The Association Française des Malades de la Thyroïde (AFMT) made the statement after receiving the results back for its own independent analytical study into the new drug, which it says shows anomalies in composition.
The new formula of Levothyrox, the primary treatment for people suffering from underactive thyroid problems and cancers, was released in February 2017 by manufacturing laboratory Merck.
It was supported by national agency l’Agence Nationale de Sécurité du Médicament (ANSM), who had asked Merck to reformulate the drug to be "more stable" than its predecessor.
Soon after, reports began to emerge that the new drug was not working, with up to half a million patients reporting the return of negative symptoms and even of thyroid cancers that had previously been kept in check by the old drug formula.
At one point, the AFMT said it was receiving over 1,000 complaints per day.
Over three million people in France - most of whom are women - rely on Levothyrox to treat their thyroid disorders.
In September 2017, health minister Agnès Buzyn announced that the previous formula of levothyroxine would be made available to patients who asked for it - but the new formula is still largely in circulation.
And while Merck has maintained that the new drug is made using the same ingredients as the old drug, and denied any suggestion of inferior composition, patient groups such as the AFMT have been lobbying for recognition that their symptoms are real, and that the new drug is not up to standard.
Now, the AFMT says that its new medical study - an analysis done in a foreign laboratory, since it says it struggled to find a French lab that would run the tests - shows that the new formula contains significantly less levothyroxine than the previous one.
This, the AFMT says, would directly explain the problems experienced patients with the new drug - including symptoms such as exhaustion, weight gain, brain fog, headaches, cramps, unsteadiness, hair loss, and depression.
The results in the study have now been passed to a judge, who has been instructed to investigate the case by authorities in Marseille.
Yet, the AFMT is calling for further analysis to be done immediately on the drug in France, to help substantiate its claims, as it says that “the public health issue cannot wait until the legal system finally acts”.
A statement by the AFMT said: “At this stage, our association does not claim, with just one single study, to have indisputable ‘proof’ - but significant proof. Because, if these results are confirmed, as we believe they will be, they could offer a rational explanation for this crisis, the origin of which still remains unknown.”
It continued: “We have seen cancerous patients finding themselves severely under-dosed with thyroid hormones; we have seen cases in which patient cancers have come back after years in remission.”
In response, the ANSM has said it cannot comment on “a study that it has not seen” and said that “a study is in process, and the justice system is doing its work”.
A press release from Merck said that the work of the AFMT is “scientifically unfounded”, and accused it of failing to give “any details on the methods used and the conditions in which these new studies were done”.
It added: “We remind people that many analyses have already been done by the authorities, which failed to find any anomalies in our product.”
The laboratory also denied any presence of another contentious molecule: dextrogyre, in its new or old formulas of the drug - another subject of the AFMT’s investigation.
Dextrogyre, another kind of thyroid drug, has come under scrutiny in recent years after being banned in the United States due to alleged side-effects including cramps, headaches and hair loss.
A statement from managing pharmacist at Merck, Valérie Leto, read: “We formally deny the presence of any kind of dextrogyre in Levothyrox, whether the old or new formula.
“Regarding the presence of a different kind of levothyroxine in the new Levothyrox formula, we formally deny that to be the case. We remind people that the active substance used in the new formula is absolutely identical to that used in the old formula (known as levogyre, or the L-T4 molecule).”
Yet, Chantal L'Hoir, president of the AFMT, has called for Ms Buzyn (above) to step down from her role as health minister, for more alternatives to Levothyrox to be made available, and for official acknowledgement of the health crisis.
Speaking to news source FranceInfo, she said: “Personally, I do not feel that Ms Buzyn is up to the job, and I ask her to stand down.
“Three and a half million batches [of the new drug] were sold when it first came out, so we cannot say that we got an ‘off batch’. In a country [like France] that calls itself ‘scientific’, this is not dignified. The health minister simply needs to recognise this health crisis urgently, and allow alternative medicines, such as TCAPS (produced by the Génévrier laboratory).
“We should also be allowed to import European products that we know that been proven to work. There are patients on Thyrofix (another alternative by the Uni-Pharma laboratory), who are doing very well.”
Ms L’Hoir added: “We are exhausted; we have been fighting our case for over a year. People are suffering; there have been deaths and suicides. The worst thing is that [our] doctors have been treated as idiots by so-called big professors of endocrinology.
“It is an impossible situation. We do not receive aid from the state or any laboratory; we are simply a citizen-led group trying to help people.”
