© Pfizer
A technician examining tablets of Paxlovid, Pfizer’s anti-Covid pill, in Freiburg, Germany, in December.
After two years of pandemic, the battle for treatments against Covid-19 remains of paramount importance. In France alone, the disease still kills more than 600 people a week. The association for drugs against neglected diseases (DNDI, for «Drugs for neglected diseases initiative» in English) is currently conducting a clinical trial, “Anticov”, in Africa in order to find molecules that already exist but have an effect against Covid-19.
So far, the trial has mainly demonstrated the effectiveness of certain treatments, but Nathalie Strub-Wourgaft, coordinator of the trial, still hopes for results for “the end of summer, following the evolution of the pandemic”. She explains to Release why she continues to test an antidepressant, even if in France, the National Medicines Agency (ANSM) spoke out against their use against Covid.
Is it still important to seek treatments for Covid-19?
Absolutely ! Today, no oral treatment is available to treat patients at risk, either for reasons of access, or for lack of data on their effectiveness. It is necessary to have a therapeutic range that also makes it possible to treat pregnant women, at risk of complications, and immunocompromised patients, for example certain HIV patients. The WHO warns against underestimating the risk of emergence of new variants. We must remain vigilant and be ready, which is not yet the case.
Why test existing drugs to find a cure?
At the start of the crisis, the research effort focused mainly on treatments for hospitalized patients. But it quickly became apparent to us that health systems in Africa could not handle a surge of patients in hospital. Also, we have decided to conduct trials to treat patients upstream, from the first symptoms, in order to avoid saturation of hospitals.
We have set up an adaptive clinical trial in thirteen countries, with 26 partner research centres, which can integrate new molecules as research progresses, but also stop trials if the first results are insufficient or excellent.
Your clinical trial is testing an antidepressant, fluoxetine, while the French Medicines Agency recently refused its use. Why ?
The ANSM considers that the data are not sufficiently substantiated and that it could reconsider its decision with new results. We’ll see when we get ours. The molecule of fluoxetine interests us for two reasons: all the clinical and preclinical scientific data demonstrating a possible effect against the virus; and because we are looking for drugs that are inexpensive, easily accessible and manageable, and whose safety of use is well known.
On the merits, for me the level of proof is the same as the Paxlovid [la pilule de Pfizer, ndlr], although the latter is much more efficient. Paxlovid reduces the risk of hospitalization by 89% and fluoxetine by 30%. But the evidence of its effectiveness is quite compelling.
But then why does no one other than you test it?
I see no rational reason for this. I think there is a reluctance towards repositioned molecules [un médicament déjà disponible, enregistré, et développé pour traiter une autre maladie]. And that’s a shame ! In recent years, we have found much better treatments for sleeping sickness through repositioned drugs. This type of molecule makes it possible to move more quickly to the market because we already know how patients tolerate them.
Another explanation could be that the files to reposition a molecule are very heavy and there is probably a problem of funding public research so that it is able to cope with it.