Covid: Xenothera's therapy, Xav-19, working against Omicron

Published by Laurent P. · Published on 3 January 2022 at 14h07
And what if, amid the fight against Covid, one could rely – in addition to the upcoming vaccine – on antibody-based treatments? After Bamlanivimab – the treatment developed by the Eli Lilly laboratory – or even Regeneron, this is now French Nantes-based laboratory Xenothera’s turn to present a treatment undergoing clinical trials, Xav-19. According to primary studies, the therapy is effective against Covid's Omicron variant, but waiting for the green light for marketing from early 2022.

Good news amid the fight against Covid… After Bamlanivimab – developed by the Eli Lilly laboratory – or even Regeneron – by the eponymous pharmaceutical company – Nantes-based laboratory Xenothera has announced they have come up with an antibody-based treatment. Called Xav-19, it is based on “polyclonal” antibodies, different from the “monoclonal” antibodies addressing the virus from one side, as the others do some from all sides at the same time, as Xenothera CEO Odile Duvaux explains.

Acccording to a press release from the laboratory issued this past December 27, the therapy is working against Covid Omicron variant: "This polyclonal antibody [...] already active on the previous variants is able to stop Omicron" according to primary in vitro results, the document reads. "Faced with the emergency health context, we are now calling for the government for early authorization so our therapy can enjoy the necessary conditions to its achievement given the failure of the monoclonal antibodies and the quick spread of the Omicron variant", Odile Duvaux added.

A molecule which clinical trials recently entered the third phase: "Our product is now in phase 3 of the clinical trials. If everything goes well, it could be approved and used from this Fall", Duvaux said this Wednesday August 18, 2021 to our peers from Le Monde. It has the same precision on its action, stating its advantage on variants: "every human being creates their own polyclonal antibodies. When I am attacked by a virus or a foreign body, I produce polyclonal antibodies. These polyclonal antibodies are then natural, but they also are more insensitive to variants. But, today, we know the variant issue is a very tricky problem", she told this December 2 on Sud Radio.

She goes on: "For now, when this medication is tested at different stages of the disease, we get a certain number of results. But these are not complete results, it means we do not have treated all the data yet", she says, before concluding: "But on these primary results, XAV-19 produces the expected effects on people tested, it cuts the risk of deterioration. As for side effects, we are totally reassured, the medication has no risk".

According to our peers from Ouest France, this treatment is based on polyclonal antibodies produced by “‘glyco-humanized’ pigs (genetically modified)” for an immune response similar to the one produced by human. It is part of a clinical trial, Polycor, that started in the Summer 2020, and through the study, it has been first inoculated to 10 patients from four different hospitals, and then 10 others, the idea being to show the product does not cause side-effects. A clinical trial that is still going on: “A wider trial is expected to begin by two to three weeks, on 400 patients. Forty hospitals in France are to be part of it” Professor François Raffi, Head of the Infectiology Department of the Nantes University Hospital said.

As for a possible issuing, if clinical trials make it to the end and meet encouraging results, it could take place in 2022, as said in mid-November by Odile Duvaux: "we are in the regulatory stage with the intention to get early access approval. A file has been issued in late September", she told our peers from Télégramme. She added: "it is being reviewed by the ANSM and the Haute Autorité de Santé and is expected to make it in early 2022 at the latest."

Xav-19 is a matter of national sovereignty”, Xenothera CEO explained in December 2020. And for good reason, the stakes are high since this treatment is to be made available for as many people as possible, in contrast to the one developed by Regeneron, far more expensive to produce. However, Xav-19is intended for patients infected by the virus for seven to ten days and hospitalized and therefore in a serious conditionProfessor Raffi went on. Good hope then to limit the death toll caused by severe cases.

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