A living medicine that fits in a spoon saves the lives of eight young people with the most common childhood cancer

A new living drug , composed of cells that could fit on a spoon and manufactured in a public hospital in Madrid, has so far saved the lives of eight young people with a very aggressive form of the most common childhood cancer, B-cell acute lymphoblastic leukemia. The patients, all under 24 years old, had been given a terminal diagnosis after multiple relapses and the cascading failure of all standard therapies. The sophisticated experimental treatment involves extracting a sample of immune cells, re-engineering them in the laboratory to increase their ability to destroy cancer cells, and then reintroducing them into the body to kill the tumor. The lead researcher, pediatrician Antonio Pérez , presented the results this Thursday at La Paz University Hospital: a 70% survival rate after more than a year and a half of follow-up.

A delighted patient, 15-year-old Lucía Álvarez from Cádiz, joined doctors, politicians, and funders at the event. Her name is the latest to be added to a hopeful list of young people who are leading this medical revolution. First was Emily Whitehead , a six-year-old American girl with seemingly fatal leukemia who, in desperation, became the first child patient treated with this experimental therapy, called CAR-T, in 2012. It worked perfectly, and her doctors now consider her cured .

Thousands of people have survived since then thanks to their own modified cells. The father of the treatment, American immunologist Carl June , speaks of resurrections “like that of Lazarus,” the biblical figure miraculously revived by Jesus Christ. However, the results are still insufficient. CAR-T cell therapies don't always work. They only manage to save half of the children with very aggressive tumors and no other alternative.

Lucía Álvarez and a dozen other patients received the new therapy when they were, on average, 12 years old. It's a state-of-the-art CAR-T cell therapy. Typically, the treatment involves implanting a kind of radar in the patients' white blood cells: a synthetic molecule capable of detecting the CD19 protein present in cancer cells of leukemia and lymphoma. The problem is that the tumor often manages to camouflage itself. The new therapy, in the words of Antonio Pérez, is like "a tandem," capable of binding to tumor cells at two points, CD19 and CD22, minimizing the risk of escape.

Thanks to this sophisticated strategy developed in La Paz, eight of the 11 patients saw their cancer disappear and become undetectable in just one month. “The treatment is short-lived; it’s a bridging therapy and must be consolidated with a bone marrow transplant,” explained Pérez. Five of the young patients were able to receive this life-saving transplant. After 20 months of follow-up, eight are still alive, representing a survival rate of over 70% for patients who had no other options for survival. The results, which should be interpreted with caution pending further trials, were published in August in the specialized journal eBioMedicine .

“I’m so happy to be here,” the 15-year-old said, her words carrying a double meaning that drew a standing ovation at the press conference. Lucía Álvarez’s case illustrates the suffering of these patients and their families. She was diagnosed with B-cell acute lymphoblastic leukemia when she was 17 months old. Chemotherapy worked very well, but at age 7 she had her first relapse, which was controlled with more chemotherapy. In the midst of the COVID-19 pandemic, she had a second relapse, with the tumor spreading throughout her nervous system. A first conventional CAR-T therapy and a bone marrow transplant achieved remission, but everything failed in succession until, with no other options, she received experimental tandem CAR-T therapy and a second transplant. Now she leads a normal life, has been able to return to school, and dreams of studying Biology.

There are only eight CAR-T cell therapy products authorized in the European Union: seven commercial and one academic, ARI-0001 , a treatment developed at the Hospital Clínic in Barcelona named after Ariana Benedé , an 18-year-old who helped drive the research forward before her death in 2016 from acute lymphoblastic leukemia. The examples of Madrid and Barcelona demonstrate that these revolutionary therapies can be developed in public hospitals, for much less money. The Swiss pharmaceutical company Novartis set a price of over €300,000 per patient for its Kymriah treatment, a CAR-T cell therapy for leukemias and lymphomas. At the same time, the Barcelona therapy cost only €90,000 .

Pediatrician Antonio Pérez heads the CRIS Unit for Advanced Therapies for Childhood Cancer, located on the eighth floor of the iconic polygonal tower of La Paz Hospital, where more than 700,000 Spaniards were born. However, the researcher has spent the last year working and learning at Great Ormond Street Hospital for Children in London, funded by the copyright of the Peter Pan character since Scottish novelist James Matthew Barrie donated it in 1929. There, Pérez met one of the British institution's most legendary patients: Alyssa , a teenager with incurable leukemia who, in 2022, became the first patient to receive cells from another person, modified with a kind of genetic pencil to prevent rejection.

Pérez's team is also now working with this genetic pencil, the so-called DNA base editors , to adapt donor white blood cells, an excellent option when patients have their own severely damaged cells or when time is of the essence. The CRIS Unit at La Paz Hospital does not receive funding from the Peter Pan rights, but it does receive funding from the CRIS Cancer Foundation , a non-profit organization that has contributed more than 10 million euros. In February 2024, the foundation announced the case of another of the 11 patients, Mathías , a 7-year-old boy treated with tandem CAR-T therapy for his aggressive leukemia, which had kept him hospitalized for half his life. In less than a month, his tumor went into complete remission.

Around 400,000 children and adolescents are diagnosed with cancer each year worldwide, according to the World Health Organization. These are very rare diseases—there are barely 1,500 cases annually in Spain—and the survival rate exceeds 80% in wealthy countries. But that is precisely why Antonio Pérez insists at every event that public hospitals must take the lead in researching new treatments, given the lack of financial incentive from the pharmaceutical industry. There are still two out of every ten children for whom no one is able to find a cure. “I am very happy to be here helping so that other children can receive treatment,” Lucía Álvarez continued.