The Thalassa clinical trial completes the final administration of treatment in patients with long COVID

The Thalassa trial, led by the Foundation in collaboration with PharmaMar, aims to analyse the potential of plitidepsin to improve symptoms in people with long COVID. This is a marine-derived active compound, obtained from an ascidian, which works by triggering cell death through a process known as apoptosis.

The study has been made possible thanks to the participation of 90 adult individuals with long COVID, who received either the treatment or a placebo. With the completion of treatment administration, the study now enters a new phase.

Although the intervention phase has been completed, participant follow-up will continue until September, with the aim of assessing clinical progression and collecting detailed data on response to the medication. This analysis will be key to determining whether this therapeutic strategy can become an effective option for a condition that, to date, still lacks established specific treatments.

Long COVID mainly affects individuals who experienced a mild or moderate initial SARS-CoV-2 infection, most of whom did not require hospitalisation. It is more common in women, with an average age between 40 and 50, and presents with a wide range of symptoms that can affect multiple organs and body systems. In many cases, these symptoms may persist for months or even years, with a significant impact on patients’ quality of life.

It is estimated that in Catalonia there are approximately 200,000 people living with long COVID, representing around 10% of those who have had the infection. At national level, this figure could reach up to 2 million people affected.

The final results of the study are expected in 2027, as a thorough analysis of all the collected data will be required to ensure robustness and scientific rigour.