Sorrento says its oral COVID-19 main protease inhibitor candidate ‘strongly’ neutralizes omicron

Sorrento Therapeutics (NSDQ:SRNE) revealed that its late-stage preclinical main protease inhibitor STI-1558 inhibited omicron virus entry and replication in cell-based assays.

Prior research indicates that STI-1558 offers broad-spectrum activity against SARS-CoV-2.

STI-1558 is distinct from Pfizer’s SARS-CoV-2 drug Paxlovid (nirmatrelvir), which pairs the SARS-CoV-2-3CL protease inhibitor PF-07321332 with ritonavir, which works as a pharmacokinetic enhancer. Sorrento developed STI-1558 to offer optimized human liver microsomal stability to avoid the need for ritonavir.

The company anticipates that STI-1558 will thus have fewer issues with drug-drug interactions.

Sorrento also noted that STI-1558 inhibited pseudovirus entry into cells in an omicron S protein-mediated pseudovirus entry assay, whereas nirmatrelvir did not.

“With omicron becoming a globally dominant variant of SARS-CoV-2 in such a short period of time, we are focused on develop…

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Pfizer bolsters COVID-19 antiviral manufacturing capacity

Although Pfizer (NYSE:PFE) has yet to receive emergency use authorization for its Paxlovid COVID-19 therapy, it plans to manufacture 80 million courses of the drug by the end of 2022. Pfizer had initially planned on making 50 million courses of Paxlovid (PF-07321332/ritonavir) in the same time frame.

An interim analysis of the Phase 2/3 EPIC-HR study found the drug to be 89% effective at reducing hospitalization or death. Pfizer announced the launch of a Phase 1 study of PF-07321332 in March.

Pfizer has inked a $5.29 billion Paxlovid deal with the U.S. government.

One course of oral Paxlovid therapy would consist of two daily 150-mg doses for five days.

Meanwhile, molnupiravir, the antiviral from Merck (NYSE:MRK) and Ridgeback Biotherapeutics, has lost some of its luster. New data suggests the drug led to an absolute risk reduction against hospitalization or death of 3% compared to placebo. Furthermore, the drug led to a relative risk reduction of…

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Pfizer to make COVID-19 pill available in low- and middle-income nations

In late October, Merck (NYSE:MRK) and its partner Ridgeback Biotherapeutics agreed to make the COVID-19 antiviral molnupiravir available in the developing world.

Now, Pfizer (NYSE:PFE) is taking a similar approach for its investigational antiviral cocktail Paxlovid, which contains PF-07321332 and ritonavir.

Pfizer, like Merck, struck an agreement with the Medicines Patent Pool (MPP) related to Paxlovid.

MPP’s mission is to expand low- and middle-income countries’ access to vital medicines. The United Nations supports the organization.

Pfizer announced earlier this month that Paxlovid was 89% effective in reducing the risk of hospitalization or death in an interim analysis of the Phase 2/3 EPIC-HR trial.

The collaboration with MPP will enable generic drug makers internationally with sub-licenses to produce Paxlovid for use in 95 countries, which comprise more than half of the world’s population.

“This license is so important because, …

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Merck finds molnupiravir cuts COVID-19 hospitalization rate in half 

The oral antiviral molnupiravir from Merck (NYSE:MRK) and Ridgeback Biotherapeutics fared well in a planned interim analysis of the Phase 3 MOVe-OUT trial.

If authorized by FDA, the pill would be the first oral antiviral for SARS-CoV-2 in the U.S.

To date, all authorized or approved COVID-19 drugs require subcutaneous, intramuscular or intravenous administration.

Merck intends to file an EUA for the oral therapy soon.

“With these compelling results, we are optimistic that molnupiravir can become an important medicine as part of the global effort to fight the pandemic and will add to Merck’s unique legacy of bringing forward breakthroughs in infectious diseases when they are needed most,” Merck CEO Robert M. Davis said in a statement.

The molnupiravir study focused on initially non-hospitalized adults with mild-to-moderate COVID-19. It found that 7.3% of molnupiravir recipients were hospitalized within 29 days. By contrast, 14.1% of placebo …

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Pfizer launches Phase 2/3 trial of COVID-19 oral antiviral cocktail

Pfizer (NYSE:PFE) has announced the launch of the Phase 2/3 EPIC-PEP study to test its oral antiviral candidate PF-07321332 as a post-exposure prophylaxis.

The EPIC-PEP study, whose name is an acronym of “Evaluation of Protease Inhibition for COVID-19 in Post-Exposure Prophylaxis,” will test the efficacy of PF-07321332 with low-dose ritonavir to prevent COVID-19 infection.

PF-07321332 and ritonavir are both protease inhibitors. AbbVie’s Ritonavir (Norvir) initially won FDA approval as an HIV treatment in 1996.

Molecular structure of PF-07321332. Image from Wikipedia.

Trial participants must be 18 or older and live in the same household as an individual with laboratory-confirmed symptomatic SARS-CoV-2 infection.

The study will enroll up to 2,660 participants.

“Given the continued emergence and evolution of SARS-CoV-2 variants and their immense impact, we continue to work diligently…

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Pfizer introduces oral SARS-CoV-2 inhibitor

An experimental oral antiviral from Pfizer that recently became the focus of a Phase 1 study was featured at the American Chemical Society Spring 2021 meeting.

Known as PF-07321332, the compound is a protease inhibitor. It works by binding to a viral enzyme known as protease to block viral replication.

Protease inhibitors are used to treat HIV/AIDS and hepatitis C, but PF-07321332 is the first oral protease inhibitor to target the SARS-CoV-2 virus.

Protease inhibitors are generally well tolerated. Side effects of protease inhibitors, in general, can include diarrhea, nausea and vomiting and insulin resistance.

Pfizer has also developed PF-07304814, a similar protease inhibitor, but that compound is intended for intravenous use.

Eli Lilly and Regeneron have developed infusion-based SARS-CoV-2 antibody drugs, but they have not been broadly used.

PF-07321332, if authorized, could be prescribed when the first symptoms of COVID-19 emerge.…

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Pfizer launches trial for novel oral COVID-19 therapeutic

An experimental oral antiviral from Pfizer will be the focus of a Phase 1 study involving healthy adults.

Known as PF-07321332, the drug has shown promise in in vitro studies against SARS-CoV-2.

PF-07321332 belongs to a class of drugs known as protease inhibitors, which are commonly used to treat HIV/AIDS and hepatitis C. Protease inhibitors bind to a viral enzyme known as protease to stop viral replication.

Pfizer believes PF-07321332 to be the first orally-administered SARS-CoV-2-specific investigational protease inhibitor to be studied in a clinical trial.

Pfizer is also researching an intravenous protease inhibitor, PF-07304814, for hospitalized COVID-19 patients in a Phase 1b trial.

The most recent trial involving the oral antiviral candidate PF-07321332 will administer multiple ascending doses to evaluate the drug’s safety and tolerability.

Pfizer says the antiviral also has potential in battling other coronaviruses in addition…

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