Mauri, the boy with Down syndrome who is fighting leukemia while waiting for the Health Department to approve the use of CAR-T therapy

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No one wants to arrive at the oncology office to receive the sad news that their child has acute lymphoblastic leukemia (ALL).

Every year

, according to the Josep Carreras Foundation.

When it happens, it's time to face reality, bet on treatments and trust the entire team of experts who make it possible.

This is the diagnosis that Miriam and Jaime, the parents of nine-year-old Mauricio, received last year.

Although everyone calls him Mauri.

The fight they face now is to get the expert committee of the Ministry of Health to grant CAR-T cell immunotherapy to their son with Down syndrome to treat his recent relapse.

"Mauri was diagnosed with acute lymphoblastic leukemia in December of last year, in 2021. From that moment we started with general treatment. The hospital that corresponds to us is the one in Gran Canaria. We live in Fuerteventura. So I had I had to move the child to Gran Canaria so that they could administer all the medication," Miriam, Mauri's mother, told EL MUNDO.

Studies show that

.

The protocol established at the Niño Jesús Hospital, one of the reference pediatric cancer centers, when a child is diagnosed with acute lymphoblastic leukemia Down is similar to that stipulated for the rest, but with certain nuances.

"With these patients it is important to have a balance between controlling the disease and controlling the toxicity of the treatments. So, we basically adapt and readjust the doses of chemotherapy, but maintaining all the protocols so that the disease does not return", explains Blanca Herrero Velasco. , the oncologist responsible for the CAR-T program at the Niño Jesús Hospital.

Thus, this high toxicity can generate complications in different organs and a greater risk of contracting infections during the chemotherapy process.

"This first stage of treatment took us about nine months. In the first month of the second phase, the maintenance phase, my son unfortunately relapsed," continues Mauri's mother.

José Carlos Lodos is the doctor specialized in Pediatric Oncohaematology at the Hospital Materno Infantil de Gran Canaria who is handling Mauri's case and together with his team evaluated the different possibilities to take the next step.

The main options on the table were hematopoietic transplant, more colloquially known as bone marrow transplant, or CAR-T cell immunotherapy.

Put simply, bone marrow transplantation involves "giving the patient a lot of chemotherapy to kill all the leukemia and infusing the patient with marrow from a matched donor."

On the other hand,

, clarifies oncologist Herrero Velasco.

Considering that bone marrow transplantation for children with Down syndrome is highly toxic, Dr. Lodos requested the other alternative: CAR-T cell therapy.

"Think that, if the chemotherapy is toxic, then the marrow transplant, which is a brutal chemotherapy...

, in fact, most have deceased or have had many complications," argues Dr. Lodos.

This pediatric oncologist is not the first to request such treatment after the first relapse of a patient with Down syndrome.

The committee of experts of the Ministry of Health is responsible for denying or approving the subsidy of this novel immunotherapy.

"In theory, the committee rejected the request because it is the first relapse. In the current protocols of any child, whether or not he is Down, in the first relapse a bone marrow transplant is done. If a second relapse occurs, it is already considered CAR-T cell therapy", adds oncohematologist Lodos.

Likewise, the oncologist at the Niño Jesús Hospital, Herrero Velasco, argues that "

The patient has to meet all the inclusion criteria and none of the exclusion criteria. In addition, from the committee assess the case individually and approve or not the suitability of the patient".

The

for patients with Down syndrome.

"I think they should use the case of Mauri to

and leukemia. In fact, it is that in the Niño Jesús Hospital they have already carried out other CAR- T to children with Down in the first relapse and very good results have been seen. That is the anger that made me when Mauri was rejected".

WHY DOES CAR-T THERAPY BENEFIT MAURI MORE THAN TRANSPLANTATION?

This immunotherapy begins when the patient undergoes a procedure, called lymphapheresis, which consists of taking the patient's T lymphocytes (specific type of defenses).

The extracted content is frozen and transported to the laboratory, which "under total quality conditions so that they are not contaminated", remarks Herrero Velasco, the desired T lymphocytes are selected.

Viral vectors containing CAR information (which derives from English and means chimeric antigen receptor) are placed in the selected cells in their nucleus.

In this way

.

Once it is verified that the T lymphocytes manage to have CAR and have the capacity to spread through the patient's immune system, they are frozen again to be sent back to the hospital.

"This whole process takes about a month. During that time you have to give the patient a treatment to stop the disease," explains the oncologist.

The objective of this "bridge" treatment, prepared according to the needs of each patient, is to find a balance between controlling the disease at the lowest possible parameters and

in order to infuse CAR-T cells as soon as they are ready.

How this CAR-T cell process differs from bone marrow transplantation is that

.

This means exposing the patient, and especially if it is a child with Down syndrome, to a very high toxicity.

Once the CAR-T cells arrive at the hospital, the patient is admitted, if not already, to receive a specific chemotherapy called lymphodepletion.

This last treatment, which lasts five days, before infusing the CAR-T, decreases the lymphocytes until the patient is left without defenses, as far as possible, so that the CAR-T can spread through the system as effectively as possible. .

Once the patient has rested for a couple of days, and in his last check-up he does not present any important infection or toxicity, the most important step for both the patient and his entire team of professionals who handle his case arrives.

"

. This is a very special moment for patients because they have already been through so much...that at that moment all their hopes they are placed there," says the person in charge of the CAR-T program at the Niño Jesús Hospital.

Once the CAR-T cell infusion is finished, the patient must be monitored for two or three weeks to watch for any type of complication.

When the patient's immune system recognizes and activates the mission of the T-CAR lymphocytes, it produces a release of cytokines, which translates into inflammation, and can trigger fever, changes in blood pressure, difficulty breathing.

Other side effects that this therapy can produce are neurological alterations such as fine tremors, subtle changes in behavior, they may be sleepy, etc.

When these patients are discharged, they have a review every four to six weeks to assess their condition and be alert for a possible relapse.

In addition, as these patients do not have B lymphocytes in their immune system, which are the ones that produce the defenses known as immunoglobulins, they receive them intravenously to prevent them from contracting infections.

Today, the little boy is admitted to the Maternal and Child Hospital of Gran Canaria while receiving specific treatment.

"We are putting Mauri on medication so that he goes into remission, that is, so that he does not have blast cells. Around the second week of November the cycle will end.

, before continuing with the bone marrow transplant", transmits his oncohematologist.

In fact, he insists and defends that "in theory it is what should be done to this child. This treatment has already been applied to other Down children and it has been seen to work very well."

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