Researchers at Brazil's National Cancer Institute (INCA), working with the Fiocruz foundation and the University of Brasilia (UnB), have developed two humanized versions of CAR-T cell therapy and validated them in laboratory tests and in mice, according to a study published in the journal Frontiers in Immunology. The goal is to produce one of the most advanced cancer treatments in Brazil at a lower cost. Today the full treatment is only available in the private health system, at R$ 2 million to R$ 2.7 million (roughly US$ 370,000 to US$ 500,000) per patient.
The results released so far are preclinical, meaning the technology has not yet been tested in humans. That is the line between what is confirmed and what remains a promise, and the researchers themselves stress this caveat in the article they published on G1.
What the tests showed
In lab assays, the two versions, named H1 and H2, killed cancer cells as efficiently as the original therapy, even when CD19, the protein the treatment targets on tumor cells, was present in reduced amounts on the cell surface. The researchers also observed the formation of memory cells, which are essential for the treatment's effect to last longer in the body.
In mouse experiments, the H1 version controlled the cancer durably and kept the animals alive for a period comparable to the conventional therapy. H2 showed weaker binding to CD19 and signs of immune cell exhaustion. H1 was therefore selected as the candidate to move forward to clinical trials in humans.
CAR-T therapy is considered the fifth pillar of cancer treatment. In it, a patient's own immune cells are collected, genetically reprogrammed to recognize the tumor, and returned to the body. Its impact has already been measured in patients: before CAR-T, people with refractory diffuse large B-cell lymphoma had a response rate of 26%, with 7% complete remission and a median survival of six months, according to the largest international review on the subject. A study published this year in Blood Advances found that after CAR-T, three-year overall survival rose from 10% to 59%, and progression-free survival from 6% to 48%.
Why the Brazilian version could cost less
Two barriers drive up the price of the therapy: the viral vectors used in production and the recognition protein, derived from a mouse antibody. The Brazilian team replaced the viral vector with a non-viral system and modified the molecule to make it more similar to a human protein, reducing the risk that the patient's immune system will reject the modified cells. According to the newspaper A TARDE, the research received funding from Decit-CNPq, FAPDF, Capes, Faperj and the Inova Fiocruz program.
In practical terms, nothing changes immediately for patients. Offering the therapy through the SUS, Brazil's public health system, depends on steps that are still ahead: clinical trials in humans, registration with Anvisa (the national health regulator) and evaluation by Conitec, the commission that decides which treatments the public system will cover. People living with leukemias or lymphomas should talk to their oncologist about options already approved in Brazil and about the possibility of joining ongoing CAR-T clinical trials in the country.