprietary data points, including sequence, structure, and biophysical properties to learn the patterns of human antibody formation against the target. This generates variants on a scale of 1-2 million per antibody chain in a process that takes less than 6 hours, a process that can take months in the laboratory.
Under the terms of the partnership, EVQLV will employ its proprietary algorithms to computationally generate and rapidly screen a large set of diverse antibody candidates to a specific target. It will then submit the sequences of high-potential antibodies to Twist who will use its synthetic DNA platform for molecular synthesis, antibody expression and functional analysis.
Financial terms are not disclosed.


Nkarta files for upsized IPO

Nkarta (NKTX) has filed an updated preliminary prospectus for its IPO of 13M common shares at $16 – 17.
A week ago, it filed for an IPO of 10M shares at $14 – 16.

Blackstone’s Life Sciences fund final close at $4.6B; strategic investments snapshot

Blackstone (BX -2.1%) says its Blackstone Life Sciences V was oversubscribed and final close is at its hard cap of $4.6B of total capital commitments, making it the largest life sciences private fund raised till date.
With its investment strategies of – strategic collaborations with established life science companies, late-stage product financings, and growth investments in emerging companies, Blackstone seeks to bring innovative medicines to patients.
In the past three months, Blackstone Life Sciences almost $1B from the fund in the following transactions:
In April, the company entered into a $2B strategic collaboration with a biotechnology company Alnylam Pharmaceuticals (ALNY -0.8%) for royalty interest acquisition in inclisiran, a Novartis-owned LDL lowering medicine that has the potential to transform the lives of patients with heart disease.
Leading a $350M investment in Reata Pharmaceuticls (RETA -1.2%) in June, Blackstone Life Sciences seeks to advance the first potential medicine for Alport syndrome, a kidney disease that afflicts children.
A $337M strategic collaboration was announced with Medtronic (MDT -1.6%) to advance the latter’s next-gen diabetes management products.