Europe is studying a promising drug to treat an ultra-rare tumor that affects young people.

BarcelonaAlthough the fight against cancer has undergone a major revolution in recent decades, with a notable improvement in patient survival rates and quality of life, there are still tumors with a very poor prognosis for which virtually no treatment is available. This is the case with an ultra-rare tumor called giant cell tumor of the tendon sheath, which has an incidence of less than one case per million inhabitants and primarily affects young people between 20 and 40 years old. Until now, the only way to treat this tumor was with surgery, but an international study has supported the use of a promising drug that significantly reduces the tumor. Currently, the drug, called Pimicotinib, has already been approved in China and is being evaluated in Europe and the United States.

The clinical trial was conducted in several countries in Asia, Europe, and the United States, and involved nearly one hundred patients with this disease. César Serrano, an oncologist at Vall d'Hebron Hospital, was one of the researchers who participated in this study, published in the journal The Lancet This Friday. The expert explains that it is a "very aggressive" tumor that affects bones and joints, irritating them and increasing tumor mass and stiffness. People who undergo surgery to remove the tumor often experience aftereffects such as chronic pain, limping, and loss of function. Unlike cancer as we know it, this tumor is not capable of metastasizing. However, it does have a high recurrence rate, meaning it reappears after surgery.

This tumor has a protein called CSF1R that stimulates its growth, acting like an "orchestra conductor," Serrano explains. The new drug targets this protein and manages to reduce tumor growth in more than half of the cases. The researchers divided the patients into two groups: one group received the drug, and the other received a placebo. After 25 weeks, patients who received the treatment experienced a significant reduction in tumor size in 54% of cases, compared to 3.2% of those who received a placebo, explains the researcher, who is also head of the Transformational Research Group in Sarcomes at the Vall d'Hebron Institute of Oncology (VHIO).

Other treatments

Aside from the promising results, Serrano highlights that the patients who received the treatment also experienced an improvement in all functional aspects affected by the disease. "It improves joint function, stiffness, pain, and the use of analgesics, and there is an overall improvement for the patient," assures the expert, who also affirms that it is a very well-tolerated drug, meaning that it does not produce toxicity in those who receive it. Currently, there is no drug approved in Spain for this tumor. However, there is one approved in the United States, but it was not authorized in "most countries of the world because it had significant liver toxicity," explains Serrano. Recently, the European Union also approved a drug called Vimseltinib to combat this tumor, but there is still no timeline for its approval in Spain. Therefore, the results of the study open the door to having a new alternative to combat this tumor and improve the lives of patients.