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A study touting a lidocaine-based treatment as the first effective therapy for Long COVID has been temporarily withdrawn from the scientific journal eClinical Medicine, Vrije Universiteit Amsterdam and Amsterdam UMC announced this week. The research, published late last year, had not been reviewed by a recognized Medical Ethical Review Committee (METC) prior to publication. The Health Care and Youth Inspectorate (IGJ) is currently investigating whether a review was required, and the study authors have announced a temporary retraction pending that assessment.
The research involved physicians at Excellent Care Clinics in Velsen-Noord, Netherlands, who treated patients with Long COVID symptoms using injections of lidocaine. For this application, the anesthetic was specially formulated by being linked to a large sugar molecule. Patients self-administered the injections four times daily, either in an arm or leg, and tracked the severity of their mental and physical symptoms using a dedicated app.
The study reported promising results: approximately three-quarters of the 103 participating Long COVID patients reported a significant reduction in their symptoms after nine months. This finding offered a potential glimmer of hope for the many individuals struggling with the long-term effects of COVID-19, a condition that continues to impact public health globally.
‘Hopeful Results’
The study garnered significant media attention, with reports appearing in newspapers and discussed on talk shows. Approximately 100,000 people in the Netherlands alone suffer from debilitating Long COVID and have been awaiting effective treatment options for years. Study participants had also been grappling with symptoms for an average of two and a half years. NRC described the findings as “hopeful,” while noting it was an “initial exploratory study.”
However, the study was conducted without prior medical ethical review. The Medical Research Involving Human Subjects Act (WMO) stipulates which studies require such review, particularly when participants receive treatment outside of standard care. Researchers stated in the publication that the ethical review was conducted after the study was completed.
Researchers now state this was because there was “no pre-set research” of any kind. They characterize the treatment as “routine patient care” at the pain clinic, noting that “lidocaine has been routinely used for decades in the treatment of neuropathic pain and other pain syndromes.” They explain to NRC that the analysis was a retrospective evaluation of treatment outcomes.
However, the method of administration – an injection in the arm or leg – and the modern formulation linked to a sugar molecule differ from standard lidocaine pain treatment. The inspectorate will determine whether this constitutes a new type of treatment that should have been reviewed beforehand.
Concerns about the study’s design had been raised previously. Participants self-selected for the study and self-reported their symptoms. To properly test a new treatment, it should be compared to another treatment or a placebo, neither of which was done in this case. Critics from patient groups and experts warned that the research could create false hope for a patient population already experiencing significant distress.
An investigation by Follow the Money revealed that the physicians and researchers at Excellent Care Clinics applied for a grant for their research from medical funding provider ZonMW in 2023. The grant was rejected “due to the quality of the research design.” The research proceeded anyway, funded by millions of euros the researchers reportedly secured through a bank loan. The researchers also filed a patent application for this use of the drug. After the study concluded, participants were required to pay for the lidocaine out of pocket, at a cost of €3,000 per month.
In a statement to NRC, the researchers said the treatment at the clinic has not been stopped. “The request to withdraw the article concerns a procedural matter regarding the qualification of the retrospective analysis, not the treatment itself.” The researchers also emphasized that the withdrawal is temporary.
